PACIFIC GAS AND ELECTRIC COMPANY
PURCHASE AND SALE AGREEMENT
1.
Technical Specifications: Appendix N2
Combined Cycle
OVERALL FACILITY CONFIGURATION............................................................... 12
1.1.
Major Components ..................................................................................................................... 12
1.2.
Balance of Plant Support Systems .............................................................................................. 12
2.
SITE CONDITIONS ....................................................................................................... 14
2.1.
Site Elevation and Barometric Pressure ..................................................................................... 14
2.2.
Temperatures .............................................................................................................................. 14
2.3.
Precipitation, Wind and Earthquake ........................................................................................... 14
3.
CODES AND STANDARDS .......................................................................................... 15
3.1.
State and Local Building Codes, Standards and Ordinances...................................................... 15
3.2.
U.S. Government Codes, Ordinances, and Standards ................................................................ 15
3.3.
American Society of Mechanical Engineers .............................................................................. 15
3.4.
American National Standards Institute ....................................................................................... 16
3.5.
Industry Standards ...................................................................................................................... 17
3.6.
Electric Utility Requirements ..................................................................................................... 19
4.
TECHNICAL REQUIREMENTS ................................................................................. 19
4.1.
System Descriptions ................................................................................................................... 20
4.2.
Plant Identification System ........................................................................................................ 21
4.3.
Supplier Factory Tests ................................................................................................................ 21
4.4.
Testing ........................................................................................................................................ 22
4.5.
Welding ...................................................................................................................................... 24
4.6.
Lubrication ................................................................................................................................. 24
4.7.
Consumables .............................................................................................................................. 25
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Technical Specifications: Appendix N2
Combined Cycle
5.
OPERATIONAL REQUIREMENTS ........................................................................... 25
6.
MAJOR MECHANICAL EQUIPMENT AND SYSTEMS ........................................ 26
6.1.
Combustion Turbine ................................................................................................................... 26
6.1.1.
Turbine Supervisory Instrumentation ................................................................................. 27
6.1.2.
Inlet Air Filter ..................................................................................................................... 27
6.1.3.
Acoustic Enclosures............................................................................................................ 28
6.1.4.
Water Wash System ............................................................................................................ 28
6.1.5.
Combustion Turbine Exhaust Duct..................................................................................... 29
6.2.
Heat Recovery Steam Generator ................................................................................................ 29
6.2.1.
HRSG Casing...................................................................................................................... 34
6.2.2.
HRSG Burner System Valves ............................................................................................. 34
6.2.3.
Duct Burners ....................................................................................................................... 35
6.2.4.
Feedwater System ............................................................................................................... 35
6.2.5.
Temperature Monitoring ..................................................................................................... 36
6.2.6.
Blowdown Tanks ................................................................................................................ 36
6.2.7.
Exhaust Stack...................................................................................................................... 36
6.3.
Steam Turbine and Associated Components .............................................................................. 37
6.3.1.
Lube and Control Oil Systems ............................................................................................ 38
6.3.2.
Gland Steam Sealing System .............................................................................................. 39
6.3.3.
Turning Gear ....................................................................................................................... 39
6.3.4.
Piping .................................................................................................................................. 39
6.3.5.
Steam Strainers ................................................................................................................... 40
6.3.6.
Drains.................................................................................................................................. 40
6.3.7.
Insulation and Lagging ....................................................................................................... 40
6.3.8.
Chemical Cleaning.............................................................................................................. 40
6.3.9.
Guards ................................................................................................................................. 41
6.3.10.
Main Steam System ............................................................................................................ 41
6.3.11.
Exhaust Hood Sprays .......................................................................................................... 41
6.3.12.
Instrumentation and Control ............................................................................................... 41
6.4.
Heat Rejection Systems .............................................................................................................. 42
6.4.1.
Condenser ........................................................................................................................... 42
6.4.2.
Steam Turbine Bypass ........................................................................................................ 44
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Technical Specifications: Appendix N2
Combined Cycle
6.4.3.
Condensate System ............................................................................................................. 44
6.4.4.
Circulating Water System ................................................................................................... 45
6.4.5.
Auxiliary Cooling Water System ........................................................................................ 46
6.4.6.
Closed Cooling Water System ............................................................................................ 46
6.4.7.
Mechanical Draft Cooling Tower (as applicable) ............................................................... 46
6.4.8.
Air-Cooled Condenser (if applicable)................................................................................. 48
6.4.9.
Pumps ................................................................................................................................. 51
6.5.
Piping ......................................................................................................................................... 55
6.5.1.
Piping Materials .................................................................................................................. 57
6.5.2.
Pipe Velocities .................................................................................................................... 58
6.5.3.
Pipe Hangers and Supports ................................................................................................. 59
6.6.
Valves ......................................................................................................................................... 59
6.6.1.
Drain and Vent Valves and Traps ....................................................................................... 61
6.6.2.
Low-Pressure Water Valves ............................................................................................... 61
6.6.3.
Instrument Air Valves......................................................................................................... 61
6.6.4.
Non-Return Valves ............................................................................................................. 62
6.6.5.
Motor-Actuated Valves....................................................................................................... 62
6.6.6.
Control Valves .................................................................................................................... 62
6.6.7.
Safety and Relief Valves..................................................................................................... 65
6.6.8.
Instrument Root Valves ...................................................................................................... 65
6.6.9.
Float-Operated Valves ........................................................................................................ 65
6.6.10.
High-Pressure Valves ......................................................................................................... 65
6.7.
Insulation and Freeze Protection ................................................................................................ 66
6.8.
Tanks .......................................................................................................................................... 66
6.9.
Heat Exchangers ......................................................................................................................... 67
6.10. Pressure Vessels ......................................................................................................................... 67
6.11. Fuel Gas Supply System............................................................................................................. 68
6.12. Water Source and Treatment System ......................................................................................... 69
6.13. Demineralized Water (Condensate Makeup) ............................................................................. 70
6.14. Wastewater Treatment and Discharge ........................................................................................ 71
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Technical Specifications: Appendix N2
Combined Cycle
6.15. Sump Pumps ............................................................................................................................... 72
6.16. Potable Water ............................................................................................................................. 72
6.17. Fire Protection System ............................................................................................................... 73
6.17.1.
General................................................................................................................................ 73
6.17.2.
Seller’s Responsibility ........................................................................................................ 73
6.17.3.
Fire Protection Master Plan and Design Basis .................................................................... 74
6.17.4.
Codes, Standards and Recommendations ........................................................................... 75
6.17.5.
Other Codes and Standards ................................................................................................. 77
6.17.6.
Materials, Equipment and System Components Listings and Approvals ........................... 78
6.17.7.
Fire Protection Water Supply and Water Storage ............................................................... 78
6.17.8.
Fire Pumps .......................................................................................................................... 79
6.17.9.
Underground Fire Protection Water Main System and Hydrants ....................................... 80
6.17.10. Fire Hydrants ...................................................................................................................... 82
6.17.11. Fire Protection and Detection System ................................................................................ 82
6.18. Fire Detection System ................................................................................................................ 87
6.19. Compressed Air System ............................................................................................................. 89
6.20. Cranes, Hoists, and Trolleys....................................................................................................... 90
6.21. Heating Ventilating and Air Conditioning ................................................................................. 91
6.21.1.
System Function ................................................................................................................. 92
6.21.2.
Buildings and Enclosures.................................................................................................... 92
6.21.3.
Air Conditioning System .................................................................................................... 92
6.21.4.
Battery Room Exhaust System ........................................................................................... 93
6.21.5.
Design Parameters .............................................................................................................. 93
6.21.6.
Standards............................................................................................................................. 94
6.22. Chemical Injection Skids, Chemical Storage, and Bottled Gas Storage .................................... 95
7.
MAJOR ELECTRICAL EQUIPMENT AND SYSTEMS .......................................... 95
7.1.
Frequency and Voltage Limits ................................................................................................... 96
7.1.1.
Frequency ........................................................................................................................... 96
7.1.2.
Voltage................................................................................................................................ 96
7.2.
Auxiliary Equipment .................................................................................................................. 96
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7.3.
Technical Specifications: Appendix N2
Combined Cycle
Synchronous Generator .............................................................................................................. 97
7.3.1.
Construction of the Generator............................................................................................. 98
7.3.2.
Accessories ......................................................................................................................... 98
7.3.3.
Generator Neutral Grounding ............................................................................................. 98
7.3.4.
Excitation Systems.............................................................................................................. 98
7.4.
Isolated-Phase Bus Ducts, Non-Segregated Phase Bus Ducts, and Generator Circuit Breakers100
7.5.
Plant Electrical Auxiliary Systems ........................................................................................... 100
7.6.
Electrical System Design and Equipment Requirements ......................................................... 102
7.7.
Automatic Generation Control Terminal.................................................................................. 103
7.8.
Generator Bus ........................................................................................................................... 104
7.9.
Neutral Grounding Equipment ................................................................................................. 105
7.10. GSU Transformer Bank............................................................................................................ 105
7.10.1.
GSU Cooling System ........................................................................................................ 106
7.10.2.
Generator Breakers ........................................................................................................... 106
7.11. Unit Auxiliary Transformer...................................................................................................... 106
7.12. System Protection ..................................................................................................................... 107
7.12.1.
Generator Protective Relaying .......................................................................................... 109
7.12.2.
Generator Bus and Transformer Protective Relaying ....................................................... 110
7.12.3.
Main Power Transformer Protective Relaying ................................................................. 110
7.12.4.
Auxiliary System Relaying ............................................................................................... 110
7.12.5.
Major Interlocks................................................................................................................ 111
7.12.6.
Lockout Relay Actions ..................................................................................................... 111
7.12.7.
Protective Relays .............................................................................................................. 111
7.13. Medium-Voltage Bus Duct ...................................................................................................... 111
7.13.1.
Non-Segregated Phase Bus Duct/Cable Bus (as required) ............................................... 111
7.13.2.
Bus Ratings ....................................................................................................................... 112
7.13.3.
Cable Bus Duct ................................................................................................................. 112
7.13.4.
Bus Ratings ....................................................................................................................... 112
7.13.5.
Conductors ........................................................................................................................ 112
7.13.6.
Medium-Voltage System .................................................................................................. 112
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Technical Specifications: Appendix N2
Combined Cycle
7.14. Low-Voltage System ................................................................................................................ 114
7.14.1.
System Configuration ....................................................................................................... 114
7.14.2.
Transformers ..................................................................................................................... 114
7.15. Switchgear ................................................................................................................................ 114
7.16. Motor Control Centers.............................................................................................................. 115
7.16.1.
Operational Requirements ................................................................................................ 116
7.16.2.
Protection .......................................................................................................................... 116
7.17. Alternate Power Source ............................................................................................................ 116
7.18. Essential Service AC System ................................................................................................... 116
7.18.1.
Uninterruptible Power Supply .......................................................................................... 116
7.18.2.
Rectifier ............................................................................................................................ 117
7.18.3.
Inverter.............................................................................................................................. 117
7.18.4.
Static Transfer Switch....................................................................................................... 117
7.18.5.
Essential Service 120V AC Distribution Panelboard ....................................................... 117
7.19. Essential Service DC System ................................................................................................... 118
7.19.1.
Batteries ............................................................................................................................ 118
7.19.2.
Battery Accessories .......................................................................................................... 118
7.19.3.
Battery Chargers ............................................................................................................... 119
7.20. Motors ...................................................................................................................................... 119
7.20.1.
4,000-Volt Motors ............................................................................................................ 119
7.20.2.
Low-Voltage Motors ........................................................................................................ 121
7.20.3.
Standby Power Generator ................................................................................................. 122
7.21. Miscellaneous ........................................................................................................................... 123
7.21.1.
Communications Section .................................................................................................. 123
7.21.2.
Security ............................................................................................................................. 124
7.21.3.
Panelboards ....................................................................................................................... 125
7.21.4.
Grounding and Lightning Protection System ................................................................... 125
7.21.5.
Cathodic Protection System .............................................................................................. 125
7.21.6.
Lighting Systems .............................................................................................................. 125
7.21.7.
Cable and Raceway Systems ............................................................................................ 127
7.22. General Wiring Requirements .................................................................................................. 130
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Technical Specifications: Appendix N2
Combined Cycle
7.23. Protective Relay Panel Functional Requirements .................................................................... 131
7.24. Workstations............................................................................................................................. 131
7.25. Testing and Checking of Electrical Equipment ........................................................................ 131
7.26. Embedded Work ....................................................................................................................... 131
7.27. Freeze Protection ...................................................................................................................... 132
7.28. Switchyard ................................................................................................................................ 133
7.28.1.
Circuit Breakers ................................................................................................................ 133
7.28.2.
Disconnect Switches ......................................................................................................... 133
7.28.3.
System Protection ............................................................................................................. 133
7.28.4.
Control .............................................................................................................................. 134
7.28.5.
Power Metering ................................................................................................................ 134
7.28.6.
Non-Revenue Metering..................................................................................................... 135
7.28.7.
Steel Structures ................................................................................................................. 136
7.28.8.
Miscellaneous ................................................................................................................... 137
7.28.9.
Switchyard Grounding and Lightning Protection ............................................................. 137
7.28.10. Stability Study .................................................................................................................. 137
8.
INSTRUMENTATION AND CONTROL REQUIREMENTS ................................ 137
8.1.
Distributed Control System ...................................................................................................... 139
8.1.1.
Performance Requirements ............................................................................................... 140
8.1.2.
Functional Requirements .................................................................................................. 140
8.1.3.
Console Design ................................................................................................................. 141
8.1.4.
Hardware Requirements ................................................................................................... 141
8.1.5.
DCS Partitioning ............................................................................................................... 141
8.1.6.
Power ................................................................................................................................ 141
8.1.7.
System Failure Protection ................................................................................................. 142
8.1.8.
DCS Communication Network ......................................................................................... 142
8.1.9.
Printers .............................................................................................................................. 142
8.1.10.
Computing Hardware and System I/O .............................................................................. 142
8.1.11.
System Cabinets................................................................................................................ 143
8.1.12.
Electrical Design Criteria.................................................................................................. 143
8.2.
Software Requirements ............................................................................................................ 144
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Combined Cycle
8.2.1.
Data Acquisition ............................................................................................................... 144
8.2.2.
DCS Interfaces .................................................................................................................. 145
8.3.
Testing ...................................................................................................................................... 149
8.3.1.
Tools ................................................................................................................................. 149
8.3.2.
Installation and Operating Instructions ............................................................................. 149
8.4.
Continuous Emissions Monitoring System .............................................................................. 149
8.4.1.
Analyzer Subsystem ......................................................................................................... 150
8.4.2.
Sample Transport System ................................................................................................. 150
8.4.3.
Stack Gas Monitoring Equipment..................................................................................... 151
8.4.4.
CEMS Data Logger .......................................................................................................... 151
8.4.5.
CEMS Enclosure .............................................................................................................. 151
8.4.6.
Documentation .................................................................................................................. 151
8.4.7.
Shipping ............................................................................................................................ 152
8.4.8.
Factory Checkout .............................................................................................................. 152
8.5.
Data Acquisition System .......................................................................................................... 152
8.5.1.
Software ............................................................................................................................ 152
8.5.2.
Data Communications System .......................................................................................... 153
8.5.3.
Reporting and Recordkeeping Requirements ................................................................... 154
8.5.4.
Quality Assurance and Quality Control Data ................................................................... 154
8.6.
Balance-of-Plant Instrumentation Installation Criteria and Installation Details....................... 154
8.6.1.
Scope of Specification ...................................................................................................... 154
8.6.2.
Instrumentation Electrical Requirements.......................................................................... 157
8.6.3.
Pressure Instruments ......................................................................................................... 157
8.6.4.
Temperature Instruments .................................................................................................. 159
8.6.5.
Level Instruments ............................................................................................................. 160
8.6.6.
Level Gauges .................................................................................................................... 162
8.6.7.
Flow Elements – Flow Nozzles and Venturis ................................................................... 163
8.6.8.
Flow Elements – Orifice Plates ........................................................................................ 163
8.6.9.
Annunciators, Alarm Switches, and Electrical Devices ................................................... 164
8.6.10.
Process Analyzers and Analyzer Systems ........................................................................ 165
8.6.11.
Pressure and Temperature Switches ................................................................................. 167
8.7.
Instrument Air and Service Air Systems .................................................................................. 167
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8.8.
Technical Specifications: Appendix N2
Combined Cycle
Field-Mounted Instruments ...................................................................................................... 168
8.8.1.
Instrumentation - General Design ..................................................................................... 168
8.8.2.
Instrument Cabinets and Local Control Panels ................................................................. 169
8.8.3.
Instrument Tubing and Piping .......................................................................................... 171
8.8.4.
Air Piping, Fittings, and Pneumatic Devices .................................................................... 173
8.9.
Steam/Water Sampling and Analysis ....................................................................................... 173
8.10. Vibration Monitoring System ................................................................................................... 173
8.11. Plant Siren System.................................................................................................................... 174
8.12. Instrument Calibration .............................................................................................................. 174
8.13. I&C Maintenance Area Requirements ..................................................................................... 174
9.
CIVIL AND STRUCTURAL WORKS ....................................................................... 174
9.1.
Design Criteria ......................................................................................................................... 174
9.1.1.
Dead Loads ....................................................................................................................... 175
9.1.2.
Live Loads ........................................................................................................................ 175
9.2.
Site Preparation ........................................................................................................................ 177
9.3.
Geotechnical Investigations ..................................................................................................... 178
9.4.
Surveying ................................................................................................................................. 178
9.5.
Site Development and Earthwork............................................................................................. 178
9.6.
Temporary Construction Facilities ........................................................................................... 179
9.7.
Facility Grading........................................................................................................................ 179
9.7.1.
Earthwork ......................................................................................................................... 180
9.7.2.
Clearing and Grubbing...................................................................................................... 182
9.7.3.
Stripping ........................................................................................................................... 182
9.7.4.
Disposal of Unusable Soils ............................................................................................... 182
9.7.5.
Erosion Control ................................................................................................................. 182
9.7.6.
Existing Underground Facilities ....................................................................................... 183
9.8.
Access....................................................................................................................................... 183
9.9.
Storm Water Drainage .............................................................................................................. 183
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Combined Cycle
9.9.1.
Clean Storm-Water Sewer and Ditch System ................................................................... 183
9.9.2.
Miscellaneous Valved Storm-Water Runoff ..................................................................... 184
9.9.3.
Sanitary and Oily Waste Water Drainage Systems........................................................... 184
9.9.4.
Sanitary Wastewater ......................................................................................................... 185
9.9.5.
Oil-Contaminated Wastewater Sewer System .................................................................. 185
9.9.6.
Process Wastewater .......................................................................................................... 186
9.10. Roads, Parking Lots, and Walkways ........................................................................................ 186
9.10.1.
Facility Roads ................................................................................................................... 186
9.10.2.
Road Width and Clearance Requirements ........................................................................ 187
9.10.3.
Road Pavement ................................................................................................................. 187
9.10.4.
Parking Lots ...................................................................................................................... 187
9.10.5.
Chemical Unloading ......................................................................................................... 188
9.10.6.
Facility Area Surfacing ..................................................................................................... 188
9.10.7.
Surfacing Plan ................................................................................................................... 189
9.11. Landscaping.............................................................................................................................. 189
9.12. Fencing and Signage ................................................................................................................ 189
9.13. Buildings .................................................................................................................................. 190
9.13.1.
Location and Footprint of Buildings ................................................................................. 191
9.13.2.
Building Requirements and Sizes ..................................................................................... 191
9.13.3.
Architectural ..................................................................................................................... 195
9.13.4.
Furnishings ....................................................................................................................... 197
9.13.5.
Building Systems .............................................................................................................. 199
9.14. Foundations for Equipment and Structures .............................................................................. 199
9.15. Concrete Work ......................................................................................................................... 199
9.16. Masonry Work.......................................................................................................................... 200
9.17. Steel Work ................................................................................................................................ 200
9.17.1.
Steel Grating and Steel Grating Stair Treads .................................................................... 200
9.17.2.
Stairs and Ladders............................................................................................................. 201
9.18. Painting and Coatings ............................................................................................................... 201
9.19. Design....................................................................................................................................... 203
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Combined Cycle
9.20. Construction ............................................................................................................................. 204
9.21. Testing and Inspections ............................................................................................................ 204
10. DOCUMENT SUBMITTALS ...................................................................................... 205
10.1. Documents To Be Submitted For Purchaser Review and Comment ........................................ 206
10.2. Performance Curves ................................................................................................................. 210
10.3. Purchaser’s Right to Receive Additional Documents for Information..................................... 211
10.4. Documents To Be Submitted Before Turnover of Facility ...................................................... 212
10.5. Drawings and Lists ................................................................................................................... 213
10.6. Instruction Books and Operating Manuals ............................................................................... 213
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1.
Technical Specifications: Appendix N2
Combined Cycle
OVERALL FACILITY CONFIGURATION
The Facility will include ______________ Units and other balance-of-plant (BOP)
systems and facilities for a complete, fully operational, combined cycle Facility. Each
Unit will include identical ___________ combined cycle power islands and balance-ofplant (BOP) systems and facilities associated with the Unit. Each power island includes
__________ combustion turbine generators (CTGs) with each CTG exhausting through a
multi-pressure-level, reheat, fired heat recovery steam generator (HRSG). Steam from the
HRSG will be fed to a steam turbine generator (STG). NOx emission control will be
accomplished using a dry low NOx (DLN) combustor as well as Selective Catalytic
Reduction (SCR) in the HRSG. An inlet air filtration system will be included to provide
suitably filtered combustion air to the CTG. CGT inlet cooling will be provided.
Power for each Unit will be generated at ____ (CTG) and ____ (STG) and stepped up
through an individual main transformer to the Utility grid. An on-site switchyard shall be
designed, furnished and installed to meet the interconnect utility, ISO and WCCP
requirements.
1.1.
Major Components
The Facility shall consist of the following major components:
1.2.

______ CTGs, complete with DLN combustors, inlet coolers, and all other
auxiliaries

______ three-pressure, reheat, unfired, horizontal gas flow HRSGs, each equipped
with an exhaust stack with dampers, transitions, expansion joints, an SCR system
to control emissions of NOx, a CO reduction catalyst system and all other
auxiliaries

________single flow exhaust, reheat steam turbine generators with auxiliaries
Balance of Plant Support Systems
The BOP support systems include, but are not limited to, the following:

One Distributed Control System (DCS) for the combined cycle facility and
balance-of-plant (BOP) control, data acquisition and data analysis.

One natural gas system

One liquid fuel system, if applicable

Main steam systems, for each of the power islands, each including cascade-type
turbine bypass for high pressure, intermediate pressure and reheat steam, and
turbine bypass directly to the condenser

Condensate systems
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Technical Specifications: Appendix N2
Combined Cycle

Feedwater systems

HRSG blowdown systems

Ammonia unloading, storage, and transfer systems

Interconnecting piping for combustion turbine liquid fuel system (if applicable),
and for steam turbine steam/condensate drain, lube oil, and seal steam systems

Condenser and cooling towers or air cooled condensers and auxiliaries

Cooling water systems (including Wet Surface Air Condenser (WSAC) if
necessary for an air cooled configuration)

Raw water treatment system

Cycle makeup water treatment system

Feed water tank

Fire/filtered water storage tank

Demineralized water storage tanks

Chemical storage and injection systems for the condensate and feedwater systems

Hypochlorite storage and injection system , if required

Domestic (potable) water system, including well or utility interconnect

Sanitary waste system

Process waste water system

Fire detection, alarm, and suppression systems

Instrument air system

Service air system

Permanent Facility communications system

Heating, ventilating and air conditioning (HVAC) systems

Storm water management system

Sampling system

Emergency power system, including emergency electric power generator

Electric power distribution system

Lighting system

Lightning protection system

Cathodic protection system

Freeze Protection system, if required by environmental conditions

Grounding system

Expansion joints
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2.
Technical Specifications: Appendix N2
Combined Cycle

Roads (including the access road), fencing and parking

Transmission interconnection facilities,

Continuous Emissions Monitoring System (CEMS), and Data Acquisition and
Handling System (DAHS)

Administrative and maintenance buildings

Hydrogen gas trailer or skid (if applicable,) and other bottle gases (e.g., CEMS,
CO2)

Natural gas line and on-site metering station per the pipeline company interconnect
requirements

Electrical transmission tie-in

Interfaces with the above temporary or mobile systems including mobile
demineralizer trailers.
SITE CONDITIONS
The facility shall be designed in accordance with the Site Conditions specified in
Appendix N3.
2.1.
Site Elevation and Barometric Pressure
The facility shall be designed based on the site elevation listed in Appendix N3.
2.2.
Temperatures
Equipment shall be designed to operate and stand down without damage throughout the
temperature range listed in Appendix N3.
2.3.
Precipitation, Wind and Earthquake
The Facility shall be designed for the maximum rainfall conditions listed in Appendix
N3. Snow Load (if applicable)
Design snow loads shall be in accordance with the requirements set forth in the California
Building Code and or local governing building code.
Design wind loads shall be in accordance with the requirements set forth in the California
Building Code and or local governing building code. The Importance Factor for wind
shall be 1.0 (non-essential facility). The applicable basic wind velocity in mph and the
site specific exposure (B, C or D) is listed in Appendix N3.
Seismic design loads shall be in accordance with the requirements set forth in the
California Building and or local governing building code. The applicable seismic zone
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shall be either Zone 4 or Zone 3 for the specific site location. The site shall be assigned a
soil profile type as substantiated by geotechnical data for the specific site. The
Importance Factor for seismic shall be 1.0 (non-essential facility). The applicable seismic
zone, soil profile type, and seismic coefficients Ca and Cv are listed in Appendix N3.
The site footprint shall not be located in a floodplain.
3.
CODES AND STANDARDS
Systems and equipment shall be designed in accordance with Codes and Standards,
Regulations, Governmental Approvals and Governmental Rules in effect at the date of
execution of this Contract. Applicable sections of Governmental Rules will be referenced
as required in the relevant technical specifications. In case of conflict among this Scope
Document, referenced Governmental Rules, and manufacturer's standard practices, the
Purchaser shall determine which will govern. Where there are no applicable
Governmental Rules, power industry practices shall apply.
3.1.
3.2.
3.3.
State and Local Building Codes, Standards and Ordinances

Code, Rules and Regulations of the State of California

California Building Code

California OSHA (CALOSHA)

Local laws, ordinances, and regulations
U.S. Government Codes, Ordinances, and Standards

Occupational Safety and Health Act (0SHA) - 29 CFR 1910, 1926

Federal Aviation Agency (FAA) - Obstruction Marking and Lighting AC No.
70/7460-IJ)

Environmental Protection Agency (EPA) - 40 CFR 423, 40 CFR 60, 40 CFR 72,
40 CFR 75, 40 CFR 112

Appendix A to Part 36, “American Disability Act Accessibility Guidelines for
Buildings and Facilities
American Society of Mechanical Engineers
The following standards of the American Society of Mechanical Engineers (ASME) shall
be followed:

ASME Boiler and Pressure Vessel Code Sections:
I
Power Boilers
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II
Technical Specifications: Appendix N2
Combined Cycle
Material Specifications
Part A: Ferrous Materials
Part B: Nonferrous Materials
Part C: Welding Rods, Electrodes, and Filler Metals
V
Nondestructive Examination
VIII
Pressure Vessels Division 1
IX
Welding and Brazing Qualifications

ASME B31.1 - Power Piping

ASME Standard TDP-1 - Recommended Practices for the Prevention of Water
Damage to Steam Turbines Used for Electric Power Generation, Part I - Fossil
Fueled Plants

ASME Performance Test Codes:
The following performance test code may be used as guidance in conducting the
performance for the overall facility:

PTC 46
Overall Plant Performance

PTC 1
General Instructions

PTC -19.1 Measurement Uncertainty
The following performance test codes may be used as guidance in conducting
performance tests if a shortfall in overall Facility performance requires individual
component testing:
3.4.

PTC - 4.4
Gas Turbine Heat Recovery Steam Generators

PTC – 6
Steam Turbines (Alternative Tests)

PTC -6 (Report) Guidance for Evaluation of Measurement Uncertainty in
Performance Tests of Steam Turbines

PTC -19.2
Pressure Measurement

PTC -19.3
Temperature Measurement

PTC – 22
Gas Turbine Power Plants
American National Standards Institute
The following standards of the American National Standards Institute (ANSI) shall be
followed:

B16.1
Cast Iron Pipe Flanges and Flanged Fittings

B16.5
Steel Pipe, Flanges, and Fittings

B16.34
Steel Valves
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3.5.
Technical Specifications: Appendix N2
Combined Cycle

B30.17
Overhead and Gantry Cranes

B133.8
Gas Turbine Installation Sound Emissions

C2
National Electrical Safety Code

C37.010
Application Guide for AC High Voltage Circuit Breakers Rated on
a Symmetrical Current Basis

C37.04
Standard Rating Structure for AC High Voltage Circuit Breakers
Rated on a Symmetrical Current Basis

C37.06
Switchgear - AC High Voltage Circuit Breakers Rated on a
Symmetrical Current Basis -Preferred Ratings and Related Required Capabilities

C37.13
Enclosures
Standard for low Voltage AC Power Circuit Breakers Used in

C37.20.1
Switchgear
Standard for Metal-Enclosed Low-Voltage Power Circuit Breaker

C37.20.2
Standard Metal-Clad and Station-Type Cubicle Switchgear

C37.23
Guide for Metal-Enclosed Bus and Calculating Losses in
Isolated-Phase Bus

C37.30
Definitions and Requirements for High-Voltage Air Switches,
Insulators, and Bus Supports

C50.41

C57.12.10
Transformers - 230 kV and below, 833/958 through 8,333/110,417
kVA Single Phase and 750/862 through 60,000/80,000/100,000 kVA Three Phase
without Load Tap C Changing, and 3,750/4,682 through 60,000/80,000/100,000
kVA With Load Tap Changing- Safety Requirements

C57.12.55
Transformers - Dry-Type Transformers Used in Unit Installation,
Including Unit Substations

C57.12.70
Terminal Markings and Connections for Distribution and Power
Transformers

C57.13
Standard Requirements for Instrument Transformers

C57.109
Guide for Transformer Through-Fault-Current Duration

C62.11
Standard for Metal-Oxide Surge Arresters for AC Power Circuits
Polyphase Induction Motors for Power Generating Stations
Industry Standards
Applicable standards issued by the following industry organizations:

American Association of State Highway and Transportation Officials (AASHTO)

American Boiler Manufacturers Association (ABMA)

American Concrete Institute (ACI)
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
American Gas Association (AGA)

American Gear Manufacturers Association (AGMA)

American Institute of Steel Construction (AISC)

American Iron and Steel Institute (AISI)

Air Moving and Conditioning Association (AMCA)

American National Standards Institute (ANSI)

American Petroleum Institute (API)

American Society for Nondestructive Testing (ASNT)

American Society for Testing and Materials (ASTM)

American Society of Heating, Refrigerating, and Air-Conditioning Engineers
(ASHRAE)

American Water Works Association (AWWA)

American Welding Society (AWS)

Anti-Friction Bearing Manufacturers Association (AFBMA)

Crane Equipment Manufacturer’s Association of America (CMMA)

Expansion Joint Manufactures Association (EJMA)

Fluid Control Institute (FCI)

Heat Exchange Institute (HEI)

Hydraulic Institute (HI) - Standard for Pumps

Illuminating Engineering Society (IES)

Institute of Electrical and Electronics Engineers (IEEE)

Insulated Cable Engineers Association (ICEA)

Instrument Society of America (ISA)

Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry

Metal Building Manufacturers Association (MBMA)

National Association of Corrosion Engineers (NACE)

National Electrical Manufacturers Association (NEMA)

National Fire Protection Association (NFPA) National Fire Codes

Pipe Fabrication Institute (PFI)

Sheet Metal and Air Conditioning Contractors National Association (SMACNA)

Steel Structures Painting Council (SSPC)

Thermal Insulation Manufacturers Association (TIMA)

Tubular Exchanger Manufacturers Association (TEMA)
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3.6.
4.
Technical Specifications: Appendix N2
Combined Cycle

Underwriters Laboratories, Inc. (UL) - fire protection equipment only

Welding Research Council (WRC)
Electric Utility Requirements

California ISO

PG&E Interconnection Requirements– see www.pge.com/about/rates/tariffbook/ferc/tih/

Western Electricity Coordinating Council (WECC)

California Energy Commission

Utility interconnect requirements for fuel (gas), power transmission, and water.
TECHNICAL REQUIREMENTS
Long-term safety, reliability, operability, and maintainability of the Facility are of
primary concern to the Purchaser. As a result, the Seller shall take prudent measures in
the design to facilitate ease of operation and provide adequate access to all equipment.
Where required to perform normal maintenance functions, facilities such as equipment
removal monorails shall be provided. Wherever practical, valves and instruments shall be
located such that they can be operated and easily accessed from grade. Where valves and
instruments normally requiring operator access must be located in elevated locations,
access platforms, handrails, and ladders shall be provided. All valves (including safety
and relief valves) and components shall be accessible for routine maintenance. Minimum
clearance over walkways and platforms shall be 7'-6". Adequate provisions for removal
of the generator rotor and turbine maintenance and laydown must be provided in the
general arrangement proposed by the Seller. Platform access with stairs shall be provided
to all metering and custody transfer points that are not readily accessible from grade. All
task lighting applications shall be arranged to provide shadow-free lighting for the area.
The proposed layout must accommodate concurrent maintenance on the steam turbine
and one of the combustion turbines with separate cranes. All lifting devices shall be
clearly stenciled with rated lifting capacity. Provisions for a maintenance trailer area
along with associated electrical, phone, and internet connections are required.
Facilities provided by the Seller must be adequate to support the number of individuals
who will be assigned to the Facility on a continuing basis, both during maintenance and
normal operations. Facilities required to support maintenance crews during maintenance
inspections/overhauls will be brought onsite on a temporary basis.
Plant must be automated and designed to be started, stopped, and operated with no more
than the specified number of employees specified in Appendix J of Seller’s Offer.
Equipment or other items that contain PCBs, asbestos, or asbestos-bearing materials are
prohibited from use, as are instruments containing mercury. All hazardous and
non-hazardous wastes generated during the construction process shall be collected and
segregated by the Seller and stored in a secure area in properly labeled drums, which
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identify the wastes contained. Disposal of such wastes shall be the responsibility of the
Seller, using the services of properly licensed technically capable subcontractors. The
Seller shall comply with all applicable local, state, and federal regulations.
Nametags and nameplates shall be provided for all equipment and instruments supplied
under this Contract. Nameplates or tags shall be constructed of stainless steel and should
be stamped, as a minimum, with the manufacturer's name, the purchase order number
under which the item was purchased, and the equipment identification number used to
identify that piece of equipment on the Seller's drawings. Nametags shall either be
permanently attached to the equipment using rivets or stainless steel machine screws or
shall be wired to the item using stainless steel wire.
The design and layout of equipment within the Facility boundary shall meet Occupational
Safety and Health Administration (OSHA) and California OSHA (CALOSHA)
permissible noise exposure levels without the use of hearing protection for a 12-hour
duration per day. Where this is not practicable, with Purchaser’s approval, these areas
may be designate as high-noise-level areas with limits indicated on the general
arrangement. In any case, the local noise ordinance shall be met, unless a variance can be
obtained from the local authority. Plant noise levels shall be within permit specifications
under all operating conditions.
Signs, fire extinguishers, marking of high noise areas requiring hearing protection, and
other items needed to meet OSHA regulations and otherwise ensure minimal risk to
personnel health and safety while at the Facility shall be provided.
All outdoor equipment and materials shall be designed and installed consistent with
expected use and environmental conditions (e.g., freeze protection, moisture & dust
controls, cooling and ventilation, heat tracing and insulation for electrical motors,
cabinets/load centers, sample, trap and chemical feed lines, etc.).
All plant equipment (pumps and motors) shall be fully isolatable to facilitate maintenance
repairs or replacement. The plant shall be designed to provide the ability to isolate each
combustion turbine generator/HRSG train independently to perform shut down work
while continuing to generate with a remaining train.
All major outside utility piping interfaces (such as incoming raw water, natural gas, and
outgoing wastewater) must be fully metered with revenue-quality instrumentation.
Power augmentation such as fogging, evaporative cooling, and steam injection may be
used provided it meets all OEM requirements.
4.1.
System Descriptions
System descriptions shall be submitted to Purchaser for approval no less than four
months before the start of the operator training program. PG&E will provide the typical
format to be used for draft system descriptions. Final system descriptions shall be revised
to reflect as-built conditions.
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4.2.
Technical Specifications: Appendix N2
Combined Cycle
Plant Identification System
The Seller shall use a uniform designation and numbering system for all plant systems
and equipment and across the entire site. The designation and numbering system shall be
coded to designate unit number or common facilities, process system, equipment name,
subcomponent or function name. The designations shall be used on all drawings,
schedules, descriptions, and other documents as well as on all nameplates, tags, and other
markings.
Equipment shall be numbered according to the following convention:

North to South – increasing numbers

East to West – increasing numbers.
The Seller shall ensure that all numbering and nomenclature of high voltage apparatus
will be in accordance with PG&E Interconnection Handbook.
Each equipment, motor, valve, instrument, control panel and pertaining apparatus shall be
provided with nameplates or tags indicating their purpose and identification designation.
The label shall also include the normal operating position for all shut-off valves. All
actuated valve tags shall include the valve and actuator reference number.
Nameplate surfaces for cubicles and control equipment shall have a matt or satin finish to
avoid dazzle. Equipment identification and components may use engraved plastic or
weatherproof nameplates, where appropriate. Name tags used on valves and
instrumentation shall be permanently attached to the equipment using rivets, machine
screws or stainless steel wire.
All major equipment shall be provided with data plates, indicating the name of
manufacturer, type, serial number, year of fabrication, main characteristics and other
information, as appropriate.
All components of the various pipe systems shall be clearly identified. Piping shall be
painted and/or marked in accordance with the fluid contained according to agreed and
approved power plant color code. Where color coding is impractical, the type of fluid
contained in the pipe shall be permanently stenciled onto the exterior surface of the pipe
or the pipe cladding at a maximum interval of every 15 feet. Piping containing hazardous
materials shall be labeled in accordance to ANSI A13.1. Both ends of all power and
instrument cables shall be clearly identified. A standard system of colors for cable cores
and wire color used for the wires in all panels, cubicles and cabinets shall be specified
and used by the Seller.
4.3.
Supplier Factory Tests
Seller specifications will require certain factory/functional tests of selected equipment,
including, but not limited to, the following:
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Technical Specifications: Appendix N2
Combined Cycle

Combustion turbine including starting motor/torque converter/gearbox and
generator

Steam turbine and generator

Heat recovery steam generator

Selective catalytic reduction system

Air-cooled condenser and auxiliaries

Boiler feed pump

Main transformers

Generator excitation system

Station service transformer

Air cooled heat exchangers

Water cooled heat exchangers

DCS

CEMS/DAHS (review of system software)
Tests will be required for other equipment as considered appropriate by Purchaser.
A preliminary list of witness and hold points to be developed by Seller and approved by
Purchaser.
Seller will review suppliers’ certified test data for compliance with specified performance
and functional criteria. Seller shall provide Buyer with test results as requested and
provide the opportunity for Purchaser to witness tests.
4.4.
Testing
Shop inspection and testing will be conducted in accordance with the requirements of
applicable codes and standards.
Seller shall furnish a table for approval by Purchaser showing inspection and testing for
all major purchase orders and field erected piping.
Pressure vessels will be shop tested per ASME Section VIII. Atmospheric tanks will be
hydrotested by filling with water. Welders will be certified per applicable codes.
Prefabricated piping to be skid-mounted will be hydrotested per ASME B 31.1 at the
fabricator’s shop when required by the applicable code or standard.
After assembly, piping systems will be given a leak test.
Assembled equipment will be visually examined.
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Technical Specifications: Appendix N2
Combined Cycle
Certified pump performance curves will be supplied for each pump based on previous
tests conducted by the vendors, except condensate pumps and boiler feed pumps, which
will be tested.
A complete functional checkout of the control panel and controls will be done at the
manufacturer’s shop before shipment.
Pressure testing, including pressure testing at 1.5 times the design pressure (unless noted
otherwise), will be specified and performed for pressure components. All pipe joints must
be exposed where pipe insulation is installed before the pressure testing. Pressure testing
shall include but not be limited to the following equipment and piping systems:

Pump casings

HP/IP steam system

HP feedwater system

Fire protection system (test pressure per NFPA)

Fuel gas system

Liquid fuel system, if applicable

Chemical feed systems

SCR ammonia system

All underground piping (other NDE may be accepted for makeup water and
blowdown piping subject to prior written Purchaser approval)

Condenser air removal system

Closed cooling water system

Potable water system

Makeup water system

Condensate system

Demineralized water system

Blowdown system
If used, the ACC will be leak tested (low pressure pneumatic test) before being placed in
service.
Water will normally be used as the test medium for hydrostatic testing. The water will be
clean and will be of such quality as to minimize corrosion of the materials in the piping
system. The hydrostatic test pressure will not be less than 1.5 times the design pressure,
but will not exceed the maximum allowable test pressure of any non-isolated
components, such as vessels, pumps, or valves. Pneumatic testing will not be used unless
approved by the Purchaser.
For non-water systems, water will be drained and piping/equipment will be dried before
placing the system in service.
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Technical Specifications: Appendix N2
Combined Cycle
Supplier’s standard functional field tests will be performed on the Facility systems and
associated components during startup.
Code stamped pressure vessels will be shop tested hydrostatically per the code.
Purchaser may, from time to time, make visual examination of the equipment and the
conditions under which it is being manufactured, both at the manufacturer’s work and on
site.
4.5.
Welding
Welders and welding procedures will be certified in accordance with the requirements of
the applicable codes and standards before performing any welding. Seller will maintain
indexed records of welder qualifications and weld procedures. Welders engaged in onsite welding will be supervised.
Welding of ferrous piping will be in accordance with ASME B31.1 and ASME Section
IX of the Boiler and Pressure Vessel Code, as well as industry standards. Fusion welding
of high-density polyethylene pipe will be performed in accordance with the
manufacturer's recommendations using equipment approved for this purpose by the
manufacturer.
Electrodes and/or welding rods to be used and the fabrication procedure to be adopted
will be in accordance with the applicable code or standard.
Before welding, the work will be heated, where necessary, in an approved manner, and
the temperature will be maintained throughout the operation.
After completion of welding, fabricated parts will be stress relieved as required by
applicable code or standard.
The extent of weld inspection and the final weld quality will comply with the applicable
standard or code. Nonconformance in welds is not acceptable. Indexed records of welder
qualifications, weld procedures, and weld inspection and repair reports shall be available
for inspection by Purchaser.
4.6.
Lubrication
The types of lubrication specified for Facility equipment will be suited to the operating
conditions, will be in the beginning of the lubrication’s life cycle, and will comply with
the recommendations of the equipment manufacturers at the time of facility turnover.
Rotating equipment will be splash lubricated, force lubricated, or self-lubricated. Oil cups
will be provided as necessary. Where automatic lubricators are fitted to equipment,
provisions for emergency hand lubrication will also be specified. Where applicable,
equipment will be designed for manual lubrication without the removal of protective
guards while the equipment is in operation. Lubrication fill, drain and sample points will
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Combined Cycle
be readily accessible. Manual lubrication provisions will be external to guards with
machinery in motion.
Wherever possible, the lubricants proposed will be readily available.
The types of lubrication specified for the Facility equipment will be suited to the
operating conditions and will comply with the recommendations of the equipment
manufacturers.
4.7.
Consumables
Seller shall replenish the Facility consumables (demineralizer water, chemicals, gases and
other) such that at Turnover of the facility Purchaser has a full supply.
5.
OPERATIONAL REQUIREMENTS
The Facility will be designed so that each Unit may be operated independently, and a
single failure of mechanical equipment common to all Units will not trip any operating
Unit.
The Facility and each Unit will be fully dispatchable with automatic generation control
(AGC). The Facility and each Unit will be capable of being dispatched from minimum to
full load, as specified in Appendix G. The Facility and each Unit will also be capable of
cycling operation. Balance-of-plant design will not limit CTG operation over the full
range of site ambient conditions.
The Facility will be started without a source of auxiliary steam. All steam required for
startup will be provided by the HRSG. Excess steam generated during startup of the first
Unit will be vented to atmosphere through silenced, startup vent valves. Once the steam
seals have been established in the STG, excess steam will be bypassed to the condenser.
Cross ties shall be provided so that steam from an operating Unit can supply steam for
startup of the remaining Units. Design of the Facility shall consider limitations on
emissions imposed by the local air district and the CEC.
The Facility does not need to have black start capability. An independent dual source of
power from the electric utility is required to meet house loads, including operation of all
necessary standby equipment and systems.
The sequence of startup varies only slightly depending upon whether the CTG is cold,
warm or hot. However, the duration of a start-up will be dependent on the initial
conditions of the plant. Each of the units that comprise the facility shall be designed to
achieve the startup times listed in Appendix N3 for the specified shutdown periods for
each Unit.
The startup and shutdown operational requirements include:

Ability to turn-down to 55% of full baseload power output or lower.
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Technical Specifications: Appendix N2
Combined Cycle

Automatic Generation Control (AGC) and load following over the full turn-down
range (55% to 100%), in accordance with the California ISO’s “Generation
Monitoring and Control Requirements for AGC/Regulation Units” as can be found
on their web site at
http://www.caiso.com/docs/09003a6080/1b/23/09003a60801b2389ex.html

Maximum allowable hot-start time of 90 minutes including all pre-ignition purges
and other permissives. Offers shall note the portion of the plant output that can be
delivered within ten minutes of request to start, and shall note any limitations to
and consequences of using of this quick starting capability.

Maximum allowable cold-start time of 4.5 hours.

Minimum downtime between combustion turbine restarts of 60 minutes.

Minimum ramp rate of 7% of guaranteed capacity per minute per combustion
turbine.

Ability to complete a hot shutdown to hot re-start cycle in less than three hours.

300 annual starts including approximately 25 cold starts.

Minimum Run Time – 4 hours or less per start.

A facility that meets all NERC requirements (cyber, site security, other).

A facility that meets the CAISO interconnection requirements including metering
and ancillary service provisions.

Alternate power source or back-up generator to meet essential loads.

Ability to meet all air emissions criteria at startup, shutdown, and for all operating
loads.
6.
MAJOR MECHANICAL EQUIPMENT AND SYSTEMS
6.1.
Combustion Turbine
Equipment is to be of proven design with large number of units in operation and
experiencing high reliability track record.
The compressor shall be a multistage axial-type and shall be directly coupled to the
turbine section. Modulating inlet air guide vanes shall be provided.
The combustion system shall be designed to maximize combustion efficiency,
combustion stability, and equipment life while meeting air emissions requirements while
firing natural gas. Control of NOx emissions shall be through dry low NOx combustors.
If liquid fuel is to be used for a back up fuel supply, the combustion system shall be
similarly designed to deliver efficient, stable, long life compliance.
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Technical Specifications: Appendix N2
Combined Cycle
The combustion controls for the dry combustion system shall automatically regulate the
proper fuel flow and mixture to meet the emissions criteria.
The turbine blades shall be designed to minimize loads due to tangential, axial, and
torsional modes of vibration under all anticipated operating conditions.
Turbine blades and nozzles shall be coated as necessary to prevent degradation from
erosion, corrosion, or deposits. Components to be coated and coatings to be used shall be
identified in the proposal. Blade coatings must be available domestically.
A complete lubrication and control oil system including reservoir, pumps, filters, pressure
regulation, cooling-heating, circulating pipe to the turbine shall be provided as described
in section 6.3.1.
6.1.1.
Turbine Supervisory Instrumentation
A complete Bentley Nevada 3500 or equal turbine supervisory instrumentation (TSI)
system with locally mounted supervisory instruments required for safe startup, operation,
and shutdown of the turbine generator shall be provided which includes the following:
6.1.2.

Vibration monitor on all the combustion turbine generator bearings using X and Y
vibration probes.

Rotor speed and one zero speed sensor.

Key phasers, three-speed and one zero-speed sensors (rotor speed).

Temperature measurements of turbine metal, CTG bearing, and generator stator.

Full data acquisition and facility control through the DCS automatic and manual
synchronizers.
Inlet Air Filter
The inlet filters to the combustion turbines shall be provided meeting the requirements of
the combustion turbine supplier. The filters shall be selected to meet the ambient
conditions and shall account for severe weather conditions such as icing, heavy rain, fog,
or dust conditions that result in high differential pressures.
A self-cleaning pulse-type filter shall be used unless not permitted by local environmental
conditions. The filters shall be selected and sized to provide minimum installed site life
of 36 months.
The high-efficiency cartridge filters shall be designed for 99.9% efficiency for removing
particles 5 micrometers (microns) and larger and 99% efficient in removing particles
2 microns and larger. The face velocity (horizontal component of the airflow) through the
filter media shall not exceed 500 ft/min.
Filter media shall be Donaldson Spiderweb or equivalent with minimum 4-year life
expectancy.
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The inlet air filter system shall include the following:
6.1.3.

Stairways, and platforms (for access and maintenance) meeting OSHA
requirements.

Interior lighting and convenience outlets.

Lifting facilities for raising and lowering filter elements from grade level to the
filter element access elevation.

A louver or weather hood to minimize the entry of rain into inlet filter.

A debris/bird screen immediately ahead of the inlet filter openings to prevent
debris and birds from entering inlet will be provided. The metal inlet screen shall
not have larger than one-inch mesh. Inlets shall have drainage holes to prevent
standing water during outages.

Differential pressure measurement across filters linked through the DCS to allow
assessment of the optimum period to change the filter pads.

A system to indicate possible inlet icing conditions (where icing conditions can be
expected). Windows shall be located in inlet ducts with lighting to enable on-line
observation of the inlet scroll and inlet guide vanes.

Filter designed to minimize re-depositing particles expelled during pulsing.

Enclosure sufficiently rigid to avoid vibration problems. Fasteners shall be suitably
locked to prevent loosening especially those on the inlet that could be ingested by
the compressor.

Manufacturer’s standard air inlet filter. Inlet face velocity shall not exceed
500 ft/min with high efficiency filters meeting the combustion turbine
manufacturer’s requirements.

Ability to change inlet air filters during on line operation with no load curtailment.
Acoustic Enclosures
The combustion turbine-generator package shall be enclosed by several connected
sections of weather protective housing structurally attached to the compartment base.
These enclosures shall provide ventilation (with 100% redundancy), thermal insulation,
acoustical attenuation, and fire protection media containment.
6.1.4.
Water Wash System
Online CTG compressor water wash systems with drains shall be provided. All valves
shall be accessible for routine maintenance. A single wash-water skid-mounted system
with permanent piping to all combustion turbines shall be provided.
A separate CTG water wash drain system shall be provided for each Unit.
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Waste water from the CTG during and after an off-line water wash procedure shall be
collected in a sump with capability to transfer the collected waste to the turbine building
sump.
6.1.5.
Combustion Turbine Exhaust Duct
The stainless steel liner covering system shall consist of mineral wool and ceramic fiber
insulation and an interior stainless steel liner. Insulation shall be retained to prevent
packing. The liner shall be retained in such a manner as to prevent movement
perpendicular to the duct and to allow axial thermal expansion and contraction.
Provisions at overlaps shall be provided to prevent the liner from buckling or being lifted
by gas flow velocities in the duct.
6.2.
Heat Recovery Steam Generator
The HRSG shall be of proven design with large number of units in operation and with a
track record of high reliability.
Steam headers and tubes designed and constructed with materials suitable for 300 startup
cycles per year and 30-year life cycle.
The HRSG shall be designed to operate in a floating-pressure and fixed-pressure mode.
Seller shall meet the Facility startup times and provide detailed explanation of the startup
sequence.
The HRSG shall be designed, fabricated, and stamped in accordance with the ASME
Boiler and Pressure Vessel Code (B&PVC), Section I and all codes and standards
required therein. Any additional state or local requirements for certification of the HRSG
pressure vessel shall be met. All materials not covered by ASME codes shall conform to
the latest edition of the ASTM standard. The Purchaser must approve other materials
being considered.
The HRSG shall be supplementary fired with natural gas only. The HRSG will be
designed not to have flame impingement.
The HRSG will have space allocated for future addition of SCR and CO catalyst if the
licensing requirements do not include these catalysts. If either catalysts are provided,
additional space for future addition of one layer of catalyst shall be provided.
The HRSG shall be suitable for operation at all loads from startup to the rated maximum
steam generating capacity. The turndown ratio and rate of load change of the HRSG shall
be compatible with the combustion turbine as far as possible. HRSG design shall include
a condensate heater bypass to maintain the minimum specified gas outlet temperature. A
recirculation system shall also be provided for condensate temperature control.
Oxygen concentration in the feedwater/steam shall be less than 7 ppb or the steam turbine
supplier requirements if lower.
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The deaerator shall be designed, fabricated, examined, tested, and stamped in accordance
with ASME Code for Boiler and Pressure Vessels, Section I and The HEI “Standards and
Typical Specifications for Deaerators.” If an integral deaerator is supplied, the deaerator
shall use the low-pressure saturated steam from the low-pressure steam drum as the
primary steam supply. Spray nozzles shall be spring-loaded, removable type made of 316
stainless steel, which shall maintain a uniform spray pattern from 10% to 110% of
deaerator design flow. The trays shall be constructed of 430 stainless steel of not less than
16 gauge average thickness. Spot-welded tray construction is now allowable. The trays
shall be fastened in place to avoid being upset. The trays shall be rigidly held in place by
straps, tie down rods, or other methods acceptable to the Purchaser.
The deaerator shall heat entering condensate to the saturation temperature corresponding
to the deaerator pressure with any oxygen content not exceeding 0.005 cc/L as
determined by the titration method specified in ASME PTC 12.3 and with a free CO2
content of zero at all loads from 10% to 110% of the deaerator design flow. At higher
condensate-entering temperatures and/or lower low-pressure steam flow requirements,
excess steam production shall be limited by allowing the deaerator pressure to float.
Minimum operating pressure shall be 15 psig. The design shall be such that, except
during the HRSG startup sequence, the deaerator shall be capable of being pegged at the
minimum pressure with steam from the high-pressure section.
For drum units, at a feedwater cut-off during design load (meaning full CT load and full
steam mass flow), the minimum run out time in the drum (at continued design load), from
normal operating level to the level at which a CT Protective Load Shedding (PLS) has to
be initiated, shall be as follows:

HP drum:
5 minutes

IP drum:
5 minutes

LP drum:
8 minutes
The steam drums shall have shop installed steam separators of sufficient size and
capacity to limit moisture carryover to the superheater. Carryover shall be less than 0.2%
for the HP, 0.04% for the IP, and 0.03% for the LP drums at rated steam production when
supplied with feedwater. Separators shall be centrifugal or inertial types.
The HP, LP, or IP evaporator pinch points at Performance Guarantee conditions shall not
be less than 12F. The HP, LP, or IP economizer approach at Performance Guarantee
conditions shall not be less than 15F.
Three 50% capacity or two 100% economizer re-circulation pumps shall be provided.
The feed pump suction piping shall be from the bottom of the low-pressure drum. One
connection shall be provided. A vortex breaker shall be provided at the suction
connection.
All parts subject to corrosion shall be constructed of stainless steel suitable for the
corrosive environment.
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The Seller shall carry out flow model testing or computer model testing to assure equal
flow distribution over the duct burners, ammonia grid, catalyst, and heating surfaces.
Results of this analysis shall be provided to the Purchaser.
All HRSG pressure containing materials shall be provided by the Seller in accordance
with the following specification without exception. Alternate satisfactory materials will
require written approval by the Purchaser.
HRSG Materials
Specification
High Pressure Superheater 1
A213 T91
High Pressure Superheater 2
A213 T22
High Pressure Evaporator
SA210A1
High Pressure Economizer
A213 T22
Reheater 1
A213 T91
Reheater 2
SA213 T22
Intermediate Pressure Superheater
SA192
Intermediate Pressure Evaporator
SA192
Intermediate Pressure Economizer
SA192
Low Pressure Evaporator
SA192
High Pressure Superheater 2 Fins
SA176 TP409
High Pressure Superheater 1 Fins
SA176 TP409
Reheater 2 Fins
SA176 TP409
Reheater 1 Fins
SA176 TP409
High Pressure Drum
SA299
Intermediate Pressure Drum
SA516GR 70
Low Pressure Drum
SA516GR 70
Condensate Heater
SA210A1
Piping
High Pressure/Intermediate Pressure/Low Pressure Feed
SA106B
High Pressure Steam
A335 P91
Intermediate Pressure Steam (check valve CKV-D650 to CR)
A335 P22
Low Pressure Steam
SA106B
Extractions (Pegging steam and fuel gas heater)
SA106B
Cold Reheat
A335 P22
Hot Reheat
A335 P91
Seller shall provide the material certification documentation for all materials and actual
thicknesses used in pressure parts of the HRSG. The use of asbestos, PCBs, or
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instruments containing mercury, in any portion of the equipment furnished, is not
acceptable.
All tube material shall be seamless for all sections of the HRSG. If HRSG tubing heat
exchange surface uses fins, they shall not be higher than 3/4 inch; shall not have a fin
spacing of more than seven fins per inch of tube length; may be serrated fins; and shall be
attached by a continuous weld. The tube fin thickness shall be a minimum of 0.049 inch.
HRSG economizer and evaporator tubes shall not be less than 1.5 inches outside
diameter. Tubes for other sections of the HRSG shall be 1.25-inch outside diameter or
greater. The use of tubes with wall thickness less than 0.105 inch is prohibited.
Tubing/fin material shall be selected based on the service conditions expected, such as
use of 430 stainless steel in areas where there is potential for oxygen presence in the
water or tube metal temperatures are expected to be lower than the dew point of the
exhaust gas. The design shall also take into account and minimize galvanic reaction of
dissimilar metals when selecting tube/fin materials.
HRSG tube bank modules shall not be greater than 15 rows of tubes in the direction of
flue gas flow. A minimum crawl space of 24 inches shall be provided between each tube
bank module. Access doors (24 inch H x 24 inch W) shall be provided between each tube
bank module on both sides of the HRSG.
Attemperators shall be provided to prevent the superheater outlet temperature from
exceeding specified limits. High-pressure (HP) feedwater shall be used for attemperation.
All duct and casing shall be designed to provide suitable drainage. Horizontal surfaces
shall be sloped or provided with a means to remove rainwater other than evaporation to
ensure runoff of rainwater. Stiffeners shall be designed in such a manner as not to impede
rainwater runoff.
All startup and safety vent valves shall be silenced as required to maintain plant boundary
noise limits.
All braces and external stiffeners shall be continuously seal-welded.
Hinged access doors shall be provided on both sides of the HRSG at each access lane and
the inlet and outlet ducts.
Drain and vent manual isolation stop valves shall be in place and accessible for routine
maintenance. Drains and vents shall be adequately sized to meet both HRSG and steam
turbine heat up specifications.
Maintenance drains shall be grouped by tube bundle banks. Drain lines from multiple
tube rows shall be routed out from underneath the HRSG where a block valve shall be
located for each tube row header. Drain piping shall be sized to minimize the time
required to drain the component being serviced and shall be at least 1½ inches.
The HRSG and auxiliary equipment shall be designed to facilitate rapid water drainage
for freeze protection during extended periods when the unit is not operating. Vent and
drain systems shall be sized so that the maximum time to drain any heat transfer section
is 45 minutes and a maximum time to drain the entire HRSG from operating conditions
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of 4 hours. In no event shall the drain valves be less than 1½ inches NPS. Intermittent
blow off is not acceptable as a means of draining the HRSG. Drains required for freeze
protection drainage shall have double isolation valves with a drain valve (to floor)
between the two isolation valves.
HRSG steam isolation valves shall be installed to allow for tube bundle hydro testing and
chemical cleanings.
HRSG construction shall be welded. No rolled or rolled and seal-welded joints shall be
permitted.
The maximum permissible tube bundle depth between access lanes shall be fifteen (15)
rows. The design shall provide access for harp section replacements.
Steam drum(s) shall have man ways of the pressure seal design in all heads. Man ways
shall be 14" x 18." Steam drum end enclosures shall be provided to ensure that drum
instrumentation does not freeze.
If required for licensing, each HRSG shall be equipped with an SCR system designed to
control NOx and Carbon Monoxide (CO) to the required emission limits. The ammonia
injection system should include, at a minimum, ammonia storage tank, unloading station,
injection pumps, blowers, mixing chamber, and controls. The storage system shall
provide onsite ammonia storage sufficient for 30 days of full-load operation. Two 100%
capacity ammonia unloading/delivery pumps and two 100% ammonia injection
fans/pumps shall be provided. Appropriate lifting devices and cranes shall be provided
for change out of catalyst.
The HRSG shall be designed to ensure that:

Flue gas temperature leaving the stack is higher than sulfur dew point temperature.

No steaming occurs in economizer tube bundles for the most anticipated operation
modes.

Insulation thickness shall be designed to meet OSHA (CAL-OSHA) and 140°F
average (over a 20-square-foot area) external casing temperature with an air
velocity of 2 mph and 100F ambient air.
Internal gas path liner shall be in accordance with the table below.
Max. Gas Temperature (°F)
Below 750
Material
C. S.
750 – 1,200
TP 409 SS
1,200 -1,400
TP 304 SS
Transition ductwork internal gas path liner shall be a 12 gauge-minimum thickness for
the floor, sides, and roof. HRSG liner shall be 12-gauge minimum thickness for floor
panels and 16-gauge thickness for sidewalls and roof.
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Steam and water passages including drums shall be completely drainable and accessible
to the drain collection system. Discharge to the environment or systems requiring manual
collection are not acceptable. All steam and water drains and vents shall be adequately
sized so that they are not a limiting factor during startup, but shall not be less than
2 inches nominal diameter. All casing drain connections shall be a minimum of 4 inches
nominal diameter. The bottom of all steam and water passages and casing drain
connections shall be a minimum 5 feet above grade.
All headers shall be adequately sized for proper distribution of water/steam flow. If
necessary, two or more inlet/outlet connections to the headers shall be provided. Flow
variation in parallel circuits shall not be more than 5%.
6.2.1.
HRSG Casing
The outer casing shall be carbon steel. Insulation shall be installed internally and covered
with a stainless steel lining. All moment connections shall be bolted.
Openings shall be provided as required for observation of all burners and igniters, flame
scanners, and maintenance access. Observation ports shall be of the air-cooled, glasswindow type. The observation ports shall be provided with aspiration and cooling air.
The Seller shall provide all necessary platforms for access to the observation ports.
6.2.2.
HRSG Burner System Valves
The HRSG burner system shall be designed in accordance with the requirements of
NFPA 850 and the following:

Double-block burner gas and vent valves and double-block pilot gas and vent
valves shall be Jamesbury model 5150-31-2236MT ball valves or Purchaser
approved equal.

Pilot and main gas charging valves (if required) and pilot gas trip valves shall be
Jamesbury model 5150-31-2236TT ball valves or Purchaser-approved equal. The
pilot and main gas charging valves shall fail closed on loss of air.

The Main gas trip valves shall be Jamesbury model F815L-22HB AA butterfly
valves or Purchaser-approved equal.

Stroke time for piston-operated valves shall not exceed two seconds.

Stroke time for pneumatically operated non-piston type valves shall not exceed
five seconds.

Stroke time for motor-operated valves shall not exceed 15 (fifteen) seconds.

All fire-safe valves shall meet the requirements of API 607.
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6.2.3.
Technical Specifications: Appendix N2
Combined Cycle
Duct Burners
Supplemental duct firing shall be provided as required to meet the guaranteed unit output.
HRSG duct burner output shall be sized to provide the maximum additional steam
generation from the HRSG without changing the unfired design heat transfer surface or
materials of construction. The duct burner pilots shall be capable of continuous duty at
loads up to and including peak load, and will be fired on natural gas.
Duct burners shall be designed for continuous operation with combustion turbine at 95%
to 100% load. The duct burners shall be capable of a turndown of 10:1 or greater.
The main gas header shall be tested under pressure to determine if the trip valves or
individual shutoff valves are leaking. The header test shall conform to the requirements
of NFPA 8506 Section 5-3.2.2.3.
All duct burner components in contact with exhaust gas shall be fabricated of stainless
steel suitable for high temperature service. Duct burner fuel isolation valves shall be
provided and the system shall be readily purged.
6.2.4.
Feedwater System
Two 100% feedwater pumps for each pressure level shall be provided for each HRSG.
All pumps shall be driven by either variable-speed motors or variable-speed fluid
couplings, with the capability to operate at minimum load without requiring recirculation.
These pumps shall be horizontal, volute, and multiple-stage ring-section pumps in
accordance with Hydraulic Institute Standards. Double-bearing design shall be used with
bearings on either side of the impellers. Impellers shall be stainless steel.
A multistage feedwater pump may also be used for HP and intermediate-pressure (IP)
supply. The pump shall take suction from the deaerator and/or feedwater storage tank.
The HP feedwater shall be piped to the HP economizer inlet. The system shall be
designed for continuous operation at flows ranging from manufacturer’s minimum
recirculation to 100% of design capacity.
At a minimum, a 5% margin on capacity and 10% margin on total head shall be added for
pump wear. The available net positive suction head (NPSH) shall be at least two times
the required NPSH of the purchased pumps.
A manual stop-check valve arranged in series shall be provided on each boiler feed pump
discharge. A warm-up line tapped off each discharge line, downstream of the stop-check
valve, for warming the boiler feed pump while in a standby mode of operation shall also
be provided. A pressure breakdown orifice shall be provided in each warming line to help
match the internal pressure in the pump casing while isolated from the feedwater
discharge header. Each pump shall be provided with a minimum flow control system to
meet the minimum flow requirements of the pump.
Chemicals shall be injected into the feedwater and HRSG to maintain water and steam
chemistry within HRSG and steam turbine manufacturer limits. The chemical injection
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points and blowdown drains shall be configured to allow control of steam and boiler
water chemistry within HRSG and steam turbine OEM specifications and within EPRI
guidelines. All chemical injection, sampling, and monitoring points shall be easily
accessible for routine maintenance.
Each feedwater and condensate chemical addition/injections systems shall include two
100% chemical injection pumps and chemical storage adequate for 7 days of operation
for each type of chemical.
Centralized sampling location with remote readout in control room shall be provided.
Motors shall be furnished and mounted by the driven-equipment supplier on a common
base plate.
The plant control system shall be designed to automatically start the standby pump when
the operating pump fails.
6.2.5.
Temperature Monitoring
Monitoring of the temperature profile in the HRSG inlet duct downstream of the burners
shall be provided. The signal(s) shall be brought as inputs into the Distributed Control
System (DCS) and displayed to the operator on the console CRTs.
6.2.6.
Blowdown Tanks
A blowdown tank shall be furnished with each HRSG. The tank shall be sized to
simultaneously accommodate all startup drains and vents as well as the normal and
startup drum blowdown from the HRSG at all operating and startup conditions. DCScontrollable motor-operated valves shall be provided in the continuous and intermittent
blowdown lines, which feed these blowdown tanks. The continuous blowdown valve
shall be an open-close type while the intermittent blowdown shall be modulating type.
Blowdown flows shall be measured. The DCS will also monitor the flow going into each
blowdown tank.
6.2.7.
Exhaust Stack
Exhaust stack shall be constructed of carbon steel with interior stack coating and, if
necessary to meet noise limitations, sound buffers. Stack drains shall be provided and
routed to the chemical waste drain system.
Exhaust system outside skin temperature shall not exceed 140°F for personnel protection
during any operating condition at summer design ambient conditions with still air (0 mph
wind speed).
Automated stack dampers are required to enable faster warm restarts.
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Stack warning lights and/or coloring shall be incorporated, as required by Federal
Aviation Authority (FAA) regulations.
6.3.
Steam Turbine and Associated Components
The STG shall be a proven design (single-shaft, 3,600-rpm) with large number of units in
operation and having a track record of high reliability. The generator shall not be
constructed using global VPI (vacuum pressure impregnation) process.
The STG unit may be located outdoors.
The unit shall be capable of a design life of 30 years of operation without distress due to
daily cycling loads.
All necessary equipment shall be provided as required for automation of the turbinegenerator unit. This shall include those items of equipment, as recommended by
manufacturer, which will allow complete turbine startup, operation, load change, and
shutdown.
The Seller shall include the turbine control system (TCS) and the turbine supervisory
instrumentation (TSI) for proper operation and protection of the turbine generator. The
steam turbine generator shall be shop-tested to meet, at a minimum, those standards
referenced in the ASME Boiler and Pressure Vessel code and manufacturer’s standard
practice.
The steam control and shutoff valves shall be designed to meet OEM performance
criteria. Steam turbine main stop valves and reheat stop/intercept valves shall be shoptested at 1.5 times the design inlet steam pressures.
The generator and its appurtenances shall conform in all respects to the ANSI standards
for synchronous machine (ANSI C50.10) and to the ANSI standard for cylindrical rotor
synchronous generators (ANSI C50.14), with their latest revisions and addenda.
Water-induction protection shall be provided to protect the steam turbine and other
sensitive equipment in accordance with the intent of ASME Recommended Practices for
the Prevention of Water Damage to Steam Turbines Used for Electrical Power
Generation (TDP-1-1998).
All warm up drain valves and steam traps properly sized and located to accommodate
steam turbine OEM start up, shutdown and on line operating criteria.
TSI instruments which are supplied as part of the STG shall be provided in accordance
with vendors’ standards, and as follows:
a.
All instrumentation shall be of heavy-duty industrial quality design with all
materials of construction suitable for the application.
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b.
All mounted instruments shall have individual shutoff and calibration valves and
shall be mounted such that the instruments may be removed without dismantling
the adjacent instruments or piping.
c.
All field-mounted instruments shall be properly protected. Instrument cabinet shall
be used, as necessary, to properly protect instrumentation.
d.
Air sets shall be furnished if instrument air pressure below 105 psig is required.
The air sets shall have a filter, reducing valve, relief valve, and input and output
gauge.
e.
Dual element temperature probes shall be furnished as a minimum. The quantity of
the probes shall be specified by the supplier and approved by the Purchaser.
f.
All thermocouples shall be ISA Type E (chromel-constantan) or Type K
(chromel-Alumel) ungrounded tip.
6.3.1.
Lube and Control Oil Systems
The facility shall include a complete lubrication system including storage, pumps, filters,
pressure regulation, cooling-heating, circulating pipe to the turbine, and instrumentation
and controls and include the following features:.
The oil reservoir will be sized in accordance with industry standards to provide a normal
operating volume of at least 5 times the flow per minute to the bearings and other
services. Electrical immersion heaters with thermostatic control shall be furnished and
shall be capable of maintaining the optimal oil temperature at minimum specified winter
design ambient temperature conditions.
Lube oil supply and drain piping, valves, and fittings may be stainless or carbon steel.
Lube oil supply piping shall be routed inside the drain line.
Two lube oil pumps with AC motor drives. As an alternate, one full capacity shaft driven
lube oil pump and one full capacity AC motor-driven lube oil pump shall be provided.
With either alternative, one partial capacity DC motor driven lube oil pump sized to
provide adequate flow during trip conditions shall be provided.
Two 100% capacity water-cooled lube oil coolers shall be provided and piped such that
one unit may be serviced while the other unit is in operation.
A duplex, 100% capacity multi-element lube oil filter with a continuous flow transfer
valve shall be provided with connections and piping for a portable centrifuge filter.
Equipment shall include two 100% oil vapor extractors with mist eliminators which meet
permit emission limits. Extractors shall purge bearing housings and reservoir of oil
vapors.
Coalescent type mist eliminators shall be provided. Oil shall be separated and returned to
the lube oil reservoir.
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Additional instrumentation shall include dual-element thermocouples for monitoring and
alarm to measure steam turbine and generator bearing metal temperatures. Bearing header
and vapor extraction vacuum pressures shall be measured and indicated locally and on
the unit control system. Lube oil pressure to each bearing or in the common lube oil
supply line shall be indicated in the unit's control system.
A lube oil conditioner shall be provided to remove particulate and free and emulsified
water content in accordance with manufacturer’s specifications. Valved connections shall
be provided to provide for installation of portable centrifuge.
Hydraulic fluid control system shall be designed to use fire resistant fluid. It shall be
provided with the following:
6.3.2.

A reservoir with access doors, float-type level gauge, and two high- and two lowlevel switches

Redundant, full size AC motor-driven pumps

Filtering equipment with in-line filters

Two full-size coolers

316 stainless steel piping from reservoir to and from turbine and to hydraulic
actuators

Dual thermocouples and indicating thermometers for indication of fluid
temperature, and pressure gauges and electronic pressure transmitters for
indication of fluid pressure
Gland Steam Sealing System
A gland steam sealing system shall be provided for the main turbine and steam seal
glands and shall include automatic steam seal regulator valves and controls for regulating
seal steam from the main steam line. In addition to the automated controls, the system
shall include hand-operated shutoff and motor-operated bypass valves, gland steam seal
condenser, complete piping system, valves, strainers, instruments, special appurtenances,
piping supports and hangers, thermal insulation, lagging, and other required specialties
for the gland seal system. The system shall also include a gland steam exhaust equipped
with desuperheating equipment.
6.3.3.
Turning Gear
Turning gear shall be furnished complete with AC electric motor drive with backup DC
motor drive. A hand crank (or pneumatic) system shall also be provided. The in and out
positions of gear mechanisms shall be indicated.
6.3.4.
Piping
All piping furnished with the equipment regardless of size and service shall be provided
with all necessary rigid and spring hangers, supports, braces, and anchors required to
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properly support the piping systems and shall include necessary expansion loops to
provide flexibility. Piping support steel length shall be limited to a maximum of 15 feet.
All welding of piping systems shall be performed by welding operators who have been
qualified in accordance with the applicable requirements of Section IX of the
ASME BP&V code.
The steam systems are designed to prevent the induction of water into the steam turbine
in accordance with the ASME Standard for Prevention of Water Induction. Drip pots with
steam traps shall be provided at low points in the steam piping, upstream of control
valves and upstream of desuperheating stations. Startup drains with drip pots shall be
provided on the steam lines. These drains shall be equipped with air-operated valves.
Drains connections to the process lines shall not be less than one third the size of the
process line (drain lines can be reduced in size thereafter). Condensate from the traps will
be routed to the condenser. Startup drains shall be routed to either the blowdown tank or
the condenser flash tank, whichever is closer.
6.3.5.
Steam Strainers
Removable steam strainers shall be provided, either furnished integral with the throttle
stop valves or as a separate unit for installation in the steam line ahead of the throttle stop
valves.
6.3.6.
Drains
Drain outlets shall be provided in sufficient number to completely drain and warm the
equipment furnished by Seller.
6.3.7.
Insulation and Lagging
All high-temperature parts of the steam turbine shall be fully insulated with blanket
materials acceptable to the Purchaser. All exposed surfaces that will have operating
temperatures of 140F and above shall be considered hot surfaces and shall be properly
insulated. The use of asbestos or any insulating materials containing asbestos will not be
acceptable in any insulation work associated with this equipment.
6.3.8.
Chemical Cleaning
The facility HRSG, main steam, and hot reheat systems shall be steam blown and
chemically cleaned with a strong acid (or other method acceptable to Purchaser) before
Facility startup. Temporary cover plates and seat blanking fixtures for main and hot
reheat stop valves shall be provided during these processes. Cover plates shall be
provided with nozzle connections.
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6.3.9.
Technical Specifications: Appendix N2
Combined Cycle
Guards
Safety guards for all revolving shafts and shaft couplings and for other exposed moving
parts of the complete turbine-generator unit shall be provided.
6.3.10.
Main Steam System
Main steam valves shall be designed so they make a tight seat when closed so that an air
or water pressure test can be performed on the main steam system. Main steam shall be
designed to withstand the hydrostatic test pressure of the boiler, which is 1.5 times the
boiler design pressure.
Control valves shall meet all requirements of the ANSI B31.1 Code and this
Specification.
6.3.11.
Exhaust Hood Sprays
A complete exhaust hood spray system shall be provided to protect the steam turbine
during startup and trip conditions.
6.3.12.
Instrumentation and Control
The Facility shall be controlled via an integrated DCS system from a central control room
as well as locally at the equipment. The DCS shall be able to start and stop the facility as
well as change loads and load follow in AGC mode.
The CTG and STG controls shall have the capability of automatically controlling the
turbine speed to prevent the unit from reaching overspeed tripping point in the event of
an instantaneous change in load from full load to no load or to maintain the grid
frequency during normal operation (both electronic and mechanical overspeed protection
shall be provided). The controls shall sequence operating functions during startup,
running and shutdown, and provide necessary protection and monitor major parameters
during all phases of unit operation. All generators shall have manual and automatic
synchronizers along with full data acquisition and controls through DCS.
The control system shall be a fault-tolerant microprocessor-based control system
complete with the operator interface CRT, printer, and field-mounted instrumentation and
control devices. The control system shall have sufficient redundancy so that a single
failure shall not result in the failure of the control system or unavailability of the turbine
generator.
The system shall include a complete Bentley Nevada 3500 or equal TSI system with
locally mounted supervisory instruments required for safe startup, operation, and
shutdown of the turbine generator that includes the following:

Vibration monitor on all the steam turbine generator bearings using X and Y
vibration probes
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6.4.
Technical Specifications: Appendix N2
Combined Cycle

Rotor speed and zero speed sensors

Dual axial probe (i.e., position) on every thrust bearing

A proximity probe continuously measuring peak-to-peak and direct eccentricity
(rotor bow) at rotational speeds down to 1.5 rpm shall be furnished.

Temperature measurements of turbine metal, STG bearing metal and drains, and
generator stator; thermocouples for alarm and control to measure turbine-generator
bearing metal and turbine and generator bearing drains temperature.

Stand-alone Bentley Nevada 3500 or equal vibration monitoring system to provide
continuous measurement and monitoring of various turbine generator supervisory
parameters.

TSI instruments, which are supplied as part of the STG, provided in accordance
with vendors’ standards, and as follows:
—
All instrumentation shall be of heavy-duty industrial quality design with all
materials of construction suitable for the application.
—
All field-mounted instruments shall be properly protected. Instrument
cabinet shall be used, as necessary, to properly protect instrumentation.
—
Dual element temperature probes shall be furnished as a minimum.
—
All thermocouples shall be ISA Type E (chromel-constantan) or Type K
(chromel-Alumel) ungrounded tip.
Heat Rejection Systems
The heat rejection system shall include condenser, cooling tower, air-cooled condenser,
and once-through cooling (whichever is applicable).
6.4.1.
Condenser
Seller shall provide either a conventional steam surface condenser or air cooled
condenser (ACC) that meets the following operational requirements:
The condenser shall be sized and designed to—

Provide continuous operation at full steam load under all ambient conditions;

Provide continuous operation with full steam turbine bypass under base load
operating conditions without duct firing;

Maintain condenser pressure within allowable operating limits with full steam turbine
bypass under base load operating conditions with full duct firing, assuming ductfiring is discontinued at initiation of bypass operation.
A steam surface condenser shall be designed for continuous operation based on a 85%
cleanliness factor and in accordance with Heat Exchanger Institute (HEI) standards.
Tubing shall be titanium with no tube gauge thinner than 24 gauge. Outer tubes shall be
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18 gauge to protect inner tubes. Tube design shall consider vibration effects and tubes
shall be properly and adequately supported. Tube sheets shall be titanium or titanium
clad. All other condenser material shall be selected appropriately to match the Facility
cooling water quality, i.e., fresh water, gray water and seawater.
The condenser shall be of all-welded construction with bolts only permitted at access
manholes, water boxes, and flanged expansion joints. Condenser shall be capable of
absorbing the energy associated with operating continuously in the maximum steam
bypass mode.

The condenser shall be a single- or two-pass design, per Seller’s preference.
The condenser shall be designed with the following features:

Condenser tube leakage troughs

Man-ways to water boxes, hotwell, and turbine exhaust hood (note: All man-way
covers shall be marked and identified as “Confined Space Entries.)

Air leakage meter

Hogging and two 100% regular operation steam ejector or liquid ring vacuum
pumps sized with capacity no less than specified by HEI

Hotwell temperature indicator

Armored hotwell level gauge glass

Two 100% capacity liquid-ring vacuum pumps and related appurtenances as well
as fully redundant steam hogging and holding systems adequately sized for start up
and on line operation (including automated steam pressure control).

One motor-operated vacuum breaker valve

Over-pressurization rupture disc

Water box cathodic protection – impressed current type (note: coal tar epoxy inside
water box covers if necessary)

Split condenser water boxes with inlet and outlet entry doors adequately sized and
located for routine maintenance. Inlet condenser tube sheet base designed to
support ease of entry for routine cleaning (configured to help catch debris and not
allow it to fall back into inlet piping).

Ability to remove one condenser half from service for maintenance with minimal
steam turbine generator curtailment.

Condenser designed and sized with an automatic steam bypass system able to
prevent a combustion turbine and/or HRSG trip after loss of the steam turbine.
Condenser shall be designed to exceed HEI tube support requirements for bypass
operation. The system shall be fully automatic with no operator actions required.
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6.4.2.
Technical Specifications: Appendix N2
Combined Cycle
Steam Turbine Bypass
A 100% steam turbine bypass system shall be included to facilitate fast plant startups or
accommodate loss of steam turbine. The bypass system will be sized to pass 100% of
the steam generated with each CTG operating at baseload without duct firing. The
bypass system does not need to be capable of bypassing the maximum steam flow with
full duct firing; rather, a steam turbine trip and accompanying trip of the duct firing
system can result in a transient condition of excess steam which will be vented to
atmosphere through HRSG vents until such time as the steam volume associated with full
load CT operation without duct firing can be safely handled by the bypass system.
Special noise control provisions will be required (e.g., bypass steam mufflers mounted
inside the exhaust duct, as well as HRSG vent mufflers). Additionally, it will be
allowable to reduce CTG load to resynchronize the STG following a trip.
6.4.3.
Condensate System
Three 50% (or two 100%) vertical can condensate pump sets shall be provided.
The condensate pumps shall be designed and constructed in accordance with the
requirements of the Hydraulic Institute (HI). The pumps shall be constructed of materials
that are suitable for condensate at minimum and maximum temperature ranges.
The condensate system shall include but not be limited to condensate pumps sized at
maximum demand with 100% steam turbine utilization. At a minimum, a 5% margin on
capacity and 10% margin on total head shall be added for pump wear.
The condensate pumps shall be capable of pumping from the condenser hotwell, through
the steam jet air ejector condenser (if applicable), gland steam condenser, HRSG LP
economizers, and any other equipment arrangements per the final cycle design. Motors
shall be furnished and mounted by the driven equipment supplier on a common base
plate.
The condensate system shall supply flow to the turbine exhaust hood spray, condensate
pump seals, steam turbine bypass desuperheater, and gland steam desuperheater.
A recirculation valve shall be provided to maintain minimum flow through the
condensate pumps. The recirculation flow is routed to the condenser hotwell. Hotwell
level shall be controlled automatically. Excess condensate is returned to the raw water
tank. Demineralized water is supplied to the hotwell when the level drops below a
predetermined level.
Sampling connections shall be provided to monitor water chemistry. Chemicals are
injected into the condensate discharge to maintain water chemistry.
The plant control system shall be designed to automatically start the standby pump when
the operating pump fails. Automatic trips of the pumps occur if the condensate level
drops below a minimum acceptable level.
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6.4.4.
Technical Specifications: Appendix N2
Combined Cycle
Circulating Water System
Circulating water system is not applicable to air-cooled condenser.
Two 50% capacity pumps shall be provided with a spare rotor. Vertical centrifugal
pumps with a design suitable for wet pit service shall be provided based on maximum
anticipated condenser demand (i.e., the greater of all CTG operation at maximum design
flow, with duct firing as needed to maximize steam turbine output or with all CTGs at
base load in full bypass mode).
The circulating water pumps shall be capable of starting without lubricating water.
Strainers shall be provided for bearing and/or packing flush piping.
Pumps shall be of the heavy-duty type suitable for continuous service under all operating
conditions and shall operate without undue strain or wear and without damage to any part
of the pumping unit. The suction branch shall be arranged vertically downwards and be
fitted with a strainer. The discharge piping and non-return valve shall be arranged to
facilitate withdrawing the complete shaft and pump casing as a unit by splitting a pipe
joint above floor level.
The Seller shall be responsible for ensuring the pump and motor operate in dynamic
balance as a unit without undue vibration or noise throughout the range of operation. The
Seller shall verify that the critical speed of the complete rotating unit (motor and pump) is
at least 25% above the operating speed.
The circulating water pump basin shall meet the suction requirements of the HI. Alarms
for high- and low-levels in the cooling tower basin shall be provided in the main control
room.
Length of the pump shall be established on the basis of the minimum specified water
level and continuous operation at flows ranging from minimum flow to maximum flow in
any pump configuration. Length of the pump shall also provide sufficient submergence
above the pump inlet to prevent vortexing (OEM minimum plus two feet).
Removable screens shall be supplied at the circulating water pump structure to protect the
circulating water pumps from debris.
The raw water system shall supply makeup to the cooling tower basin to replace
evaporation losses and blowdown. Makeup water flow shall be controlled automatically
by the plant control system based on water required to replace evaporation losses and
blowdown in order to maintain the design cycles of concentration as indicated by
conductivity.
Circulating water shall be analyzed locally for pH (range 2–12) and for conductivity
(dual range = 0–20, 0–200, units = μmhv). This information shall be provided to Operator
through the DCS.
Two 100% chemical injection pumps and chemical storage adequate for 30 days of
operation. Tower makeup, blowdown, chemical injection and monitoring equipment
automated and accessible for routine maintenance, with remote readout in control room.
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Motor-operated circulating water pump discharge valves shall be of the slow-closing and
opening type to minimize hydraulic transients. These shall be designed to avoid damage
from water hammer and reverse rotation of the pump during startup and shutdown, under
the normal operating scenario, including a unit trip.
6.4.5.
Auxiliary Cooling Water System
Two 100% capacity pumps and cooling water heat exchangers, each isolatable for routine
cleaning and tube plugging without plant curtailment, shall be provided.
The system shall include auxiliary cooling water pumps, all piping, valves, instruments,
and accessories as necessary for a complete operating system. Equipment materials and
filters upstream of the heat exchangers shall be suitable for the water quality expected in
the system. Seasonal introduction of debris shall be considered in the design of the filters
upstream of the heat exchanges. The filters shall be self-cleaning with automatic
actuation on differential pressure.
The pumps are to be located as an integral part of the wet cooling tower design in
conjunction with the circulating water pumps.
6.4.6.
Closed Cooling Water System
The closed cooling water system shall be designed for removing the maximum heat
rejected from all the auxiliary equipment identified and rejecting it to the atmosphere.
Two 100% capacity pumps and cooling water heat exchangers, each isolatable for routine
cleaning and tube plugging without plant curtailment shall be provided. An elevated
water surge tank shall be provided for surge capability, system makeup, venting, and
adequate net positive suction head (NPSH) for the closed cooling water pumps.
The cooling water heat exchangers and pumps shall be sized to supply adequate cooling
water to the closed loop system. The system shall be designed to provide adequate
cooling for the site conditions. The system design shall permit shutdown and
maintenance of the individual items of equipment without interruption of the cooling
function of the rest of the system
6.4.7.
Mechanical Draft Cooling Tower (as applicable)
The cooling tower shall be of the counter flow type. The cooling tower shall be capable
of cooling the circulating water flow to a cold water temperature required to maintain
condenser vacuum within allowable operating limits over the full range of operating
conditions, including duct firing and full bypass mode.
Cooling tower fans shall be two-speed or variable speed. The cooling tower and all
components shall be of noncombustible or fire-retardant materials to the extent practical.
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Technical Specifications: Appendix N2
Combined Cycle
Plastic materials (PVC and CPVC) used in tower construction shall be of special
formulations to promote rigidity and shall be low in plasticizers and highly resistant to
ultraviolet exposure.
Fill material shall be of sufficient thickness and be adequately supported so that it is rigid
enough not to sag, up to a water temperature of 140°F. Design of the fill system shall
provide freedom for expansion and contraction without overstressing the fill material;
however, sufficient restraint shall be provided to prevent the fill from working loose
under the continuous effects of water splash and tower draft. The fill selection should
take into account the quality of the make-up water and the type of chemical treatment
system being provided.
When used as fill material, plastics shall have the following flame characteristics:
Flame spread rating
Not over 25, as rated by Underwriters Laboratories, and in
accordance with ASTM Test Method E 84
Self-extinguishing
In accordance with ASTM Tunnel Test D 635
Fuel contributed
0
The water distribution system shall be capable of operating with water quantities varying
between 15% below and 15% above the design water flow per tower cell or quadrant.
The distribution of water to individual nozzles shall be such that the flow to each nozzle
does not deviate from the average flow per nozzle by ±5%.
The distribution system shall include valves for sectionalization, permitting removal of
each individual tower cell or quadrant from service for inspection, cleaning, or repair.
Isolatable cells shall be designed to accommodate routine online cleaning and
maintenance activities
Drift eliminators shall be multipass type to limit drift to a maximum guaranteed value
0.002% (should be verified by a functional test) and designed to drain water back to the
cold water basin. Eliminators shall be wood, PVC, fiberglass-reinforced polyester, or a
suitable neoprene-coated material. Cooling tower drift shall meet permit limits and not
impact plant equipment, substation, operations, or offsite areas.
Tower shall be divided into single cells, each capable of being operated independently,
by full-width partition walls. Construction shall be with reinforced fiberglass or concrete,
with no wooden components. The cooling tower basin shall be a split design for part-load
operations during maintenance.
Each fan shall be directly connected to its motor through a totally enclosed, heavy-duty
gear reducer and drive shaft. Fan, gear, shaft bearings, and motor shall be mounted on a
common galvanized-steel base plate. Fan motors shall not be located in the fan stack or
air plenum.
If required, the cooling tower shall be equipped with a plume abatement system to
minimize visible plume as required by local or state regulations and permits.
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A complete fire protection system shall be provided for the tower, including stairways.
The system shall be of the dry deluge type designed in accordance with National Fire
Protection Association (NFPA) 214 and shall have the approval of the Purchaser’s fire
insurance underwriters.
Cycles of concentration shall be consistent with the make-up water quality and to
maintain cooling blowdown to within allowable wastewater discharge permit limits.
The cooling tower shall be designed and located to provide crane access for picking fans,
blades, and motors. A permanent hoisting crane shall be located on the fan deck to
support maintenance activities.
6.4.8.
Air-Cooled Condenser (if applicable)
Each air-cooled condenser (ACC) shall be the A-frame type of a proven design, with
windwalls to minimize wind effects. The ACC shall also be supplied with a deaerator and
condensate collection tank, all required spargers and baffle plates for bypass operation,
and makeup water deaeration (via the deaerator).
The air-cooled condenser shall be sized to meet the performance guarantee and shall be
sized and designed to—

Provide continuous operation at full steam load under all ambient conditions;

Provide continuous operation with full steam turbine bypass under base load
operating conditions without duct firing;

Maintain condenser pressure within allowable operating limits with full steam turbine
bypass under base load operating conditions with full duct firing, assuming ductfiring is discontinued at initiation of bypass operation.
The condenser package shall include the following items:

Steam duct from turbine exhaust flange to condenser, including expansion joints,
guides, manholes, anchors, and hangers

Support structure for steam duct

Steam duct drain pot(s) and drain pot pump(s)

Steam distribution ducting

Fin tube bundles

Electric-actuated sectionalizing valves

Condensate collection headers

Air moving system including fans, gearboxes, couplings, motors, pressure
switches, vibration switches, fan rings, and guards

Steel support structure, fan deck, and frames, including associated siding material
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
Instrumentation sensors, local indicators, transmitters, and control actuating
devices

Complete system logic drawings including narrative form for incorporation into
plant DCS

Noise attenuation features/devices

Condensate tank with support saddles, level indicator, and transmitter

Steam jet air ejection system plus steam jet hogger

Surface coatings, including structural steel and fan deck plate-work to be
galvanized; stair treads, grating, handrails, and walkway surfaces to be galvanized;
steam ducting, steam headers, and piping to be outside primer-coated; and partition
walls, wind walls, and siding with finish coating

Over pressurization rupture disc

Vacuum breaker system complete with one motor-operated vacuum breaker,
discharge piping, debris cover, and all other required components to complete the
system.

Welded ductwork connecting the steam turbine exhaust with the ACC, including
welded expansion joints (except the steam turbine exhaust may be a dog-bone
type), drain pots (with redundant pumps), supports, and all appurtenances.
Expansion joint at the steam turbine interface may be non-metallic. Automatic
steam duct header isolation valves will be provided if required for freeze
protection.

Steel tubes with steel fins (aluminum fins of a proven design may be used)

Wind walls with architectural siding to match turbine building

Automatic louvers if required for freeze protection

Two-speed fans

Instrumentation and controls for automatic operation via the DCS during normal
operation, bypass steam operation, and shutdown, as well as remote manual
operation with minimal operator actions during plant startup.

Instrumentation for monitoring potential freezing conditions via the DCS in the
ACC, including automatic controls to prevent freezing from occurring

Deaerator designed to achieve turbine dissolved oxygen criteria during startup and
normal operation. Guaranteed dissolved oxygen shall be no greater than 7 ppb.

Condensate collection tank sized for 5 minutes of water storage between the
normal liquid level (half full) and minimum level

The ACC and associated auxiliaries designed to produce condensate without
subcooling (per heat balances)

Semiautomatic tube cleaning system (high pressure water wash type)

Readily accessible and easily replaceable rupture disk
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
Technical Specifications: Appendix N2
Combined Cycle
All piping, valves, instrumentation, and appurtenances for a complete and operable
system. Steam duct sectionalizing valves, if used, are reinforced to prevent
distortion of the valve body due to duct forces.
The ACC will be sized for steam turbine exhaust conditions associated with plant
operation under the ISO Guarantee and Summer Average Conditions specified in
Appendix G. Piping.
Piping materials, fabrication, and erection shall be in accordance with ANSI B31.1
“Power Piping” except as noted otherwise herein. All in-service piping with design
temperatures 750°F or above shall be seamless. Electric Fusion Welded Pipe (EFW) may
be used, as long as all requirements of ANSI B31.1 are met.
The identifications and paint colors of all pipe-work shall be approved by the Purchaser.
Extra strong or schedule 80 shall be used for all piping 2 inches and smaller, except for
stainless steel construction where schedule 40S may be used. Socket weld construction
shall be used for all piping 2 inches and smaller. Threaded connections at equipment shall
be provided with unions.
Minimum corrosion allowances for all piping systems shall be per ANSI B31.1
requirements and standard industry practices for facilities with a 30-year design life.
Natural gas systems shall use butt weld construction for all sizes 2.5 inches and larger.
Water and water-based systems using steel pipe may be either butt weld or flange
construction for sizes 2.5 inches and larger.
All critical above-ground pressure piping, including, as a minimum, the cycle makeup
water supply line and all underground pressure piping, shall be hydrostatically tested at
pressures required by ANSI B31.1.
Any shower/eyewash located outside shall be freeze-protected with electric heating
tracing with suitable controls to prevent overheating of water.
A weld QA/QC program shall be implemented during construction and shall include
various non-destructive tests including radiograph and dye penetrant. Copies of the
QA/QC program and test results shall be available to Purchaser and be included in the
turnover packages
Piping systems shall be designed with high-point vents and low-point drains. Drains with
accessible restricting orifices or steam traps with startup and blowdown drains and
strainers/crud traps will be installed in low points of steam lines where condensate can
collect during normal operation.
Steam piping systems will be sloped in the direction of steam flow, where feasible, with a
minimum slope of 1/8 inch per foot. Condensate collection in piping systems will be
avoided by installing accessible automatic drain devices and manual devices as
appropriate. Steam drain lines will be sloped at 1/4 inch per foot. With Purchaser
approval, Seller may alter this general design requirement if it becomes impractical to
maintain strict adherence; however, the piping will still be designed to drain properly.
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Technical Specifications: Appendix N2
Combined Cycle
The minimum slope shall be maintained throughout the operating temperature range,
where possible. Where multiple steam turbine stop valves are provided, they shall be
connected to the steam header through a branch connection that is raised above the
nominal run of the header. The branch shall slope back to the header. Desuperheating
stations shall be provided with generously sized drain pots at appropriate locations
downstream of the station. Provisions shall be made to minimize the possibility of
leaking spray water flow to an upstream position.
Steam lines fitted with restricting devices, such as orifices in the process runs, shall be
provided with adequate drainage upstream of the device to prevent water from collecting
in lines.
Means shall be provided to fill and clean loop seals.
Flanged spool pieces shall be provided for critical equipment disconnects. Hose and
process tubing connections to portable components and systems shall be compatible with
the respective equipment suppliers’ standard connections for each service.
Piping and piping supports shall be designed and fabricated in accordance with the
requirements of the applicable standards and codes for the maximum anticipated service
conditions.
Piping 2-1/2 inches in diameter and larger and normally operating above 400 ºF (critical
pipe) shall be analyzed for flexibility and piping stresses. Stresses in piping systems shall
not exceed the allowable stresses established by the applicable piping code. The piping
systems shall be designed so that forces imposed on equipment do not exceed the forces
allowed by the equipment manufacturers.
Piping to and from outdoor tanks shall allow for tank settlement.
In general, piping shall be supported from steel members attached to the floor or roof
above or from steel brackets fixed to the building steel. The cutting of floor beams, roof
beams, or reinforcing steel in concrete is not permitted. Piping loads transmitted to
equipment shall not overstress connection points (i.e., pump suction/discharge nozzles).
All high energy piping shall be top supported with spring hangers.
6.4.9.
Pumps
All pumps shall be designed for continuous operation unless otherwise specified.
All pumps shall be installed in positions convenient for operation and servicing. Where
multiple pump installations are required, each pump and its associated equipment shall be
arranged in such a manner as to permit easy access for operation, maintenance, and pump
removal without affecting plant operation. Lifting lugs, eyebolts, and other special tackle
shall be provided to permit easy handling and removal of the pump and its components.
Standard types of pumps shall be used wherever possible. Only proven products and
models are to be supplied.
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Strainers (startup or permanent) shall be installed in the suction piping of horizontal
pumps or sets of pumps. The driver shall be mounted on an extension of the pump
bedplate and shall drive the pump through a flexible coupling with OSHA coupling
guard.
Pumping systems with variable flow requirement shall have a recirculation line for pump
protection. As a minimum, pumps with motors rated for 25 hp and above shall be
supplied with a recirculation line for protection. The recirculation line shall normally be
routed to the source from which the system takes suction. Modulating or two-position
automatic recirculation valves or restriction orifices shall be used as applicable. For the
boiler feedwater pump, a modulating automatic recirculation control valve or combined
recirculation/check valve shall be used. Pumps furnished for each application shall be
sized to accept an impeller at least 1/8 inch larger in diameter than the impeller specified
without having to change the pump casing.
Vent and drain plugs shall be fitted, where necessary, at suitable points on the pump
casing. Oil system pump vents and drains shall be provided with valves. Horizontal splitcase pumps shall allow the removable half casing and impeller to be withdrawn without
disturbing any of the process piping or valves. Horizontal end-suction pumps shall allow
the impeller to be withdrawn from the motor end without disturbing the motor or
discharge piping.
Where part-load (e.g., two 50%) duplicate pumps for the same service are provided, they
shall be capable of operating in parallel.
6.4.9.1
Pump Types
Centrifugal pumps shall be used wherever possible. Positive displacement screw pumps
may be used when handling fuel and lubricate oils, and reciprocating pumps will be
accepted for chemical dosing and metering purposes.
6.4.9.2
General Design and Construction
All pumps shall be designed to withstand 1.5 times the pump shut-off pressure, under
maximum suction pressure conditions, unless otherwise specified. All pump shafts shall
be of ample size to transmit the full output from their drivers. Impellers shall be fitted to
the shaft in a suitable manner that will permit the transmission of the maximum torque
developed under any operating condition and removal without damage to either impeller
or shaft.
All pumps shall be selected such that they do not cavitate under the expected range of
operating conditions.
Renewable wear rings shall be fitted to the casing and impeller.
All pumps shall be constructed of materials specifically designed for the conditions and
nature of the pumped fluid and to resist cavitation, erosion, and corrosion.
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Seals shall be provided and must meet the working conditions. For centrifugal pumps,
mechanic seals shall be adopted.
Centrifugal pumps shall preferably be of the horizontal-shaft type unless specified
otherwise. Each horizontal pump shall be mounted with its driving motor on a common
baseplate of rigid construction. The baseplate shall be provided with a drip tray fitted
with a drain line and valve.
The construction of the pump casing shall be two parts, an upper part and a lower part,
for easy maintenance.
Vertical-shaft centrifugal pumps may be employed when pumped liquids are at or near
their boiling point. Pumps for such duties must be carefully sited to ensure that the Net
Positive Suction Head Available (NPSHA) under all operating conditions will be
adequate for the type of pump employed. The NPSHA values represent the worst
operating conditions, i.e., the lowest atmospheric pressure, lowest suction pressure of the
pump, and highest temperature of the pumped fluid.
Horizontal shaft, 3,600 rpm pumps of the centrifugal type shall have balanced impellers
and at least two bearings. The driver shall be mounted on an extension of the pump
bedplate and shall drive the pump through a flexible coupling.
Centrifugal pumps shall be of rigid-shaft design and shall be designed such that the first
critical speed of the pump, when coupled to its driver is at least 10% higher than the
maximum operating speed. The entire rotor assembly shall be statically balanced, and
dynamic balancing is required in one of the following cases:

Pump speed exceeds 1,500 rpm, capacity exceeds 200 gpm and impeller diameter
exceeds 6 inches,

Pump speed exceeds 1,500 rpm for pumps of two or more stages.
Pumps shall operate smoothly throughout the speed range in reaching their operating
speed. Where necessary the pumps are to be fitted with devices to ensure a minimum
through-flow.
The piping upstream of a pump shall be at least as large as the pump suction connection.
Velocity shall be limited to 5 fps if there is a suction lift (negative pressure).
6.4.9.3
Pump Characteristics
Where a number of pumps are used for the same purpose, they shall be suitable for
parallel operation and shall be interchangeable.
The pump head characteristics shall be such that the head will continuously increase with
decreasing flow quantity with a maximum head reached at zero flow. Generally, a head
increase of 15% above the duty point at zero flow will be acceptable.
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Full pump characteristic curves giving head/capacity, efficiency/capacity, power
absorbed/capacity, and net positive suction head required/capacity shall be provided for
all pumps.
Unless otherwise specified, the capacity of all pumps shall be so determined that under
normal operation, their total rated running output is 110% of the process flow, if the
suction level is controlled, and 115% of the process flow, if the suction is uncontrolled
(i.e., free suction pump).
6.4.9.4
Fittings
All pumps shall be installed with isolating valves, a discharge non-return valve, and
suction and discharge pressure gauges, unless otherwise stated. All positive displacement
pumps shall be fitted with a discharge relief valve. Provisions for temperature
measurement shall be made in all pump suction and discharge pipe sections adjacent to
the pump flanges.
All couplings and any intermediate shafting shall be supplied with removable type
coupling guards that shall cover the rotating parts and comply with the stipulations on
guards in the relevant section of this Specification.
Coupling halves shall be so matched as to ensure accurate alignment. Horizontal shaft
pumps shall be driven by the motor through an approved type of flexible coupling. Pintype flexible couplings shall not be used. Vertical shaft and in-line pumps may be driven
directly by the motor through a rigid coupling provided the motor thrust bearing has
adequate margin to take care of the pump’s maximum thrust.
All pumps other than submersible pumps shall have temporary strainers fitted in the
suction pipe-work during initial start-up and commissioning. Pumps shall be provided
with permanent strainers together with differential pressure gauges and alarm facilities.
Air release valves shall be fitted to all pumps at suitable points on the pump casing unless
the pump is self-venting due to the arrangement of the suction and discharge nozzles.
Drainage facilities shall be provided on the pump casing or adjacent pipe-work to
facilitate the dismantling of pumps.
6.4.9.5
Bearings
All bearings shall be of ample surface area and, for large pumps, shall be of the automatic
oil-lubricated sleeve type.
On pumps utilizing ball or roller bearings, the inner race shall be fitted directly onto the
shaft and reliably fixed by a shoulder on the shaft. Bearings on vertical-shaft pumps shall
be so spaced as to prevent shaft whipping or vibration under any mode of operation.
Bearing housing on horizontal shaft pumps shall be so designed that the bearings can be
replaced without removing the pump or motor from its mounting.
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Bearing housing on horizontal shaft pumps shall be effectively protected against the
ingress of water, pumped fluid, and dust with suitable non-ferrous deflectors.
All bearings oil wells shall be fitted with visual oil level indicators and local
thermometers. Means of draining bearing housings shall be provided.
6.5.
Piping
All materials for piping, valves, fittings, pressure vessels, and associated piping
components shall conform to the applicable ANSI Codes. All power piping shall conform
to ANSI B31.1 piping codes. Valves shall be appropriate for the pressures and
temperatures of each specific application. Gate valves shall not be used for throttling.
ANSI Class 125 valves are not acceptable, except for potable water plumbing and
circulating water system. All power piping, valves, and fittings shall be insulated using
materials consistent with the overall quality and design of the Facility. Insulation shall
provide for the expansion and contraction of the piping as will occur during off-line and
on-line Facility modes. Seller shall provide adequate pipe support systems to allow pipe
expansion, contraction, and appropriate seismic loads, if any.
Supporting straps around pipe flanges or valves are not acceptable. Anchors will be
attached to pipes by approved means.
Where pipe runs pass through open penetrations, floors, or walls, either individually or
collectively, floor or wall collars or other approved curbing shall be provided. Floor
collars shall extend to an approved height.
Each pipe shall be fitted at the ends to prevent the ingress of dirt during transportation
and storage.
Care shall be taken during final assembly and commissioning that pipes are cleaned and
free of grit, scale, jointing material, and/or tools.
Domestic water piping material shall be in accordance with applicable plumbing code
and suitable for the well water chemistry.
Compressed air piping between air compressors and air dryers shall be galvanized carbon
steel, copper, or stainless steel. Compressed air piping downstream of air dryers
(instrument air) shall be copper or stainless steel. Other compressed air piping
downstream of the receiver(s) (service air) shall be stainless steel, galvanized carbon
steel, or copper. HDPE may be used for any underground compressed air piping, if
approved by Purchaser.
Instrument air branches shall be taken from the top of the mains. Service air branch pipe
to points of use shall terminate in positive locking Schrader-type hose coupling.
Piping may be routed on overhead pipeways or sleeperways; it may be supported from
the building structure using pipe supports or rod hangers; or it may be buried. Space for
electrical and instrument conduit runs shall be provided on the pipeways and sleeperways
as required. Underground piping shall be provided with adequate corrosion protection, if
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required. Fire water loop piping and potable water piping shall normally be routed
underground.
All steam lines shall be provided with means of gravity drainage.
Carbon steel lines 2 inches and smaller shall be Schedule 40 minimum. For the 2-inch
and smaller alloy steel lines, the minimum pipe wall thickness shall be calculated based
on design conditions.
Minimum pipe size shall be ½ inch, except for connections to equipment. Pipe sizes 1-1/4
inches and 5 inches shall not be used except for connections to equipment.
Pipe wall thickness calculations shall be based on the lowest strength component in the
system, considering all factors, including the possibility of pipe and fittings having
different maximum allowable stress values, and/or manufacturer’s minus tolerance.
Individual pipeline material classifications shall be developed for each class of service.
These material classifications shall define the valves, pipe, fittings, flanges, gaskets, and
bolting to be used.
Welded piping 2 inches and smaller shall be socket-weld construction, and welded piping
2-1/2 inches and larger shall be butt-weld construction. All threaded piping shall be
Schedule 40 minimum. Maximum line size for threaded connections shall be 2 inches.
Piping systems and components shall be stress analyzed, if required, for thermal
flexibility, support, pressure, vibration, seismic, fluid or gas flow reactions, and
environmental factors, including effects on equipment.
Piping flexibility shall be obtained through pipe routing or expansion loops unless
limitations of space or economics dictate the use of flexible connectors.
Expansion loops, when installed in a horizontal plane, may be offset vertically to clear
adjacent piping. Flexible connectors are to be used only when it is not feasible to provide
flexibility by other means.
The piping flexibility analysis shall consider the most severe operating temperature
condition sustained during startup, normal operation, upsets, or shutdown. The analysis
shall be for the maximum temperature differential. The effect of installation temperature
and solar temperatures shall be considered in determining the maximum temperature
differential. Analysis shall include relief valve opening and stop valve closure.
As a minimum, computer analysis shall be performed on the following piping systems:

Main steam from HRSG to the interface points at the steam turbine and surface
condenser

HRSG feedwater supply from high-pressure feedwater pump to HRSG

All piping over 250°F or piping subject to dynamic transients or high-velocity
steam flows
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The pipe support design for turbine steam bypass system(s) will include devices to
restrict pipe dynamic loads, if required by the design.
Seller’s pipe stress engineer shall verify proper installation and setting for all pipe
supports (1) before initial heat up, and (2) during initial operation at full plant load or
other maximum operating conditions (where possible).
6.5.1.
Piping Materials
All pipe-work shall be designed, fabricated and tested according to the requirements of
the approved standard with the consent of the Purchaser incorporating any other features
as required by this Technical Specifications.
The material of the piping shall be equal to or better than the following technical
requirements.

For design metal temperature up to and including 750°F, carbon steel (including
plate material) shall be used.

For design metal temperature between 750°F and 990°F, Type P22 alloy steel shall
be used.

For design metal temperature above 990°F, Type P91 alloy steel shall be used.
The outside of the embedded pipes shall be protected by coatings.
Underground piping systems may use PVC or HDPE pipe where appropriate based on
design conditions. Buried steel pipe shall be coated and wrapped and cathodic protection
should be considered as required by the soil conditions. Carbon steel bolts for mechanical
joints shall be wrapped. Cast iron valves may be used for wastewater, potable water, and
fire protection only.
Lubricating oil piping shall be made of A53 (ASME) or equivalent material, with
Schedule 40 minimum pipe thickness or equivalent standard thickness. Pressure piping
shall be of seamless pipe. The pipeline from last filter on the generator oil supply
manifold to the generator group connecting point shall be made of stainless steel. The
control oil pipeline shall be stainless steel seamless pipe.
The cooling water and fire protection water piping shall be made of carbon steel.
The pipes used for acids or caustic solutions shall be made of anti-corrosive material. The
chlorine piping shall also be of anti-corrosive material.
Instrument compressed air piping shall be made of stainless steel. The joints of piping
shall be welded and, for thread-type joints, sealed weld shall be applied.
Demineralized water pipe shall be made of stainless steel.
Piping materials under special conditions shall be as follows:

Sodium hydroxide — Stainless steel or semi transparent FRP
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
Hydrochloric acid — Polyvinyl chloride pipe or FRP

Other chemicals — Polyvinyl chloride pipe or FRP
The materials of the piping leading from drains, vents, and so on to the shutoff valve on
the main pipe shall be made of the same material as the main pipe.
Potable water piping shall be schedule 80 PVC pipe or HDPE and fittings with bronze
valves except for exterior piping in rack shall be schedule 80 A53 galvanized with 3000#
cadmium plated A105 threaded fittings. Potable water shall supply safety showers and
eyewashes, which shall be furnished for the following locations:

Battery room (s)

Acid and caustic, ammonia or urea storage tank area(s)

Chemical feed storage and metering area
All unwrapped and un-lagged pipes outside buildings which are subject to corrosion, in
addition to the normal design wall thickness, shall have an additional corrosion allowance
that is sufficient to ensure a minimum service life of 30 years and is, in any case, no less
than 2 mm. All other pipes shall have a suitable corrosion allowance for 30 years’ service
life.
Piping shall be so arranged as to provide clearance for the removal of any piece of
equipment requiring maintenance with a minimum dismantling of piping and for easy
access to valves and other piping accessories required for operation.
Overhead piping shall have a minimum vertical clearance of 7 feet 2 inches above
walkways and working areas and be of sufficient height above roadways to enable
removal of the largest/heaviest equipment from the Facility.
All pipe-work shall be fabricated with appropriate connections used for pressure gauges,
thermometers and any other corollary device as required by the plant design. Appropriate
connections for Performance Test instrumentation shall also be provided.
No pipe-work shall be run in trenches carrying electrical cables.
Maximum design velocity of fluids through piping shall take into account water hammer,
erosion, and pressure drop of fluid in the lines.
Double-wall piping with leak detection shall be provided for underground piping
containing hazardous chemicals.
6.5.2.
Pipe Velocities
The velocity of flow in pipes is not to exceed the following values unless otherwise
specifically mentioned:
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ft/s
Steam lines
Saturated steam greater than 25 psia (and superheated steam
with less than 25 F superheat
210
Superheated steam (with a minimum of 25 F superheat)
330
Low pressure wet steam (including saturated steam up to 25 psia)
125
Water lines
Condensate piping and hot suction piping
Heater drain piping
12
7
General Service Piping including Drinking, fire fighting, raw and
10
Demineralized water lines
10
City Service piping
7
General pump suction lines
3
Condensate delivery lines
10
Air Lines:
Compressed air pipelines
80
Gas lines
Fuel gas supply lines (with insulation to reduce noise levels)
6.5.3.
170
Pipe Hangers and Supports
When located outdoors, corrosion-resistant variable and constant springs shall be
furnished that consist of all galvanized components except for the spring or coil, which
shall be neoprene coated. Rods, clevises, weldless eyenuts, and turnbuckles shall be
galvanized. All other hanger components may be painted per the requirements of section
on painting.
Steam pipe hangers shall be designed (lockable) to accommodate hydro testing.
6.6.
Valves
Valves shall be installed to meet valve manufacture’s recommendation. For example,
valve with vertical actuator shall not be installed with actuator in any other way but
vertical.
Nameplates on safety and relief valves shall indicate manufacturer’s name, model
number, size, set pressure, capacity, orifice size, materials, and approving authority stamp
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symbol. Each safety and relief valve shall be supplied with a test certificate issued by the
approving authorities and shall be subject to the Purchaser’s approval.
All valves and valve actuators shall be accessible for operation and maintenance.
Block valves shall be provided for all equipment, except the air-side of rotor air coolers.
Valving and other accessories shall be positioned and physically spaced relative to other
equipment so as to allow convenient access for operation and maintenance. Crowding of
piping, components, and accessories shall be avoided.
Valves shall be arranged for convenient operation from an appropriate floor level or
platform and shall be provided with extension spindles or gearing, as required. Deviations
from this design criterion require Purchaser approval before design finalization. Where
extension spindles are fitted, all the thrust when opening or closing the valves shall be
taken directly on the valve body and all pedestals shall be mounted directly on floor
girders or other stationary members. Chain operators are not acceptable. Valves, valve
handwheels, and/or valve actuators shall not infringe on Purchaser-reserved spaces or
walkways. Valve pedestals shall be of approved design and be fitted with an indicator to
show whether the valve is open or closed.
All valves shall be arranged to close when the handwheel is rotated in a clockwise
direction when looking at the handwheel from the operating position. The direction of
rotation to close the valve shall be clearly marked on the face of each handwheel.
All steam and water valves operating at less than atmospheric pressure shall have
inverted Teflon stem packing.
Hand-actuated valves shall be operable by one person. Gear operators shall be provided
on manual valves when the rim pull required to open or close the valve is greater than
100 pounds.
Valve materials shall be suitable for operation at the maximum working pressure and
temperature of the piping to which they are connected. Steel valves shall have cast or
forged steel spindles. Seats and faces shall be of low friction, wear-resistant materials.
Valves in throttling service shall be selected with design characteristics and of materials
that will resist erosion of the valve seats when the valves are operated partly closed.
Valves with position stops that limit the travel of each valve in the open or closed
position shall have the stops located on the exterior of the valve body to provide clear
indication of full open and close positions.
In general, the valves specified shall be standardized to use the same valve type and
manufacturer to the extent possible.
Except where otherwise specified or approved, gate valves greater than 3 inches in
diameter in high pressure classes will be of the parallel slide type or flexible wedge type,
and, when in the fully open position, the bore will not be obstructed by any part of the
gate. The internal diameter of valve ends will be the same as the internal diameter of the
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pipe. Gate valves in pressure classes 1500 and above, standard port size, will be used
whenever suitable. Gate valves in high pressure classes will have butt-welded joints
except where otherwise specified or approved.
Valves will not be installed in an inverted position.
6.6.1.
Drain and Vent Valves and Traps
Double valving shall be provided for drains and vents in Class 900 or higher piping
service.
Drain traps shall be complete with air cock and easing mechanism. Internal parts shall be
constructed from corrosion-resistant materials and be renewable. Trap bodies and covers
shall be cast or forged steel and be suitable for operating at the maximum working
pressure and temperature of the piping to which they are connected. Traps shall be piped
to the drain collection tank or to sumps, and condensate shall be returned to the cycle if
convenient.
Drain valves shall have cast or forged steel bodies with covers and glands of approved
construction. Spindles shall be of stainless steel, and materials shall be suitable for
operation at the maximum working pressure and temperature of the piping to which they
are connected.
Where valve seats are shrouded, the design of the shroud shall be such as to prevent
foreign matter from lodging in the valve seat.
6.6.2.
Low-Pressure Water Valves
Low-pressure water valves shall be butterfly type of steel or cast iron construction. Cast
iron valves will have cast iron bodies, covers, gates (discs), and bridges; the spindles,
seats, and faces will be bronze. Fire protection valves will be UL-approved butterfly
valves that meet NFPA requirements.
Low-pressure valves carrying liquids or gases at sub-atmospheric temperatures (e.g.,
carbon dioxide storage) will be designed to meet ASHRAE and applicable industry
requirements for refrigeration piping.
6.6.3.
Instrument Air Valves
Instrument air valves shall be ball type of bronze construction, with valve face and seat of
approved wear-resistant alloy. An isolation valve shall be provided at each branch point
from main headers.
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6.6.4.
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Combined Cycle
Non-Return Valves
Non-return valves for steam service shall be in accordance with ANSI standards and
properly drained. Non-return valves in vertical positions shall be provided with bypass
and drain valves. Bodies shall be provided with removable access covers to enable the
internal parts to be examined or renewed without removing the valve from the pipeline.
Non-return valves shall be provided on the discharge of all centrifugal pumps (and other
pumps that allow backflow) to minimize manual operator actions during system filling, to
prevent system backflow/drainage following pump trip or shutdown, and to prevent
backflow from desuperheaters (where applicable). Check valves are not required for the
closed cooling water pumps. Purchaser approval is required for any deviations to this
requirement.
6.6.5.
Motor-Actuated Valves
In general, the Facility shall be designed to minimize the manual actions required by
plant personnel during startup, shutdown, and normal operation, and to conform to the
level of automation required for Facility staffing as discussed in Section 4.1. Seller shall
review system design with Purchaser during detailed design to assure this requirement is
satisfied. Air-operated valves may be used in lieu of motor-operated valves with prior
approval of Purchaser.
Motor-actuated valves will be fitted with both hand and motor operating gear. Motor
actuators will include torque switches to stop the motor automatically when the valve
gate has reached the "full open" or "full closed" position. The motor actuator will be
placed in a position relative to the valve such that there is no leakage of liquid, steam, or
corrosive gas from valve joints onto the motor or control equipment.
The hand and motor actuation mechanisms will be interlocked so that the hand
mechanism is disconnected before the motor is started.
Motor actuators will be provided with approved seating control consisting of a slipping
clutch or other torque limiting device that limits seating force to an acceptable level.
6.6.6.
Control Valves
Control valves in throttling service will generally be the globe-body cage type with body
materials, pressure rating, and valve trims suitable for the service involved. Other style
valve bodies (e.g., butterfly, eccentric disk) may also be used when suitable for the
intended service. Block valves shall be provided upstream and downstream of all
modulating control valves except for the main steam bypass. Bypass valves shall be
provided except where bypass valve use is impractical or presents a potential safety
hazard, as approved by Purchaser.
Control valve actuators shall be the pneumatic-spring diaphragm or piston type. The
actuator shall be sized to shut off against at least 110% of the maximum shutoff pressure.
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Actuators shall be designed to function with instrument air pressure ranging from 60 to
125 psig.
All control valves shall be sized such that minimum specified flow results in at least 20%
stem lift, normal flow results in 75% stem lift, and maximum flow results in 90% stem
lift for equal percentage valves and 85% for linear valves. Parallel, split-range control
valves may be necessary to meet this requirement, including the HP drum level and LP
drum level applications. The use of a manual bypass valve to meet this requirement is
unacceptable.
Valves shall be designed to fail in a safe position.
Control valve body size shall not be more than two sizes smaller than line size, unless the
smaller size is specifically reviewed for stresses in the piping and calculations are
provided to Purchaser for record purposes.
Where flanged valves are used, minimum flange rating shall be ANSI 300 class. Control
valves in 600 class service and below shall be flanged where economical.
Critical service valves shall be defined as ANSI 900 class and higher valves in sizes over
2 inches.
Severe service valves shall be defined as valves requiring anti-cavitation trim, low noise
trim, or flashing service, with differential pressures greater than 100 psig.
In general, control valves shall be specified for a noise level no greater than 90 dBA
when measured 3 feet downstream and 3 feet away from the pipe surface.
Valve actuators shall use positioners and the highest pressure, smallest size actuator.
Handwheels shall be furnished only on those valves that can be manually set and
controlled during system operation (to maintain Facility operation) and do not have
manual bypasses.
Control valve accessories, excluding controllers, shall be mounted on the valve actuator
unless severe vibration is expected.
Solenoid valves supplied with the control valves shall have Class H coils. The coil
enclosure shall normally be a minimum of NEMA 4 but be suitable for the area of
installation. Terminations will typically be by pigtail wires.
The DCS shall monitor both “Open” and “Closed” position switches for motor-operated
valves and pneumatic-operated control valves used for “On-Off” service. Position
switches will not typically be provided for control valves used for “throttling” service.
Where required, automatic combined recirculation flow control and check valves or
orifices (provided by the pump manufacturer) shall be used for pump minimum flow
recirculation control. Modulating or two-position automatic recirculation valves or
restriction orifices shall be used as applicable. For the boiler feedwater pump, modulating
automatic recirculation control valve or combined recirculation/check valve shall be
used.
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Body material and rating shall conform to piping specifications as a minimum.
In no case shall the valve body minimum rating be less than that permitted by piping
specifications.
Control valve body size shall be 1-inch minimum. Sizes such as 5-inch body shall not be
used. Body sizes smaller than 1 inch may be used for special applications with 3/4-inchand-under line size, and for pressure regulator services. Reduced ports shall be used as
required. Body size shall not be more than two pipe sizes smaller than the line. Valves for
on-off service shall normally be line size.
Valve type and size shall be selected taking into account such factors as cost, operating
and design conditions, fluid being handled, rangeability-required allowable leakage,
noise, and any other special requirements. For general services, the following types shall
be considered:

Cage Guided Globe Valves with balanced or unbalanced type trim.

Single seated globe valves may be either top and bottom or top guided.

Eccentric Rotating Plug Valves of the throttling type.

Ball Valves of the throttling type.

Butterfly Valves with either conventional or shaped discs.

Special Body Types may be considered for special applications such as slurry
handling, highly erosive or viscous streams, and noise control.
Characteristics of the inner valve shall be determined by the following system
characteristics:

Equal Percentage Characteristics shall normally be used on loops that have large
variations in valve pressure drops, fast pressure control loops, and most flow
control loops. In processes where no guidelines are available, equal percentages
shall be used.

Linear Characteristics shall normally be used for most level control, slow pressure
control loops, and loops where the measurement is linear and the variation in the
pressure drop across the control valve is small. Linear characteristics shall be used
for three-way valves and for two-way valves used in three-way service.

Quick Opening Characteristics shall normally be used for off-on service and for
direct connected regulators using low lift.
Valve trim shall be stainless steel minimum, hardened for erosive service. Severe service
conditions may dictate consideration of other materials.
Guide bushings shall be of corrosion-resistant material. It is preferred that the guide
material be a minimum of 125 Brinell harder than the trim.
Packing glands shall be equipped with flange-style gland followers, secured by two bolts.
A lubricator with steel isolating valve shall be provided where packing lubrication is
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required. Packing shall be Teflon below 450°F and Graphoil for temperatures of 450°F
and higher. No asbestos is permissible.
Extension bonnets shall be provided on throttling services above 450°F and below 0°F, or
in accordance with the manufacturer's recommendation. On-off control valves shall use
high temperature packing in lieu of extension bonnets when practicable.
Piston actuators shall be furnished with pneumatic trip valve, volume tank, piping, and
necessary components to lock-in supply air pressure on loss of supply air pressure to
actuator to ensure proper failure position.
Split ranging of control valves shall be done electronically using independent DCS
outputs. Pneumatic split ranging is not allowed.
Positioners may be electric/pneumatic or smart type. Electric/pneumatic positioners shall
have two gauges and a smart type one.
Valve leakage class shall conform to ANSI B l6.104, “Control Valve Seat Leakage.”
6.6.7.
Safety and Relief Valves
Safety valves and relief valves shall be provided as required by code for pressure vessels,
heaters, and boilers. Safety and relief valves shall be flanged and installed vertically.
Piping systems that can be overpressurized by a higher pressure source shall also be
protected by pressure relief valves. Equipment or parts of equipment that can be
overpressurized by thermal expansion of the contained liquid shall be provided with
thermal relief valves.
6.6.8.
Instrument Root Valves
Instrument root valves and condensate pots shall be specified for operation at the working
pressure and temperature of the piping to which they are connected. Double valving will
be provided for instrument taps in Class 900 or higher service. Root valves for Class 600
and lower may be 1/2 inch. All other systems will have ¾-inch root valves.
6.6.9.
Float-Operated Valves
Float-operated valves shall be provided with small-bore float-operated pilot valves
connected into each system, where necessary, to eliminate water hammer. Floats shall be
arranged to operate in a baffle tank, designed to prevent a turbulent water surface around
the float.
6.6.10.
High-Pressure Valves
Steel valves will have cast or forged steel spindles. Seats and faces will be of low friction
and wear resistant.
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Valves used for throttling service will be designated to prevent erosion of the valve seats
when the valves are operated in a partly open condition.
Valves over NPS 2 inches in size and rated in pressure Class 900 and above shall be
provided with pressure seal bonnets. Systems with pressure ratings of Class 900 or
greater shall use double valve for vents and drains to the atmosphere. Valves over NPS
2 inches in size and rated in pressure Class 600 and below shall be provided with bolted
or welded bonnets “T” pattern, or “Y” pattern bonnetless style design.
Valves under NPS 2 inches in size will be provided as follows:

For Class 600 and under, use bolted bonnet.

For Class 900 and over, use welded bonnet “T” pattern, or “Y” pattern bonnetless
style.
ANSI pressure Classes 900 and 1500 flexible wedge gate valves shall be specified with
pressure seal bonnet/cover joint, stellited integral or welded-in seat rings, lubricated
bearing yoke sleeve (NPS 6 and larger), bolted gland, and the disc provided with stellited
seating surfaces.
ANSI pressure Class 600 flexible wedge gate valves shall be provided with bolted gland
arrangement, integral or welded-in seat rings, provision for back seating, bolted-ring type
body/bonnet joint, and yoke drive sleeve with ball or needle bearings and booster station
as described above, except they will not include the bolted ring type body/bonnet joint.
6.7.
Insulation and Freeze Protection
All piping subject to freezing shall be freeze protected with electric heat tracing cable as
described in the Electrical section. Piping shall be insulated with mineral fiber per ASTM
C547, Class 2 for operating temperatures up to 500F and calcium silicate per ASTM
C533, Type 1 for higher operating temperatures. Insulation shall be covered with a
“stucco” embossed aluminum lagging per ASTM B209, Alloy 3003, Temper H14 (halfhard) with a thickness of 0.016 ±0.003 inches. The insulation and lagging system will
provide a cold face temperature of 140°F at an ambient air temperature of 95°F in still
air.
Anti-sweat insulation will be flexible elastomeric cellular insulation conforming to
ASTM C534.
6.8.
Tanks
Large outdoor storage tanks shall be welded or seamless construction. Drains and other
design features shall be provided as required to prevent damage to the tank wall during
extended outages in subfreezing weather. Tanks shall be sized to provide the required
storage volume that accounts for freeze losses.
Demineralized water tanks shall be shop-coated internally with a fused-glass coating.
Coated tank material surface profiles shall be suitable for coating application, Coatings
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shall extend completely under all gaskets, and special provisions shall be made at all
plate ends to prevent corrosion (e.g., use of stainless steel edge coat).
Nozzles on water tanks subject to freezing shall project into the tank by a distance
sufficient to permit continued operation with an ice layer on the inside of the tank wall.
Maintenance drains near the tank bottom shall be provided for complete tank drainage.
Containment systems shall be provided for all tanks containing potentially hazardous
liquids, including ammonia. Leak detection systems shall be provided, as required by
regulations or permits. All tank containment areas shall be furnished with drains and lowpoint sumps.
Manholes, where provided, shall be at least 24 inches in diameter. Ladders and cleanout
doors shall be provided on storage tanks as required to facilitate access/maintenance.
Provisions shall be included to allow proper tank ventilation during internal maintenance.
Unless otherwise specified or approved, tanks used for the storage of oil, raw water,
treated fresh water, and condensate shall be carbon-steel-plate stiffened and stayed in an
approved manner where necessary.
Pipe connections for tanks shall be made to welded pads or reinforced nozzles, the
thickness of which shall not be less than 1-1/2 times the diameter of the joint studs. Joint
stud holes shall not be drilled through the pads. Pipe connections shall be made with
studs and not cap bolts.
Tanks that are to be insulated and lagged shall be provided with external lugs where
necessary.
A corrosion allowance of 1/16 inch for carbon steel and low chrome alloys shall be used,
except for lined or internally coated tanks.
Overflow connections and lines shall be provided and be at least one pipe size larger than
the largest input line or combination of inputs that can discharge simultaneously.
6.9.
Heat Exchangers
Heat exchangers shall be provided as components of mechanical equipment packages and
may be shell-and-tube or plate type. Heat exchangers shall be designed in accordance
with Tubular Exchanger Manufacturers Association (TEMA) or manufacturer’s
standards. Fouling factors shall be specified in accordance with TEMA or HEI.
Thermal relief valves shall be provided for heat exchangers as required.
6.10.
Pressure Vessels
Pressure vessels shall be designed to ASME VIII standards and in accordance with state
and local requirements.
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Pressure vessels shall include the following features and appurtenances:

Process, vent, and drain connections for startup, operation, and maintenance

Materials compatible with the fluid being handled

A minimum of one manhole and one air ventilation opening (e.g., handhole) where
required for maintenance or cleaning access

Shop-installed insulation clips spaced not greater than 18 inches on center for
vessels requiring insulation

Relief valves in accordance with the applicable codes

Vessel capacity consistent with design requirements of the system and not less than
required to absorb the maximum anticipated system transients.
Carbon steel tanks shall have a minimum corrosion allowance of 0.06250 inch. Where
practical, coated pressure vessels shall be avoided.
6.11.
Fuel Gas Supply System
The fuel gas supply system shall include natural gas filtering, compression equipment,
and pipeline to accommodate the complete operating range of the turbine(s) and duct
burners without affecting the stable operation of the Facility. The fuel conditioning
equipment shall process the fuel to meet the OEM requirements for the fuel (including
temperature and pressure) to the equipment.
Fuel gas conditioning system shall include the following equipment:

Electric motor-driven natural gas compressor(s) (if required). Each gas compressor
shall service 100% of one combustion turbine and include knock-out drum,
scrubber, coalescent gas filter, and gas heaters that use waste heat or cycle heat
source to ensure that natural gas quality meets the requirements of the CTG
supplier while improving overall cycle efficiency

One fuel gas drain tank

Pressure regulating station

Natural gas metering station with bypass

Natural gas heaters (if needed)
The minimum fuel processing standards shall be as follows:


Dry scrubber upstream of the compressors:
—
Filtration shall be 100% effective for particles 3 microns or larger at design
flow rate.
—
Outlet gas shall contain no more than 0.10 gallon of entrained liquid per
million standard cubic feet of gas.
Clean up (coalescing filter) requirements and sizing (one set per combustion
turbine)
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—
Two coalescing filters shall be 100% effective for particles 0.3 microns or
larger.
—
The two filters shall operate in parallel so that there is no need to shut down
the turbine while performing maintenance on one of the filters.
—
The coalescing filters can handle small slugs of liquids up to about
10 gallons.
—
Each filter shall be sized to handle the flow associated with the turbine
operating at full load.
—
Piping shall be carbon steel upstream of the filters and stainless steel
downstream of the filters to the combustion turbines.
If required by the manufacturer, the Seller shall furnish and install equipment necessary
to heat the fuel to a temperature acceptable to the gas turbine manufacture using either
hot returned condensate, low-temperature HRSG economizer water, low-pressure steam,
or other suitable means within the restriction of the Facility’s Permit.
Wobbe index control shall be provided if, based on the historical fuel supply variations
and combustion turbine requirements, it is necessary to have stable operation including
prevention of plant tripping.
Seller shall supply individual fuel gas regulators and associated relief valves for the gas
consuming components if necessary to prevent exceeding the manufacturer’s maximum
allowable supply pressure to such components.
One gas compressor shall be dedicated to each combustion turbine. Gas compressor
piping shall enable the use of any gas compressor with any combustion turbine.
The gas compressors shall be provided with suction regulation and bypass, including
bypass cooler, and shall meet the full range of operation for the combustion turbine from
minimum to maximum combustion turbine operation including gas necessary for duct
firing (unless separate supply from the natural gas upstream of the gas compressor is
provided).
The fuel gas system shall be designed to supply the total combustion turbine load
demands and HRSG duct burner demand under all ambient conditions. The design shall
allow the ability to change out filters and dryers online with no supply restrictions. In
addition, the system shall be designed to allow continued operation of a combustion
turbine with either gas compressor out for service.
Cathodic protection shall be provided on the gas pipeline to meet PG&E gas
interconnection requirements or AGA as applicable.
6.12.
Water Source and Treatment System
Adequate supply source shall be available to support year round plant at full load
operation.
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Source water quality and temperature shall be within each application’s specified
requirements.
The makeup water treatment shall be fully automated, instrumented and be provided with
redundant pre-filtering system. The water source system shall include but not be limited
to pumps, piping, valves, and insulation. The cooling tower (if applicable) makeup water
system shall be designed for an instantaneous flow rate equivalent to the maximum water
requirements. All pumps shall be sized to maintain an adequate supply of cooling tower
makeup water (if applicable) and provide the water flow required by all other plant
systems.
The water source onsite storage tank shall be designed to store fire protection water in the
lower portion and water for the other systems in the upper portion. The tank shall be
sized for 8 hours of facility operation at full load (this does not include the water required
per NFPA requirements).
For fire protection, the tank is sized to meet NFPA requirements of two hours of storage
capacity for the worst case demand. The upper portion of the tank shall have sufficient
storage to meet raw water demand for a safe shutdown of the plant in the event of a loss
of off-site water supply. The tank shall be constructed of mild steel. Chlorine or other
suitable biocide shall be introduced into the tank on a periodic basis to control biological
growth. A recirculation system for the tank shall be provided to ensure adequate mixing
of the chlorine or other suitable biocide.
Adequate chemical storage shall be provided for 30 days of operation.
6.13.
Demineralized Water (Condensate Makeup)
The makeup water treatment system provides boiler feedwater and makeup closed cycle
cooling water. It also provides quality water for gas turbine inlet air evaporative cooling
(water quality to meet OEM requirements) and any other applications required higher
quality water.
The demineralizer system shall be capable of providing steam-cycle make-up water at a
continuous rate equal to at least the plant’s maximum daily consumptive water use
(including allowance for regeneration) when operating at maximum peak load.
Demineralized water storage capacity shall be sufficient to support a minimum two days
of July peak plant service with 24 hours per day combustion turbine(s) inlet evaporator
cooling (if provided) and 16 hours per day of power augmentation (if provided) including
two start/stop cycles per day. One redundant train of demineralizers shall be considered
not operating.
The system shall be fully automated system with critical controls, instrumentation and
alarms available both locally and into the control room (able to start, operate and stop
unmanned).
All water treatment and regeneration equipment shall be fully enclosed and climate
controlled. Building shall be adequately sized and designed for ease of removal of large
equipment (including roll up doors, overhead crane, and trolley).
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The makeup water treatment system shall consist of and not be limited to a water
treatment plant, a raw water tank, a filtered water tank, reverse osmosis (RO) unit, and a
demineralized water tank. The quality of the RO water and demineralized water produced
by the water treatment system must meet the equipment manufacture’s requirements and
EPRI’s recommendations for major equipment such as CTG, HRSG and STG.
Condensate/start up polishing filter system shall be provided with automatic control
either locally or from control room (designed for automatic regeneration with no service
restriction). Piping connections for portable condensate polishing systems and
demineralizer system shall be provided. The piping connections, piping, and valving shall
enable maintenance of the permanent equipment without disruption in demineralized
water supply or polishing requirements.
Full redundancy of all chemical pumps and for raw water supply and final product outlet
shall be provided.
Chemical storage adequate to support 30 days of full capacity water production shall be
provided. All chemical equipment, instrumentation and piping shall be properly shielded
in accordance with OSHA requirements.
All pumps shall have suction/discharge flange and bolt connections.
The demineralizer piping arrangement shall be plumbed to allow for use of portable
demineralizers.
6.14.
Wastewater Treatment and Discharge
The wastewater treatment and discharge shall be designed to process and treat all waste
streams in accordance with approved discharge permit requirements.
Equipment drains and floor drains from the chemical feed and water treatment areas shall
be collected in chemical waste sumps, which shall be provided with sump pumps. A pH
monitor shall be provided in the sumps to monitor the sump water and alarm in the case
of a chemical spill.
Boiler blowdown shall be sent to a blowdown tank, cooled by mixing with service water
and collected in a common wastewater sump. Combustion turbine evaporative cooler
bleed water shall also be routed to the wastewater sump.
Wastewater containing hydrocarbons shall be collected separately and treated in an API
oil/water separator system that discharges into the chemical waste sump. Areas of
potentially significant oil spillage shall be contained within a curbed area (Also refer to
the Civil section).
The Seller shall dispose of all wastes from initial chemical cleaning of the HRSG and
piping. Disposal of these wastes shall be in accordance with applicable environmental
regulations. The Purchaser shall approve the subcontractor selected to transport and/or
dispose of these wastes.
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Sewage and storm water collection and transfer facilities or treatment facilities shall be
provided if offsite services are not available.
Segregated collection systems shall be provided for oily and chemical wastewater.
Neutralization and detoxification shall be provided for all chemicals containing
wastewater streams (e.g., demineralizer regeneration, chemical storage, acid cleaning, gas
turbine washing, other wash water)
If “zero discharge” is permitted, the specifications shall be reviewed and accepted by the
Purchaser.

Vendor will provide two independent sources of waste processing heat.

If “zero discharge” is permitted, system will be adequately designed and automated
to minimize labor burden of plant staff.

Related equipment designed to have capacity for at least 120% of maximum
expected operating requirements.
In addition, 100% redundancy shall be provided for all critical chemical treatment and
wastewater processing pumps, motors and compressors.
Adequate chemical storage for 30 days of operation shall be provided.
6.15.
Sump Pumps
Duplex submersible sump pumps shall be furnished as required. The pumps shall be sized
for one pump to operate and the other pump to be spare. The pumps shall be equipped
with guide bars for removal and automatic discharge connections.
A control panel complete with auto/manual control, starters, level switches, etc., shall be
included. Both pumps shall operate at high-high level.
6.16.
Potable Water
Permanent potable water for personnel use, service/fire water supply, and supply to the
water treatment system shall be provided. This can be from the local water district. The
Seller is to install all potable water supply piping and accessories including all off-site
work. The Seller’s scope includes all tie-ins, metering, and piping necessary to bring the
potable water to the site. All applicable construction permits are by the Seller.
The Facility potable water system shall consist of potable water generation and
distribution system equipment, including valves and backflow preventors as required.
The water distribution system shall be sized to deliver peak demand to each building at a
normal pressure of 40 psi and a maximum pressure of 80 psi. Minimum pipe size for
building service shall be ¾ inch.
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6.17.
Technical Specifications: Appendix N2
Combined Cycle
Fire Protection System
6.17.1.
General
The requirements for the design, manufacturing, testing, supply, and delivery of a
complete stand-alone fire protection and fire detection alarm and notification systems,
and related subsystems, sprinkler systems, fixed water spray systems, fire protection
water supply systems, clean agent extinguishing system, standpipe and hose station
connections, and hand held portable fire extinguisher, hereinafter referred to collectively
as the fire protection system.
Compliance with this Specification does not relieve the Seller of the responsibility of
designing, fabricating, and furnishing a system in accordance with National Fire
Protection Association (NFPA) requirements and recommendations, applicable State of
California Building and Fire Codes, Standards and Amendments, Federal and County
Codes, and the local authorities having jurisdiction.
The fire protection systems and related subsystems are intended as a life safety system
and equipment protection, and shall be designed and supplied consistent with that
objective.
The fire protection systems specified herein is intended for installation by Seller(s)
familiar with the design, manufacture, installation, testing and proper application of such
systems.
It is not the intent to specify all details of design and construction. The Seller shall
ensure that the equipment as been designed, fabricated, erected and tested in accordance
with all building and fire codes, standards, recommendations and governmental
regulations applicable to the specified services.
The fire protection system specified herein is intended to be operated by the power
station operating staff. As such, it is required that the systems be designed and supplied
so as to be "user-friendly" to the extent that the Power Plant employees can reasonably be
expected to operate them effectively under emergency conditions.
6.17.2.
Seller’s Responsibility
The Seller shall be responsible for the design and supply of fully operational fire
protection systems. The Seller shall be responsible for all material, labor, logistical and
technical resources, and coordination necessary for the complete execution of all
particulars of this Specification.
All work performed pursuant to this Specification shall be complete in every respect,
resulting in fully operational fire protection systems supplied entirely in accordance with
the applicable codes, standards, manufacturer's recommendations, product listings and
this Specification. All work which does not conform to these requirements shall be
subject to replacement, at the Purchaser's sole discretion, with work which does conform,
at the Seller's own expense.
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The fire protection systems supplied shall be designed in a consistent manner throughout
the premises and all components shall be able to operate to meet all requisite functions in
a consistent manner, to the satisfaction of both the Purchaser and the Local Statutory
Authorities. It shall be the Seller’s responsibility to interface and receive approval from
the authorities having jurisdiction for the proposed fire protection system.
All design drawings and calculations shall be signed and sealed by a State of California
Registered Professional Engineer currently practicing engineering in the State of
California. In addition to other submittals required by this Specification, the Seller shall
provide submittal packages for transmittal to the Local Authorities having Jurisdiction for
review, comments and approval of the various fire protection designs, equipment and
installations.
6.17.3.
Fire Protection Master Plan and Design Basis
The Seller shall be responsible for preparing a Fire Protection Master Plan and Design
Basis. This shall consist of as a minimum the following documents:
a.
Building and Fire Codes, and Life Safety Compliance Review Report
b.
Fire Risk Evaluation Report
c.
Hazardous Area Classification Evaluation
Building and Fire Codes, and Life Safety Compliance Review – The report shall identify
and address for each building, pre-engineered and/or pre-fabricated building, equipment
enclosure and/or structure, and outdoor process, equipment and storage areas at a
minimum the following:
a.
Applicable building and fire codes, standards, recommendations and amendments.
b.
Building classification, occupancy and permitted construction types.
c.
Building height and area limitations.
d.
Fire resistance requirements for floors, exterior and interior walls and structural
supports.
e.
Egress and exiting requirements.
f.
Detailed exit analysis and calculations. Prepare exit analysis drawings
documenting occupant loads, required exit widths, occupant load distribution and
travel distances.
g.
Combustible and flammable gases and liquids process equipment and storage fire
protection, quantity limitations, and storage requirements.
h.
Accessibility requirements.
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i.
Fire Department access and fire fighting facilities.
j.
Occupancy and area separation requirements.
k.
Fire alarm and detection systems.
l.
Sprinkler/Standpipe and fire hose station requirements (duration, flows, pressures
and densities).
m.
Fire protection water supply requirements.
n.
Emergency power and lighting requirements.
o.
Smoke control and ventilation requirements.
p.
Elevator Requirements
The Building and Fire Codes, and Life Safety Compliance Review shall be performed by
a State of California Fire Protection and Engineering (FPE) Firm experienced in the
preparation of fire protection master plans, building code reviews and reports and
exit/egress analysis calculations and diagrams.
Fire Risk Evaluation - A NFPA 850 fire risk evaluation shall be initiated as early in the
design process as practical to ensure that the fire prevention and fire protection
recommendations as described in this document have been evaluated in view of the plantspecific considerations regarding design, layout, and anticipated operating requirements.
The evaluation should result in a list of recommended fire prevention features to be
provided based on acceptable means for separation or control of common and special
hazards, the control or elimination of ignition sources, and the suppression of fires. The
fire risk evaluation should be approved by the owner prior to final drawings and
installation.
Hazardous Area Classification Evaluation - The basis for classification evaluation shall
be NFPA 70 (National Electrical Code [NEC]), NFPA 497, API 500, vendor information
and other standards, as applicable.
All three documents shall be submitted to the local statutory authorities and the Purchaser
for review, comment and approval.
6.17.4.
Codes, Standards and Recommendations
The fire protection systems shall be designed in accordance with the specified codes,
standards and recommendations, all applicable statutory requirements and amendments,
and the EPC Specifications.
The specified codes, standards and recommendations shall include:

Local Adopted Codes, Standards and Amendments
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The local building and fire codes, standards, recommendations and amendments to be
used shall be determined during the Contractors Building and Fire Codes, and Life
Safety Compliance Review.

National Fire Protection Association (NFPA) Codes, Standards and
Recommendation’s
a.
NFPA 10, Standard for Portable Fire Extinguishers.
b.
NFPA 12, Standard on Carbon Dioxide Extinguishing Systems.
c.
NFPA 13, Standard for the Installation of Sprinkler Systems.
d.
NFPA 14, Standard for the Installation of Standpipe, Private Hydrants, and Hose
Systems.
e.
NFPA 15, Standard for Water Spray Fixed Systems for Fire Protection.
f.
NFPA 16, Standard for the Installation of Foam-Water Sprinkler and Foam Water
Spray systems.
g.
NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection.
h.
NFPA 22, Standard for Water Tanks for Private Fire Protection.
i.
NFPA 24, Standard for the Installation of Private Fire Service Mains and Their
Appurtenances.
j.
NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based
Fire Protection Systems.
k.
NFPA 30, Flammable and Combustible Liquids Code.
l.
NFPA 37, Standard for the Installation and Use of Stationary Combustion Engines
and Gas Turbines.
m.
NFPA 50A, Standard for Gaseous Hydrogen Systems at Consumer Sites.
n.
NFPA 54, National Fuel Gas Code.
o.
NFPA 68, Guide for Venting of Deflagrations.
p.
NFPA 70, National Electrical Code.
q.
NFPA 72, National Fire Alarm Code.
r.
NFPA 85, Boiler and Combustion Systems Hazard Code
s.
NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating
Systems.
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t.
NFPA 92B, Standard for Smoke Management Systems in Malls, Atria, and Large
Spaces
u.
NFPA 101, Life Safety Code.
v.
NFPA 204, Standard for Smoke and Heat Venting.
w.
NFPA 214, Standard on Water Cooling Towers
x.
NFPA 221, Standard for FireWalls and Fire Barrier Walls.
y.
NFPA 291, Recommended Practice for Fire Flow Testing and Marking of
Hydrants.
z.
NFPA 497, Recommended Practice for the Classification of Flammable Liquids,
Gases, or Vapors and of Hazardous (Classified) Locations for Electrical
Installations in Chemical Process Areas.
aa.
NFPA 780, Standard for the Installation of Lightning Protection Systems.
bb.
NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems.
6.17.5.
Other Codes and Standards
American Petroleum Institute (API) 500, Recommended practice for Classification of
Locations for Electrical Installations at Petroleum Facilities Classified as Class I,
Division 1 and Division 2.
The following referenced document(s) provide recommendations for fire protection of
electric generating plants based on good industry practice and the applicable for the
project sections shall be used and implemented (should recommendations shall be
changed to “shall”).
a.
NFPA 850 – Recommended Practices for Fire Protection for Electric Generating
Plants and High Voltage Direct Current Converter Stations.
b.
Electric Power Research Institute (EPRI) Document - EPRI NP-4144, Turbine
Generator Fire Protection by Sprinkler System, Project No. 1843-2, Final Report
1985.
The specified standards define minimum requirements only. They do not necessarily
include all requirements necessary to satisfy the applicable local statutes, as interpreted
by the Local Statutory Authorities, or the EPC Specifications.
Unless otherwise indicated, the issue of the specific code, standard or recommendations
in effect at the time of the “construction plan submittal to the Local Statutory
Authorities” shall apply.
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The Contractor shall be subject to the interpretation of the Local Statutory Authorities as
final arbitrator of any disputes relative to the applicable statutory requirements.
Acceptance of the installed systems by the Local Statutory Authorities is required.
In the event of differences between the requirements of the applicable codes, referenced
standards and the EPC Specifications, the more stringent requirement(s) shall apply.
If there are conflicts between the applicable codes and standards and the EPC
Specification, it is the Contractor’s responsibility to immediately bring those conflicts to
the attention of the Owner for resolution, in writing.
6.17.6.
Materials, Equipment and System Components Listings and
Approvals
All materials, equipment and system components furnished, shall be new and approved
by local statutory authorities (approved for use by the State of California Fire Marshal)
and listed by Underwriters Laboratory (UL /ULI) and/or approved by Factory Mutual
Research Corporation (FM) for their intended use. All equipment shall be designed and
installed in accordance with the applicable codes, standards and recommendations, the
manufacturer’s recommendations, and within the limitations of their UL listing and/or
FM approvals. The Contractor shall provide evidence of listing and/or approvals of all
equipment and combinations of equipment with his submittals.
All materials, equipment and system components for which UL listing categories exist
shall be ULI listed for the intended application.
All materials, equipment and system components for which UL listing and/or FM
approval is required shall be listed in the current edition of the UL or FM Fire Protection
Equipment Directories and shall be delivered to the project site with factory applied, UL
and/or FM stickers. Components, which do not meet these requirements, are not
acceptable.
Components for which UL listing, FM approval, and the State of California Fire Marshal
approval are "pending" are not acceptable.
All system components are subject to the approval of the Purchaser with regard to their
fitness for the intended application.
6.17.7.
Fire Protection Water Supply and Water Storage
The required fire protection water supply (fire flow and duration) shall be designed in
accordance with the applicable codes and standards.
The water supply for fire protection shall provided directly from a dedicated supply in a
combination Factory Mutual Approved water storage tank. The fire water reserve will be
based on the minimum required fire protection water flow and flow duration. The plant
raw water interface at the storage tank will be located at a point above the guaranteed fire
water level of a minimum of three hundred thousand (300,000) gallons.
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The tank shall be provided with:
a.
Fire protection water low level supervisory alarms and low temperature
supervisory alarms both monitored by the plants fire detection and alarm system
per NFPA 22 and 72, and the DCS/PLC system.
b.
OSHA approved handrails, guardrails and ladders for inspection and maintenance
of the tank.
c.
A supplemental heating system to maintain the water temperature of the tank above
the required NFPA 22 requirements.
d.
A Factory Mutual (FM) Approval metal tag indicating that the tank is FM
Approved affixed to the exterior of the tank by the tank manufacture.
e.
Meeting the requirements as specified within other sections of the EPC
Specification.
6.17.8.
Fire Pumps
The site shall be provided with two (2) Factory Mutual Approved fire pumps both located
within a fire pump house enclosure constructed of masonry construction. The fire pumps
shall be sized to meet the applicable code requirements and the largest postulated fire(s)
per the Risk Evaluation.
The types of fire pumps that shall be provided are as follows:
a.
One (1) 100% electric motor-driven centrifugal fire pump.
b.
One (1) 100% diesel engine-driven centrifugal fire pump.
One (1) pressure maintenance pump (jockey pump) shall be provided to maintain
pressure in the underground fire protection water main system and also will be located in
the fire pump house.
The fire pumps shall be separated by each other by a two (2) hour rated fire barrier wall.
The diesel engine driven fire pump shall be installed with a residential low noise type
muffler.
Each fire pump area shall be provided with:
a.
An automatic wet pipe sprinkler system.
b.
Low temperature supervisory device per NFPA 72.
c.
Ventilation system.
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All fire pump and sprinkler valves within each fire pump area shall be provided with a
valve supervisory (tamper) switch. The use of butterfly valves is prohibited.
The liquid fuel storage tank for the diesel engine driven fire pump shall be of double wall
construction with tank leak detection system. The tank shall be able to be refueled from
both outside the pump house (external fuel connection with tank level gauge) as well as
inside the pump house.
Terminals shall be provided on the controller for remote monitoring and annunciation
(individual) by the plant fire detection and alarm system for the following supervisory
alarm conditions of the following conditions:
a.
Engine running (separate signal).
b.
Controller selector switch in off or manual positions (separate signal).
c.
Trouble on the controller or engine (This includes critically low oil pressure, high
engine jacket coolant temperature, failure of engine to start, overspeed shutdown,
battery failure (Battery Set 1), battery failure (Battery Set 2), battery charger
failure, and low engine oil or engine jacket coolant temperature).
d.
Low fuel oil level in day tank.
e.
Day tank leak.
Terminals will be provided on the controller for remote monitoring and annunciation
(individual) by the plant fire detection and alarm system for the following supervisory
alarm conditions of the following conditions:
a.
Pump operating.
b.
Power loss (all phases supervised).
c.
Phase reversal.
d.
Phase failure.
The fire pumps shall be designed and installed such that either fire pump can be taken out
of service with out effecting the use and operability of the other fire pump and the
pressure maintenance pump.
The design, installation, and testing of the fire pumps shall be in compliance with the
requirements of NFPA 20, 70 and 72.
6.17.9.
Underground Fire Protection Water Main System and Hydrants
The underground fire protection water main system and fire hydrants shall be arranged
around the structures, process areas including outdoor equipment throughout the power
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plant and switchyard. The size of the loop piping shall be based on the calculated
maximum demand and the requirements of NFPA 24 and per the Risk Evaluation.
The underground fire protection water piping will be constructed of a combination of
cement lined ductile iron and Factory Mutual (FM) Approved high-density polyethylene
pipe (HDPE-Class 200).
The minimum underground fire protection water main pipe sizes are as follow:
a.
Underground loop – 10 inch for cement lined ductile iron and 12 inch for HDPE.
b.
Laterals to fire hydrants less than 25 feet on a dead end main - 6 inch for cement
lined ductile iron and 8 inch for HDPE.
c.
Laterals to fire hydrants 25 feet and greater on a dead end main - 8 inch for cement
lined ductile iron and 10 inch for HDPE.
Thrust blocks shall be provided for all underground fire protection pipes.
Exception: – Thrust blocks for HDPE pipe can be eliminated with written approval
submitted to the Purchaser for review by all the following:
a.
Factory Mutual Engineering and Research (FMRE). This document shall include
all special requirements by FMRE that need to be provided so that the thrust blocks
can be eliminated.
b.
Local Statutory Authorities
c.
HDPE manufacturer and supplier
The underground loop shall be connected to the stations fire pumps using two parallel
lateral underground water mains (primary and back up) with post indicator valves located
on both sides of the lateral and between both of them.
Gate (curb box) valves are provided for each yard hydrant to isolate it from the
underground loop for maintenance purposes, in the event of mechanical damage, and/or
line rupture. The underground loop shall be provided with post indicator valves (PIV’s)
to isolate sections so that not more than four (4) fire protection users (i.e. fire hydrants,
fixed fire suppression systems, stand pipes, etc.) are out of service due to a single line
break. The Seller shall verify if additional isolation controls are required per local code.
Laterals to buildings and outside equipment that have water based fire suppression
system shall be provided with outside isolation water control supply valves using PIV’s
(with valve supervisory (tamper) switches) to isolate the water supply.
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6.17.10.
Technical Specifications: Appendix N2
Combined Cycle
Fire Hydrants
The distance between fire hydrants around the Power Island fire loop shall be a maximum
of 250 feet and hydrants shall not located within 40 feet of building structures as required
by NFPA 24. Additional hydrants shall be provided so that no exposure is more than 250
feet from the nearest hydrant so that a fire hose can be used.
The fire hydrants shall be provided with two hose connections and one fire pumper
suction connection.
The entire design and installation of the underground fire protection water supply main
system shall be in compliance with the requirements of NFPA 24 and 291, and the local
Statuary Authorities.
6.17.11.
Fire Protection and Detection System
The following fire protection and detection shall be provided:
Equipment, Area,
and/or Building
Fire Protection
Suppression System
Type
Detection or Actuation Devices
Buildings
Control Building
Class II hose stations
Manual pull stations located at each
located throughout the
exterior exit door
entire building, except in
the Control Room, battery
rooms and electrical
rooms.
Control Room
Double Interlock preaction sprinkler system
Smoke detectors at the ceiling level
and beneath all raised floors
Maintenance Shop
Automatic Wet Pipe
(includes Tools / Storage Sprinkler System
Room and beneath all
Mezzanine)
Warehouse (includes
Automatic Wet Pipe
Storage Room and above Sprinkler System
Interior Roof)
I & C Shops
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Automatic Wet Pipe
Sprinkler System
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Equipment, Area,
and/or Building
Fire Protection
Suppression System
Type
Technical Specifications: Appendix N2
Combined Cycle
Detection or Actuation Devices
General Office Areas,
Automatic Wet Pipe
Corridors, File & Copy
Sprinkler System
Room(s), Conference
Room, Janitor and Storage
Room and Lunch Room
Both Women’s and Men’s Automatic Wet Pipe
Combination Wash
Sprinkler System
Rooms and Locker
Rooms
Telephone and
Communication Rooms
Automatic Wet Pipe
Sprinkler System
Operator Equipment and
Storage Rooms
Automatic Wet Pipe
Sprinkler System
Electrical Equipment
Rooms
Pre-action sprinkler
Spot type smoke detectors.
System – Electric Release
Battery Rooms
Pre-action sprinkler
Smoke detectors at the ceiling.
System – Electric Release Note: If the room is classified per the
Fire Protection Master Plan and
Design Basis, explosion proof smoke
detectors are required.
Electronics Rooms
Pre-action sprinkler
Spot type smoke detectors, including
System – Electric Release beneath raised floors.
Gas Compressor
Building/Enclosures
None
Gas Detectors
Gas Processing and/or
Control Equipment. Inc
None
Gas Detectors
Combustion Turbine
Generators
Total flood gas (by
generator manufacturer)
Contractor to provide network
system. Main panel to annunciate all
alarm, troubles and supervised
conditions.
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beneath raised floors.
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Equipment, Area,
and/or Building
Technical Specifications: Appendix N2
Combined Cycle
Fire Protection
Suppression System
Type
Detection or Actuation Devices
Each Combustion Turbine
Fuel Gas Conditioning
Skid
Spot type heat detectors.
Each Combustion
Turbine: CEMS
Enclosure.
Spot type photoelectric smoke
detectors.
Each Combustion
Turbine: Packaged
Electronic Control Center.
Spot type photoelectric smoke
detectors.
Transformers
Each Main Transformer
Automatic Water Spray
(Deluge) System. Dry
Pilot Sprinklers (Head)
looped around each Unit,
maximum of 10 ft on
center, and in accordance
with NFPA 72.
Each Reserve Aux
Transformer
Automatic Water Spray
(Deluge) System. Dry
Pilot Sprinklers (Head)
looped around each Unit,
maximum of 10 ft on
center, and in accordance
with NFPA 72.
Steam Turbine
.
.
Steam Turbine (ST)
Automatic dry pipe
Pedestals: Turbine
sprinkler system
underfloor and
mezzanines, including ST
skirt (lagging)
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Equipment, Area,
and/or Building
Fire Protection
Suppression System
Type
Detection or Actuation Devices
Steam Turbine: Lube oil
reservoir, conditioner,
piping and Hydrogen seal
oil unit
Dry Pilot Sprinklers
(Head) looped around the
Unit, maximum of 10 ft on
center, and in accordance
with NFPA 72.
Steam Turbine and
Generator Bearings: ST
Bearings
Automatic and manual
Spot type heat detectors.
preaction sprinkler system
(spray) with electronic
heat detection for alarm
only.
Steam Turbine: Electrical
Enclosures
Spot type smoke detectors.
Chem Feed Equipment
Enclosure
Manual pull stations at each exit
door. Spot type smoke detectors.
Demineralized water
pump enclosure
Manual pull stations at each exit
door, Spot type smoke detectors.
Water Treatment
Building: Cooling Tower
Electrical Room
Spot type smoke detectors
Water Treatment Building Automatic wet pipe
Manual pull stations at each exit
sprinkler system. Class II door.
hose station located
throughout the entire
building.
Warehouse and Storage
Buildings.
Automatic wet pipe
Manual pull stations at each exit
sprinkler system. Class II door.
hose station located
throughout the entire
building.
Cooling Towers
Non-Combustible Type
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Equipment, Area,
and/or Building
Technical Specifications: Appendix N2
Combined Cycle
Fire Protection
Suppression System
Type
Detection or Actuation Devices
Factory Mutual Approved Automatic suppression in
accordance with NFPA
214.
Factory Mutual Approved Automatic suppression in
Materials Only
accordance with NFPA
214.
The specified required fire protection and fire detection outlined in the table above
defines minimum requirements only. The table may not include all requirements
necessary to satisfy the applicable local statutes, as required by the Local Statutory
Authorities, or the EPC Specifications. The Contractor shall be responsible for providing
all additional fire protection and fire detection as determined by the Fire Protection
Master Plan and Design Basis reviews and analyses.
All outdoor sprinkler system releasing valves subject to freezing shall be installed in a
heated weatherproof insulated enclosure. Each enclosure shall be provided with a low
temperature enclosure monitoring device monitored and annunciated by the fire alarm
control panel in the control room. Heats tracing and/or insulating sprinkler isolation and
control valves, releasing valves and sprinkler piping is prohibited.
All valves controlling and/or isolating water for fire protection use shall be provided with
valve supervisory (tamper) switches.
All sprinkler system releasing valves shall be externally re-settable without having to
remove the front inspection cover. Acceptable sprinkler equipment manufactures are
Viking and Grinnell.
All above ground sprinkler piping located outside shall be hot dipped galvanized steel.
All sprinkler hangers and rolled grooved fittings and couplings shall be galvanized.
Sprinkler pipe hangers for cooling tower sprinkler systems shall be stainless steel
including for dry – pilot piping.
The use of butterfly valves to control and/or isolation fire protection water is prohibited.
All valves controlling and/or isolating CO2 shall be provided with valve supervisory
(tamper) switches.
Each Class II and Class III fire hose station shall be provided with the following.
a.
One 1-1/2 inch adjustable pressure restricting angle valve.
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b.
One heavy duty FM approved hose reel, suitable for the specified fire
hose.
c.
One hundred feet of FM approved 1-1/2 inch single polyester jacket,
synthetic rubber lined fire hose, with couplings and connections.
d.
One 1-1/2 inch fully adjustable hose nozzle rated for Class A or B
fires. Hose stations located near electrical equipment shall be
provided with nozzle rated for use on electrical fires.
e.
One 2-1/2 inch Fire Department Valve Connection
f.
Fire hose reel cover
A complement of 20-pound type, portable fire extinguishers rated for Class A, B, and C
fires shall be installed in accordance with local building code and NFPA 10. In addition,
portable CO2 extinguishers shall be located in areas containing sensitive electrical and
telecommunication equipment, such as the control room and the switchgear rooms. One
portable wheeled dry-chemical extinguisher will be located in the GT area to provide
extended manual suppression capability. Fire Extinguishers containing water or waterbased agent and Listed for Class C shall not be used.
6.18.
Fire Detection System
The Main Fire Protection Panel (MFPP), located in plant main control room, shall be
integrated fire detection, evacuation signaling and auxiliary function control system:
The system shall be of the multiplex type.
The system shall be capable of providing point identification addressable for each
individual fire and supervisory alarm-initiating device.
The system Central Processing Unit (CPU) shall have sufficient system expansion
capability to monitor a minimum 200 initiating device circuits/zones.
The sensors of the Fire Alarm Systems shall be addressable.
Acceptable Fire Alarm Equipment Manufactures:
a.
Notifier
b.
Edwards System Technology
The system shall be designed and equipped to receive, monitor and annunciate all signals
from fire and supervisory alarm initiating devices and circuits installed throughout the
site including combustion turbine and associated ancillary equipment fire suppression and
fire detection systems and equipment. The Seller shall provide remote stand alone fire
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alarm panels through out the site networked to the MFPP such that failure of the MFPP
will not inhibit the operability of any fire protection system from automatically operating.
The fire alarm system shall monitor and annunciate three distinct types of signals:
a.
Fire alarms, including signals initiated by manual fire alarm stations, smoke
detectors (confirmed signals only), heat detectors, and water flow discharge
pressure switches, induct smoke detectors, combustion turbine. Fire alarms
shall be audibly and visually annunciated at the Control Room MFPP and
shall initiate automatic evacuation signaling, remote signaling and auxiliary
control functions as specified.
b.
Supervisory signals, including signals initiated by sprinkler valve supervisory
switches, supervisory pressure switches, high system air pressure and low
system air pressure, low air, supervisory contacts associated with monitored
fire pump controllers, fire water storage tank level, temperature, common
trouble contacts of monitored subsystems, manual control switches for
auxiliary functions and status annunciation contacts for devices controlled by
the fire alarm system as auxiliary functions. Supervisory signals shall not
initiate automatic evacuation signaling or auxiliary control functions.
c.
Trouble conditions, including signals initiated by the system in response to
fault conditions detected in supervised circuits and/or components. Trouble
conditions shall be audibly and visually annunciated at the Control Room
MFPP. They shall not initiate automatic evacuation signaling or auxiliary
control functions.
Fire alarm and supervisory alarm initiation circuits shall be Style "A" or "B", as described
in NFPA.
Signaling line circuits shall be style "1" or "2" as described in NFPA.
Indicating device circuits shall be "Class B", supervised with end-of-line supervisory
components, capable of operating during a single ground condition.
All wiring required for proper system operation, except as specifically allowed herein,
shall be electrically supervised for opens and shorts to ground. Wiring faults on
supervised circuits shall initiate trouble conditions.
Trouble signals shall be indicated on the MFPP in the Control Room.
Evacuation signaling circuit trouble signals shall be indicated on the MFPP in the Control
Room.
Any single open or single ground condition on any non-addressable initiating device
circuit or non-addressable auxiliary function circuit, such as the circuits between
addressable monitor/control modules and their associated monitored/controlled device(s)
shall cause a trouble signal on their associated addressable circuit.
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All control components shall be placement supervised such that removal of any module
shall cause a trouble signal on the MFPP in the Control Room.
All fire alarm control and releasing equipment, devices and wiring shall be protected
against electro-magnetic/radio frequency interference or induced voltages caused by AC
power circuits, electrical transformers, motors or switchgear, electronic equipment,
fluorescent lighting fixtures, hand held portable radios, cellular phones or other devices.
The system shall be designed and installed so as to be unaffected (with all control cabinet
face plates installed and in the open position) by the operation of hand held, portable
radios of up to 5 watts, or portable cellular telephones of up to 1 watt, within 12 inches of
any system component(s).
All circuits shall be segregated and/or shielded as necessary to eliminate audio and/or
electrical crosstalk between circuits. Where necessary, separate, isolated power supplies,
shielded equipment cabinets, or other appropriate means of eliminating
interference/crosstalk shall be provided.
Combination fire alarm tone horns and stroke lights shall be installed in pairs (one fire
and one stroke light) above each manual fire alarm station with additional devices
provided as necessary for optimum audibility and visibility.
Fire alarm bells, horns horn strobes, strobes, trouble horns, and chimes shall be installed
as determined by the Fire Protection Master Plan and Design Plan.
Horns and strobe lights shall be on separate circuits.
Fire detection warning horns separate from the Facility annunciator shall be stationed in
locations throughout the entire Facility. The warning horns shall be audible from any
location within the Facility boundary and shall continue to sound until silenced at the
central control panel.
Several rotating light or strobe beacons separate from those provided for the Facility
annunciator shall be stationed to allow visible indication of a fire condition from any
location within the Facility boundary. These beacons shall be clearly visible during
daylight or sundown hours.
To allow manual initiation of a fire alarm, manual pull stations shall be distributed
throughout the Facility. The manual pull stations shall be equipped with a dual action
releasing lever to reduce chances of accidental operation.
6.19.
Compressed Air System
The compressed air system shall consist of an instrument air and a station air system.
The instrument air system shall have adequate dryers and filters to meet OEM quality
specifications. Two 100% heatless dryers with two 100% filters shall supply dry (-40°F
dew point at 125 psig), oil free air for use by control systems and instrumentation.
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Use of compressed air supplying the instrument air distribution header (via the instrument
air dryer) for such auxiliary functions as purge air (except for instruments) is
discouraged. Instrument air shall be provided in the Facility's instrument/maintenance
area.
The station air system shall be a separate compressor and distribution system which
provides air for maintenance tools and shall have valved access points at convenient
maintenance around the facility. The air shall be dry and clean.
Adequate instrument compressed air storage shall be provided to facilitate emergency
shutdown of the plant. The instrument air receiver and piping shall provide a minimum of
3 minutes of compressed instrument air (pressure above minimum instrument
requirement) for plant shutdown without instrument air compressor operation.
The major components of each of the Facility's compressed air system consist of the
following:
6.20.

Two 100% or three 50% instrument air compressors and connection for portable
compressor

One service air compressor – identical to the instrument air compressor.

One air receiver for each system

Two 100% instrument air dryer and filters for oil removal. Ability to change out
compressed air dryer elements and filters on line with no plant curtailments

Instrument air distribution header

Station air distribution header
Cranes, Hoists, and Trolleys
Maintenance of the combustion turbine, steam turbine and generators will be performed
using mobile construction cranes. During the design phase of the project and before any
site construction, the Seller shall provide written descriptions for all disassembly and
reassembly lifts required for all major scheduled inspections and overhauls of the turbines
and generators. This will include descriptions of the use and sizing of fixed and mobile
cranes. The Seller shall also provide models or drawings to demonstrate the ability to
avoid all fixed interferences while completing all required movements and lifts and the
ability of the specified mobile cranes to be driven to the required locations using only the
road surfaces and maintenance pads designed for maintenance crane loadings.
All equipment in the plant shall be provided with a convenient arrangement for slinging
or handling during overhaul.
A catwalk shall be provided on the pipe bridge to enable personnel movement between
the steam turbine deck to all HRSG platforms by the drums.
Davits will be provided on (but not limited to) for the following:

Combustion turbine inlet filters
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
Each HRSG

Cooling tower

CEM platform at the stack
Technical Specifications: Appendix N2
Combined Cycle
Fixed cranes and hoists will be designed, manufactured, erected, and tested in accordance
with the specified standards and codes. All crane structures and associated lifting tackle
will be tested at lifting loads 25% in excess of the rating of the crane. Lifting cables will
have enough length to lift loads the entire height without intermediate stops to adjust
lifting tackle. Cranes and lifting tackle over 5 tons lifting capacity will be electrically
operated and controlled from floor level
Each item of lifting equipment will comply with the minimum requirements of the
applicable standards and codes with regard to:

Identification markings

Tests and inspection

Quality/grade of material

Dimensions
Brakes of an approved type will be fitted to the lift and hoist and to the hoisting,
traversing, and dwelling motions of each crane. The brakes will be designed to operate
automatically on interruption of the electrical supply to the motors and to arrest and hold,
at any position, the greatest load carried by the motor. Brake design will minimize shock
loading during application of the brakes. Crane hoists will be equipped with an
independent manually operated brake, capable of holding the maximum load lifting
capability of the hoist.
A separately mounted “stop” push button (“E-Stop”) will be provided in such a position
as to be readily available for use by the operator. The emergency stop push button will
trip the main contactor.
Electrically operated hoists will be fitted with automatic self-sustaining brakes. Electrical
motors will be rated for at least 40 starts per hour.
6.21.
Heating Ventilating and Air Conditioning
HVAC shall be provided for all buildings. The HVAC System shall heat, ventilate and/or
air-condition plant buildings and enclosures for personnel comfort, equipment
environment protection and/or freeze protection. HVAC System design generally shall
comply with ASHRAE Handbooks and Standards.
Electric heaters in air-conditioned areas and ventilated areas shall provide any necessary
space heating.
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6.21.1.
Technical Specifications: Appendix N2
Combined Cycle
System Function
HVAC systems shall maintain the environmental conditions in terms of space
temperature and humidity, air quality, and building pressurization in order to provide
efficient equipment operation and comfortable working conditions for personnel.
6.21.2.
Buildings and Enclosures
The following discussion applies to buildings, rooms, areas, and enclosures.
Due to the high ambient outdoor temperature conditions, maintenance of indoor
environmental conditions shall be accomplished with air conditioning system where
ventilation systems are normally used. Areas such as electrical switchgear rooms and
battery rooms shall be maintained at temperatures above those typical for air conditioned
environments, yet below temperatures equal to or in excess of the outdoor ambient design
temperature. Pre-filter and final filters shall be used for all areas that are either airconditioned or ventilated. Pre-filter efficiency shall be 30% and final filter efficiency
shall be 80% based on ASHRAE 52.1-1992 or approved equivalent international
standard.
Explosion-resistant construction shall be used in all battery rooms where hydrogen may
be developed or released.
The fresh air intakes for the control room shall be elevated and separated by at least 3 to 5
feet vertically and 10 to 15 feet horizontally. Also, fresh air intakes shall not be located
on the same wall as any ventilation discharge from the battery rooms.
All ductwork shall be galvanized steel. The duct system shall include fire dampers,
balancing dampers, insulation, flexible connections, etc., needed for a complete system.
Products shall meet NFPA 90A or approved equivalent international standard, and fire
dampers shall meet UL 555 or approved equivalent international standard. No products
used in the duct construction shall exceed the maximum rating of 25 for flame-spread and
the rating of 50 for smoke-developed and fuel-contributed obscuration.
A ventilation system shall be provided in the water treatment area. In general, this shall
consist of powered roof or wall exhaust fans and sidewall manual intake louvers, as
determined by physical arrangement of the facility. All air supplied to ventilated areas
shall not be filtered, unless required for equipment protection.
6.21.3.
Air Conditioning System
A split packaged air conditioning system(s) shall be installed for rooms requiring air
conditioning including the main control room, offices, storage areas, and battery room.
The system(s) shall provide constant volume air supply with a variable outside air supply
capability of 10% - 100% (economizer) to achieve energy conservation. When outdoor
air temperature and humidity conditions permit, the system will utilize outside air in lieu
of refrigerant for cooling. Each unit shall be provided with a compressor, evaporator coil,
detached air-cooled condenser, electric heating coil, and a pre-filter and final filter. The
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Technical Specifications: Appendix N2
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HVAC system will continuously operate the year round. For the control room, two 100%
capacity HVAC systems shall be provided, one operating and one as standby.
The HVAC split units for the air conditioning system shall include a mixing section with
fresh air, exhaust air, and return air dampers, filter section (including pre-filter and final
filter), electric pre-heating coil section, cooling coil section, supply fan section and
return/exhaust fan section. The air conditioning system final filter shall meet the
requirements of 80% atmospheric dust spot efficiency based on ASHRAE Standard 52.1
or approved equivalent international standard.
Duct-mounted electric reheat coils shall be provided for zone temperature control as well
as high humidity control.
Careful consideration shall be taken for locating outdoor air intakes and air-cooled
condensers away from prevailing wind direction and from airborne sand and dust.
6.21.4.
Battery Room Exhaust System
The exhaust system in the battery room shall be operated continuously to maintain
negative pressure and to avoid accumulation of hydrogen gas or leakage to neighboring
rooms. Ducted exhaust intake shall be directed upward to remove hydrogen accumulated
at ceiling and in beam pockets. Discharge air shall exceed the air supply by 15%. The
supply air for the battery room shall come from the air conditioning system.
Indoor air temperature shall be kept below 85°F. Exhaust air rate shall meet the
requirement of not less than ten volume air changes per hour. Two 50% capacity in-line
exhaust fans shall be provided.
Exhaust fans and motors shall be of explosion proof design.
6.21.5.
Design Parameters
Control Building HVAC system indoor design temperatures are summarized below:
Room
System Type
Indoor Environmental Conditions
Control room/ Offices/ I&C
maintenance/ Administration
Building/ CEMS Enclosure
HVAC
75 ± 4°F, 50% RH
Battery room
HVAC
85 ± 5°F
Electrical switchgear,
switchyard control house
HVAC
As required
The indoor environmental conditions shall be met based upon the internal heat gain in the
room and outdoor ambient design conditions as listed.
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Combined Cycle
Service
Equipment Description
Control room/battery room
HVAC Split Packaged Unit 2 x 100%
Switchgear
HVAC split packaged Unit
Administration building
HVAC Split Packaged Unit
Offices, I&C maintenance
room/ and CEMS Enclosure
HVAC Split Packaged Unit
Warehouse/mechanical
maintenance area
Wall/roof exhaust, louvers, dampers
Cooling tower chemical feed
building
Exhaust power roof ventilators and wall louvers
Gas compressor building
Wall/roof exhaust, louvers, dampers
Electrical building
Supply fans, dampers, louvers
Fire pump enclosure
Supply fans, dampers, louvers
Guard shack
HVAC, self-contained package, through-wall
Mechanical building
Supply fans, dampers, louvers
6.21.6.
Standards
The following standards or other international standards as approved by the Purchaser
shall be used in the design of the HVAC system.



ASHRAE Handbooks (Latest Editions):
—
Fundamentals
—
HVAC Systems and Equipment
—
HVAC Applications
—
Refrigeration
ASHRAE Standards:
—
52.1, Method of Testing Air Cleaning Devices Used in General Ventilation
for Removing Particulate Matter
—
15, Safety Code for Mechanical Refrigeration
—
62, Ventilation for Indoor Air Quality
—
90.1, Energy Efficient Design of Buildings
ANSI/ASME Standards:
—
ANSI/ASME B31.5, Refrigeration Piping

SMACNA Standards:

HVAC Duct Construction Standards, Metal and Flexible
—
Round Industrial Duct Construction
—
Rectangular Industrial Duct Construction Standards
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

NFPA Standards:
—
90A - Installation of Air Conditioning and Ventilating Systems
—
90B - Installation of Warm Air Heating and Air Condition Systems
—
204 - Smoke and Heat Venting
IEC Standards:
—


6.22.
Technical Specifications: Appendix N2
Combined Cycle
529 - Degree of Protectors for Electrical Equipment
ARI Standards:
—
410 - Forced Circulation Air-Cooling and Air Heating Coils
—
430 - Central Station Air Handling Units
AMCA Standards:
—
210-85 - Laboratory Methods of Testing Fans for Rating
—
500-89 - Test Method for Louvers, Dampers, and Shutters
Chemical Injection Skids, Chemical Storage, and Bottled Gas
Storage
The location of the chemical injection skids, distance to injection points, and line sizing
shall be considered to ensure appropriate addition of chemicals avoiding long transport
times and gassing issues.
Appropriate location in buildings or sunshades shall be provided based on the chemical
requirements for the chemical storage areas, chemical skids, and transport injection lines.
Bottled gas storage areas shall be provided with sunshade covers.
Sunshade covers shall consider seasonal changes in solar exposure and daily exposure
from sun movement.
7.
MAJOR ELECTRICAL EQUIPMENT AND SYSTEMS
The plant shall be designed to run down safely to stop condition with no damage to
equipment in the event of loss of auxiliary power.
The plant electrical equipment and systems shall be designed to provide a safe,
coordinated, cost-effective, reliable, operable, and maintainable power generation and
delivery system. The scope of supply shall provide the necessary equipment for delivery
of the generated power and energy to the interface points, provide the necessary
equipment to support the plant auxiliary mechanical and electrical equipment, and
provide the protection and control features for the Project.
The major components of the plant electrical systems shall include the following:
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7.1.
Technical Specifications: Appendix N2
Combined Cycle

Synchronous generator, complete with excitation system and appurtenances
Generator and controls designed to be able to meet all WECC operating
requirements.

Bulk hydrogen storage sufficiently sized for six generator purges and fills (if
hydrogen cooled generators are provided).

Bulk carbon dioxide storage sufficiently sized for six generator purges (if
hydrogen cooled generators are provided).

Generator step-up transformers (GSUs) for the turbine generators.

Isolated phase bus duct for the turbine generators.

Plant electrical auxiliary systems (AC and DC).

Plant switchyard, operating at a voltage to be selected by the Seller, depending on
the existing transmission facilities in the vicinity of the location selected for the
Project.

Transmission lines voltage and length to be selected by the Seller, as required,
from the plant to the nearest point of connection in the existing transmission
system.
Frequency and Voltage Limits
7.1.1.
Frequency
In addition to WECC requirements, the facilities shall be capable of continuous operation
for the periods defined below.
7.1.2.
Frequency Range
Minimum Sustained Operation
58.8 to 61.2
Continuous
57.5 to 58.8
10 minutes
Voltage
The Project shall be designed to accommodate continuous operation of the units when the
transmission system voltage measured at the switchyard is within 5% of the rated value,
subject to reactive power flow level restrictions associated with the units. Additionally,
the plant shall be able to operate momentarily (up to 1 minute) for voltage variations of
+20% and -10%.
7.2.
Auxiliary Equipment
The plant associated auxiliary equipment shall be designed and constructed to comply
with the requirements described below.
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7.3.
Technical Specifications: Appendix N2
Combined Cycle

Control and protection equipment shall comply with the ANSI/IEEE and NEMA
standards with respect to permissible variations in frequency and voltage.

The system shall be designed so that the steady-state bus voltages shall be within
+5% of the nominal value, even though the auxiliary equipment shall be selected
with a broader range of operation.

The voltage variation for the auxiliary equipment shall be in accordance
with ANSI/IEEE and NEMA standards. Auxiliary equipment shall be able to
accept voltage variations of 10% under steady-state conditions and of 20%
under conditions of disturbance.
Synchronous Generator
The generators shall provide their nominal power output within the range of 5% of their
nominal voltage, at any operating point within a range of power factor of 0.9 lagging to
0.95 leading. The Seller shall provide information on the output capability of the
generators at other power factors outside of this range.
The electric generator associated with the turbine shall be of proven design with a large
number of units in operation connected to a 60-hertz grid experiencing high reliability
record and comply with the ANSI/IEEE standards, and their capacities shall match or
exceed the nominal output of the corresponding turbine throughout the whole range of
operating power factors and voltages specified below, over the full range of ambient
temperatures specified. The insulation of the generator stator and field windings shall be
non-hygroscopic, Class F type, complying with ANSI/IEEE standards, but having a rated
load operating temperature not exceeding that of Class B under any operating condition
within the specified output. The global vacuum pressure impregnation process shall not
be utilized for the insulation system. Coils shall be of the B stage type or VPI type
individually cured before insertion into the generator.
The generator shall be hydrogen cooled or totally enclosed water-to-air cooled
(TEWAC). The cooling system shall be rated such that load reduction of the turbine
generator is not required even under extreme ambient temperature conditions.
The quality of the generators and accessories shall be in accordance with International
Standardization Organization (ISO)-9001, EN 29001 or BS 5750 Part 1, or other
equivalent international quality standards.
The generators shall be designed in accordance with IEEE standards C50.10 “General
Requirements for Synchronous Machines” and C50.13 “Cylindrical Rotor Synchronous
Generators,” but hydrogen-cooled generators shall meet all rated conditions with a
maximum cold gas temperature of 46°C. The generators shall be capable of operating
under the frequency conditions specified above.
The continuous operating voltage range of a generator shall be of +5% at any load up to
full load. The operating power factor range shall be of 0.90 lag to 0.95 lead as a
minimum. The generators shall be able to provide full output at the lowest continuous
operating voltage and lowest power factor within the specified range.
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Technical Specifications: Appendix N2
Combined Cycle
The generator rotational speed shall be of 3,600 rpm, and it shall be designed to support a
momentary overspeed arising from a full load rejection, without damage or abnormal
vibrations. Generator voltage shall be manufacturers’ standard.
7.3.1.
Construction of the Generator
The construction of the generator shall use proven, modern technology, so it will provide
reliable, trouble-free operation in accordance with the stated plant life expectancy. The
generator shall not be constructed using global VPI (vacuum pressure impregnation)
process. Closed-air-cooled or hydrogen-cooled generator shall be supplied with automatic
purge system.
The stator core shall be built of thin, high permeability, low-loss, silicon steel segmental
punchings with a high interlaminar resistance, thereby reducing the losses caused by eddy
currents.
The stator windings shall consist of single-turn bars with their conductors transposed in
the slot area.
The rotor body shall be built from a solid block and machined to accept the rotor
windings whose ends must be held securely by 18 Mn -18 Cr alloy steel rings. After
assembly, the rotor shall be dynamically balanced.
7.3.2.
Accessories
The generators shall be provided with all required accessories for an efficient and
continuous operation within its whole range of operation, including closed circuit waterair coolers if required, bearing oil coolers, lubrication oil pump, RTDs for thermal
protection relays, CO2 fire protection system, and H2 detectors (if hydrogen-cooled
generators are supplied), etc. Current transformers for instruments and relays shall be
provided as needed for all the protection, metering, and indication functions.
7.3.3.
Generator Neutral Grounding
Generator neutral grounding equipment shall consist of a single-phase, encapsulated dry
type distribution transformer with a secondary loading resistor. The resistor and the
distribution transformer shall provide high-resistance grounding to the generator system
to limit the magnitude of any ground fault current to approximately 10 A.
7.3.4.
Excitation Systems
The generators shall be provided with fast-acting high initial response excitation systems
of the rotating brushless type or of the potential-source-rectifier type. Brushless exciters
are preferred. A crowbar system shall be provided to allow for negative current in case of
pole slip. Each excitation system shall have enough capacity to allow the corresponding
generator to operate at its maximum continuous operating voltage and at the rated power
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factor under all ambient conditions. If static design, the excitation system shall have the
ability to change out exciter brushes on-line.
Potential-source-rectifier exciters, if supplied, shall be provided with a field circuit
breaker and discharge resistor having an inverse voltage characteristic.
The excitation system shall be provided with automatic and manual voltage regulators.
The automatic voltage regulator (AVR) shall maintain the terminal voltage of the
generator at the value set by the operator, with negligible drift, throughout the whole
operating range without instability and will comply with WECC requirements. The
manual regulator will be used for test purposes and as a back up in case of failure of the
AVR. An automatic follower shall be provided between the AVR and manual regulator
so that a bumpless transfer can be made between them.
The excitation system shall have the following features and functions:

Minimum excitation limiter

Maximum excitation limiter

V/Hz limiter

Reactive drop (line drop) compensation

Cross current compensation

Redundant power bridge and controls

AVR failure detection with automatic changeover to the backup channel without
the need to trip the unit

Internal electronics diagnosis and failure detection alarm and trip functions as
needed

Power system stabilizer - PSS test report shall be prepared and submitted for
California ISO approval
—
All semiconductor components used in the excitation systems shall be
conservatively rated and protected from transient surges to ensure reliable
operation and service.
—
Protections included in the excitation systems shall include over-voltage,
over-current, fuse failures of the potential transformers, and power supply
failure to the AVR, as well as thyristor and pulse failure functions in case of
potential-source-rectifier exciters, if supplied.
—
The excitation system shall operate in conjunction with the turbine starting
equipment in case that solid state starting equipment is supplied.
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7.4.
Technical Specifications: Appendix N2
Combined Cycle
Isolated-Phase Bus Ducts, Non-Segregated Phase Bus Ducts, and
Generator Circuit Breakers
The connection between the generator and the GSU transformer bank shall be made via
isolated-phase bus ducts with a voltage rating similar or higher than the corresponding
generator terminal voltage.
Depending on the scheme selected to supply the auxiliary load of the plant, a generator
circuit breaker may also be provided between the GSU transformer bank and the
generator. In this case, the GSU and auxiliary transformers shall be energized at all times,
enabling the supply of the auxiliaries when the unit is not in service. A tap bus off the
main bus shall be provided to feed the primary winding of the unit auxiliary transformer
(UAT).
The isolated-phase bus shall be fabricated with high conductivity aluminum or copper
and shall satisfy the requirements of IEEE C37.23-2003 “IEEE Standard for MetalEnclosed Bus.” It shall be of the continuous type in which the magnetic fields outside the
bus are reduced to a minimum value, with shorting plates at the ends of the buses and at
the equipment connections.
The continuous current capacity of the buses shall be adequate to carry the full output of
the unit at the lowest operating voltage (95%) and power factor, at all ambient
temperatures under direct solar radiation.
If non-segregated phase bus is used, the requirements shall be identical, except those
specific to that type of bus.
The momentary (peak) current and thermal (3 second) withstand capabilities of the buses
shall exceed the maximum generator contribution during the sub-transient period and
shall also exceed the maximum system contribution limited by the impedance of the
proposed transformer, at the maximum transient voltage of 120% of the rated value. It
shall also have an additional margin to absorb any increase in the system short circuit
level during the life of the plant. The capacities of the taps off the main bus shall exceed
the combined currents from the system and from the generator with the same margins.
The generator circuit breaker, if provided, shall have a capability similar to or higher than
those of the buses. The interrupting capacity shall be similar to the momentary capability
of the buses, at the maximum transient recovery voltage available.
The bus and/or generator breaker shall be provided with current transformers, voltage
transformers, and surge protection devices. Cubicles shall be provided for those devices.
See section on Generator bus for additional details.
7.5.
Plant Electrical Auxiliary Systems
The system shall be designed with the current technical equipment available and
generally accepted good engineering practices. The system shall be resistance grounded.
The facility shall be easily maintained and designed with an emphasis on high
availability, high reliability for continuous operation as a baseload station. The system
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shall be flexible to feed power to various buses within the facility from alternate sources,
as needed, when an equipment problem arises. Built-in redundancies and duplicities in
power feed arrangement within the plant power distribution shall be included by
providing double ended substations, battery back-ups, and uninterruptible power supplies
(UPS).
All transformers shall be selected from standard commercially available kVA/MVA
ratings for their nominal and force-cooled ratings.
The transformers for double-ended substations shall be fan-cooled, identical to each
other, and sized to support the loads as follows:

During normal operation with the full-rated tie-breaker open, both transformers
shall support the individual loads on the respective buses they feed, leaving
capacity margins as specified below for future expansion and operate within the
self-cooled rating.

During one source operation with one main breaker open and the full-rated tiebreaker closed, either transformer shall support the combined loads on both buses
without exceeding its highest fan cooled capacity, with a 10% spare ampacity
margin.
The new facility shall have an individual transformer connected to an individual
generator. The plant auxiliary loads shall be divided in a logical fashion. Any
multiple units (two 100% pumps, fans, battery chargers, etc.) shall be fed power
from two different sources. The cables related to this type of redundancy shall be
routed in two different power and control trays to preclude common mode failures.
The design of the system shall include capacity for future load additions by the Plant.
After the Plant is fully operational, the Plant shall be left with the following spare
capacity minimum.

Power transformers – 10% of highest fan cooled ampacity

MV and LV switchgear bus ampacity – 10%

MV and LV switchgear breakers – two spare cubicles per bus with a minimum of 1
CB of each frame size, per bus

MCC bus – 20% ampacity

MCC units – spare units various ampacity with a minimum of 1 unit of each
size/type, for size 1 and 2 starters and CBs

Lighting transformers – 20% ampacity

Lighting panel bus ampacity – 20% ampacity

Lighting panelboard breakers – 20% spare of various ampacity with a minimum of
1 CB of the highest rating, excluding main CBs

Uninterruptible power supply – 20% ampacity

UPS panel bus – 20% ampacity

UPS breakers – 10% ampacity
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7.6.
Technical Specifications: Appendix N2
Combined Cycle

DC batteries – 1.2 Design Margin

DC panel – 20% ampacity

DC breakers – 20% spare of various rating with a minimum of 1 CB of the highest
rating, excluding the main CB.
Electrical System Design and Equipment Requirements
In general, the electrical systems and equipment described in this section shall, as a
minimum, comply with the applicable requirements of NFPA 70 (National Electric Code)
in areas where applicable, such as office buildings, and ANSI C2 (NESC), as well as the
applicable equipment standards published by ANSI, IEEE, and NEMA. Circuit breakers,
switchgear, and MCCs shall be UL approved.
All Facility electrical equipment, including bus, breakers, transformers, motor control
centers, etc., shall be designed to withstand the maximum available fault current.
The Seller shall perform an EasyPower study on the electrical system and shall provide
the study to the Purchaser. A preliminary study shall be done before any equipment
purchase. A final shall be done when complete data on furnished equipment is available.
During all operating conditions with all electrical power distribution equipment in service
(e.g., no tie breakers closed) other than during the starting of large motors, the voltage at
motor terminals shall be maintained between 90% and 110% of motor rated voltage.
Temporary voltage drops during motor starting shall not extend below 80% of the motor
rated voltage at the terminals of the largest motor on the buses being started, and nonstarting motors on the same bus shall not have a bus voltage of less than 90% of rated
voltage.
All electrical ac auxiliary systems (medium & low voltage) must adequately mitigate arcflash hazards as addressed in NFPA-70E and meet the following minimal requirements:

All breakers, bus, starters, and cables in medium and low voltage switchgear,
MCCs, switchboards, load centers, and panel boards must be able to have
maintenance performed solely in a de-energized state, without unacceptable
impacts to the rest of the plant (i.e. critical equipment must still be able to run)

Systems shall be designed to limit max arc-flash hazard to 25 cals/cm2 @18inches
from live part

Breakers requiring racking, shall have remote racking devices

Other devices/schemes such as maintenance switches and zone protection shall be
explored in addressing these hazards
Arc flash hazard calculations shall be made for all medium and low voltage ac electrical
systems down to the 120v level per PG&E calculation guidelines and labeled per PG&E
labeling standards.
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7.7.
Technical Specifications: Appendix N2
Combined Cycle
Automatic Generation Control Terminal
Breakers and MCCs shall be UL approved.
The DCS shall include an automatic generation control terminal (AGCT) or Remote
Intelligent Gateway (“RIG” as defined by the California ISO), which will support remote
dispatching of the Facility by the California ISO. Redundant MODBUS data-links
between the AGCT and plant DCS, and between the AGCT and the SCADA/EMS RTU
shall be provided. The AGCT must comply with the California ISO’s “Generation
Monitoring and Control Requirements for AGC/Regulation Units”, as found on their web
page at http://www.caiso.com/thegrid/operations/gcp/requirements.html. Additional
capabilities may be allowed, as approved by the California ISO.
Following is an example of an AGCT system description. The Facility shall include a
system that shall contain similar features. The Automatic Generation Control Terminal
(AGCT) shall be equipped as follows:

One communications port – DNP 3.0 protocol

One configuration and maintenance terminal

One V.32, 9600 baud (DNP 3.0 port)

One remote programming port with the fastest available dial up modem
(supervised by SCADA signal to enable remote access capability)

Analog input points, solid-state multiplexors, and precision scaling resistors (as
required)

Analog reference power supply (as required)

Contact input points, MCD status (as required)

Analog output points, ±1 mA or 4-20 mA (as required)

8-position sliding link terminal blocks (as required)

Service and maintenance manuals (for Purchaser’s use)

Power input 120VAC

NEMA 1 Enclosure with full height doors front and rear
The AGCT also has the following additional requirements:

Additional communications ports shall be provided to directly input watt/VAr hour
and watt/VAr instantaneous input information from all meters. This information
shall be relayed via modbus port to Plant control system.

Two communication ports, one master and one slave, shall be provided for
communications with the Local Utility RTU.

Two communication ports, one master and one slave, shall be provided for
communications with the Plant control system.

Additional communications ports with modems as necessary for Utility or
California ISO requirements.
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Combined Cycle
In general, the following signals shall be provided:

MW, MVAR, MWh, MVARh, for each generator and for auxiliary power used.

Substation frequency and voltage

NOx emissions from each source

Breaker status for each generator breaker

Breaker status and alarms for all switchyard breakers

MW , MVAR, and line voltage for each transmission line

Total fuel flow, high side fuel pressure, fuel Btu content, and fuel specific gravity

Voltage regulator status (automatic/manual) for each generator

AGC high limit, AGC low limit, AGC plant load (total all generators), AGC in
remote

AGC remote demand

Remote programming enabled

Other analog and digital inputs and outputs may be required by the California ISO
to meet current standards.

Dedicated telecommunications circuits meeting the requirements of the California
ISO shall be installed to allow control and monitoring via the AGCT or RIG.
The Seller shall consult with Purchaser to assure the compatibility of the new AGCT
system with the requirements of the Dispatcher and/or SCADA/EMS.
Seller shall provide a California ISO certified Data Point Gateway (DPG) in accordance
with the requirements of Technical Standard “Monitoring and Communications
Requirements For Units Providing Only Energy and Supplemental Energy.”
Seller shall provide a CAISO certified revenue metering system. In accordance with the
requirements of Technical Standard
7.8.
Generator Bus
Each generator shall be connected by a pre-installation-tested copper (or tinned copper)
low-flux design isophase bus or segregated phase bus for generators less than 70 MVA,
as described below.
Generator bus shall be provided between the generator and generator breaker, and the
generator and GSU for each turbine. A section of tap bus with removable link shall be
provided to connect each unit auxiliary transformer (UAT). The removable link shall
allow a UAT to be removed from service without permanently losing the CTG. A section
of the tap bus shall also be provided, as required, for the generator excitation system.
Generator bus connections shall be arranged such that bends in the generator buses shall
be minimized, and overall bus lengths shall be as short as practicable.
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Each section of generator bus shall be of self-cooled bus construction.
Bus space heaters shall be supplied on bus sections for condensation control. Expansion
joints shall be provided as required to accommodate thermal expansion of the bus.
7.9.
Neutral Grounding Equipment
Generator neutral grounding equipment shall be furnished with each generator bus.
7.10.
GSU Transformer Bank
The generator shall be connected to an individual GSU transformer to increase the
voltage of the generated power and energy from the generator terminal voltage to the
power system transmission voltage. The transformer shall be designed to IEEE and ANSI
Standards and shall be rated with a capacity that allows full output of the total of the
individual units through the operating range of power factors and voltages at all ambient
temperatures at the facility site, but in no case at a power factor less than 0.9. The rated
capacity of the transformer shall be stated for a 65C average winding temperature rise
over 40C ambient. If the supply scheme for the plant auxiliary load is such that there is a
possibility that auxiliary power is not taken from the generator bus of a unit at any given
time, the capacity of the corresponding main step up transformer shall be selected to
allow delivery of the gross output of the unit to the power system under the conditions
specified above.
The GSU transformer bank shall be oil-filled and forced-air cooled designed for
generator step-up voltage operation according to the ANSI Standards C57.12.00. The
windings shall be made of electrolytic copper, and the core shall be made with grainoriented high-permeability low-loss magnetic steel.
Online condition monitoring system (oil and gas analyzer) shall be supplied for each
main bank.
The rated voltage of the transformer bank shall be based on the generator voltage and the
transmission system voltage. The impedance of the transformer shall be the standard low
impedance design selected by the manufacturer but shall not impose a significant
restriction in the transfer of real or reactive power to the grid. The impulse test level and
power frequency withstand voltages shall be in accordance with ANSI Std. C57.12.00 for
the range of operating voltages.
Each transformer shall be mineral-oil-filled, conservator type, with a no-load tap changer
capable of operation from ground level, with visible indication of tap position, capable of
padlocking. Manual tap changers shall be provided with two 2.5% taps above and two
2.5% below rated voltage. All tap positions shall be fully rated for the highest transformer
MVA rating.
Transformers shall have standard accessories including but not limited to fault pressure
relays, mechanical pressure relief devices, magnetic liquid level gauge with alarm
contacts, top oil temperature indicator with alarm contacts, winding temperature indicator
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with alarm contacts and a combustible gas device. An on-line condition monitoring
system shall be provided for the gas analyzer and top oil temperature devices. The
transformers shall be designed, manufactured and tested in accordance with ANSI, IEEE,
and NEMA standards.
Each transformer bank shall connect its generator to a switchyard bay. For all
transformers, losses should be minimized at full-load operation. The oil inside the
transformer shall be isolated from the atmosphere by means of an elevated expansion
tank with an enclosed air cell. Transformer Basic Impulse Levels (BIL) shall be based on
column 1, Table 4 of IEEE Standard C57.12.00-2000 for Power Transformers.
The CTG main power transformer’s nameplate rating shall be 10% greater than the
maximum combustion turbine generator rating at the fan rating to allow for potential
upgrading of the CTG systems. The STG main power transformer nameplate rating shall
be 10% greater than the maximum steam turbine output at worst case condition.
The oil-filled transformers shall be installed such that they will not present a hazard to
any surrounding equipment in case of a fire, through the use of physical separation or
firewalls. If firewalls are required, adequate space to allow sufficient airflow for proper
transformer cooling shall be provided, and NFPA 850 shall be adhered to.
Surge arresters shall be supplied for each high-side bushing. Those arresters shall have
ground conductor brought to grade on insulators to facilitate monitoring of leakage
current. Surge arresters for main power transformers shall be station class rated and shall
coordinate with the BIL of the transformers.
7.10.1.
GSU Cooling System
Cooling equipment controls shall be arranged so that no single fault in the control
circuitry can cause a loss of more than one half of the cooling system capability. The
transformer cooling equipment controls shall be arranged so that a single remote contact
can shut down fans, regardless of the mode of operation selected. Manual control
switches shall be provided in the control cabinet to allow testing and maintenance of the
cooling fans. Controls shall provide for changing the sequence of cooler groups.
7.10.2.
Generator Breakers
The generator circuit breakers, if provided, shall be SF6 breakers and designed,
manufactured, and tested in accordance with the latest standards of ANSI, particularly
ANSI C37.013, and NEMA.
7.11.
Unit Auxiliary Transformer
The Facility shall include two factory tested unit auxiliary transformers as described
below.
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The two individual unit auxiliary transformers shall supply power to station auxiliary
loads and both shall be directly connected to the generator bus. Each transformer shall
have a medium-voltage secondary. The transformer high-voltage windings shall be
connected between the main transformer and the generator breaker through a tap in the
generator bus, while the secondary windings shall be connected to the medium-voltage
switchgear through either non-segregated phase bus (NSPB) or cable bus and a main
breaker in the switchgear.
Each transformer shall be mineral-oil-filled, outdoor type, with a no-load tap changer
capable of operation from ground level, with visible indication of tap position, capable of
padlocking. Tap changers shall be provided with two 2.5% taps above and below rated
voltage. Transformers shall have standard accessories including but not limited to fault
pressure relays, mechanical pressure relief devices, magnetic liquid level gauge with
alarm contacts, top oil temperature indicator with alarm contacts, and winding
temperature indicator with alarm contacts, and combustible gas device. Transformers
shall be ONAN/ONAF/OFAF with the second stage of forced cooling to be for future
load capability. The average winding temperature rise at full load capability of each stage
shall be 65C over 40C ambient.
The design shall provide two transformers so that the failure of one transformer will not
shut down or limit the output of the station. Each transformer’s output will feed one bus
so if a unit auxiliary transformer fails, its bus will be automatically picked up by the
circuit breaker that connects the two busses. The unit auxiliary transformers shall be
accordingly sized. Unit auxiliary transformer losses shall be minimized at full load
operation. The oil inside the transformer tank shall be isolated from the atmosphere by
means of an elevated expansion tank with an enclosed air cell.
7.12.
System Protection
The Facility shall incorporate the values required based on the Insulation Coordination
Study and the equipment supplier recommendations, and the final design shall provide an
adequately protected safe and reliable system.
The protection design of the combustion turbine and stream turbine generators shall
include, but not be restricted to, the following:

1 - Beckwith M-3420 Generator Protection System:
—
1 - Volts/Hertz, 24
—
1 - Undervoltage, 27
—
1 - Reverse Power, 32
—
1 - Loss of Field, 40
—
1 - Negative Sequence, 46
—
1 - Breaker Failure, 50BF (low-side generator breaker application)
—
1 - Inadvertent Energization, 50/27
—
1 - Voltage Controlled Overcurrent, 51V
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—
1 - Overvoltage, 59
—
1 - Voltage Transformer Fuse Loss, 60FL
—
1 - Generator Ground (95%), 59GN
—
1 - Under/Overfrequency, 81
—
1 - Generator Differential, 87G
1 - Beckwith M-3430 Generator Protection System:
—
1 - Backup Distance, 21
—
1 - Volts/Hertz, 24
—
1 - Undervoltage, 27
—
1 - Reverse Power, 32
—
1 - Loss of Field, 40
—
1 - Negative Sequence, 46
—
1 - Breaker Failure, 50BF (low-side generator breaker)
—
1 - Inadvertent Energization, 50/27
—
1 - Overvoltage, 59
—
1 - Voltage Transformer Fuse Loss, 60FL
—
1 - Generator Ground (100%), 59GN/27TN
—
1 - Under/Overfrequency, 81
—
1 - Generator Differential, 87G
In addition, the protection design shall include, but not be restricted to, the following:

Three Lockout Relays, 86

Power transformers (main step-up and Unit service)

—
Auxiliary transformer (isolated phase bus) ground detection
—
Transformer differential relay (87T)
—
Transformer neutral overcurrent relay (51TN)
—
Transformer phase overcurrent relays (51/50), other than main step-up
transformers
—
Transformer fault pressure relay (63)
—
Oil level switch (71Q)
—
Oil temperature (26Q)
—
Winding temperature (49)
—
3 Lockout relays (86)
Medium and LV (load center) buses
—
Bus undervoltage relaying for alarm (4.16 kV bus only)
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


7.12.1.
Technical Specifications: Appendix N2
Combined Cycle
—
Incoming phase and ground time overcurrent (4.16 kV bus only)
—
Feeder phase timed and instantaneous overcurrent and ground overcurrent
—
Transformer neutral overcurrent
4 kV motors and 6.6 kV starting motor
—
Phase overcurrent (instantaneous and timed)
—
Ground timed overcurrent
—
Undervoltage and loss of voltage (motor protector)
—
Stator overtemperature
—
Self-balancing primary differential overcurrent (induction motors greater
than 1,500 hp)
—
Phase current unbalance (induction motors greater than 1,500 hp)
460 V motors fed from MCCs
—
Phase overcurrent (instantaneous and timed)
—
Ground timed overcurrent (motors 20 hp and above)
Panels, transformers, heaters, and miscellaneous loads fed from MCCs
—
Phase overcurrent protection
—
Ground-timed overcurrent (feeders 100 A and larger)
Generator Protective Relaying
The following generator protective relays and protection schemes shall be provided:

Phase fault protection, generator differential

Ground fault protection during normal operation and for ground faults close to the
neutral

Short reach loss of field with time delay and long reach loss of field

Negative sequence

Dual volts per hertz with stepped activation

Voltage balance

Generator motoring protection

Synchronism check

Exciter and generator field ground fault protection

Over excitation protection

Transfer trip from switchyard or substation

Stator over temperature protection
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
Undervoltage protection

Generator breaker failure protection

Lockout relay for generator breaker trip

Start-up over current relay
7.12.2.
Technical Specifications: Appendix N2
Combined Cycle
Generator Bus and Transformer Protective Relaying
Protection for the generator bus and main power transformers shall be provided by the
same relaying systems used to protect the generator against phase faults and ground
faults, and will include the following:

Differential (87B)

Neutral overvoltage (59N)
7.12.3.
Main Power Transformer Protective Relaying
At a minimum, the following main power transformer relays and protection schemes
shall be provided:

Main power transformer, generator breaker, and generator bus zone differential
relaying

Fault pressure relaying

Mechanical fault pressure relief device

Transformer differential relays, primary
7.12.4.
Auxiliary System Relaying
The auxiliary system shall be protected, including relay protection, as listed below:

Unit auxiliary transformer shall be protected by a single 3-phase differential relay

Unit auxiliary transformer shall be high-resistance grounded with ground
indication

Unit auxiliary transformer shall have instantaneous and overcurrent protection, as
well as differential protection.

Medium-voltage bus supply and tie breakers shall have overcurrent relays, one per
phase

Medium-voltage loads shall have zero sequence ground detection

Medium-voltage loads shall have instantaneous and overcurrent protection, one per
phase

Manual bus transfer synch-check relaying.
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7.12.5.
Technical Specifications: Appendix N2
Combined Cycle
Major Interlocks
The major generator and transformer electrical equipment interlocks include the
following:

The generator breaker cannot be closed unless the excitation system breaker is
closed.

The excitation system breaker cannot be tripped by control switch unless the
generator breaker is open.

When both main power transformer high side breakers are open, neither can be
closed unless its respective generator breaker is open.

When only one main power transformer breaker is closed it cannot be opened until
its respective generator breaker is opened.
7.12.6.
Lockout Relay Actions
One lockout relay shall be associated with generator protection only, and all trips
requiring the opening of the generator breaker and removing excitation shall operate this
lockout relay. The operation of this relay will not cause the trip of the combustion
turbine, which will continue to fire to provide heat and airflow for the HRSG.
A second lockout relay shall be provided for the generator to clear the associated
substation breakers and shall transfer trip the generator protection lockout relay.
7.12.7.
Protective Relays
All protective relays shall be digital-type with industry standard communications port
provided with external targets to show relay operation to assist operator in determining
which relays have operated.
7.13.
Medium-Voltage Bus Duct
7.13.1.
Non-Segregated Phase Bus Duct/Cable Bus (as required)
Non-segregated phase bus shall be copper bus insulated with a thermosetting insulation.
The non-segregated phase bus duct shall be a self-cooled design. The bus shall be rated to
carry the maximum nameplate output of the equipment it serves +10% continuously
under the maximum temperature rises specified by ANSI C37.20.
Vapor barriers or fire stops must be supplied at all building wall/floor entrances to
prevent the transfer of indoor and outdoor air as well as maintain the fire rating of any
penetrated walls or floor.
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7.13.2.
Technical Specifications: Appendix N2
Combined Cycle
Bus Ratings
Ampacity of buses shall be rated for the maximum operating conditions with an
additional ampacity margin of +10%.
7.13.3.
Cable Bus Duct
Cable bus used in the between each unit auxiliary transformer and the medium-voltage
switchgear buses must be factory tested. All cable bus shall be preassembled at the
factory before shipment to ensure fit-up dimensions and shall come assembled (if
possible).
7.13.4.
Bus Ratings
Cable bus shall be sized for the maximum operating conditions with a margin of +10%.
7.13.5.
Conductors
Conductors for the cable bus shall be copper and shall conform to the specifications for
medium voltage cable as indicated in this specification. They shall be arranged and
transposed periodically such that there is an equal sharing of current between the
conductors (and optimized for load balance).
Cable bus shall be a continuous run with no cable splices.
7.13.6.
Medium-Voltage System
A medium-voltage auxiliary system shall be provided to feed motors and other
medium-voltage loads. This medium-voltage system shall distribute power to HRSG,
STG, and CTG electrical auxiliaries (including the CT starting motors) during normal
operation, startup, and shutdown. The system shall consist of at least two auxiliary
transformers and two switchgear lineups. The switchgear shall be located indoors or in
pre-fabricated electrical equipment enclosures complete with lighting, cooling, and
heating.
7.13.6.1
System Configuration
The medium-voltage system shall consist of a medium-resistance grounded system
powered through a delta-wye auxiliary transformer. The medium-resistance grounded
system shall limit ground fault current to 400A.
The medium-voltage system provides power to motors and power center transformers.
Motor feeders shall utilize breakers or starters while transformer feeders shall utilize
breakers. Relay protection shall be as specified in Section 7.12.4 of this document. In
addition, any motor loads shall input B phase current into the distributed control system
to monitor potential overload conditions and to alarm before the trip of the motor. All
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medium-voltage relaying shall be multi-function. The devices shall be connected via
modbus to the plant DCS system for monitoring. All medium-voltage breakers and
starters shall utilize 125-Vdc control power and shall be designed to eliminate arc
flashing and personnel hazards in accordance with NFPA standards, and shall be
designed and located for safe operation, with proper identification, indicating lamps,
mechanical racking devices, etc. Lamps indicating breaker status shall also be located
next to the associated breaker control switch in the control room.
The design shall minimize the danger of arc flash and the requirement to use full body
PPE. An overall study of arc flash potential shall be delivered to the Purchaser and each
breaker shall be labeled with the arc flash rating and PPE supplied located in the vicinity
of the breaker.
Metering quality CTs and VTs shall be provided on the low side of the unit auxiliary
transformers connected to revenue quality four quadrant meters located in the protective
relay panel for eventual transmission of data to the California ISO via the AGCT or RIG.
Instrument transformers shall have an accuracy of 0.3% or better. Revenue meters shall
be ANSI C12.1 metering accuracy and shall be located so as to allow collection of data as
required by the California ISO.
7.13.6.2
Operational Requirements
The medium-voltage switchgear breakers and starters shall be metal-clad, draw out,
vacuum type, with a copper bus. Two-high switchgear is acceptable.
All medium-voltage switchgear breakers and starters shall be electrically operated
vacuum devices. Control of incoming medium-voltage switchgear breakers, main and
reserve, shall be provided at the switchgear. Synchronizing requirements for the
incoming main and reserve breakers shall include a synchrocheck relay with dead bus
sensing capability. All breakers and starters shall typically be operated by remote control
from the DCS CRT console. The equipment shall be rated 5000 volts, 3-phase, 60-hertz,
and operate at 4160 volts, nominal.
Ring-type current instrument transformers shall be furnished. The thermal and
mechanical ratings of the current transformers shall be coordinated with the circuit
breakers. Their accuracy rating shall be equal to or higher than ANSI standard
requirements. The standard location for the current transformers on the bus side and line
side of the breaker units shall be front accessible to permit adding or changing current
transformers without removing high-voltage insulation connections.
Voltage transformers and/or control power transformers up to 15-kVA, single-phase shall
be mounted in draw-out drawers contained in an enclosed auxiliary compartment. Selfcontained extendible rails shall be provided for each drawer to permit easy inspection,
testing, and fuse replacement. A mechanical interlock shall be provided for control power
transformers to require the secondary breaker to open before the drawer can be
withdrawn.
The Seller shall furnish one set of switchgear manufacturer accessories for test,
inspections, maintenance, and operation.
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Each unit of the switchgear shall be furnished with space heaters for humidity control to
prevent condensation of moisture within the switchgear.
7.14.
Low-Voltage System
The low-voltage auxiliary system shall distribute power to heat recovery steam generator,
and combustion turbine generator low-voltage Facility electrical auxiliaries during
normal operation, startup, and shutdown. The main components are the power center
transformers, 480V switchgear, and MCCs.
The ratings required shall be based on the Seller’s Insulation Coordination Study.
7.14.1.
System Configuration
The low-voltage system consists of a 480V system powered from power center
transformers. Each power center transformer is fed from the medium-voltage switchgear.
7.14.2.
Transformers
Transformers shall be 480 volts. The transformers shall be dry type, with fan cooling.
The impedance of the transformers shall be a standard value and shall be selected to
allow the use of commercially available power center breakers, molded case breakers,
and combination starters while limiting voltage drop on the bus during the starting of the
largest motor to 80% of the nominal bus voltage. The low-voltage system shall be
designed to avoid the need for current limiting reactors. The transformer shall have
standard two 2.5% above and below rated primary voltage taps.
7.15.
Switchgear
The switchgear buses shall be connected in a double-ended arrangement with a normally
open tie breaker.
Low-voltage switchgear shall have a copper bus. The low-voltage switchgear breakers
shall be electrically operated, draw out type. The switchgear will be located indoors or in
prefabricated electrical equipment enclosures. Control of incoming low-voltage
switchgear breakers and the bus tie breaker shall be provided at the switchgear. All
480-V main and tie breakers shall typically be operated by remote control from the DCS
CRT console. All feeder breakers to MCCs and distribution panels shall also be
electrically operated. The protective system shall include a communication interface to
the plant DCS for system monitoring.
Ring-type current transformers shall be furnished for instrument transformers. The
thermal and mechanical ratings of the current transformers shall be coordinated with the
circuit breakers. Their accuracy rating shall be equal or higher than ANSI standard
requirements. The standard location for the current transformers on the bus side and line
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side of the breaker units shall be front accessible to permit adding or changing
transformers without removing high-voltage insulation connections.
The use of “Smart Switchgear” (Switchgear with integral remote logic) is acceptable,
providing the switchgear supplier has demonstrated a proven system suitable for
interconnection with the plant DCS system. If used for control and serial linked between
MCCs and plant DCS, this system requires redundant fiber optic data paths routed
through independent raceway minimizing single failure probability.
When power is required to two or more identical major equipment items on each
generating unit, the power to one of these items shall be supplied from the other bus.
Auxiliary equipment shall be fed from the same bus as its associated major equipment.
Cables to redundant services must be routed in separate raceways.
Each vertical section shall be furnished with space heaters to prevent condensation of
moisture within the switchgear.
7.16.
Motor Control Centers
Motor control centers (MCCs) shall be indoor, enclosed, dead-front, freestanding units.
All phase buses shall be insulated or isolated copper and shall be plated at all connection
points or joints. A silver- or tin-plated copper ground bus shall be provided and shall
extend the full length of the MCC. MCC load feeders consist of a circuit breaker or the
combination of a circuit breaker, control power transformer, and magnetic contactor.
Minimum starter size is Size 1. Circuit breakers shall be the molded case type. In
addition, each 480V combination starter shall be provided with a three-phase thermal bimetal overload relay. MCCs shall have a minimum short-circuit rating of 42,000 amps
symmetrical, and the short circuit value of the system shall be confirmed by calculation
in E-tap. Motor control center wiring shall be Class I, Type B, per NEMA ICS 2. For
each starter size used, 5% spares shall be provided, with a minimum of one spare of each
size used per unit. A minimum of 20% spare terminal points shall be provided in each
starter. If smart MCCs are used, Class II Type C wiring shall be provided.
Motors connected to 480V power centers and MCCs shall be rated 460V. Motor-operated
valves shall be fed from MCC starters if the FVR starters are not furnished with the
MOVs.
Any remote MCCs shall have NEMA 3R walk-in enclosures supplied with space heaters
and filtered ventilation openings with fans.
Combination starters shall consist of magnetic-only circuit breakers and starters. Each
starter shall be furnished with individual fused and grounded control power transformer,
2NO and 2NC, plus seal-in auxiliary interlocks.
The use of “Smart MCCs” (MCCs with integral remote logic) is acceptable, providing the
switchgear supplier has demonstrated a proven system suitable for interconnection with
the plant DCS system. If used for control and serial linked between the MCC and the
Plant DCS, this system requires redundant fiber optic data paths routed through
independent raceway to minimize single failure probability.
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Space heaters shall be furnished at the bottom of each vertical section of all outdoor
motor control centers to prevent condensation of moisture within the enclosures.
7.16.1.
Operational Requirements
All 480V power center main or tie breakers shall be electrically operated air circuit
breakers. Manual control of incoming 480V switchgear breakers and the bus tie breaker
shall be provided locally. Low-voltage electrically operated breakers shall typically be
operated by remote control from the DCS CRT console.
Typically, when an MCC load is a component of a system, remote automatic control is
provided or control is available on a local control panel for that system. Local control
stations are provided at motors that are not controlled from the DCS; e.g., sump pumps.
7.16.2.
Protection
Overcurrent protection for power center breakers shall be provided by direct-acting solidstate trip relays. At the MCC level, motor circuit protectors shall be used for motor
circuits, and non-motor feeder breakers shall be protected by thermal magnetic circuit
breakers. The thermal overload relays provided with MCC combination starters shall be
wired to trip.
7.17.
Alternate Power Source
An alternate power source external to the Facility and sourced from the local substantial
power source shall be provided for the essential service AC and DC systems. A meter
shall be provided to measure power usage. The alternate source shall be selected by the
operator if the standby generator does not start.
7.18.
Essential Service AC System
The essential-service AC system provides clean, 120V AC, single-phase, 60-hertz power
to essential control, instrumentation, and equipment loads that require uninterruptible AC
power.
The following items discussed below shall be included in the essential service system.
7.18.1.
Uninterruptible Power Supply
The Facility shall include one primary UPS system for the major plant control system.
The UPS system shall be supplied with 30% spare capacity above calculated
requirements. The output rating of the UPS system(s) shall be 120 V, single-phase, 0.8
lagging PF to 1.0 PF, at 40°C ambient. UPS will be a true AC-DC-AC conversion type
consisting of an inverter, with an alternate DC source supplied from the station service
batteries, a rectifier and a static transfer switch. The static transfer switch will be
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connected to a second inverter as the alternate supply. Output of the UPS and the second
inverter will connect to a manual maintenance bypass switch to the instrument AC
panelboard.
7.18.2.
Rectifier
The rectifier shall be used to supply power to the static inverter. The voltage regulation
shall be less the ±1% from no load to full load with a ±10% variation in supply voltage.
The rectifier shall function as specified with a ±3% variation in supply voltage frequency.
In the event of rectifier failure, the first alternate transfer will be to the station battery
supply.
7.18.3.
Inverter
The inverter shall be of the ferro-resonant design.
The inverter voltage regulation (transient response) shall not exceed the following limits
under the range of conditions specified with loads of 0.8 lagging to 1.0 PF.

For steady-state loads, ±2.0% from 0 to 100% full-rated load, 15 to 40°C ambient,
and 105 to 140V DC input.
For sudden application or removal of 100% of full-rated load, the change in inverter
output voltage shall not exceed ±10% after 0.5 cycle and ±2.5% after 1 cycle
7.18.4.
Static Transfer Switch
The static switch shall be single-pole and double-throw. The switch shall be capable of
carrying the continuous, short time (overload) and short circuit specified for the UPS
system.
The switch shall be used for automatic transfer between the synchronized static inverter
and the alternate AC supply. When the normal power supply is lost, the static switch shall
transfer to the filtered, regulated, alternate supply within 0.25 cycle. The alternate supply
will directly feed redundant DCS power supplies.
A static switch continuity monitor and latch circuit to prevent the static switch from
returning to the inverter supply after an internal fault had developed shall be included.
7.18.5.
Essential Service 120V AC Distribution Panelboard
One panelboard, 120V single-phase, two-wire, shall be furnished. Fast-acting circuit
breakers shall provide overcurrent protection without necessitating operation of the UPS
static transfer switch.
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7.19.
Technical Specifications: Appendix N2
Combined Cycle
Essential Service DC System
The essential-service DC system provides a reliable source of power for the essentialservice AC system and critical control and power functions during normal and emergency
Facility operating conditions. The DC systems shall be operated ungrounded except
through high resistance ground detectors and instruments.
A DC system shall be supplied for the switchyard independent of the station DC.
The station battery room shall be located indoors in a climate-controlled area to ensure
maximum battery life. Battery room floor shall be treated with an acid-resistant floor
sealant. Batteries shall be rated by industry standards on the basis of a nominal 24-hour
average temperature of 77°F. Class I, Division 1 vent fans exhausting outdoors shall be
provided to avoid a buildup of hydrogen and a Class I, Division 1 unit heater shall also be
provided. Curbed areas without drains shall be provided surrounding the battery cells for
the containment of acid spills in the event of a cell crack or rupture. An eye wash and
shower facility shall be provided for rinsing eyes and skin in the event of acid contact. A
monorail or other means shall be included in the design of the battery rooms to assist in
removing or replacing cells.
The following items discussed below shall be included in the essential service system.
7.19.1.
Batteries
The Facility shall include a minimum of two (2) 125-Vdc battery systems. One battery
shall supply the emergency oil pumps, station switchgears, station emergency lighting,
and all other dc requirements. The second battery shall support the uninterruptible power
supply (UPS) loads. The storage battery shall be provided with a heavy duty type battery
rack. The rack shall be arranged in steps so that none of the cells are directly above the
others. Battery racks shall have the appropriate UBC seismic rating.
Battery cells shall be the lead-acid type with pasted plate grids of lead-calcium alloy
contained in transparent plastic jars. The number of cells shall be 60 for 130V systems.
The minimum cell voltage at the end of the duty cycle shall not drop below 1.751
volts/cell so that the minimum battery terminal voltage does not drop below 105V.
Sealed, valve regulated batteries shall not be provided.
The duty cycle shall include a minimum of 60 minutes of power for the UPS system at
the inverter rating, the CT & ST manufacturer’s recommended time for DC motor loads,
4 hours of emergency lighting, and breaker operating power at the end of the 4-hour duty
cycle. In addition to the required duty cycle, batteries shall be sized to include a 25%
aging factor, a 20% design margin, and temperature correction factor based on expected
battery room temperature limits. Battery bank and charge system designed to support two
full load trips within a 3-hour duration. Batteries shall have a 20-year life.
7.19.2.
Battery Accessories
Two sets of the standard battery accessories shall be provided:
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7.19.3.
Technical Specifications: Appendix N2
Combined Cycle
Battery Chargers
The Facility shall include two 125-Vdc battery chargers for each battery system. These
two chargers feeding a battery system shall be powered from two separate sources of AC
power.
Each battery charger shall be sized to furnish 100% of the current required to recharge
the battery from discharge condition to the fully charged condition in 24 hours while
maintaining the continuous normal steady-state loads. The chargers shall be capable of
regulated and filtered voltage operation with the battery disconnected (battery eliminator
type), with a maximum ripple of 100 mV rms under these conditions. Battery chargers
shall have load sharing features and temperature compensation feature
The battery charger shall have a voltage regulation of ±0.5% from no load to full load
with a ±10% supply voltage variation. It shall operate properly over ±5% supply voltage
frequency variation. It shall be provided with an automatic load limiting feature that shall
limit the output current to 110% of its rated load without tripping the AC or DC breaker
or blowing fuses. It shall also be capable of picking up a discharged battery without
tripping.
The power supply for each charger shall be 480V, 60 Hz, three-phase.
The battery charger shall be designed to prevent the battery from discharging back into
the charger in case of AC power failure or other charger malfunction.
The battery charger shall be equipped with standard generating station accessories,
including undervoltage relays, ground detectors, overload protection, adjustable float and
equalize charger settings and timers.
Thermal magnetic circuit breakers of suitable current carrying and interrupting capacity
shall be used.
7.20.
Motors
All motors shall be designed for direct across the line starting and shall not exceed a class
B insulation system temperature rise as defined by ANSI C50.41. All motors 10 hp and
above shall be provided with motor spaceheaters. Motors shall be of the highest
efficiency available for the specified application. Motors shall be ANSI C50.41
compliant. All stator windings shall be copper.
7.20.1.
4,000-Volt Motors
All motors 250-hp and larger shall have the following characteristics:
Type
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Horizontal or vertical, single-speed, squirrel-cage,
induction.
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Voltage rating, phase, frequency
4,000 volt, three phase, 60 Hz.
Horsepower rating
1.15 Service factor motors, not less than 115% of the
brake horsepower required by the driven equipment
when operating at design conditions, and not less
than 100% of the brake horsepower required to
operate the driven equipment at its maximum
requirements.
Nameplate
Shall state the service factor and comply with ANSI
C50.41.
Enclosure
WPII for outdoor applications and ODP for indoor.
Class of insulation
Class ”F” vacuum pressure impregnated. Insulation
system shall be sealed in accordance with ANSI
C50.41.
Temperature rise of windings (maximum by
resistance)
In conformance with ANSI C50.41 standards for
Class B insulation with 1.15 service factors.
Bearings
Horizontal motors – split sleeve bearings of the oil
ring type. A sample drain line shall be provided for
obtaining bearing oil samples.
Vertical motors – Kingsbury thrust and ball guide.
Ambient temperature range
See this specification and utilize site specific
conditions.
Limitations on starts
In accordance with ANSI C50.41, a nameplate shall
designate the maximum permissible number of starts
and the required cooling period when motor is started
under conditions of (a) cold rotor and (b) warm rotor
(after running continuously at full load for a period of
one hour).
Locked rotor (starting) torque at rated
voltage and frequency
Not less than 80% of full-load torque.
Pullup and breakdown torques
The torque of the motor shall be 15% above the load
torque requirement throughout the entire speed
range at 85% of motor-rated voltage with 80% pullup
torque as a minimum.
Locked rotor current
Not to exceed 650% of full load.
Base
Soleplates are required.
Sight glasses
Sight glasses shall be furnished in place of oil cups
on all oil-filled bearings.
Preparation of storage
Motors shall be prepared for extended outdoor
storage by protecting the motor bearings with either a
protective grease covering or liquid preservative. The
motors shall be tagged to show that a preservative
has been used. The procedure to be followed before
motors are placed in operation shall also be indicated
on that tag.
Heaters
Heaters which total more than 1200 watts in capacity
shall be rated for 480 volt AC three-phase and
heaters totaling less than 1200 watts in capacity shall
be rated for 120 volt ac, single phase. They shall be
derated for extended life and shall be sized to
prevent condensation at the ambient conditions at
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Technical Specifications: Appendix N2
Combined Cycle
specific site.
Grounding
Two copper ground pads, diagonally opposite side of
the motor with drilled and tapped holes suitable for
attaching two-hole NEMA grounding lugs shall be
included.
Direction of rotation
Motors shall have the direction of rotation marked on
a nameplate for the supply voltage sequence of T1 T2 - T3.
Magnetic center
The magnetic center at rated load shall be marked
on all motors.
Motor test
Motor test shall be performed with motor terminal
housing installed on motor.
Air filters
Removable dry type complete with stainless steel
filter screens.
Lifting lugs
Suitable lifting lugs shall be provided for hoisting
motors during installation and for maintenance
purposes.
Sound levels
Per ANSI C50.41.
Instrumentation
Motor winding temperature(s) shall be provided using
a minimum of two (2) per phase, 100-OHM platinum
RTD(S). External junction box shall be provided for
easy termination of these motor winding
temperature(s) which shall be connected to the
Facility control system for monitoring.
Thermocouples
Motors with sleeve and plate type thrust bearings
shall have Type K bearing thermocouple. External
junction box shall be provided as per above
7.20.2.
Low-Voltage Motors
All motors 200-hp and smaller shall have the following characteristics:
Type
Horizontal or vertical as required, single-speed,
squirrel-cage induction, energy efficient, mill and
chemical duty type. Cast iron frames and copper
windings only.
Voltage rating, phase, frequency
460 volts, three-phase, 60 Hz, for all motors rated at
½ hp through 200 hp, 115 volts, single-phase, 60 Hz,
for all motor ½ hp and smaller.
Horsepower rating
The nameplate horsepower rating shall be equal to,
or greater than, the requirements of the driven
equipment when operating at design conditions and
motor shall be able to handle the maximum capability
of the driven equipment within their service factor
rating. This relation shall be provided for all operating
speeds and conditions.
Service factor
1.15
Ambient temperature range
Site specific ODP indoors.
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Combined Cycle
Nameplate
Shall state the service factor and comply with NEMA
MG-1.
Enclosure
TEFC totally-enclosed, ventilation, and cooling as
applicable to the environment. Explosion-proof
motors shall be provided only where necessary to
meeting the hazardous location requirements.
Class of Insulation
Class F
Temperature rise of windings
(maximum by resistance)
In conformance with NEMA MG-1 standards for
Class B insulation.
7.20.3.
Standby Power Generator
The facility shall include one standby emergency power generator (fuel oil or natural gas)
with all necessary accessories and auxiliary equipment.
The standby generator shall consist of the following:

One multicylinder, in-line or vee, stationary type liquid-cooled, diesel, engine
driver with a standby rating capable of powering loads required for the safe
shutdown of the unit in the event of loss of offsite power supply.

The starting system, consisting of heavy-duty electric driven cranking mechanism,
over-cranking protection, starting battery, engine-mounted generator for battery
charging, complete with voltage regulator, and starting battery trickle charger

One generator output shall have a circuit breaker and electrical protective devices

One automatic transfer switch with control and sensing devices

The standby generator will be indoors or have a weather enclosure to protect the
equipment from the elements
The unit shall be capable of starting either manually or automatically either locally or
from the control room and, in either case, closing to a dead bus.
Upon receiving a start signal, the unit shall be capable of starting automatically without
local attendance, reaching synchronous speed and rated voltage and frequency within 30
sec and be ready to accept load to its rated capacity.
During periodic tests, the unit shall be capable of starting on manual signal, accelerating
to synchronous speed and rated voltage within 30 sec, and then accepting loading using a
resistor load bank equivalent to approximately 100% of the unit kW rating.
During all loading conditions, the transient voltage drop at any sequence step shall be
limited such that the generator voltage is not less than 80% of nominal voltage, and
frequency is not less than 95% of nominal. In addition, the voltage at the generator shall
recover to within 90% of nominal voltage and the frequency to within 98% of nominal
within 2 sec after each load application.
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7.21.
Technical Specifications: Appendix N2
Combined Cycle
Miscellaneous
7.21.1.
Communications Section
The communication system shall be protected from onsite and offsite radio and electrical
interference, including use of two-way radios. Two-way radios and cell phones will be
used in the control room. The DCS and electrical components shall be provided taking
into account their use.
One telephone and one LAN communications shall be provided in each of the offices, file
room, kitchen area, lunch area, conference room, communications room control room
operator consoles, DCS room, I&C area; and maintenance area. A minimum of 8
additional phones shall be located strategically throughout the plant.
Facility communications shall be comprised of voice/data/video systems. This includes a
plant wide paging system, gate and security cameras, gate card readers, internet and LAN
connections, emergency siren/horn, DCS communication, phone system and the
appropriate communications links between the generating plant and the California ISO
for revenue meter data and plant control/data via the AGCT/RIG. The Seller shall
design, install, test, and prove systems based on the current standards, codes, and industry
guidelines related to the V/D/V systems as listed, but not limited to the following:

NEC including articles 640, 645, 725, 760, 770, 800, 830 and any other applicable
articles specific to the situation.

NECA guide to low-voltage and limited energy systems.

NFPA including NFPA 70, 72, 75, 101, 780

NESC containing ANSI/IEEE C2, as they relate to single building systems and
their integration into the entire power plant building integration.

ANSI/IEEE standards including 142-1991 or later, 1100-1999 or later and any
other applicable standards specific to the situation.

ANSI/TIA/EIA standards including latest of 568A, 569A, 570A, 606, 607, 758,
and any other applicable standards specific to the situation.

NEIS – National Electrical Installation Standards
.
Facility communications shall be comprised of voice/data/video systems. These includes
a plant wide paging system, gate and security cameras, gate card readers, internet and
LAN connections, emergency siren/horn, DCS communication, phone system and the
appropriate communications links between the generating plant and the California ISO
for revenue meter data and plant control/data via the AGCT/RIG. The Seller shall design,
install, test, and prove systems based on the current standards, codes, and industry
guidelines related to the V/D/V systems as listed, but not limited to the following:

NEC including articles 640, 645, 725, 760, 770, 800, 830 and any other applicable
articles specific to the situation.
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Combined Cycle

NECA guide to low-voltage and limited energy systems.

NFPA including NFPA 70, 72, 75, 101, 780.

NESC containing ANSI/IEEE C2, as they relate to single building systems and
their integration into the entire power plant building integration.

ANSI/IEEE standards including 142-1991 or later, 1100-1999 or later and any
other applicable standards specific to the situation.

ANSI/TIA/EIA standards including latest of 568A, 569A, 570A, 606, 607, 758,
and any other applicable standards specific to the situation.

NEIS – National Electrical Installation Standards.
7.21.2.
Security
The Seller shall furnish and install a security system as described below, which includes
security requirements for gate, including signal raceway (video, intercom, card reader,
etc.), power, lighting, gate operators, and concrete pedestal for card reader. A station
security system shall be provided and shall conform to the requirements of the Purchasersupplied design criteria, including card reader access control, color low-light, remotelyoperable pan-tilt-zoom multi-camera closed-circuit TV, intercom system, independent
automatic gate control for Facility site and switchyard, perimeter detection system for all
fencing and gates on the perimeter of the Facility site and switchyard, and selectable
frame rate video recording system. Sufficient cameras shall be provided to allow view of
entire site perimeter.
The Facility shall include moveable (remote actuated) security cameras around the
perimeter fence and entrance gate(s), which shall be connected to close-circuit TV
(CCTV) equipment for viewing in the central control room. In addition, a security camera
shall be placed for viewing the control room. The CCTV equipment shall be arranged to
view the complete plant site. The security cameras shall be remotely accessible from
Purchaser’s offsite general offices.
The security system shall include CCTV video matrix/switcher, and recording facility
shall be located in the central control room. The CCTV system shall be integrated with
the plant DCS alarm system.
An access control system shall be provided to integrate the security systems and to
provide remote access and control. The perimeter detection system output shall tied to
the access control system for notification of the activation of the detection system. The
CCTV system shall be tied to the detection system via outputs and inputs so that the
CCTV system will move the nearest camera(s) to the activated alarm zone. The access
control system shall record activity from the card readers and the relay inputs. The access
control system shall send notification to a remote central station via a dedicated
communication link to be provided by Buyer. The central station shall have the ability to
view the on site records of the access control system and the digital recorders live video
and stored images.
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7.21.3.
Technical Specifications: Appendix N2
Combined Cycle
Panelboards
Panelboards shall be UL-listed and conform to the latest issues of the National Electrical
Code and NEMA Panelboard Standard PB 1. Panelboards shall be rated for 480 Vac
Service or 120/208 Vac service. A minimum of 20% spare breakers shall be provided. A
completed directory card and frame shall be provided on the inside of the door.
7.21.4.
Grounding and Lightning Protection System
The Seller shall furnish and install the grounding system, which shall consist of bare,
stranded copper cable (if the soil permits) and copper weld rod buried in the soil and
spaced in a grid pattern sized as required for safe step-and-touch potentials. Each junction
of the grid shall be securely bonded together by an exothermic weld. The ground grid
pattern (size and number of ground rods or ground wells) shall be determined using soil
resistivities measured at the Facility site. A sufficient number of ground rods shall be
installed and welded exothermically to the grid to ensure a low-resistance earth
connection. These rods shall be situated throughout the grounding system to minimize
voltage gradients that occur during faults.
All structures, conduit, cable tray, and electrical equipment shall be grounded per the
NEC or applicable state and local standards.
The lightning protection system shall be designed, furnished, installed, and tested in
accordance with the latest applicable NFPA Standard 780, ANSI/UL Standard 96A, and
any other applicable codes and standards.
Grounding and lightning calculations shall be provided to Purchaser
7.21.5.
Cathodic Protection System
The Facility shall include an impressed current cathodic protection system for all
underground metallic components. This system shall be completely isolated from the
electrical ground grid. A study survey and calculations shall be provided to the Purchaser.
The cathodic protection system shall be designed, installed, and tested in accordance with
the latest issue of NACE International, ICEA, NEMA, ANSI, and any applicable local or
national codes.
A cathodic protection survey is required before turnover to verify complete equipment
protection.
7.21.6.
Lighting Systems
The Facility lighting system shall provide illumination for Facility operation under
normal conditions, and emergency lighting to perform manual operations during outage
of the normal power source, and include all equipment specified herein.
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The work shall be performed in accordance with the National Electrical Code (NEC) and
applicable local codes in a manner consistent with recognized good practice for power
station service.
Interior lighting shall be high-power-factor fluorescent, or color-corrected high-powerfactor hp sodium, depending on the area.
Exterior and road lighting shall be high-power-factor, color-corrected, high-pressure
sodium.
Outdoor lighting shall be designed to minimize transmission of light beyond the plant
boundary through the use of directed lighting, guarded luminaries, etc. Lighting fixtures
shall be located and adjusted for the maximum useful light output. Accessibility for
maintenance shall be considered.
All indoor fixtures shall be controlled at the lighting panel/switches located at the
entrance areas. Photo-cells shall control outdoor lighting circuits and shall include bypass
switches.
Lighting panels shall be sized with a minimum of 20% future spare capacity. Lighting
panels shall be provided with a variation of spare breakers and blank spaces.
Circuits at the distribution panel shall be wired in such a manner that they are balanced
within ±15% between the phases.
For normal unit operation, the lighting system shall provide illumination in all facility
areas to the levels required by ANSI/IES RP-7.
7.21.6.1
Lighting Transformers
Transformers shall be sized as required for the connected and future loads, enclosed
three-phase, 60 Hz, self-cooled.
Lighting transformers shall be rated on the basis of full load of the lighting panel
including the future spares/spaces with a margin of +10%.
7.21.6.2
Receptacles
480-Vac, 3-phase, 60A welding receptacles with integral on/off switches shall be located,
as a minimum, at each HRSG platform, at grade near both ends of each turbine, and in all
remote equipment locations and maintenance buildings, and shall not be located in
classified areas.
Single-phase 120-Vac convenience outlets shall be 15A duplex. They, shall be, as a
minimum, located for convenient access in all buildings and control cubicles and shall
not be located in classified areas. “GFCI” outlet ground fault interrupter type, with
watertight covers, are required for all outdoor convenience receptacles. In maintenance
areas, 50 ampere and 20 ampere single-phase receptacles are required. In addition, 480volt 3-phase 100A, welding receptacles with integrated circuit breakers are required.
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7.21.6.3
Technical Specifications: Appendix N2
Combined Cycle
Emergency Lighting
Emergency exit signs shall operate continuously. Exit signs shall identify all exits and
shall be visible from all directions of the access route. Exit signs with an arrow indicating
the direction of travel shall be used as necessary to direct personnel to the nearest
appropriate exit. Exit sign placement shall be such that no point on the exit route is more
than 100 feet from the nearest visible exit sign.
The emergency lighting systems primarily consists of lights fed directly from the 125Vdc station battery for control room, electrical, and computer equipment room areas.
This system is supplemented by self contained battery pack units and emergency lights.
The self contained battery pack units shall be 4-hour rated with nickel cadmium cells.
Emergency lighting is required in all operating areas.
7.21.7.
Cable and Raceway Systems
Cable and raceway systems shall, at a minimum, meet regulatory requirements and the
following specifications.
5000 Volt Cable
Conductors
Copper, Class B stranded, annealed
Insulation material
Ethylene-propylene-rubber (EPR), 133%
insulation level
Jacket for single or multiplexed cables
Per NEC and UL listed as type MV-90
suitable for use in cable tray
Conductor shield
Extruded semi-conducting thermosetting
compound
Insulation shield
Extruded conducting thermosetting
compound
Metallic insulation shield
Nonmagnetic copper tape
Voltage
5000 volt
600 Volt Power Cable
Conductors
Copper, Class B stranded, annealed, with a
tin or lead-alloy coating, minimum No. 12
AWG
Insulation material
Ethylene-propylene-rubber (EPR), 90C or
cross linked polyethylene (XLPE) rated 90C
Jacket for single conductor or multiplexed cables
Per NEC and UL listed as type TC
Voltage
600 volt
600 Volt Control Cable
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Combined Cycle
Conductors
Copper, Class B stranded, annealed, with a
tin or lead-alloy coating, No. 14 AWG
Insulation material
Ethylene-propylene-rubber (EPR) or cross
linked polyethylene (XLPE), ), rated 90oC
Jacket for multi conductor cables
Per NEC and UL listed as Type TC (No PVC)
Voltage
600 volt
Wire colors for multiconductor cables
NEC Table E-2
Instrument Cable
Conductors
Copper, stranded 18 AWG, minimum
Insulation material
90oC, fire retardant XLPE
>90C, TFW Teflon tape and Kapton tape
over the Teflon
Jacket over each twisted pair or triad
Per NEC and UL listed as Type PLTC (No
PVC) XX check on jacket material
Shield
Each pair individually shielded, overall shield
is 1.5 mil aluminum or copper-mylar laminate
tape
Copper Drain wire
One per shield
Voltage
300 volts
Thermocouple Cable
Conductors
ANSI Type E, chromel-constant, or ANSI
Type K, chromel-alumel,18 AWG for single
pair, 22 AWG for multi-pair
Insulation material
<90C, fire retardant XLPE
>90C, TFW Teflon tape and Kapton tape
over the Teflon
Jacket overall
Per NEC and UL listed as Type PLTC (No
PVC)
Shield
Each pair individually shielded, overall shield
is aluminum or copper-mylar laminate tape
Voltage
300 volts
All of the above cable shall conform to, and equipment tests shall be conducted in
accordance with, the latest applicable standards of American National Standards Institute
(ANSI), Underwriters' Laboratories (UL), the Insulated Cable Engineers Association
(ICEA), the Institute of Electrical and Electronics Engineers (IEEE), and the National
Electrical Manufacturer's Association (NEMA), unless otherwise stated herein.
All cables shall meet or exceed flame test requirements of IEEE 1220.
All cable shall be “sunlight resistant” and for use in cable trays (“for CT use”).
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Cable with PVC insulation is not allowed.
Instrumentation and thermocouple cable shall be twisted with a minimum twist frequency
of 3 inches, or 4 twists per foot.
Voltage transformer and current transformer leads shall be No. 10 AWG minimum.
All control and instrument leads for the external connections shall be brought out to
terminal blocks mounted in terminal boxes, control boards, or panel in an accessible
location, including all spare contacts.
Cable shall be identified with identification markers at both ends after cables have been
permanently routed, positioned, and terminated.
Cable shall be installed in compliance with the cable manufacturer's recommendations on
minimum pulling temperatures and maximum pulling tension. All cable ends shall be
sealed from contamination during the pulling operation and during storage on cable reels.
A thermal calculation shall be performed and provided to the Purchaser where large
concentrations of power cables occur in the duct runs to ensure the temperature does not
exceed the maximum cable temperature.
Splicing of cables in raceway shall not be allowed. The Seller shall receive approval from
Purchaser for any cable that needs to be spliced before the cable is pulled.
A four-tray cable segregation system shall be furnished that shall include mediumvoltage power, low-voltage power, control, and instrumentation. The instrument tray
shall be solid bottom while other trays shall be ladder type.
The cable tray system shall be designed, fabricated, and installed in accordance with the
latest edition of NEMA Standard Publication No. VE-1 - Cable Tray Systems, load/span
class designation NEMA Class 12C. The maximum cable fill on cable trays shall be 40%
per the National Electrical Code. All cable trays shall be galvanized steel, except that
outdoor trays shall be aluminum.
Flat cable tray covers shall be furnished and installed on all instrument trays, and on
power and control trays indoors where the tray passes under grating and on all outdoor
trays. Covers on power trays shall be raised covers.
Cable trays shall be identified before the installation of any cables. Cable trays shall be
identified in a distinct, permanent manner with identification numbers at reasonable
intervals in accordance with the Purchaser’s standards.
Wires shall not be run unprotected in the Facility. Wire not run in cable trays shall be run
in conduit. The proper size of all conduits shall be determined in accordance with the
National Electric Code (NEC). All trays shall be sized in accordance with the number of
cables and total fill area of cables that they will contain in accordance with the National
Electric Code. Junction and pull boxes shall conform to UL Standard UL 50. Galvanized
coatings for steel boxes shall conform to ASTM A 525 designation G90 for dry locations
and G210 for wet and outdoor locations.
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Combined Cycle
Power and control conduits with wall thickness suitable for use in concrete-encased duct
banks shall be used and supported by pre-fabricated spacers. PVC Schedule 40 conduit
may be used for underground duct runs.
All instrumentation and communication cables installed in underground duct banks shall
be routed in RGS (rigid galvanized steel) conduits. Inner duct shall be provided with each
run of fiber optic cable over its entire length.
Concrete-encased duct banks shall be reinforced under roadways and other areas to
withstand heavy equipment forces over the duct during construction and operations.
All duct banks shall have a minimum slope of 0.25% and be arranged to drain toward
manholes.
Manholes and handholes shall be placed at distances that facilitate cable pulling without
exceeding permissible cable pulling tensions and/or side wall pressures.
Conduits and duct banks shall be installed as required to complete the raceway system.
Duct banks shall use bends with large radius sweeps to minimize pulling tensions.
Adequate spare (20%) conduits shall be installed in duct banks for future use, and each
duct run shall include a minimum of one RGS cell.
7.22.
General Wiring Requirements
Terminal blocks shall be rated 600 volt, 20 amps. A permanent marking strip, identified
in accordance with Seller’s wiring diagrams, shall be furnished on each terminal block.
At least 20% (two per 12-point terminal block) spare terminal points shall be furnished.
All control wiring internal to panels shall be 600V, Type SIS, No. 14 AWG minimum,
copper conductors with Class D stranding. Class K stranding shall be provided where
wiring is subject to flexing, such as across hinged panels.
All power wiring internal to panels shall be 600V, No. 12 AWG minimum. Power cable
#8 AWG and larger shall have copper conductors, with 90°C, heat, moisture, and flameresistant ethylene-propylene-rubber (EPR) insulation and Hypalon jacket. The EPR
insulation shall meet the physical and electrical requirements for Type I insulation as
designated in ICEA S-68-516, Sections 3.6.1 and 3.6.2. Power cable internal to panels
which is #10 AWG or #12 AWG shall be Type SIS with copper conductors and Class D
stranding.
All wiring internal to panels shall be capable of passing the flame test requirements of
UL 44, Section 56.
Wiring shall be terminated using compression-type, ring-tongue terminals that firmly grip
the conductor. Both ends and at each terminating point of each wire shall be uniquely
identified with permanent, heat-shrinkable wire markers.
Splicing of wiring is prohibited. No more than one wire plus one jumper shall be
connected to any one terminal point.
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All 480V wiring shall be segregated from other control wiring and low-voltage devices
by means of an insulated barrier.
Only one ground connection shall be provided for each instrument circuit. Ground
connection for shield wiring shall be nearest the power source.
All switchgear assemblies shall be furnished completely wired. With the exception of
control and AC power buses, all other alarm and control wiring for extension to remote
equipment or for interconnection between compartments shall terminate at terminal
blocks.
Wiring shall be neatly arranged and clamped securely to panels to prevent movement or
breaking. A maximum of 12 wires shall be in a bundle in order to facilitate tracing of
wires. Wiring clamps and supports at hinge transition points shall be properly sized to
prevent chafing of insulation when the cubicle door is opened and closed. Metal clamps
must have insulating inserts between the clamps and wiring. Nonmetallic clamps are
preferred.
All signal level cables installed in underground duct shall be in RGS conduits. There
shall be an independent raceway system for the telephone/communications system.
7.23.
Protective Relay Panel Functional Requirements
The Protective Relay panel shall be located in a conditioned space and shall contain all
protective relaying not integral to the switchgears or the CTG protection cubicles.
7.24.
Workstations
PC-based workstations (DCS, CEMS, etc.) should reflect state-of-the-art technology and
shall be furnished and installed with all necessary furniture and 100% redundancy for all
operator and engineer work stations and operator interface consoles.
7.25.
Testing and Checking of Electrical Equipment
Testing for each piece of equipment shall be conducted to ensure normal and safe
operation of the Facility. All tests shall be in accordance with applicable ANSI, IEEE,
and NEMA standards. Documentation shall be provided to Purchaser before facility
turnover showing completed testing and turnover of systems for operation.
7.26.
Embedded Work
All conduits embedded in floors, walls, foundations, duct, etc., shall be hot-dipped
galvanized rigid steel conduit, which shall conform to ANSI C80.1, “Rigid Steel
Conduit-Zinc Coated”. Electrical metal tubing (EMT) can be used for indoor lighting
circuits, in and out of walls, but not in concrete.
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7.27.
Technical Specifications: Appendix N2
Combined Cycle
Freeze Protection
If applicable, the facility shall be designed to operate in freezing weather, to go through
periods of freezing weather while operating or shut down, without damage, and to
maintain any process chemical temperatures. Design ambient temperature for freeze
protection and temperature maintenance systems are shown in Appendix N3.
Freeze protection and temperature maintenance of pipes shall be provided and shall be
accomplished with straight runs of heat tracing cable attached and covered with Teflon or
other thermal insulating material. Heating cables shall be provided for all outdoor piping
smaller than 2 inches, tubing, gauges, and instrumentation containing fluids subject to
freezing. Space heaters or heated enclosures shall be used for items where heating cables
and insulation is not practical. Heating and heat tracing required for process fluid
temperature regulation will be provided by the system equipment suppliers.
Freeze protection circuits shall be fed from dedicated freeze-protection distribution
panels that are energized through thermostatically controlled contactors. The freeze
protection distribution panelboard, as well as the main breaker, contactor, auto-offmanual control switch, control wiring, and indicating lights, shall be contained in an
outdoor weatherproof control panel enclosure. Temperature maintenance circuits shall
have a dedicated NEMA 4 panel containing main and branch circuit breakers,
temperature control components, and alarms contact outputs. All circuits shall be marked
in distribution panels to facilitate location of the proper circuit in case of problems. In
addition, P&IDs shall be marked to indicate the location of all individual freeze
protection circuits, the location of power feeds, the location of any splices or tees, and
any other features that will facilitate maintenance and testing of the system.
Electrical heat tracing system power shall be fed from switchboards to dedicated freeze
protection transformers that step the voltage down for distribution through the dedicated
circuit breaker panelboard. The voltage shall be maintained at ±10% of the system rated
voltage. Each distribution panelboard shall be provided with approximately 20% spare
circuits for future expansion.
Freeze protection control circuits shall be designed to switch the entire panelboard on
when the temperature falls below 40°F and switch the entire panelboard off when the
temperature rises above 45°F. A circuit shall also be provided to alarm if the panelboard
is not energized for temperatures below 35°F and to alarm if the panelboard is energized
for temperatures above 50°F. A pilot light indicating the circuit is energized and an
ammeter showing circuit current shall be located at or near the heat trace distribution
panel.
Heat-tracing cables shall be designed for operation at a nominal 120 volts ac, singlephase. Heat tracing cables shall be run parallel to the length of the pipe or line and shall
not be spiraled. Each run should provide indication that the cables are operating.
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7.28.
Technical Specifications: Appendix N2
Combined Cycle
Switchyard
The design of the switchyard, including equipment, structures, protective relaying, etc.,
shall be in accordance with the facility requirements and PG&E’s design standards,
particularly in regard to layout and spacing of equipment, structures, and conductors.
The configuration of the switchyard shall be designed to support routine maintenance
activities such as main bank insulator washes and switchyard work.
The switchyard shall include all electrical equipment and supporting structures necessary
for interconnection into the California ISO system with no single contingency failure of
the plant interconnection facilities or the transmission system resulting in a total plant
outage.
Major requirements for the switchyard are discussed in the following sections.
7.28.1.
Circuit Breakers
The switchyard shall use a ring bus system of circuit breakers (Purchaser’s approval
required). One and one-half breakers are required at each interconnection point to the
switchyard. The breakers shall be insulated with SF6 gas and shall be equipped for
outdoor installation.
Circuit breaker accessories including current transformers (CTs), auxiliary contacts,
space heaters, alarms, etc. shall be furnished as required for the installation.
All circuit breakers shall include relaying accuracy CTs for the protective relay schemes
and metering accuracy CTs to be used for metering purposes. Metering accuracy CTs
shall be as defined below under “Metering.”
7.28.2.
Disconnect Switches
There shall be two manually operated disconnect switches in the ring bus for each circuit
breaker and one disconnect switch for each circuit entering or leaving the substation. The
manual switches shall be used for isolation of circuit breakers and incoming/outgoing
lines. The switches are not required to have load break capability. The switches shall be
group-operated. The switches shall have auxiliary contacts installed for remote status.
The configuration of the switches shall be arranged in a manner that maintains the
required air gap clearances in the open position. ANSI phase spacing shall be maintained
for all switches.
7.28.3.
System Protection
Each circuit entering/leaving the substation shall be furnished with appropriate protective
relaying. Lockout relays shall be furnished to accomplish all necessary interlocking.
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Each of the circuit breakers shall be furnished with breaker failure schemes. Breakers
shall not be furnished with breaker reclose relays and schemes. Lockout relays shall be
furnished to accomplish all necessary interlocking.
A small control house shall be included for the switchyard protection relays, battery, and
chargers and shall have a conditioned environment.
Synchronizing of all the generators to the utility system is to be done across the mediumvoltage generator circuit breakers.
7.28.4.
Control
The circuit breakers shall be controlled from the plant control house. All circuit breaker
disconnect switches shall be manually operated. All circuit breakers shall have two
125-Vdc trip coils. One trip coil shall be powered from the plant 125-Vdc battery and the
other trip coil from the switchyard and battery.
7.28.5.
Power Metering
Revenue-quality metering systems shall be designed, installed and certified in accordance
with the latest conformed California Independent System Operator tariff as can be found
on their web site at http://www.caiso.com/docs/2005/10/01/2005100114481329995.html.
The revenue metering systems shall be capable of collecting and processing real-time
data from the generating plant, and transmitting it to the California ISO’s Meter Data
Acquisition System (MDAS). The revenue-quality metering system shall consist of the
following, unless otherwise approved by the California ISO:

Voltage transformers shall be installed on each phase of each circuit leaving the
substation. Each voltage transformer shall meet the requirements of the
California ISO as specified in Section 10 of the tariff and the Metering Protocol
(including Appendices A-G).

Current transformers shall be installed on each phase of each circuit leaving the
substation. Each current transformer shall meet the requirements of the California
ISO as specified in Section 10 of the tariff and the Metering Protocol (including
Appendices A-G).
Polyphase solid-state revenue quality meters shall be installed to collect and process data,
and shall be capable of transmitting the data to the California ISO’s MDAS. Each meter
shall meet the requirements of the California ISO as specified in Section 10 of the tariff
and the Metering Protocol (including Appendices A-G and Appendix J). The quantities to
be collected and processed by the metering system are identified in the California ISO’s
tariff and Metering Protocols.
Alternatively, combination metering units containing potential and current elements may
be installed in place of separate voltage and current transformers on the high side of the
generator step-up transformers. The electrical, mechanical and accuracy characteristics of
combination metering units shall be the same as individual VTs and CTs.
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7.28.6.
Technical Specifications: Appendix N2
Combined Cycle
Non-Revenue Metering
Shorting-type terminal blocks will be provided to allow instruments to be removed
without disrupting current transformer circuits.
The accuracy of the switchgear/panel type metering current transformers shall be in
accordance with ANSI/IEEE C37.20.1 for low-voltage switchgear, and in accordance
with ANSI/IEEE C37.20.2 for medium-voltage switchgear consistent with current
transformer ratio, burden, mechanical, and thermal duty. The accuracy of voltage
transformers will be 1.2% or better.
The following indications will be provided on the DCS or on the turbine control/relay
panels or local panels:
Location of Indications
For Each Generator
Generator Meters/Transducers:
1 - Watt-hour Meter
Control Panel, DCS
1 - Watt Transducer
1 - Digital Monitor w/Serial Link DM1:
1 - Generator Watt Output
DCS
1 - Generator Var Output
DCS
1 - Generator Power Factor Output
DCS
3 - Generator Current Output
DCS
3 - Generator Voltage Output
DCS
1 - Generator Frequency Output
DCS
1 - Digital Monitor w/Serial Link DM2:
3 - System Voltage Output
Control Panel, DCS
1 - System Frequency Output
Control Panel, DCS
1 - Digital Meter, DM4:
1 - Exciter Field Voltage
Relay Panel, DCS
1 - Exciter Field Current
Relay Panel, DCS
Automatic Synchronizer System:
Relay Panel
1 - Synchroscope and Lights
1 - Automatic Synchronizer, 25A
1 – Manual Synchronizer, 25M
Non-revenue metering at the High Voltage switchyard
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Location of Indications
Facility auxiliary power
Total real power usage of auxiliary loads (watts)
4.16 kV switchgear
Total reactive power usage of auxiliary loads (vars)
4.16 kV switchgear
The following for 4 kV and 480 V load center buses
Local indication
Bus voltage, all phases (switched)
Incoming current, all phases (switched)
Current through feeder breakers, one phase
Phase current for motor feeds, three-phase
480 V motor control centers
No metering provided
The following 125 V dc system (STG Facility battery)
Local indication
Battery amperes
at dc switchboard
Bus voltage
at dc switchboard
Negative-to-ground voltage
at dc switchboard
Positive-to-ground voltage
at dc switchboard
Blown fuse
at each fused switch in dc
switchboard
Bus undervoltage
at dc switchboard
Charger output volts and amperes
Charger alarms
Common trouble alarm for the 125 V dc system.
DCS
The following for 120 V ac UPS system
Local indication
Inverter input volts and amperes
Inverter output amperes, voltage, and frequency
Inverter alarms
Common trouble alarm for the UPS system.
7.28.7.
DCS
Steel Structures
Galvanized steel structures shall be supplied to support switchyard electrical equipment
and to connect the units to the switchyard as required. Structure loading shall be in
accordance with ASCE-7 and the National Electrical Safety Code (NESC) loads as
appropriate. These structures are to conform to the local utility company requirements.
Clearances shall conform to the standard design clearances of the NESC.
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Each main power transformer and utility tie connection shall be connected to the
switchyard by an overhead line and aluminum bus tube. These lines shall use bare ACSR,
AAC, or ACSS conductors and shall run from the main power transformers to their
respective positions in the switchyard. Transformer termination structures shall be
supplied at both ends. Dead-end structures shall be furnished at each transformer position
and shall provide adequate clearance over the roadways within the plant. These structures
shall be designed to accommodate the full load of the line. The design loads of the line
shall be in accordance with the loading specified by the NESC for the site area.
7.28.8.
Miscellaneous
The switchyard shall include all necessary miscellaneous commodities such as cable,
conduit, lighting, bus tube, fittings, insulators, and surfacing necessary for a complete
switchyard installation.
7.28.9.
Switchyard Grounding and Lightning Protection
The Facility switchyard grounding system shall meet the requirements of the latest
revision of IEEE Standard 80, Safety in Substation Grounding.
The switchyard ground grid shall consist of buried copper ground conductors and ground
rods connected in a grid configuration. The conductors shall be interconnected with an
exothermic welding process. The ground grid shall be connected to the facility grounding
system at multiple points. Connections to the transmission lines’ shield wires shall be
confirmed upon an analysis of the ground grid.
The ground grid shall be sized to keep the calculated step and touch potential to safe
levels as defined by IEEE 80. The main conductors shall be sized for a maximum fault
current based on expected system conditions.
The Facility shall include lightning protection provided by shield wires and lightning
masts. The lightning protection shall conform to IEEE standards and/or industry
practices.
7.28.10.
Stability Study
The Seller shall perform a stability study to ensure that the generators are capable of
operating without damage during transient conditions in the switchyard.
8.
INSTRUMENTATION AND CONTROL REQUIREMENTS
The instrumentation, control systems, UPS system, and electrical power circuits for
critical equipment shall be designed in such a way that no single control system,
instrument failure, controller failure, fuse, or circuit breaker shall interrupt the operation
of more than one piece of redundant equipment. The plant shall be designed to eliminate
common mode failures.
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It is required that the number of different control systems be minimized as much as
possible. The intent is to simplify maintenance and operation of the plant control systems.
This should be considered when selecting the control system for the STG, Plant DCS,
duct burner management system, etc. All control consoles (CTG, STG, BOP) shall be of
the same manufacturer for the plant main control room.
Instruments and controls that are supplied as part of the STG package shall be provided
in accordance with vendor’s standards except as follows:
The DCS, CTG, and STG control systems shall be provided with the following features
furnished by the supplier:
a.
A remote control console/workstation for the STG and the CTGs (one per CTG)
shall be mounted in the plant main control room. This console shall provide all the
functions of the local control consoles for the CTGs. In addition, it shall be
possible to perform all necessary workstation functions (programming, graphic
display changes, etc.) from this console.
b.
Two color printers shall be mounted in the main control room. These printers shall
print all alarms, logs, historical data, graphic displays, etc.
c.
The CTG and STG control packages shall be serial linked to the Plant DCS. This
link will be used for data acquisition and monitoring of the CTGs and the STG. In
addition, critical control functions will be hardwired to the Plant DCS to allow
critical functions to be performed from the Plant DCS.
d.
All transmitters and indicators shall be capable of being maintained while the unit
is on line and shall be provided with root valves. Root valves are required for
critical trip instrumentation. Double root valves shall be provided for high pressure
steam and feedwater services.
e.
Factory Acceptance Testing (FAT) of the complete control package shall be
performed using Vendor's standard testing procedures. All software logics,
hardware, graphics, and alarming shall also be verified during the FAT. The tests
shall be performed before shipment. (Purchaser approval of control screens is
required.)
f.
Triple redundant transmitters/switches shall be provided for critical measurements
or equipment trips.
The CTG, STG, and the DCS system power supplies shall be redundant to comply with
the single failure criterion.
Turbine stress monitoring shall be included in the CTG and STG control systems.
Mechanical equipment on standby status shall automatically start upon a trip of the
operating equipment. All backup pumps shall automatically start to maintain Plant
production rates.
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All instrumentation and systems shall be designed to provide safe and reliable operation
of each Unit in accordance with all applicable codes and standards.
Main and redundant process transmitter inputs shall be provided for critical control loops.
Inputs shall be brought into different I/O modules for integrity.
Current-to-pneumatic (I/P) converters shall be used to provide the interface between the
electronic control signals and pneumatically actuated control valves. The converters shall
be responsive to the basic control signals for the system and shall have a 3-15 psi output.
Feedback from I/P converters mounted on control valves shall be sent to the DCS for
control system tuning purposes. Actual Line valve position feedback shall be from
position transmitters provided for split range control valve applications only, to provide
CRT indication for the operators.
The system shall be designed to require a minimum of operator action. The control
system shall include all necessary logic to change the operating mode for selector stations
safely under various operating conditions.
The system shall be designed to ensure transfer from manual to automatic and vice versa
with no operator balancing or upset in the individual control loops.
All backup pumps should be able to auto-start from the DCS on primary pump trip, low
suction pressure, and low discharge pressure, at a minimum.
The Seller shall keep a master set of the Contractor’s and vendor's wiring drawings; CTG
and HRSG control system configuration, cabinet arrangement, and power distribution
drawings; instrument index; instrument and control valve data sheets; and P&IDs marked
with all as-started up changes. All as-started up changes shall be incorporated into the
final drawings, documents, etc., which are to be submitted to the Purchaser before
turnover of the project.
Plant control system shall be capable of day-ahead programming of key events (i.e.
turning over unit to California ISO remote dispatch). The Seller shall be fully responsible
for the interface design with the California ISO remote dispatch system.
The plant shall be operable from the control room by a single operator under all normal
conditions from minimum to full load. Startups and shutdowns may require an operator in
the field.
Automatic steam drain and sky vent valves shall be controllable locally and/or from
control room.
8.1.
Distributed Control System
A microprocessor-based distributed control system (DCS) shall be provided for
controlling, monitoring, indication, alarm, and historical functions. CRTs located in the
main control room shall serve as the primary operator interface. This system shall
monitor, alarm, and provide limited control of the combustion gas turbines and steam
turbine. CTGs and the STG remote CRTs shall be provided in the main control room for
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detailed controlling, alarming, and monitoring of the combustion gas turbines and steam
turbine. A MODBUS or Ethernet communication link for data acquisition shall be
provided between the turbine controls and the DCS for each combustion turbine and
steam turbine. Control functions between the DCS and turbine control systems shall be
via hardwired signals.
Any normally operating auxiliary systems during normal startup and shutdown operation
of the Plant shall be controlled through the DCS. The DCS shall be capable of allowing
control and data to be passed between the ISO and the plant’s AGCT or RIG system.
The microprocessor-based DCS shall be complete with design, engineering, materials,
manufacture and assembly, optimization, documentation, testing, and field services.
The DCS shall include automatic control and monitoring of the startup, shutdown, and
normal operation of the Plant systems through redundant Plant communication loops.
The DCS shall provide automatic and manual control of all major subsystems.
The Facility shall include a master clock system synchronized with satellite (GPS)
complete with antenna, accessories, and equipment. This master clock system shall
provide time synchronization signals for all control systems for the plant requiring time
synchronization.
8.1.1.
Performance Requirements
The system shall be properly protected from voltage surges that normally occur in a
power plant. Inputs, outputs, and other connections shall meet the surge withstand
requirements of ANSI C37.90a.
The devices shall have input to output isolation, shielding, separation of circuits, surge
suppression, and other measures to meet these provisions.
The system shall operate satisfactorily without air-conditioning and with ambient
temperatures from 40F to 110F at a relative humidity of 20% to 95%, non-condensing.
8.1.2.
Functional Requirements
Remote I/O and logic cabinets may be used within the Plant. Redundant fiber-optic data
highways must be used and must be physically separated from each other and routed in
different raceway systems between the remote I/O and logic cabinets and the control
room operating consoles. All engineering functions must be able to be performed
remotely via an engineering console located in the control room equipment area.
The operating staff at the facility will be kept to a minimum. Therefore, a high level of
automation and reliability is required. Each system shall be capable of operating on full
automatic. Fail-in-place lock-up features upon loss of air or signal shall be provided as
appropriate for the application. The DCS shall alarm all abnormal process and operating
conditions, system component failures, loss of air on critical control valves, etc., to
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ensure safe and efficient operation of the Unit. Alarms shall also be provided to meet the
requirements of all applicable fire protection. The operator shall have the ability to tag
out equipment (fans, pumps, valves, dampers, etc.) from the CRTs for work performed by
maintenance personnel. When a piece of equipment is tagged out by the operator, the
operation of that device by the control system shall be inhibited in the system logic. The
graphics displays shall indicate when a device is tagged out.
8.1.3.
Console Design
The control system shall be designed to allow Plant operation by a minimum number of
operators. All Plant systems shall be operable from the main control room. The console
shall consist of, but not limited to, the following:
8.1.4.

Five DCS CRTs

Five keyboards

Sequence-of-events recording

Combustion turbine control CRT (one per CTG) (with keyboards, printer[s], etc.)

Steam turbine control CRT (with keyboards, printer[s], etc.)
Hardware Requirements
The following paragraphs define the general requirements for the hardware and software
for the DCS and other microprocessor-based control systems:
8.1.5.
DCS Partitioning
The DCS, CTG, and STG control systems shall be divided into subsystems. The number
of subsystems shall be agreed to by the Purchaser. The logic hardware for each
subsystem shall be independent from the other subsystems. Critical safety-related
communications between subsystems shall be through hardwired I/O. All other
communication shall be by data-highway. Redundant processors shall be provided for
each subsystem and its control I/O.
8.1.6.
Power
Redundant power feeds shall be provided to the DCS, CTG, and STG control systems.
The primary feed shall be 120 Vac from the plant UPS. The secondary feed shall be from
the plant 125 Vdc distribution system.
A failure of a power supply shall not affect system operation. Failure of any power
supply shall be alarmed on the CRTs on the main control room and Plant maintenance
personnel shall be capable of replacing power supplies with the system on-line. Modular
power supplies may be provided as a substitute for 100% power supplies provided they
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are supplied on an N+2 configuration per cabinet. In addition, loss of any battery backup
power should be alarmed in the DCS.
8.1.7.
System Failure Protection
No single hardware or software failure shall affect normal control of the Plant.
System programs and configurations shall reside in nonvolatile memory. Any volatile
memory shall be easily re-installed.
System failures shall be alarmed and logged on a printer.
8.1.8.
DCS Communication Network
The Plant's DCS communication network shall consist of a single redundant datahighway loop, to which the DCS shall be connected. DCS shall be connected to the
redundant data-highway loops with redundant communication hardware. The
communication hardware shall have automatic loop transfer capability to provide
protection against a single loop failure. Loss of either data-highway loop shall be
alarmed. The data-highway shall permit all devices in each system to interface with one
another. No single equipment failure shall interrupt communications between
subsystems.
Individual points shall be scanned, system communications completed, and control signal
outputs updated at least once every 1/3 second. All data on CRT displays shall be updated
at least once every second. CRT graphics displays shall be fully displayed with all current
live data within 2 seconds after the request for the display has been initiated.
8.1.9.
Printers
The system shall include color graphics-capable quiet printers. Three printers and stands
are required. One printer shall be dedicated to alarms. Alarms shall be printed in red.
Cleared alarms shall be printed in black. The other printer shall be for logs and graphic
displays printing.
8.1.10.
Computing Hardware and System I/O
Redundant process equipment (pumps, fans, etc.) shall have its control located on
different I/O cards. Process status data from an individual piece of equipment shall be
wired to the same input card, except for signals from redundant transmitters, which shall
be wired to different input cards.
The meaning of “contact” within the scope of this specification shall be an electromechanical relay contact, or a solid-state switch, such as a triac, transistor, or
semiconducting rectifier. Contact ratings shall be compatible with the controlled loads.
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Each subsystem shall be shipped with a minimum of 10% spare I/O installed. This I/O
shall be wired out to terminals. The loading of all system controllers shall not exceed
60%.
Sufficient spare rack and cabinet space shall be available at shipment to expand the logic
capacity and I/O capacity of each subsystem by at least 10% by adding the appropriate
modules and equipment.
8.1.11.
System Cabinets
Cable entry into system cabinets shall be through the top or bottom. Cable supports shall
be provided in each cabinet. Cables shall not block access to any cabinet hardware for
equipment inspection, maintenance, or removal and replacement.
A high-temperature alarm for each logic cabinet shall be provided and displayed on the
console CRTs.
Terminations from the field shall be terminated on vendor's standard termination unit.
Not more than one wire shall be connected to one terminal block point except where
jumper wires are necessary, in which case two wires may be connected for internal
wiring.
Each I/O point including spares shall be provided with vendor’s standard terminals. No
more than one wire shall be connected to one terminal, except where jumper wires are
necessary.
8.1.12.
Electrical Design Criteria
All control devices and components shall be heavy-duty type suitable for operation at
120 Vac or 125 Vdc. Insulation of coils shall permit continuous operation at a
temperature of 130C.
Contacts for external control circuits shall be heavy-duty type. The contacts shall have an
AC interrupting capacity of ten times their normal rating and shall not Appendix
excessive arcing or contact bounce.
Relays with exposed contacts shall not be used.
The voltage for contact interrogation is 125 Vdc/120 Vac for the DCS, CTG, and STG.
All limit switches shall be heavy-duty snap-action types.
The DCS, CTG, and STG control system cabinets shall include the following:

Cabinet ground bus: Bus for grounding cabinet, rack, and equipment grounds

Insulated or common ground bus: Bus for grounding instrument and control cable
shields
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All cabinet ground buses will be grounded to building steel.
Wire markers on both ends of each wire that is longer than 12 inches shall be provided
with indelible designations in accordance with the DCS supplier’s wiring diagrams.
8.2.
Software Requirements
8.2.1.
Data Acquisition
A data acquisition system (DAS) shall be provided as part of the DCS and shall include a
performance and monitoring package to track the unit and plant performance. The system
shall average, weight average, and integrate pressures, temperatures, flows, calculated
values, etc., as required for the performance calculations, logs, etc. An OSI-PI system
shall also be provided. OSI-PI system shall interface with the independent PI system
through the plant DCS. The PI system shall have 200% of the plant DCS I/O count
capability with 2-PI process book licenses. The DAS shall, as a minimum, perform the
following functions:
8.2.1.1
Sequence-of-Events Recording
The DCS shall provide scanning of not less than 150 digital (contact) inputs for the
sequential events recording (SER) system. These inputs shall be scanned to discriminate
between contact operations, which occur a minimum of one millisecond apart, and print
them in their proper sequence when they are opening and closing. Each event shall be
printed on the log printer as an individual event. The complete time shall be parted out in
hours, minutes, seconds, and milliseconds with each sequential event contract status
change.
The DCS shall include sufficient buffer storage in the data acquisition system memory
structure for the SER programs to ensure that the system will not fail to detect a contact
operation due to storage or print buffer filling.
The DCS shall include the SER program to permit storage of the sequence of events log
in the Historical Storage and Retrieval (HSR) system in addition to printing the
information on the log printer. The HSR shall be sized large enough to store all sequenceof-events logs.
8.2.1.2
Logging
The system shall log pre-selected variables at one-hour intervals beginning at 1:00 AM.
Values shall be printed at the end of each 24-hour period at midnight on the log printer.
The variables shall consist of calculated values, averaged values, integrated values,
instantaneous values, weight-averaged values, or the maximum value for the time period.
The variables and the exact format of the log shall be agreed to by the Purchaser. Data
shall be logged on sheets in column form with data for any given variable tabulated in
one vertical column.
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The data currently being accumulated for the log shall be protected in case of system
failure. The log program shall automatically re-initiate the accumulation of data
following a system fail over without loss of data.
8.2.1.3
Historical Data Collection, Storage, and Presentation
A historical data collection, storage, and presentation (HCSP) system shall be provided
that will fully automate the collection, storage, retrieval and presentation of plant data.
The HCSP shall provide a centralized collection of information, a real-time database and
a historical data archive. The HCSP shall interface with all of the plant real-time systems
(CTG Control System, BOP DCS, etc.) simultaneously and shall be capable of reading
and writing to these systems. The HCSP shall be complete with server, monitor, RAM,
hard drive, tape backup, CD ROM drive, etc.
8.2.1.4
Graphics Displays
The graphics displays for use by the operators on the CRTs shall be developed in
accordance with the Seller's standard utility format. Graphic displays are subject to
approval by Purchaser. The DCS shall include spare capacity of 20% for the number of
graphic pages for future additions.
8.2.2.
DCS Interfaces
The DCS shall be designed to interface with other Plant systems, specifically the CTG
control system, steam turbine control system, the chemical feed system, gas metering
system, power electronics monitoring/control system, and data acquisition system.
Except as noted, packaged systems including the demineralized water treatment will be
programmed into the DCS. The continuous emissions monitoring system (CEMS), the
gas compressor system controls, and the fire protection system will be stand-alone
systems. Where programmable logic controllers (PLC) are used, these control systems
will be an Allen Bradley 540E or approved equivalent, with a data highway type
connection to the DCS.
The DCS will be configured by the DCS supplier with information and coordination
provided by the Seller. A consistent control and instrumentation philosophy will apply
throughout the plant to minimize diversity of equipment type and equipment
manufacturer. Either 48 Vdc or 24 Vdc will be used for the digital input wetting voltage.
8.2.2.1
Chemical Feed System Control
The facility shall include the primary and secondary process signal inputs (flow, specific
conductivity, etc.) between the sampling system and DCS.
The chemical feed systems shall be controlled through the DCS. The DCS shall generate
all applicable chemical feed system alarms.
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8.2.2.2
Technical Specifications: Appendix N2
Combined Cycle
CTG and HRSG Combustion Control Interface
The DCS shall be designed to control by feed-forward action, with system calibration and
final correction provided by feedback action. The control equipment furnished shall
include all feed-forward devices and other equipment to provide complete stability under
all conditions of dynamic steam load changes. Feed-forward demands shall be developed
for CTG demand, feedwater flow, fuel flow, steam pressure, and other required plant
parameters. The system shall control the operation of the CTG inlet guide vanes (IGV)
through the CTG control system, and supplemental HRSG firing in a manner that will
provide fast response to the steam load demand without allowing unacceptable steam
pressure deviation.
The DCS shall be fully interfaced with the CTG control system. Critical control and
protection/trip functions shall be hardwired between the DCS and the CTG control
system. The communication interface to the CTG control system shall be provided in
accordance with CTG supplier requirements for DAS functions and non-critical control
signals. The DCS shall control the CTG to match the HRSG steam load requirements.
The DCS shall interface to the CTG control system to manage the following analog and
digital CTG control functions:

Startup sequencing through synchronization.

Speed and load control.

Temperature control.

Safety control including:
—
Automatic safe shutdown (ramp down)
—
Selected shutdown (ramp down)
—
Emergency shutdown (fuel shutoff)
The Facility shall include sufficient manual control capability for CTG speed, generator
voltage, and excitation such that a single operator can control the Plant from the main
electrical panel.
Inputs for fuel gas flow to each CTG and each HRSG shall be provided.
8.2.2.3
HRSG Burner Control and Fuel Safety (if applicable)
The duct burner (HRSG burner control and fuel safety system) shall be controlled in a
dedicated processor within a programmable logic controller (PLC) with redundant CPU
with necessary interface signals to the Plant DCS. Each HRSG shall have a dedicated
PLC.
The burner control and fuel safety systems shall meet the requirements of NFPA 8506.
The purge, prelight, and fuel safety portion of the PLC and PLC/DCS interface shall act
to prevent both an explosion of fuel and air mixtures within the HRSG and overheating of
the HRSG pressure parts. It shall accomplish the preventive actions through the following
protective functions.
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
It shall monitor HRSG operating conditions, and upon detection of a condition
hazardous to personnel or to equipment, it shall generate an HRSG master fuel trip
(MFT) signal.

It shall rapidly shut off all fuel input to the HRSG by removing all the fuel firing
equipment and related Plant auxiliaries from service upon recognition of an MFT.

It shall prevent the admission for fuel to the HRSG until a completion of a formal
purge cycle with its associated permissives.
The duct burner PLC shall perform these major functions:
8.2.2.3.1

It shall provide safe light-off, continuous supervision of operation, and shutdown
of the pilot.

It shall provide automatic, semiautomatic, and manual operation and supervision of
main burner systems.

It shall provide the status of the pilot and individual burner flames.
HRSG Master Fuel Trip
A hard-wired direct HRSG MFT push-button (located in main control room), separate
from and redundant to the fuel safety system, shall provide HRSG protection in the event
of loss of function of the fuel safety system. The direct HRSG MFT push-button shall trip
the HRSG MFT relay and close the fuel trip valve.
The HRSG MFT first out indication shall be provided on the CRTs to indicate the
initiating cause of the MFT. This indication shall reset when the HRSG MFT relay is
reset.
8.2.2.3.2
Purge
The purge control shall incorporate a continuous purge of the HRSG to ensure that the
HRSG is free of any accumulation of combustibles for light off and that the HRSG will
remain so during operation.
Completion of the HRSG purge shall be indicated to the operator. The operator shall
initiate reset of the master fuel trip from the CRTs. An HRSG purge shall be required on
any master fuel trip.
Indications to the operator of the status of the purge and firing in permissives and the
progress of the HRSG purge shall be provided.
8.2.2.3.3
Pilot Operation
The HRSG pilot shall remain in service continuously during CTG operation. Operator
shall have the capability to remove pilot from service if desired.
Pilot status indication on the console CRTs shall include the following:
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8.2.2.3.4

Pilot flame detected

Pilot valve open

Pilot valve closed
Technical Specifications: Appendix N2
Combined Cycle
Duct Burner Operation
The HRSG duct burner shall be placed into service and removed from service
automatically, or manually by the operator from the console CRTs.
Any shutdown shall be logged. Any abnormal shutdown shall be alarmed.
Duct burner indication on the console CRTs shall include the following:
8.2.2.3.5

Burner flame detected

Burner valve open

Burner valve closed
DCS Control of Duct Burners
The operator shall be able to perform all major control functions through the DCS
operator consoles, including the following:

Individual control of main burners

Individual control of pilot burners

Initiate purge
In addition, all "first-out" information shall also be available through the DCS operator
consoles.
8.2.2.4
STG/DCS Control Interface
The DCS shall be fully interfaced with the STG control system. Critical control and
protection/trip functions shall be hardwired between the DCS and the STG control
system. The communication interface to the STG control system shall be provided in
accordance with STG supplier requirements for DAS functions and non-critical control
signals. The DCS shall interface to the STG control system to manage the following
analog and digital STG control functions:

Startup sequencing through synchronization.

Speed and load control.

Temperature control.

Safety control including:
—
Automatic safe shutdown (ramp down)
—
Selected shutdown (ram down)
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—
Technical Specifications: Appendix N2
Combined Cycle
Emergency shutdown (fuel shutoff)
The Facility shall include sufficient manual control capability for STG speed, generator
voltage, and excitation such that a single operator can control the Plant from the DCS
control console.
8.3.
Testing
A standard factory acceptance test (FAT) of the complete control package including all
software, hardware, graphics, and alarming shall be provided.
The FAT shall be performed in the factory by the Seller and witnessed by the Purchaser
or Purchaser representative before shipment.
8.3.1.
Tools
One complete set of all special tools, software, and appurtenances required for
maintenance and operation shall be furnished with each system. The Seller shall itemize
the special tools and software that shall be furnished. If no special tools and software are
required, the Seller shall make a clear statement to this effect before Turnover to the
Purchaser. Any such tools required shall become the property of the Purchaser.
8.3.2.
Installation and Operating Instructions
One preliminary set of installation, operating, and maintenance instructions shall be
available for use by Purchaser during the factory simulation test.
System logic diagrams, configuration drawings, and schematics shall be bound in a
separate volume of the instruction manual and shipped within two months of system
shipment. Drawings shall be 11" x 17."
The installation and operating instruction books shall be complete to provide necessary
details for the installation, operation, and maintenance of all control systems and
equipment furnished for the Plant. Refer to section on Documentation for the detailed
requirements for the Instruction Books and Operating Manuals.
8.4.
Continuous Emissions Monitoring System
The Facility shall include a continuous emissions monitoring system (CEMS) for the
Plant subject to Purchaser’s approval. A CEMS shall consist of a continuous duty, remote
type analyzer subsystem with an extractive probe sampling system for each of the
generating units and a common data acquisition system. A maximum of two analyzer
subsystems may be installed in one CEMS shelter. 100% redundancy on CEMS sample
and monitoring equipment shall be provided.
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The CEMS shall be complete in all respects while meeting the requirements of this
section. The Seller shall develop the EPA and any local monitoring plans, which shall be
subject to Purchaser’s review.
The system shall be designed to comply with the Quality Assurance Procedures of 40
CFR Part 75, Appendix B. In addition, the system shall be designed to comply with all
applicable EPA installation, performance, testing, quality assurance procedures, and
requirements set for the in 40 CFR Part 60, as well as all applicable requirements of state
and federal air quality permits.
The CEM system shall be a complete and tested system ready for reliable commercial
operation. Failure of any system component or control shall be alarmed at the data logger
in the control room.
8.4.1.
Analyzer Subsystem
Each generating unit's analyzer subsystem shall consist of one sample transport system
and one set of continuous emissions monitors for the following flue gas constituents. The
Facility shall include all analyzers required as per permits and EPA requirements, which
include the following:

Nitrogen oxides (NOX) – dual range (low and high level)

Oxygen (O2)

Other as required
The system shall be sized and constructed to provide a transit time from the stack probe
to the analyzer no greater than 6 minutes.
All of the analyzers, data logger, and manual control switches for each unit shall be
housed in a single standard 19-inch rack. Rack space shall not be shared between
generating unit systems. The space for pumps, filters, chillers, and other items may be
shared between unit systems, but each item must be clearly identified by unit.
The CEMS shall be complete with analyzers, data logging, calibration gases, etc. At
Turnover, the Seller shall furnish a 6-month supply of certified gases in rechargeable
cylinders for each flue gas constituent to be monitored. These gases shall include zero
cal, span cal, low linearity check, and mid range linearity check. Each gas cylinder shall
be supplied with an appropriate two-stage regulator and shall be connected to the sample
transport system. All tubing on the exterior of the CEMS building shall be 316 stainless
steel tubing or tubing with a stainless steel jacket. These cylinders shall become the
property of the Purchaser and remain on the Plant site.
8.4.2.
Sample Transport System
Separate sample transport systems shall be provided for each generating unit that would
have emissions. A separate umbilical bundle shall be provided for each unit. This
umbilical bundle shall be self-limiting heat traced and contain all cable and tubing
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required to connect the stack probe to the CEMS. Each umbilical shall be long enough to
reach from the probe to the termination point in the CEMS shelter without splicing.
The heat tracing for each umbilical bundle shall be the temperature-controlled type and
shall be an integral part of the umbilical. A temperature controller shall be provided
inside the CEMS shelter for this heat tracing.
Sample probes shall have a sufficient length to meet EPA requirements and to obtain a
representative sample. Heated probes and the necessary provisions to prevent failure due
to moisture or other flue gas constituent shall be supplied. If required by the equipment
manufacturer, automatic probe cleaning shall be furnished. Automatic probe cleaning
shall be controlled through the CEMS data logger.
8.4.3.
Stack Gas Monitoring Equipment
Stack gas analyzers shall have a proven track record in meeting EPA requirements on
multiple units and shall be subject to Purchaser’s approval.
8.4.4.
CEMS Data Logger
CEMS shall include all hardware, software, and configuration needed to provide a system
that meets all requirements of 40 CFR Part 75.
8.4.5.
CEMS Enclosure
The Facility shall include sample conditioning system, analyzers, power supply system,
and lighting in a CEMS enclosure/shelter. The enclosure/shelter shall be sturdy and
suitable for power plant application. The enclosure/shelter shall be walk-in, dust-tight,
and weather-tight and built in accordance with the local building code requirements.
The CEMS enclosure/shelter shall have one HVAC system as defined in the Mechanical
HVAC section.
The analyzers and data-loggers shall be connected to the plant UPS.
A maintenance switch shall be provided to allow manual calibrations. The maintenance
switch shall provide a signal to the Data Logger as being in ‘Maintenance Mode.’ Only
when the maintenance switch is active shall the manual calibration valves and switches
be energized.
8.4.6.
Documentation
Installation, operating, and maintenance instructions shall be provided by the Seller for
each item in the CEMS system and building. These instructions shall be provided both in
hardcopy and on a CD-ROM. Hardcopy manuals may be scanned into Adobe Acrobat 3.0
or later and then included on the CD-ROM.
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8.4.7.
Technical Specifications: Appendix N2
Combined Cycle
Shipping
The complete CEMS shall be shipped to the site assembled with all the CEMS apparatus,
analyzer subsystem, sample transport system, and interior shelter features mounted in
place.
8.4.8.
Factory Checkout
The Seller shall check the CEMS at the factory before it is shipped to the site to ensure
that the CEMS meets all EPA requirements before shipment.
8.5.
Data Acquisition System
The Seller shall provide a complete data acquisition system (DAS) with software and
hardware. The DAS, which shall fully comply with all applicable requirements of 40
CFR Part 75, shall be located in the Plant’s main control room. It shall be capable of
interfacing with the data logger on that Plant site. The system shall collect, store,
calculate, edit, display, and print out data and other information as set forth in the
requirements that follow.
The polling computer shall include the following items at a minimum:

A current Pentium or equivalent processor, with a minimum 512 MB RAM, 32X
CD ROM, 4 mm tape backup, 80-GB hard drive, CD RW drive, 8MB AGP video,
Ethernet card, and 56K modem.

21-inch video display terminal, high-resolution color monitor (VGA or superior 1600 x 1200 at 75 Hz-26mm dot pitch).

Report printer

All interconnecting cables.

Full duplex Ethernet connectivity/capability for Plant LAN connection.
The computer, CRT, printer and other equipment shall be mounted on a workstation/desk
with an accompanying printer stand. This workstation shall be in its own space in the
Plant control room.
8.5.1.
Software
The system program shall provide the following features:

Multi-task operation such that data can be collected in background mode allowing
report generating or data editing in foreground mode.

Printer backup such that a printer failure shall not cause the program to stop. All
printer output is to be stored, so that when the printer is ready, the system will print
in sequence all reports generated during the time the printer was unavailable.
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8.5.2.
Technical Specifications: Appendix N2
Combined Cycle

Auto-restart such that should a system failure occur, it would automatically restart
itself when the failure is cleared. This feature eliminates the need for any manual
reloading of the system program.

Editing of all data on reports such that the revised data will be included in any
requested report, unless otherwise specified.

Internal clock/calendar with automatic leap year and operator-controllable daylight
savings time adjustments.

Keylock feature to limit access to program parameters using multi-level
passwords.
—
One level for operators to call up reports
—
One level for engineers to edit report
—
One level for technicians for diagnostics, etc.

Ability to download data in ASCII format.

Capability of expanding if other emission monitoring points or types is added.

Program backup on a CDROM for reloading should the system fail. The actual
source code should be supplied in hard copy format.

Software with standard REASONS CODES

Video display terminal, to provide
—
Real-time view of all measured and calculated parameters
—
Combustion turbine, duct burner, and monitor status
—
Visual alarm indication of potential emission standard violations, excessive
monitor calibration drift, or monitoring system failure
—
Graphics & trending

Hourly data transfer to the non-volatile memory or C hard drive and then daily
transfer to the D hard drive.

Software to support remote interrogation by modem

Users Manual based on Purchaser specific software

Calculations, record keeping, reporting, bias adjustment, automatic data
substitution procedures, and other requirements set forth in 40 CFR Part 75.
Data Communications System
Fiber optic cable shall be used between the polling computer and each data logger. This
cable shall be installed in its own conduit.
The Seller shall provide all fiber optic modems and telephone connections required for
the system to interface with state/federal reporting agency.
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8.5.3.
Technical Specifications: Appendix N2
Combined Cycle
Reporting and Recordkeeping Requirements
The data acquisition system shall automatically compute and cause to have printed all
information required pursuant applicable 40 CFR Part 60 Subparts and Appendices, 40
CFR Part 75; and all applicable EPA regulations, Purchaser's EPA permits, and
Purchaser’s local permits.
8.5.4.
Quality Assurance and Quality Control Data
The data acquisition system shall be required to record and maintain data pertaining to
daily and periodic monitor calibrations and checks and all other monitoring data quality
assurance and quality control procedures. The records generated and maintained shall be
sufficient to satisfy all applicable quality assurance and quality control provisions of
40 CFR Part 75 and 40 CFR Part 60.
Data will be recorded daily for each gaseous pollutant, dilutent, and flow monitor, as
applicable.
Periodic testing and certification procedures are required to assure monitoring data
quality. The data to be recorded periodically for each gaseous pollutant, dilutent, and
flow monitor, as applicable, shall meet all applicable requirements of 40 CFR Part 75 and
40 CFR Part 60.
At requested intervals, such as quarterly, the CEMS shall be capable of producing reports
based on edited and unedited data. The data acquisition system shall compute and cause
reports to be printed, when requested by the operator. The data processor shall be
designed to store sufficient data to produce these reports. Power supply failure shall not
erase the stored data or the program.
The data acquisition system shall be capable of compiling and generating quarterly
reports pursuant to the requirements of 40 CFR Part 75, and 40 CFR Part 60, as
applicable, and of any applicable state regulations, and as required by Purchaser's air
quality permits. The data acquisition system shall be capable of producing these reports
in printed and electronic format suitable for submission per the Plant reporting
requirements. The reports shall meet all EPA reporting requirements.
8.6.
Balance-of-Plant Instrumentation Installation Criteria and Installation
Details
8.6.1.
Scope of Specification
The following criteria cover the general requirements for the installation of
instrumentation and control systems.
The scope of work covered by this specification includes, but is not limited to,
installation and support of field instruments, instrument impulse lines, pneumatic signal
lines, sample lines, and local instrument cabinets.
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Combined Cycle
The use of eyewash stations and showers shall be alarmed in the DCS.
No primary sensor full-scale signal level, other than thermocouples, will be less than
10 mV or greater than 125 V.
To the extent practical, instrumentation will be standardized.
Instrument analog signals for electronic instrument systems shall be 4 to 20 ma dc.
Instrument analog signals for pneumatic instrument systems shall be 3 to 15 psig.
Use of pneumatic controls shall be limited to applications where sub-supplier standard
designs cannot be provided without them.
Local indicating controllers (if required) shall be furnished with an auto-manual function
switch.
The following units of measurement shall be used in process measurement and control.
English units are preferred, but metric units may be used when in common practice:
Parameter
Units of Measurement
Temperature
degrees Fahrenheit (o F)
Pressure
pounds per square inch gauge (psig)
inches of water column (in wc) or (inH2O)
pounds per square inch absolute (psia)
inches of mercury absolute (HgA)
Level
General
percent
Tank Gauge
linear feet, inches, and tenths of inches
Deviation from normal level
Flow
Liquids
gallons per minute (gpm)
pounds per hour (pph or #/hr)
Gases and Vapors
standard cubic feet per minute at 60 OF (SCFM)
standard cubic feet per hour at 60 OF (SCFH)
Steam and Boiler Feedwater
pounds per hour (pph or #/hr)
Solids
pounds per hour (pph or #/hr)
tons per day (tpd)
Steam & Water Sampling
pH
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Parameter
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Combined Cycle
Units of Measurement
Specific conductivity
S/cm
Cation conductivity
S/cm
Degassed cation conductivity
S/cm
Dissolved oxygen
parts per billion (ppb)
Silica or sodium
parts per billion (ppb)
Oxygen scavenger
parts per billion (ppb)
Sulfate, phosphate, chloride
parts per billion (ppb)
Permanently attached stainless steel tags shall be purchased with all major instrument
equipment. Each tag shall carry the item tag number. This tag is in addition to the
nameplate, which provides the manufacturer's model number and other data.
Thermocouple and test wells shall have the material of construction stamped on the well.
If tag numbers are assigned to these wells, the number shall also be stamped on the well.
Instruments in vapor or gas service shall generally be mounted above the sensing point.
Instruments in liquid, steam, or condensable vapor service shall generally be mounted
below the sensing point. If accessibility, visibility, or clearance requirements preclude
either of these situations, provisions shall be made in the instrument piping configuration
to ensure proper operation of the instrument. Close-coupled line-mounted pressure and
temperature gauges are mounted above the sensing point and are excluded from the
aforementioned.
Instrument root valves at piping or equipment connections shall be accessible from grade,
platform, stairway, or permanent ladder. Indicating instruments that must be visible for
automatic control adjustment or manual operation shall be visible from the adjustment or
operating point. If plot or piping arrangement precludes this, other provisions shall be
made for indication at the adjustment or operating point. Indicating instruments not in the
above category shall be visible from operating aisles or passageways.
Instruments shall be located so that required clearances are maintained for walkways,
accessways, and operation and maintenance of valves and equipment.
Blind transmitting instruments shall generally be line-mounted as near the sensing point
as practical. Instruments shall not be line-mounted when temperature or vibration from
hydraulics or operating equipment will affect the operation of the instruments or cause
damage to instrument piping.
Local recording and/or control instruments, except displacer-type level controllers and
flange-mounted transmitters, shall generally be remote mounted at grade or outside
platform handrails.
When practical, remote-mounted instruments will be grouped and have common
supports.
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Instrument piping shall generally be routed through pipeways and areas provided for the
routing of plant piping, and the piping shall be routed such as to protect it from damage
during plant operation and maintenance. Routing of instrument piping will be controlled
by the Field Control Systems Supervisor or Engineer.
Instrument piping shall be supported from pipe supports, pipe, and any other permanent
structure, except as follows:

Instrument piping shall not be supported from uninsulated hot (125°F and above)
or cold (40°F and below) pipes.

Instrument piping supports shall not be welded to stress-relieved equipment or
internally lined equipment. Instrument piping supports shall be sufficient to
maintain the piping in a neat manner. Instrument process piping having horizontal
runs greater than 5'-0" or combined horizontal and vertical runs greater than 10'-0"
shall be supported. The maximum length of unsupported tubing at a bend shall be
4'-0".
Process connection size shall be a minimum of 1/2-inch NPT. See Section 2.25.8.8.
All instruments and instrument process lines subject to freezing shall be heat traced, filled
with seal fluid, and purged or otherwise protected from freezing. Preference will be given
to heat-traced sensing lines and heated enclosures. The instruments and process lines
shall be identified on the P&IDs.
8.6.2.
Instrumentation Electrical Requirements
Enclosures for electrical instruments shall comply with requirements of the Electrical
Area Classification in which they are installed. If the manufacturer of certain instruments
cannot provide enclosures suitable for the area, purging of the enclosure with inert, dry
air or gas shall be given consideration. Cases for locally mounted instruments and devices
shall be weatherproof as a minimum.
Terminals for electrical interconnections including thermocouple wire shall be clearly
identified to indicate polarity, electrical ground where applicable, and test connection.
Terminals for purchased items shall normally be identified in accordance with
manufacturer’s standard marking.
Electrical conduit connections for locally mounted instruments shall normally be
internally threaded, where available as manufacturer’s standard option. Connections shall
be suitable for the Electrical Area Classification in which the instrument is installed.
8.6.3.
Pressure Instruments
Pressure gauge case sizes shall be 4.5 inches.
Connections shall normally be 0.5-inch MNPT for 4.5-inch locally mounted gauges.
Receiver gauges and 1.5 to 2.5-inch gauges shall be 0.25 inch NPT.
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Wherever necessary for Facility operation, either industrial-type, 4.5-inch diameter
pressure gauges with white face and black scale markings or indicating pressure
transmitters shall be provided.
Dials shall be white, non-rusting metal or plastic with black figures. Manufacturer’s
standard dial faces shall be provided. Dials or pointers shall be field adjustable for zero
alignment. These requirements do not apply to 1.5-inch and 2-inch gauges.
Steam pressure sensing transmitters or gauges mounted above the steam line shall be
protected by a loop seal or a siphon. Siphons shall be installed on pressure gauges in
steam service as required by the system design.
Pressure gauges on process piping shall generally be visible 10 feet from an operator's
normal stance at floor level and shall be resistant to Facility atmospheres.
Pressure gauge accuracy shall be ±0.5% of full range per ANSI Specification B40.1,
Grade 2A.
Pressure devices on pulsating services shall be equipped with pulsation dampers.
Pressure devices subject to shock during equipment starts, stops or transient conditions
shall be installed on an isolated gauge panel.
In general, pressure instruments shall have linear scales with units in psig.
Fire protection system pressure gauges shall be designed in accordance with
Underwriters Laboratories (UL) standards.
Pressure test points shall be equipped with isolation valve and cap or plug.
Pressure gauges shall be provided with either a blow-out disk or a blow-out back.
Pressure gauges shall have acrylic or shatterproof glass faces.
ACC vacuum shall be measured by an absolute pressure transmitter and shall be
indicated in the central control room.
Differential pressure instruments shall normally be of the manometer type, either liquidfilled, bellows, or force-balance type according to requirements.
Pressure gauge elements in contact with process fluid shall normally be 316 stainless
steel, except where the process requires a special material. Elements above 1,000 psig
shall be bored instead of drawn with threaded and backwelded connection to the socket
and tip. Bronze elements shall normally be used for air service.
Sockets and tips shall be stainless steel for stainless steel bourdon tubes, and brass for
bronze bourdon tubes, in accordance with manufacturer's standards.
Overpressure protection shall be 1.3 times the maximum tube rating to prevent permanent
set or loss of calibration from continuous overpressures. For services of 0 to 60 psi and
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below, wide bourdon tubes shall be furnished with external gauge protectors. Gauges
shall be vacuum protected.
Ranges shall be so specified that the gauges normally operate in the middle third of their
scales. Gauges on pump discharges shall be specified for over-range protection beyond
the pump shut-in pressure or relief valve setting. Gauges on vessels shall be specified for
overrange protection not less than 1.2 times the vessel design pressure.
Cases for gauges in the process area and in process service shall be solid front, phenolic
with a screwed ring, or plastic turret type with a snap ring. Cases shall be weatherproof,
and metal cases shall be protected with weather-resistant black paint.
Weep holes shall be provided on the case bottom of all gauges located in humid areas
unless the case already has sufficient ventilation.
Diaphragm protectors shall be used where necessary to protect gauges from corrosive
fluids. They shall have 0.5-inch NPT screwed or flanged connections in accordance with
piping specifications.
8.6.4.
Temperature Instruments
Temperature elements and dial thermometers shall be protected by thermowells except
when measuring gas or air temperatures at atmospheric pressure. Temperature test points
shall be equipped with thermowells fitted with caps or plugs.
Dial thermometers shall have 5-inch diameter (minimum) dials and white faces with
black scale markings and be every-angle type and bimetal actuated. Dial thermometers
shall generally be visible 10 feet from an operator's normal stance at floor level (viewing
area) and be resistant to Facility atmospheres.
If a thermocouple is inaccessible, the leads shall be brought to an accessible junction box.
Thermocouples (if used) shall be dual-element, ungrounded, spring-loaded, ChromelConstantan (ANSI Type E) or Chromel-Alumel (ANSI Type K) for general service.
Thermocouples general application shall normally be magnesium-oxide insulated
sheathed type. Thermocouple shall be constructed with a 316SS sheath of 0.25-inch
diameter.
Thermoelectric properties, temperature limits, and limits of error of thermocouples and
thermocouple extension wires shall conform to ANSI Standard MC 96.1.
Identification of thermocouples shall be by a wired-on metal tag indicating the code or
tag number.
Thermocouple heads shall be the cast aluminum type with an internal grounding screw.
Conduit connection shall be 0.75-inch. Connection to the thermocouple assembly shall be
0.5-inch NPT.
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In general, temperature instruments shall have scales with temperature units in degrees
Fahrenheit. Exceptions to this are electrical machinery resistance temperature detectors
(RTDs) and transformer winding temperatures, which are in degrees Celsius.
RTDs shall be either 100-ohm platinum type or 10-ohm, copper, three-wire circuits
(R100/R0-1.385), and ungrounded. The element shall be spring-loaded, mounted in a
thermowell, and connected to a cast aluminum head assembly.
Where ASME Performance Test Codes (e.g., PTC-6 Steam Turbines) are applicable to
power cycle piping, they shall be used as the criteria for determining well lengths.
Thermal-filled system instruments shall be gas or liquid filled stainless steel capillary
type.
Material shall be a minimum of ANSI Type 304 stainless steel machined from bar stock
in a tapered configuration. Other materials may be specified as required by the piping
specifications. The alloy used shall meet the process metallurgical requirements.
The temperature process connections shall be 1-inch NPT where screwed connections are
allowed by the piping classification. Where flanged connections are required by the
piping classification, they shall be designed to mate against a 1.5-inch raised face or ring
joint flange in accordance with the piping specifications. Weld in thermowells shall be at
least 1-inch diameter.
Special protecting tubes for high temperature applications of chrome iron, incoloy, or
other special materials shall be used as required by the temperature and the process
materials.
Thermowells in combining streams shall be a minimum of 10 pipe diameters downstream
of the junction for liquid services and 30 pipe diameters for vapor services.
Brass plug and chain shall be provided with all test wells.
Thermowells shall be designed to avoid root stress failure due to vibrations induced by
wake vortices. Where the standard thermowell is designed to withstand the maximum
fluid velocity permitted in the piping design standards, individual wake frequency
calculators are not required.
Dials of 3-inch diameter may be used in mechanical equipment lube and seal oil service
or other auxiliary service.
Installation of thermocouples, thermowells, test wells, and thermometers shall be in
accordance with utility and good engineering practice unless otherwise specified.
8.6.5.
Level Instruments
A graphic indication on the DCS CRT (driven by the differential pressure level
transmitters on each drum) will be provided to meet the ASME drum level monitoring
requirements in the central control room.
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Reflex-glass, liquid-free, or magnetic level gauges (Penberthy or equal) will be used.
Sump pump motors will be controlled by displacer or float-type level switches supplied
by the sump pump manufacturer.
Level transmitters for measuring the level in storage tanks vented to atmosphere (e.g.,
makeup water storage tank, demineralized water storage tank) will generally be the
flange-mounted differential pressure type flush diaphragm and will be equipped with
local indication as well as central control room indication.
Differential pressure type level instruments will normally be used for all services except
for vacuum services. When differential pressure type instruments are to be mounted at or
below the taps, they shall be furnished with zero elevation or suppression adjustment.
External displacement type instruments shall normally conform to the following:

Material shall normally be fabricated carbon steel, with stainless steel displacer
and Inconel torque tube. Where vessels are of alloy construction, body material
shall be equivalent or better.

Air fins or heat insulators shall be used at operating temperatures above 400°F and
below 0°F for displacers with pneumatic pilots. Where displacers with electronic
transmitters are used, they shall have air fins or heat insulators above 250°F and
below 0°F.

Connections shall normally be 1.5-inch flanged with bottom-side and top-side
connections. Flange ratings shall be in accordance with vessel trim specification.

Rotatable heads shall normally be specified.

Transmitter Output shall be 4 to 20 ma dc.
Direct operated type level controls (e.g. ball float, mechanically linked valve) shall be
used on utility service only.
Special level problems will arise periodically and will require special level measuring
devices such as internal displacers or floats, bubblers, and electronic types (capacitance,
ultrasonic, nuclear, conductive, or electrical resistance).
8.6.5.1
Liquid Level Columns (Bridles)
Liquid level bridles shall be used to minimize the number of vessel nozzles where
numerous level instrument connections are made to the same vessel.
The bridle upper connection shall be flooded with process fluid for interface
measurements.
The top and bottom connections of the bridle shall be made directly to separate nozzles
that are not connected to vessel inlet or outlet nozzles.
The bottom connection of the level bridle shall be located a minimum of 2 inches higher
than the top of the vessel outlet when vessel discharges from the bottom.
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Level bridle piping shall not have bends that will trap dirt or water.
8.6.5.2
Storage Tank Instruments
Tape gauges shall be provided.
Water tanks shall be equipped with flange-mounted level transmitters with local
indication.
Fuel tanks shall be equipped with flange-mounted smart transmitters and a servocontrolled displacer gauge or approved equal.
Tanks containing fuel and hazardous material shall instrumentation that can be tested
without draining of contents.
8.6.6.
Level Gauges
Typically, magnetic follower-type level gauges shall be provided except for steam drum
and supplier skids. Supplier skids shall use the supplier’s standard devices where suitable
for heavy industrial use. Where glass gauges are provided by skid suppliers, gauge and
ball checks shall be provided.
All vessels other than storage tanks, where actual level or interface level is measured for
indication or control, shall have a level gauge.
Alloy construction (normally 304 stainless steel) shall be used for all wetted parts where
the application requires it, and on applications below 20°F.
Frost protection shall be provided where operating temperatures are below 32°F.
Visibility shall cover the operating range of the level instrument(s). In alarm and
shutdown service, the visibility shall normally cover the range of all level instruments
including the shutdown point. Level glasses shall be visible from grade, platform, or the
related instrument.
Connections of gauge glasses shall normally be 0.5-inch or 0.75-inch NPT female top
and bottom. Other connection orientations may be used where required.
Where necessary, level glass cocks shall meet vessel trim specifications and shall be
considered a combination block valve and safety shut-off cock. They shall have a 0.75inch solid-shank NPT male inlet with 0.5-inch or 0.75-inch NPT female spherical union
gauge connection. A ball check shall be furnished.
Where standard gauge valves do not comply with the applicable piping standard, gate
valves and ball check valves shall be substituted. The gate and check valves shall be
installed in the horizontal line to the vessel, with tees provided for vents and drains.
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8.6.7.
Technical Specifications: Appendix N2
Combined Cycle
Flow Elements – Flow Nozzles and Venturis
The flow elements for feedwater flow to the HRSG will be laboratory-calibrated venturi
flow nozzles. Venturi nozzles shall also be used for all flows used for primary control of
the HRSGs or steam turbine. Orifice plates may be used for other flow measurements.
Flow transmitters shall be the differential pressure type with the range matching (as
closely as practical) the primary element.
Linear scales and charts shall be used for flow indication and recording.
In general, feedwater flow meters shall be temperature-compensated when the water
temperature is greater than approximately 250oF; critical steam and natural gas flow
meters (if applicable) shall be temperature and/or pressure compensated; and airflow
measurements shall be temperature compensated.
Differential-pressure-type instruments shall normally be used for flow measurements
where suitable for the application.
Flow transmitters shall be the essentially zero volume displacement differential pressure
type. Bodies shall normally be carbon steel with stainless steel internal trim, unless other
materials are required for the particular services. Overrange protection equal to the body
rating shall be provided.
Wherever possible, the maximum differential range in inches of water shall not exceed
the static absolute pressure in psia in a compressible fluid application. Span shall be
continuously adjustable over at least a 5:1 ratio.
Variable area flow meters may be used for small flow rates where local indication is
required. They may also be used where rangeability, nonlinearity, viscosity, or the
hazardous nature of the fluid makes the differential-pressure-type instrument
unsatisfactory. They shall normally be the armored type with magnetic pick-up, except
for water and air below 200 psig and 1-inch-or-smaller lines where glass tubes may be
used. All glass tube area meters shall have front and rear plastic guard plates.
Positive displacement meters shall be used to measure those flows where a highly
accurate integrated flowing quantity is desired.
8.6.8.
Flow Elements – Orifice Plates
Orifice plates of the square-edged concentric type shall be specified except where
unsatisfactory for the application. Plate dimensions shall conform to ASME MFC-3M.
Weep holes shall be provided in steam and gas flow installations where there is possible
condensation or in liquid flow where there is possible gas entrainment. Materials shall
normally be Type 304 stainless steel unless special materials are required for the service.
For gas and vapor service, the differential pressure range in inches of water normally
shall not exceed the static absolute pressure in psia.
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Orifice bores will be calculated using ASME MFC-3M and ISO 5167.
Flange taps shall normally be used in accordance with ASME MFC-3M. For special
alloys and 14-inch-and-larger pipe sizes, in 150-psi classification, throat taps may be
used. One-half-inch NPT is the normal tap size for 300 psi through 600 psi flange rating.
Three-quarter-inch is the tap size for 900 psi through 2,500 psi flange rating. Where
threaded connections are not permitted by the pipe class, socket weld connections shall
be used.
The minimum orifice flange rating shall be 300 psi ANSI except for lines 14 inches and
larger, where 150 psi ANSI is the minimum. The use of higher rated flanges, or of facing
type, shall be as called for in piping specifications.
Ring-type plate holders shall be manufacturer's standard plate mounting. Ring facing
shall be oval ANSI standard unless otherwise required by piping specifications.
Orifice taps for horizontal pipe runs shall normally be oriented horizontal for clean
liquids and steam, and vertical-up for gases.
Venturi tubes, low-loss tubes, and flow nozzles shall be used where high-pressure
recovery is necessary and/or where only low inlet pressure is available.
Averaging pitot tubes shall be used where the pipe diameter is too large for acceptable
orifice plate design in applications such as pump minimum flow bypass control, or where
normal straight pipe requirements are not met. The element may have two pipe diameters
of straight pipe upstream and downstream mounted in a plane parallel to the maximum
disturbance.
Other types of flow elements should be considered where their use is desirable and the
above-mentioned elements are not applicable.
Integral orifice meters (combination primary element-measuring device) shall normally
be used for meter runs of less than 1.5 inches with a suitable strainer upstream of the
meter.
Eccentric type orifice plates shall be used for fluids containing two phases. The eccentrictype orifice plates shall have the bottom of the orifice bore flush with the bottom ID of
the pipe. Eccentric orifice plates shall be used only in horizontal runs.
8.6.9.
Annunciators, Alarm Switches, and Electrical Devices
Annunciator design shall be in general accordance with ISA RP-18.1 "Specifications and
Guides for the Use of General Purpose Annunciators."
Switches and shutdown for alarms and interlock systems shall be used for on-off
applications only. When outdoor installations are required, they shall meet the area
classification and be weatherproof. Switches in equipment shutdown service, where
practical, shall be directly connected to the process. Wiring for switches shall be two
conductors and shall not use the common wire technique.
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Switch contacts shall be specified as two single-pole double-throws (Form C) wherever
the double mechanism does not induce unacceptable dead band. However, only one
function per enclosure shall be specified (i.e., alarm only or interlock only). On shutdown
circuits, the second contact on the enclosure may be used for alarm, but proper signal
separation shall be maintained in the conduit system.
Switch action for alarms, shutdowns, and interlocks shall normally be closed circuit at
normal operating conditions and open circuit for abnormal condition.
Level switches shall normally be the external float cage type with 1-inch NPT socket
weld or screwed connections. Body material and rating shall conform to piping
specifications. Internal trim shall be stainless steel unless other materials are required for
the service. Level switches in alarm services may be receiver switches when there is a
level transmitter as part of the system.
Pressure switches for direct connected process and utility service shall normally be
diaphragm or bourdon-tube type with materials suitable for the service. They shall meet
the required electrical classification and shall have micro switches. Connection sizes shall
normally be 0.5-inch NPT.
Temperature switches, locally mounted in Division 1 or 2 locations, shall be filled system
bulb type or expansion type. They shall meet the electrical classification and shall have
micro switches. Separable sockets shall be furnished. Temperature switches mounted in
the central control room or on a local panel shall normally be thermocouple actuated with
cold-junction compensation and be completely adjustable.
Flow switches for direct operation by process fluids may be of the sight flow, rotameter,
or paddle type for low accuracy requirements. Orifice plate and differential-pressure type
shall be used for high accuracy requirements.
Solenoid valves shall normally be used as pilots to actuate other instruments directly
connected to process fluids. Valve bodies for solenoid valves shall follow the piping
specifications when used in process lines. Manufacturer's standard brass shall normally
be used on air service.
When outdoor installations are required, they shall meet the area classification and shall
be weatherproof. Preferred voltage rating is 120 Vac. Coils for solenoid valves shall be
hi-temp molded and encapsulated and specified for continuous duty at rated voltage and
frequency. Coils for direct current shall be supplied with internal spike suppressors.
8.6.10.
Process Analyzers and Analyzer Systems
All analyzers are to be completely piped, interconnected, and checked out for proper
functional operating conditions.
Complex process stream analyzer systems shall be installed in a waterproof cabinet,
enclosed house, or shelter. These shall include the following provisions:
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
Enough working space shall be allowed for proper maintenance of the analyzers
within the house.

Analyzer houses and cabinets shall be of metal or fiberglass construction and
equipped with a door, lock, and key.

These enclosures shall be located as close to the process sample points as practical.
More than one analyzer measuring and sample system may be installed in a single
enclosure if the sample line length is within the analyzer manufacturer's
specifications.
All necessary calibration and operating gases shall be provided including gas cylinders
and regulators. CEMS equipment shall be according to manufacturer’s recommendations.

Analyzers requiring gases for continuous operation shall be provided with dual
facilities for uninterrupted service.

Calibration standards and facilities shall be supplied for zero and span check where
specified.

Protected outdoor storage racks adjacent to the analyzer houses shall be provided
for the carrier and calibration gas cylinders (including inventory) and their
associated regulators. Process sample regulators shall also be located on the
outside of the analyzer houses.
The sample systems shall be designed to deliver clean, representative samples to the
analyzers at the proper temperatures, pressures, physical conditions, and flow rates.

All wetted components shall be 316 stainless steel, or equivalent, unless other
materials are required to minimize contamination and corrosion. Main line class
pipe may be used in high-temperature samples.

Appropriate measures shall be taken to prevent plugging of sample lines due to
freezing, condensation, or solids.

Where sample recovery systems are required, provision for drains shall be made in
the building design.

Transportation time from sample point to analyzer shall be less than 2 minutes for
chromatographs and less than 1 minute for other analyzer types. Fast circulating
loops and/or bypass lines shall be used to achieve fast response times except where
such a design would cause EPRI guidelines to be violated or sample composition
to be changed.

For fuel gas samples, the pressure shall be reduced at the sampling point to
increase the velocity through the sample system and reduce time lag (except in
CEMS equipment where the manufacturer’s recommendations are to be followed).

All sample and bypass lines shall have flow indicators, such as rotameters.

Bypass flows and discarded samples shall be routed to chemical safe drains or
vented safely to atmosphere.

Adequate facilities shall be provided to protect against unwanted backflow,
overpressure, or other abnormal conditions.
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
Technical Specifications: Appendix N2
Combined Cycle
When sample conditioning components require heating, they shall be located
inside a heated and insulated cabinet or enclosure.
The analyzer and sample system shall be vendor assembled and pretested in the vendor's
shop before shipment, unless otherwise specified.
Electrical wiring of analyzers shall conform to the National Electrical Code and
applicable local codes. For large instruments such as analyzers that cannot be mounted in
an explosion-proof box, air purging may be required. ISA RP-12.4 should be followed. If
possible, the analyzer houses should be mounted in nonhazardous areas.
Process control loops that include an analyzer shall normally be cascaded. In some cases
where the analyzer output is continuous and not delayed, direct control may be provided.

Holding circuits shall be provided when the analyzer output is intermittent. The
output of this device may be used for trend recording in addition to providing a
signal for a control loop.

Converters to provide a current or pneumatic output shall be provided if required.
CTG and STG non-control instrumentation shall be available through the DCS, if
possible. Such information will include the following:

Bearing metal thermocouples

Bearing drain thermocouples

Generator RTDs

Steam turbine metal temperatures

Non-contacting vibration probes
8.6.11.
Pressure and Temperature Switches
Field-mounted pressure and temperature switches shall be provided in either NEMA
Type 4 housings or housings suitable for the environment.
In general, switches shall be applied such that the actuation point is within the center onethird of the instrument range.
8.7.
Instrument Air and Service Air Systems
Branch headers shall be provided with a shutoff valve located at the takeoff from the
main header. The branch headers shall be sized for the air usage of the instruments
served, but will be no smaller than 3/8 inch. Each instrument air user shall have a shutoff
valve and filter located at the instrument. Each service air user shall have a shut-off
valve.
Instrument air of suitable quality shall be provided for calibration of CEMS oxygen
analyzers.
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A minimum of 10 service air connections shall be provided around the facility – locations
shall be coordinated with the Purchaser.
8.8.
Field-Mounted Instruments
Where practical, field-mounted instruments shall be grouped together. They shall be
mounted in areas accessible for maintenance and relatively free of vibration and shall not
block walkways or prevent maintenance of other equipment.
Field-mounted instruments shall be of a design suitable for the area in which they are
located. Freeze protection shall be provided as required.
Individual instrument supports shall be prefabricated, off-the-shelf, 2-inch pipe stand
type.
Individual field instrument sensing lines shall be run in horizontal and vertical lengths
that do not affect signal response.
In general, local control loops shall use a locally mounted indicating controller (pressure,
temperature, and flow).
In general, liquid level controllers shall be the indicating, displacement type with external
cages.
Instrument racks and individual supports shall be mounted to concrete floors, to
platforms, or on support steel in locations not subject to excessive vibration.
8.8.1.
Instrumentation - General Design
All instruments and equipment shall be installed in a manner that ensures reasonable
protection against mechanical damage, wetting, and extremes of heat or cold.
Instrumentation shall be handled at all times so as to protect it from damage to the
internal mechanisms. Instrumentation shall be stored in accordance with the
manufacturer’s recommendations until installation. Final locations and orientations must
be selected for accessibility, repair, and calibration in place, for easy access to the rear of
the instruments (if needed), and for disconnection without resorting to cutting, burning,
or welding.
Instrument supports shall not be mounted on or connected to handrails, stairways, or
machinery or to any equipment subject to movement under load.
All pipe-mounted temperature and pressure indicators and bridle-mounted level gauges
shall be mounted so as to provide direct visual readings from operating decks and
accessibility for maintenance. If pipe-mounted instruments are subject to freezing, they
shall be appropriately freeze protected.
Electronic process transmitters shall be two-wire, smart type.
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Temperature, pressure, and differential-pressure transmitters, switches, and transducers
shall be mounted on either stands or racks or in local instrument cabinets as long as
instruments are properly protected, including environmental protection (heat traced).
Instruments that can be logically grouped shall be installed on racks or in local instrument
cabinets. Instrumentation, accessories, and all other equipment shall be located and
mounted such that calibration, maintenance, and removal work can be performed on any
one piece of equipment without disturbing another. Adequate clearance shall be provided
so that calibration, adjustments, and connections are easily accessible without need of
instrument removal. All instrument covers shall be provided with adequate clearance
space for removal. Equipment shall be arranged such that work can be performed easily,
without need for special tools.
Instruments and manifold valves shall be easily accessible for calibration. All pressure
and differential-pressure transmitters shall be installed with instrument manifolds. All
differential transmitters shall be installed with three-valve or five-valve manifolds. Two
valve manifolds shall be used for all static pressure transmitters.
Orifice flanges and flow nozzles or venturis shall be oriented such that taps are
horizontal, neither above nor below the centerline of the pipe. Flow orifice plates shall be
installed only after applicable piping has been flushed or blown down.
Each pressure connection, except for relief valves, shall have a root valve. Double block
and bleed valves are required for relief valves that would require an entire plant outage to
service. Each temperature connection shall have a well that will withstand the maximum
system pressure and whose velocity rating to withstand vibration exceeds the maximum
fluid velocity to which the well may be subjected. Thermocouple material shall be
compatible with the main process pipe material.
All external electrical connections of junction boxes and cabinets shall be made to
terminal blocks. The wiring and terminal blocks for different voltage classes shall be
physically separated in order to minimize electrical noise and hazard to personnel.
Terminal blocks shall be provided with marker strips.
Instruments shall be mounted in a manner that prevents vibration effects. Snubbers or
other suitable damping devices shall be provided for pulsating services.
8.8.2.
8.8.2.1
Instrument Cabinets and Local Control Panels
Local Instrument Cabinet Installation
Instrument cabinets shall be secured to structural steel or to concrete. Cabinets shall be
electrically grounded. Bolting to bare or galvanized metal shall be used for attaching a
ground strap.
Instrument cabinets shall have sufficient clearances for the required blowdown piping
and headers, door swing radius, etc., and the cabinets shall be completely accessible for
maintenance.
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The cabinets shall be installed and anchored in place so that they are level, plumb, and
properly aligned in accordance with the above mounting requirements.
Cabinets shall not be supported by handrails. All instrument line penetrations into
instrument cabinets shall be through bulkhead fittings (couplings). Bulkhead couplings
shall be supplied on instrument cabinets for each instrument location. Top entry of
instrument cabinets or instrument cabinet junction boxes is prohibited. Bottom entry is
the preferred method for conduits.
8.8.2.2
Local Instrument Cabinets
Local instrument cabinets shall be constructed of high-quality galvanized commercial 12
gauge sheet steel plate or stainless steel, flat and free of pitting. All cabinet sections shall
be continuous with no weld joints. Welding shall join seams between assembled sections.
Cabinet doors shall have 3-point latches.
The cabinets shall be provided with thermostatically controlled heaters and fully
insulated for freeze protection and humidity control. The cabinets shall be designed to
maintain an inside temperature of 60F with an ambient temperature of 0F.
Each cabinet shall contain an instrument air supply bulkhead. All instrument air supply
lines shall contain tubing valves for isolation purposes. Every air supply shall contain a
valved outlet for maintenance uses.
8.8.2.3
Cabinet Painting and Coating
All sheet steel used in the construction of the cabinets (except stainless steel) shall be
suitably painted.
8.8.2.4
Instrument and Control Wiring and Instrument Cabinet Wiring
Instrumentation and control wiring shall be installed in accordance with the requirements
of the Electrical section.
Both ends of each wire shall be identified with labels that are indelibly imprinted on heatshrunk plastic tubing. Wire identification shall consist of a from-to device identifier.
8.8.2.5
Painting and Coating
Where galvanized coating has been removed or degraded due to cutting, welding,
scratches, etc., it shall be refinished to original manufacturer’s specifications.
The Seller shall touch up all equipment finish paint coats damaged while under the
control of the Seller. The Seller shall use paint of the original specification color and
finish.
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8.8.2.6
Technical Specifications: Appendix N2
Combined Cycle
Marking
The Facility shall include stamped stainless steel tags for process root valves, each
instrument, and panel or cabinet.
8.8.3.
8.8.3.1
Instrument Tubing and Piping
Instrument Tubing
Tubing usage shall be permitted for the following applications:

Inside local instrument cabinets

At a pneumatically-operated final control element

Sample lines

When properly protected and supported from root valve to instrument
All tubing shall be ASTM 213 type 316 stainless steel (except in acid service), both
seamless and annealed and properly rated for temperature and pressure applications.
Copper tubing shall be ASTM B-75 and shall be permitted only for instrument air service
inside instrument cabinets and (individual) branch applications.
Tubing shall be installed so that sags and low spots are avoided. All tubing cuts shall be
made with a roller-type tubing cutter and shall be deburred. All tubing bends shall be
made with an approved mechanical bender to avoid flattening of the bends.
All tubing fittings shall be compression type, Parker Hannifin CPI or Swagelok. The use
of flared-type fittings shall not be accepted and is strictly prohibited. Pipe dope or Teflon
tape shall not be used on the tubing-side threads of compression fittings.
Tubing runs requiring support shall be run in Tube Track.
Each instrument sensing line shall terminate with a main line class blowdown valve
mounted adjacent to or below the instrument cabinet.
Instrument sensing lines for draft measurements and other very low-pressure and
differential-pressure measurements shall be 1-inch minimum O.D. Instrument sensing
lines for other pressure and differential pressure measurements shall be 0.5-inch
minimum O.D. The length of the sensing lines shall be kept as short as possible to
minimize instrument sensing errors
Tubing used to connect instruments to the process line shall be 3/8 inch OD x 0.049 WT
seamless soft annealed copper ASTM B-75 (Instrument air service) or 3/8 inch OD x
0.065 WT SS seamless ASTM A-213 or A-269 Type 316 RB 80 Hardness as necessary
for the process conditions.
Instrument tubing fittings shall be the compression type. One manufacturer shall be
selected for use and be standardized as much as practical throughout the Facility.
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Differential pressure (flow) instruments shall be fitted with three-valve manifolds, while
two-valve manifolds shall be specified for other instruments as appropriate.
Instrument installation shall be designed for correct sensing of process variable. Taps on
process lines shall be located in such a manner that sensing lines do not trap air in liquid
service or liquid in gas service. Taps on process lines shall be fitted with a shutoff (root
or gauge valve) close to the process line. Root and gauge valves shall be main-line class
type valves.
Instrument tubing, including freeze protection, shall be supported in both horizontal and
vertical runs as necessary. Expansion loops shall be provided in tubing runs subject to
high temperatures. The instrument tubing support design shall allow for movement of the
main process line.
8.8.3.2
Instrument Piping
Instrument piping, when required for proper protection, shall be in accordance with the
main process piping design. Instrument pipe wall thickness shall be based on the main
process pressure and temperature design.
Piping runs shall be installed with continuous slopes to process connection or instrument
connection as required.
Instrument line pipe shall be bent whenever possible.
8.8.3.3
Instrument Tap Installation Criteria
Each instrument tap shall have a main line class root valve. Instrument pressure taps in
horizontal process piping should generally be mounted on the top centerline where the
process is air or gas. When the process is steam or a liquid, instrument pressure taps
should generally be mounted on the side centerline of the process pipe. There shall not be
any instrument taps on the bottom of process lines.
Instrument pressure taps shall be located such that there is undisturbed flow in the area of
the tap. Thus, there should not be any device or component that could cause flow
disturbance for a distance of at least 10 pipe diameters upstream and downstream
distances should be no less than one foot.
Thermowells should generally be mounted on the top centerline of horizontal process
piping. Thermowells should generally be located at least 5 pipe diameters or one foot
(whichever is greater) downstream of any instrument pressure tap or flow tap.
8.8.3.4
Piping Supports
Hangers and supports shall be located such that sags and low spots in piping are avoided.
The design shall consider the relative motion that may exist between pieces of equipment
due to thermal expansion and/or vibration. The Facility shall include expansion loops
where required.
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8.8.4.
Technical Specifications: Appendix N2
Combined Cycle
Air Piping, Fittings, and Pneumatic Devices
All instrument air piping shall have low point drains, and all vertical risers shall have
collection pots and drains.
Instrument air secondary branch headers for the supply of instrument air to analog control
equipment shall not be used to supply solenoid-valve-operated air cylinders.
An air filter pressure regulator with outlet gauge shall be supplied for each individual
instrument air user. The air filter pressure regulators shall be mounted on the instrument
air piping near the end user using a flexible hose connection between the regulator and
the end user.
All instrument air piping and tubing shall be purged of extraneous material by blowing
clean, dry, oil-free air through the system before final connection.
All pipe-threaded fittings shall use either Loktite, pipe sealant with Teflon, or Teflon tape
to seal the connection. The use of lead-base pipe dope is not acceptable.
8.9.
Steam/Water Sampling and Analysis
The steam and water sampling and analysis system shall be provided to monitor the
performance of the steam, condensate, and feedwater cycle, to monitor the quality of
various process fluids, and to provide sufficient data to operating personnel for the
detection of any deviation from control limits so that corrective action can be taken.
The system shall condition samples by pressure and temperature reduction and measure
flow, temperature, pressure, cation conductivity, specific conductivity, pH, sodium,
silica, and dissolved oxygen, etc. The Facility shall include a centralized station to
provide analysis for various samples as needed for the proper operation of the plant.
Samples shall be taken from various points in the plant and routed to a centrally located
steam/water analysis panel. Pressure and temperature reduction shall be provided to suit
each analyzer. Pressure reduction shall be provided by pressure-reducing valves, and
temperature reduction shall be provided through sample coolers. Provision shall also be
made for the grab sample for each sample.
The samples shall then be directed to automatic analyzers and results fed to the DCS for
monitoring, recording, and controls.
8.10.
Vibration Monitoring System
State-of-the-art vibration monitoring equipment shall be provided for the CTG, STG, and
all large rotating machinery, including motors and pumps/fans over 500 bhp. The
vibration system shall be complete with vibration sensors and monitors. The vibration
information shall be available to the operator, maintenance people, and plant engineer’s
office.
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8.11.
Technical Specifications: Appendix N2
Combined Cycle
Plant Siren System
The Seller shall provide a plant siren system, which shall provide a sound level minimum
of 5dB above ambient levels throughout the plant.
Consideration shall be given to which type of loudspeaker is more suitable for the
environment to which it will be subjected.
8.12.
Instrument Calibration
All instruments shall be field-calibrated per manufacturer’s specification after installation
at the site. Calibration sheets shall be completed and handed over to the Purchaser for
records and for future use. All instrumentation used in testing shall be calibrated within
60 days of a test.
8.13.
I&C Maintenance Area Requirements
An I&C area in the maintenance area shall provide for I&C maintenance. The Seller shall
furnish I&C area equipment that are generally needed in the I&C maintenance area.
The power feeds to the I&C Area shall not share a breaker with feeds to welding
machines or to mechanical equipment in the maintenance area.
9.
CIVIL AND STRUCTURAL WORKS
The civil and structural works shall include all investigations, assessments, permitting,
design, construction, testing, inspection, and other activities as required to complete the
Facility in accordance with the minimum requirements of this specification and the
requirements of all local, state, and Federal codes and regulations.
9.1.
Design Criteria
Unless superseded by law or regulation, these design criteria govern the requirements
regarding dead and live loads, other loads, and loading combinations in the design of
structures. The loads specified herein are the minimum loads to be considered in the
design.
Steel structures shall be designed by either the working stress method (ASD) or load
reduction factor method (LRFD).
Reinforced concrete structures shall be designed by the ultimate strength method.
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9.1.1.
Technical Specifications: Appendix N2
Combined Cycle
Dead Loads
Dead loads shall be considered as the weight of all permanent construction, including
walls, floors, ceilings, stairways, all fixed empty vessels and equipment, built-in
partitions, structures, fireproofing, insulation, piping, and electrical conduits.
9.1.2.
Live Loads
Live loads shall be defined as those loads produced by the use and occupancy of the
buildings or other structures and do not include environmental loads such as wind load,
snow load, rain load, earthquake load, or dead load. Live loads on a roof are those
produced (1) during maintenance by workers, equipment, and materials and (2) during
the life of the structure by movable objects. Live loads shall be uniformly distributed over
the horizontal projection of the specified areas and shall have the minimum values noted
below.
9.1.2.1
Platforms, Walkways, and Stairs
A uniform live load of 100 pounds per square foot (psf) shall be used. In addition, a
concentrated load of 2 kips shall be applied concurrently to the supporting beams to
maximize stresses in the members, but the reactions from the concentrated loads shall not
be carried to the columns.
A uniform load of 50 psf shall be used to account for piping and cable trays where
applicable. Where the piping and cable tray loads exceed 50 psf, the actual loads shall be
used.
9.1.2.2
Pipe Racks
A minimum uniform load of 100 psf shall be used for each level of the pipe racks. Where
the piping and cable tray loads exceed 100 psf, the actual loads shall be used. In addition,
a concentrated load of 5 kips shall be applied concurrently to the supporting beams to
maximize stresses in the members, but the reactions from the concentrated loads shall not
be carried to columns.
Hangers for piping and equipment loadings, anchor forces, and other restraining forces
shall be determined by engineering analysis. In areas where numerous miscellaneous
small bore piping, conduit, and cable tray loads will exist, an additional uniform load to
be determined by the structural engineer shall be added to the design loads.
9.1.2.3
Ground Floor (Slab at Grade)
Design shall be based on equipment weight, storage, or laydown weight or a uniform load
of 250 psf, whichever is greater.
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9.1.2.4
Technical Specifications: Appendix N2
Combined Cycle
Thermal Forces
Thermal forces caused by thermal expansion of equipment and piping under all operating
conditions shall be considered.
When portions of a structure are not free to expand or contract under temperature
variations, allowance shall be made for stresses resulting from temperature change. When
portions of a structure are subject to unequal temperature variations, allowance shall be
made for stresses resulting from the variation.
9.1.2.5
Dynamic loads
Dynamic loads shall be considered and applied in accordance with the manufacturer,
specifications, criteria, recommendations, and industry standards.
Vibration load shall be defined as those forces that are caused by vibrating machinery
such as pumps, blowers, fans and compressors, and turbine generators.
All supports and foundations for vibrating equipment shall be designed to dampen
vibrations and as required by the equipment manufacturers. Allowance will be made for
such dynamic effects, including impact, by increasing the computed live load value by an
adequate percentage.
For structures supporting elevators, machinery or craneways, design for impact shall be
as required by ASCE 7-95.
9.1.2.6
Truck Loads
Roads, pavements, underground piping, conduits, sumps, and foundations subject to truck
traffic shall be designed for HS-20-44 loadings in accordance with AASHTO Standard
Specifications.
A surcharge load of 250 psf shall be applied to the Facility structures where accessible to
truck traffic.
9.1.2.7
Wind Loads
All structures shall be designed for a basic wind velocity shown in Section 2.3 (see
Appendix N3).
9.1.2.8
Seismic Loads
Structures shall be seismically designed in accordance with the requirements of the State
of California.
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9.1.2.9
Technical Specifications: Appendix N2
Combined Cycle
Other Loads
Other loads used to predict the structural response of structures shall include hypothetical
loads representing the influence of piping, including water hammer, and loads at anchor
points and electrical installations not included in the normal dead or live loads. Pressure
or suction loads such as encountered in ductwork shall be taken into account, including
dynamic loads from operating equipment.
Earth pressures shall be defined as the active and passive lateral forces associated with
soil and hydrostatic pressures.
Handrails/guardrails for stairs, platforms, or other uses shall be designed to withstand a
lateral load of 20 pounds per linear foot (plf) or 200 pounds applied in any direction at
any point on the top of the rail.
9.1.2.10
9.1.2.11
Allowable Stresses

Concrete:
In accordance with ACI 318 Code

Masonry:
In accordance with the California State Building Code
Load Combinations
Appropriate loading combinations shall be used for structural steel and reinforced
concrete to comply with applicable codes and standards and with vendor requirements.
9.1.2.12
Factor of Safety
Minimum factors of safety for all structures, tanks, and equipment supports shall be as
shown below:
9.2.

Overturning
1.50

Sliding
1.10 for seismic load
1.50 for wind load

Buoyancy
1.25

Uplift due to wind
1.50
Site Preparation
Site preparation shall consist of clearing and grubbing and the placing and compaction of
fill with slopes and embankments designed in such a fashion as to be stable and capable
of carrying anticipated loads from either equipment or structures.
Materials from clearing and grubbing operations shall either be removed from the jobsite
and be properly disposed of or, if suitable, reused on site.
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Combined Cycle
Erosion and sediment control measures shall be taken on a site-wide basis to prevent or
minimize erosion and sediment transportation associated with the new construction.
Measures shall be in accordance with applicable codes, regulations, and permits.
Root mats shall be removed to a depth of not less than 6 inches below existing grade, and
holes shall be refilled with material suitable for embankment and compacted.
Environmentally sensitive areas shall be identified and protected during construction.
9.3.
Geotechnical Investigations
A detailed soils investigation, which shall be the basis for plant foundation work, shall be
preformed. The results of the investigation and recommendations shall be documented in
an engineering report certified by a geotechnical engineer who is familiar with the
various types of soils that exist in the area of the facility, including the geologic and
seismic conditions. The certified geotechnical report shall be made available to the
Purchaser for information. The Seller shall be responsible for and assumes all risks
associated with the site selection including but not limited to variations in soil quality,
seismic conditions, and contamination.
The site preparation work and foundation selection shall be engineered to mitigate any
effects of soil shrinkage and expansion and settlements. If necessary, soil stabilization,
remediation, and/or piles shall be provided in the power block areas and other areas as
required to ensure settlements, and differential settlements are acceptable with respect to
all settlement sensitive equipment including, but not limited to, the turbines.
The soils investigation shall also determine whether the soils are corrosive to buried
ferrous metals. The Facility shall include appropriate corrosion protection for all buried
pipes in accordance with good engineering practice and this specification.
9.4.
Surveying
The Seller shall perform the following:
9.5.

Provide property survey and a property map of the site area and any required
surveying outside the site boundary.

Ensure that the plant arrangement, including the switchyard area, is within the
property boundaries, including set back requirements and any easement restrictions
including any drainage or utility easements.

Survey the site and applicable offsite areas for underground lines, facilities, and
obstructions.
Site Development and Earthwork
The site shall be developed as required for both the initial construction and the final
operating conditions of the Facility. The initial earthwork services shall be performed
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Combined Cycle
based on the results of the geotechnical investigations and topographical surveys.
However, the final site work shall meet all minimum requirements of this specification
and as required by the detailed plant layout. Site preparation shall consist of clearing and
grubbing and the placing and compaction of fill with slopes and embankments designed
in such a fashion as to be stable and capable of carrying anticipated loads from equipment
or structures.
The final site elevation shall be graded to above 100-year flood level.
9.6.
Temporary Construction Facilities
The Seller shall provide all temporary facilities required to construct the facility,
including the items noted below. All temporary facilities shall be removed as required or
upgraded to meet the final plant requirements.

Installation and maintenance of temporary construction access road

Installation and maintenance of construction parking and construction laydown
areas

Construction trailers and facilities as required by construction, testing, inspection,
engineering, supervision, management, and other personnel

Use of or improvement of existing railroad spur close to the facility to allow offloading of equipment, if required. Improvements to existing roads to transport
equipment from the available spur to the site (if applicable).

Improvements to existing roads to transport equipment to the site, either temporary
for construction purposes or permanent to support plant maintenance and operation
activities.

Construction of temporary drainage facilities

Providing temporary erosion control during earthwork

Final grading and cleanup after the Facility is essentially complete

Restoration of all areas affected by the construction of access road, parking, and
laydown areas following project completion (as required by Seller’s agreements)
Adequate space shall be provided for Seller-provided temporary trailer(s) for Purchaser’s
construction and operation staff. Trailers shall be equipped with temporary furnishing,
HVAC, and set up for phone and high-speed internet access during plant construction and
commissioning until turnover. The trailers shall be located on site, in close proximity to
the power block construction and to the Contractor’s and Seller’s management and
supervisory personnel trailers.
9.7.
Facility Grading
Facility grading shall include the following items:
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9.7.1.
Technical Specifications: Appendix N2
Combined Cycle

Shape the natural grade as required to accommodate permanent Facility equipment
and construction facilities while minimizing earthwork

Obtain proper cross section, longitudinal slopes, and curvature for roads

Raise grade if necessary to eliminate flooding from external water courses due to
the 100-year rainfall. The 100-year runoff from uphill drainage areas shall be
diverted around the Facility and returned to the natural drainage course in a
manner acceptable to the permitting agency. The plant grade shall be located at
least 3 feet above 100-year flood level

Construct adequate in-plant surface drainage to discharge the 10-year runoff
without flooding roads and the 50-year runoff without flooding plant facilities

Prepare excavation for storm water pond dikes

Obtain proper area slopes to provide drainage without ponding

Construct stable, erosion-resistant earthen side slopes

Prepare sub-grade for foundations, including consolidation, soil remediation, mass
excavation and backfill, pile driving, etc. as required to mitigate unacceptable
settlements and to provide sound bearing for the facilities. These provisions shall
meet or exceed the requirements noted in the geotechnical report.

Prepare sub-grade to receive fills, where required

Prepare site grading that shall incorporate site slope, site drainage, road and
erosion protection

Remove root mats to a depth of not less than 6 inches below existing grade; holes
shall be refilled with material suitable for embankment and compacted.

Identify environmentally sensitive areas and protect them during construction.
Earthwork
Excavation, grading, backfilling, and compaction shall be performed as dictated by the
soil characteristics of the site, geotechnical study, the Facility design criteria, applicable
codes and standards, and good engineering practices. Earthwork shall be performed in
accordance with applicable regulations and permits.
The work shall include removing and disposing of unsuitable materials such as organic
matter from areas on which fill is to be placed, and excavating and deposing of materials
from areas where existing grade is to be raised. Grading of cuts, fills, and drainage
ditches shall be provided as required.
At no time will filling operations proceed when the ground or fill material is water
soaked.
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9.7.1.1
Technical Specifications: Appendix N2
Combined Cycle
Grading
Graded areas shall be smooth, compacted, free from irregular surface changes, and sloped
to drain.
The final grade adjacent to equipment and buildings shall be at least 8 inches below the
finished floor slab unless otherwise specified and shall be sloped away from the building
to maintain proper drainage.
Finish site grading shall be adequately established to deter surface pooling and promote
surface drainage away from equipment and structures.
9.7.1.2
Backfilling
Areas to be backfilled shall be prepared by removing unsuitable material and rocks. The
bottom of an excavation shall be examined for loose or soft areas. Such areas shall be
excavated fully and backfilled with compacted fill.
Backfilling shall be done in layers of uniform, specified thickness. Soil in each layer shall
be properly moistened to facilitate compaction to achieve the specified density. In order
to verify compaction, representative field density and moisture-content tests shall be
taken during compaction.
Granular load-bearing backfill shall be sound, durable crushed rock, clean sand and/or
gravel.
Selected suitable backfill material shall be available at the site or borrowed as required to
satisfy Facility design criteria.
Trench bedding material shall be clean sand, as required.
Where it is necessary to remove only a portion of the unsuitable materials and backfill,
the backfilling operation shall begin by stabilizing the existing materials to enable
proofrolling or normal construction equipment to operate thereon.
9.7.1.3
Compaction
Structural fill supporting foundations, roads, and parking areas shall be compacted to a
minimum of 95% of the Modified Proctor maximum dry density in accordance with
ASTM D1557. Embankments, dikes, and backfill surrounding structures shall be
compacted to a minimum of 90%. General backfill shall be compacted to at least 85%.
Areas compacted by hand-operated mechanical tampers shall be compacted to the same
minimum compaction as the rest of the fill. Care shall be taken so that the fill in these
areas is integral with the rest of the fill.
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9.7.2.
Technical Specifications: Appendix N2
Combined Cycle
Clearing and Grubbing
Areas to be graded shall be cleared of all vegetation. Waste from clearing shall be
disposed of offsite in accordance with state and local regulatory requirements.
9.7.3.
Stripping
All topsoil and other organic materials shall be stripped from the areas to be graded
before starting earthwork. Topsoil shall be placed in a temporary stockpile for later
recovery and use for landscaping the site. The stockpile shall be provided with temporary
erosion control facilities. Unused materials shall be disposed of offsite unless approved
by the Purchaser.
9.7.4.
Disposal of Unusable Soils
Excavated materials unusable for fills shall be spread on site. These materials shall be
graded so as to not interfere with proper drainage off the site nor result in the creation of
any potential wetlands. Any material unsuitable for reuse shall be disposed offsite in
accordance with the requirements of state and local authorities.
9.7.5.
Erosion Control
Temporary facilities shall be provided for control of erosion and turbid runoff during
earthwork operations and from graded areas until they are stabilized. Temporary facilities
shall be acceptable to local authorities. The Seller shall be responsible for obtaining any
necessary erosion control permits.
Permanent erosion control facilities for surface runoff as required for ditches and slopes,
such as riprap, headwalls, grass, rock surfacing and slope pavement, shall be provided
and be acceptable to regulatory agencies and Purchaser.
All excavations shall be carried out and supported in such a manner as to prevent
flooding or ponding of water and damage or interference to structure, services, or stored
equipment/materials.
Excavations for foundations shall be sealed with a concrete mud mat or seal slab, if
required, as soon as possible after being excavated and inspected.
Fill materials shall be suitable for the intended purpose and shall not include materials
hazardous to health, material susceptible to attack by ground or groundwater chemicals,
material susceptible to swelling or shrinkage under changes in moisture content, highly
organic or chemically contaminated materials, or any other unacceptable materials. The
Seller is solely responsible for the removal or replacement of existing contaminated soil,
buried debris or foundations whether or not the Purchaser is aware of contaminated soils
or unacceptable soils on site.
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Combined Cycle
Compaction of fill materials shall be carried out as soon as practicable after deposition of
fill materials. Fill shall be compacted to the densities appropriate to the design
requirements, fill type, and depth of layers.
9.7.6.
Existing Underground Facilities
The Seller shall be totally responsible for identification, disposition, redesign, relocation,
removal, etc. of any underground lines, utilities, obstructions, etc. that are present within
the Facility, or outside the Facility if work is to be performed outside the Facility.
Normal precautionary procedures shall be used when excavating to mitigate the potential
for property damage or personal injury should unknown obstructions or materials exist.
9.8.
Access
The Seller is responsible for the heavy haul route and for any necessary improvements.
The Seller shall coordinate this work with other entities as required.
9.9.
Storm Water Drainage
A rainwater collection system shall be provided for collection of non-contaminated site
rainwater runoff. Collected site rainwater shall be transferred to a rainwater collection
basin.
The Facility shall be provided with the following drainage systems:

Clean storm water sewer and ditch system

Oil-contaminated runoff sewer system

Process wastewater sewer system
Surface drainage systems inside the Facility shall be sized to discharge the 10-year,
24-hour runoff without flooding roads and the 50-year, 24-hour storm event without
flooding the Facility and equipment. The storm events shall be as defined by U.S.
Department of Commerce, Technical Paper No. 40, Rainfall Frequency Atlas of the
United States, or local regulations if more stringent.
A storm-water pond must be provided such that runoff from developed properties shall
not exceed the rate of runoff that would naturally occur from the undeveloped tributary
area during and immediately after the maximum storm event that would be expected to
occur once every ten years.
9.9.1.
Clean Storm-Water Sewer and Ditch System
Clean storm water runoff is runoff from Facility areas not subject to contamination. Clean
storm water shall be collected via a storm water sewer and ditch system and discharged to
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the storm water pond, and then off the Facility property at a single discharge point.
Effluent shall be conveyed and discharged into the natural drainage course in accordance
with 40 CFR Part 43 and the requirements of the Facility’s NPDES permit. The Seller
shall obtain any required discharge permit.
The following areas shall be provided with a storm sewer system:

Entire power block area within the loop road around equipment

Administration/control/maintenance building and adjacent parking lot

Building roof drains
The storm sewer system consists of catch basins for collecting surface water and an
underground piping system with manholes at all junction points and turns.
The storm water runoff system shall be designed and constructed in accordance with
ASCE Manual No. 77, ”Design and Construction of Urban Storm Water Management
Systems,” or local jurisdictional code, whichever is most stringent.
Roof drains from the administration/control/maintenance building shall discharge directly
into a storm water sewer system and not flow over parking lots, ground slabs, etc.
Storm sewers shall be used where possible. Where areas cannot be drained via storm
sewers, then draining via an open ditch system consisting of trapezoidal ditches with
culverts at roads may be used.
When culverts are utilized, the inlets and outlets shall be provided with permanent
erosion protection.
The slope angle for ditch side slopes shall not exceed 3H to 1V. If a steeper slope is
provided, appropriate slope protection shall be provided.
9.9.2.
Miscellaneous Valved Storm-Water Runoff
Transformer spill containment basins shall have a sump with valved outlet for draining
collected rainwater to the clean storm water runoff drainage system.
9.9.3.
Sanitary and Oily Waste Water Drainage Systems
The sanitary sewer network for each building shall be collected and treated. Discharge of
clarified effluent from the plant shall comply with applicable local, state, and Federal
regulations.
General plant oily waters shall be collected in an oily water collection system basin.
These waters include oily equipment drains from the steam turbine area, gas turbine area,
HRSG area, fire pumps, and workshop oily drains.
Oily waste from the transformer areas shall be collected in a transformer oil collection
basin. The oil collected in the basin shall be pumped out periodically.
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9.9.4.
Technical Specifications: Appendix N2
Combined Cycle
Sanitary Wastewater
Sanitary wastewater shall be collected by gravity, discharged to a lift station, if required,
and preferably pumped to the nearest off-site connection point available in the local
jurisdiction’s sanitary waste system. The system shall be designed and installed in
accordance with all state and local requirements. If applicable, the Seller shall contract
with the local jurisdiction to receive sanitary sewer discharge from the Facility at a price
acceptable to Purchaser. Sanitary lines shall be of PVC pipes and shall meet the building
codes for the local jurisdiction. Alternatives to sanitary wastewater collection may be as
follows, subject to approval by Purchaser and to meeting all local and state requirements
and permitting restrictions:

Septic treatment system, and discharged via percolation into the ground

Packaged sanitary wastewater treatment plant and then discharged to a natural
water course or through cooling water blowdown discharge facilities

Waste stabilization pond and discharged to a natural water course
9.9.5.
Oil-Contaminated Wastewater Sewer System
An oil-water sewer system shall be provided to collect discharges from areas that have
potential for oil contamination, including the following:

Floor and equipment drains with the potential for contamination with oily wastes

Turbine area floor and equipment drains

Boiler feed pumps

Maintenance area (including air compressor room/area)

Storage area (lube oil drums)
Areas where only minor oil leakage is possible shall have equipment-skid-attached
containment for local collection and subsequent cleanup, when required.
Oil-contaminated runoff shall be directed by gravity to an oil separator. Oil separator
effluent shall be combined with other onsite wastewater streams and routed to the
wastewater sump. The oil separator shall be provided with sludge removal facilities and,
if required, an integral effluent pump structure. The following shall be provided:

One double-wall steel oil separator

Coalescing plates providing 15 mg/L effluent quality

Waste oil transfer pump to transfer oil to a tank truck for disposal

Packaged effluent lift station with two 100%capacity pumps

Pipeline to transport effluent to the wastewater sump
All equipment having the potential to spill oil and not buried underground shall be
contained in a curbed area in order to prevent spillage.
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Underground gravity lines carrying oily wastewater will not require double containment
piping.
9.9.6.
Process Wastewater
Discharges to the process wastewater sewer system shall be non-oily wastewater with a
potential for chemical contamination. These include equipment drains such as HRSG
drains and area or building drains that contain potentially chemical contaminated runoff.
These areas shall be collected using floor drains, trenches, or sumps and piped to the
wastewater sump. At a minimum, the following areas shall be included:

Water treatment facility floor and equipment drains

Chemical bulk storage area building drains

Chemical tank spill containment area drains

Chemical truck spill containment area drains

Sample panel building drains

Chemical lab sink drain

Battery room emergency shower and eye wash drains
Batteries shall be provided with a curbed containment within the battery room.
Process wastewater, including blowdown and equipment drains, shall be pumped to a
wastewater sump. Major discharges shall be contained and cleaned up as required.
9.10.
Roads, Parking Lots, and Walkways
The plant roads shall be asphalt concrete on sub-base of properly stabilized soil aggregate
mixture. All other areas around and below the power block equipment shall be
bituminous asphalt on sub-base of properly stabilized soil aggregate mixture. The paving
and sub-base thickness shall be based on design and construction traffic loads. The main
plant road shall be a minimum of 25 feet wide. The road inside of the switchyard area
may be rock surfaced only. All road surfaces shall be designed and paved to allow for
proper drainage (puddling of water is not acceptable) and to allow transportation of heavy
equipment and materials throughout the plant.
Where mobile cranes will be located for lifting of heavy equipment associated with the
combustion and steam turbines, a single concrete pad shall be provided per crane
position. Pad area shall be sufficient to enable crane adjustment for lifting.
9.10.1.
Facility Roads
The main Facility access road shall be connected to an existing terminal point of an
adjacent public access road to the Facility. Similarly, a secondary (emergency) plant
access road shall also be provided and connected to an alternate public access road or as
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approved by the Purchaser. These intersections and roads shall meet all applicable local,
county, and state requirements and shall be approved by local authorities as required.
A looped interior Facility road shall be provided around the power block area. Other
interior Facility roads shall be provided where access is required to equipment, pump
structures, or entrances to buildings or enclosures. The location and extent of facility
roads shall be indicated on a general arrangement site development plan drawing
provided by the Seller to the Purchaser for approval.
9.10.2.
Road Width and Clearance Requirements
The minimum road widths shall be as follows:
Total Width
(ft)
Paved Width
(ft)
Shoulder Width
(ft)
Access Roads
33
25
4
Interior Roads
26
20
3
Entrances to Enclosures
22
16
3
Road
Clearance requirements over roads shall be a minimum of 22 vertical feet from the high
point of the road to the bottom of the lowest overhead obstruction. Side clearance, from
the centerline of road to any significant off-road obstruction, shall be 20 feet.
9.10.3.
Road Pavement
Road pavements shall be designed for AASHTO H-20 truck loads and loads due to a
65-ton wheel-mounted maintenance crane.
Parking lot pavement and all accessible areas of the power block shall be designed for
passenger cars and light trucks.
Design life of the asphalt pavement shall be 10 years.
9.10.4.
Parking Lots
Paved parking lots for passenger cars and light trucks shall be provided adjacent to the
control room, administration, maintenance, warehouse, and water treatment areas. The
number of spaces shall be based on the number of plant personnel plus additional space
for visitors and shift turnover, as well as spaces required by regulatory agencies.
Stalls shall be 90 degree angle, 10 feet wide, 19 feet long.
At least one stall shall be provided for handicap parking in close proximity of the control,
administration, and maintenance areas. Handicap stalls and location shall comply with
requirements of the Americans with Disabilities Act (ADA) and local regulations.
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All stalls shall be concrete or asphalt paved, striped, and provided with precast concrete
wheel stops and signage as required.
9.10.5.
Chemical Unloading
Chemical unloading areas including truck pads shall be contained to prevent releases
from entering the environment. Appropriate coatings shall be provided inside the
containment areas.
9.10.6.
Facility Area Surfacing
Final area surfacing shall be provided as follows:
Type
Minimum
Thickness
Reinforced concrete
8 in.
Location
All chemical truck unloading and spill
containment areas for water treatment
chemicals and other hazardous chemicals
20-foot width in front of all roll-up doors
Maintenance pads around equipment
required for maneuvering and positioning
cranes, fork lifts and other wheeledvehicles
Access areas to equipment (see below)
Wire mesh reinforced
concrete
4 in.
5.0-foot wide sidewalks between building
doors
Base material or crushed
rock area surfacing (well
graded material with
maximum size of 1 inch)
(ASTM D2940, ASTM
D448, Size No. 57 or
similar)
Design cross
section
providing
adequate load
bearing
capacity for
equipment and
vehicular traffic
All unpaved areas outside the loop road
with the potential to support maintenance
equipment, mobile cranes, fork lifts and
other wheeled vehicles
Base material or crushed
road area surfacing (wellgraded material with
maximum size of 1 inch,
ASTM D448, Size No. 57
or similar. Color or
gradation to be
distinguishable from
drivable surface areas).
4 inches
All areas loop road not requiring vehicular
access
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Interior of the switchyard (if allowed)
Unpaved access pathways from loop road
to equipment, enclosures
Areas requiring vegetative control, if
required
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Minimum
Thickness
Type
Technical Specifications: Appendix N2
Combined Cycle
Location
Crushed rock area
surfacing (ASTM D448,
size no. 3)
Design cross
section
providing
adequate load
bearing
capacity for
equipment, 8inch minimum
25-foot minimum on all unpaved sides of
the cooling tower or width as required to
run cranes used to remove fans, blades
and motors.
Seeding or other
appropriate ground cover
N/A
All disturbed areas outside of the power
block or otherwise unpaved or surfaced
Ditches
Crushed rock
9.10.7.
Good
Engineering
standard
Construction laydown areas
Surfacing Plan
The paving plan including cross-section shall be drawn on a copy of the general
arrangement drawing. Asphalt and crushed rock surfaces shall be provided as required by
Seller-provided, Purchaser-approved operation and maintenance plan.
Space shall be available and identified on the Facility site for maintenance laydown. This
space shall be indicated in the paving plan.
9.11.
Landscaping
The Seller shall provide any landscaping of the facility as required by local requirements,
zoning, permitting, or authorities. As a minimum, landscaping (with automatic irrigation
systems) and signage shall be provided at the entrances, and landscaping provided
adjacent to the administrative building areas.
9.12.
Fencing and Signage
The plant property lines shall be identified with appropriate signage and fence.
Security fencing shall be provided around the entire Facility area with separate security
fencing around the entire switchyard.
Site perimeter fencing shall be 6-foot-high chain link topped by an extension arm holding
three strands of barbed wire at 45 facing out. (Fencing shall have pipe line posts at
maximum 10'-0" centers, and a top and bottom tension wire.) The chain link fence,
holding three strands of barbed wire, shall be recessed 1'-0" minimum inside the property
line.
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Combined Cycle
All posts, rails, fabric, wire, and gates shall be galvanized. Interior road gates and
secondary plant access gates shall be 6-foot high by 25-foot wide manually operated
double swing gates. A secondary gate with lock shall be provided. The secondary gate
location shall be reviewed and accepted by the Purchaser.
The fencing shall be grounded.
The gate across the main access road to the Facility shall be a motor-operated slide gate
designed for use as a gate for an industrial facility. Gate shall be designed to be operated
both from the control room and locally using a card reader. A permanent goose-neckmounted card reader, standard-mounted lighting fixture, an intercom, and a fixed camera
for viewing persons using the card reader/intercom shall be provided at the main gate. A
gatehouse sufficient for two people with HVAC and communications (video to plant
security systems and phone line) shall be provided.
The storm water pond shall be isolated and locked separately, if required by local
building officials.
The switchyard fencing shall be 8 feet high and shall be considered independent of the
Facility. The gates entering the switchyard shall be manually operated gates. Fencing
layout, including gates, shall be shown on the design drawings.
The fence shall be grounded to limit step potentials below the permissible touch levels of
IEEE 80.
Rights-of-way shall be marked as required by code and law.
9.13.
Buildings
The Seller shall supply and install all buildings as required for the facility. These
buildings shall include, but not be limited to, administration/control building,
warehouse/maintenance area building, water treatment building, cooling tower water
treatment building, emergency generator building (if necessary), electrical switchgear
building, gas compressor building, and switchyard control building.
Power generation equipment need not be placed inside buildings provided the equipment
is supplied with adequate enclosures and is suitably protected from the environment
conditions at the site and maintenance work can be safely and efficiently performed.
Noise attenuation measures shall be provided to meet all local, state, and Federal
requirements.
These buildings may be pre-engineered buildings, provided all specified design criteria
are satisfied as well as requirements by local, state, and Federal building codes and
permitting agencies. Pre-engineered buildings shall be designed as partially enclosed in
accordance with the requirements of the MBMA Low Rise Building Systems Manual.
The miscellaneous electrical equipment enclosures for the CEMs, switchgear, MCCs,
power distribution centers (PDCs), fire water pump, etc. may be modular, insulated
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Combined Cycle
weather-tight structures purchased with the equipment, provided all specified design
criteria are satisfied in appropriate sections of this specification.
9.13.1.
Location and Footprint of Buildings
The control room, offices, warehouse, file storage, lunch room, and maintenance areas
shall be located in a centralized area in close proximity to each other and in close
proximity with the power block.
Plant buildings shall be designed to accommodate no less than the specified number of
employees as determined in the plant pro forma.
Office space, file storage area, warehouse, and control room shall be sized appropriately
for a 30-year plant service life.
Adequate chemical storage space shall be provided for 30 days of operation.
Buildings shall be adequately sized and designed for ease of removal of large equipment.
9.13.2.
Building Requirements and Sizes
The control, administration, maintenance, and warehouse areas shall be arranged to
provide sufficient space for plant operations and maintenance activities. These areas may
be combined into one building (and may be one or two stories with a high-bay/low-bay
arrangement). The warehouse, maintenance, and areas shall be designed with 20-foot
(minimum) eave height. The control room, electrical switchgear room, battery room,
administration facilities, instrument and electronics area shall have minimum 14-foot
eave height.
The buildings shall house areas including the administration areas, control room, control
equipment room, battery room, electrical equipment, communications room, maintenance
area (including an I&C area), and warehouse. These buildings will be enclosed, weather
tight buildings. The high-bay areas will contain the plant maintenance area and
warehouse area and shall include a roll-up steel door(s) to accept large pieces of
equipment. The low-bay areas will contain the station control room, battery room,
electronics room, offices, and washroom and locker area.
The control, administration, maintenance, and warehouse areas shall be provided with
power receptacles, and telephone and communications connections, as required and
applicable. The maintenance and warehouse areas shall be provided with service and
instrument air drops, service water drops, and welding stations. The quantity and
locations are subject to Purchaser approval.
Only the administration, control, and maintenance areas shall be designed to meet the
requirements of the Americans with Disabilities Act (ADA), unless additional areas are
required by local or state authorities.
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Technical Specifications: Appendix N2
Combined Cycle
Space allocation for the various buildings and work areas are noted below. Building and
work areas sizes are approximate and will be finalized during the detailed design phase of
the project.
Buildings and Work Areas
Size (Sq Ft)
Minimum Inside
Height (ft)
Buildings
Administration/ Control Building
5,000
10
Warehouse Building
6,000
18
10,000
18
Boiler Feed Building (one per HRSG)
1,700
10
Cooling Tower Water Treatment
1,125
10
900
16
Gas Compressor Building
1,600
20
Electrical Switchgear Building
3,000
10
Switchyard Control House
1,800
10
1,000
10
DCS Room
400
10
Communication Room
200
10
Men’s Restroom
150
8
Women’s Restroom
150
8
Lunch Room & Kitchen
280
8
File Room
200
8
Training Room/Library
200
8
Conference Room
400
8
Manager’s Office
200
8
Six Staff Offices (size per office)
150
8
Reception/Clerical
200
8
Janitor’s Closet
40
8
Storage Closet
40
8
2,000
18
400
8
1,500
18
400
8
Water Treatment Building
Emergency Generator Building
Administration/Control Building Rooms
Control Room
Warehouse Building Rooms
Spare Parts and Inventory Storage
I&C Area
Maintenance Area
Men’s Restroom & Lockers
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Buildings and Work Areas
Women’s Restroom & Lockers
9.13.2.1
Technical Specifications: Appendix N2
Combined Cycle
Size (Sq Ft)
400
Minimum Inside
Height (ft)
8
Administration/Control Building
The administration area shall include office space for supervisory and administrative
staff. Additional office space to accommodate operators on shift shall be provided.
The control room shall be sized for complete access to the control equipment and direct
access to the site for operations. The room shall be equipped with a raised computer floor
a minimum of 12 inches above the recessed monolithic concrete floor unless otherwise
approved by the Purchaser. The room shall have incandescent lighting placed to reduce
glare on the computer screens. Windows with window treatments shall be provided,
located to allow viewing of the power block area. Wiring for the control equipment shall
be behind walls or under the floor. Exposed conduits shall not be allowed in the control
room. Electrical panels located in the control room shall be wall-mounted units. Conduits
and wiring shall not be exposed. No floor mounted panels are allowed.
The administration area shall include offices for plant personnel, a reception area at the
main entrance, janitorial closet, storage closet, file room, training room/library, lunch
area, conference room, kitchen (with cabinets, fixtures, and appliances), and men’s and
women’s restrooms. The control room area shall include the control room, DCS room,
and communications room.
Floor drains shall be provided in the restrooms and under the raised computer floor of the
control room.
9.13.2.2
Electrical Switchgear Building
The electrical switchgear shall be housed in a building, preferably located near the
control room. A reinforced concrete vault with checkered plate access covers shall be
provided below the switchgear equipment to facilitate cable access. Access to the
electrical room shall be provided by one 12-foot high by 10-foot wide roll-up door and
double, hollow-metal fire-rated doors to the outside. All areas shall have an exposed
structure with 10-foot wall liners to protect the insulation. The DC battery system shall be
located in the electrical switchgear building.
9.13.2.3
Warehouse/Maintenance Building
The warehouse/maintenance building shall be single story and insulated. The building
shall contain men’s and women’s restrooms/locker rooms, maintenance area, I&C area,
and spare parts and inventory storage areas. The facility shall include personnel doors and
two 16-foot high by 12-foot wide electric roll-up doors. The roll-up doors shall be located
to facilitate truck and forklift access to the warehouse area and the maintenance area.
Translucent panel skylights shall be provided.
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Combined Cycle
Reinforced concrete grade slabs in the maintenance area, I&C area, and warehouse areas
shall be treated with a floor hardener and oil-resistant sealer to accommodate
maintenance or laydown. Interior partitions shall be gypsum wallboard on metal studs.
The wall between the maintenance area, I&C area, and warehouse shall be concrete
masonry unit (CMU) material. The warehouse/maintenance building shall be an exposed
structure, but the walls shall have 10-foot high interior liners to protect insulation.
Floor drains shall be provided in the maintenance area, I&C area, and restrooms. The
men’s and women’s restrooms shall be tiled and be provided with full-size lockers (20 for
men and 10 for women), benches, and showers.
The exterior walls of the warehouse building shall be the interior metal liner panel of the
insulated metal siding. The floor shall be a monolithic concrete slab with an epoxy wear
coating. The ceiling shall be open to the exposed building steel and insulated roofing.
Private office areas and a lunchroom are not required in the warehouse. Telephone and
LAN communications shall be provided.
A minimum of 15-foot x 15-foot reinforced concrete foundation, curbed and drained to
the oil water separator, shall be provided adjacent to the building for a drum storage area.
The building foundation shall have a grating covered trench that slopes to the sump. The
sump and trench shall be drained to the oily waste sewer system.
9.13.2.4
Water Treatment Building
Water treatment building area shall have a minimum eave height of 20 feet, or more if
required by equipment layout. The water treatment building shall contain the water
treatment equipment, water and steam sampling panels, chemical laboratory, controls and
electrical equipment room, chemical storage area, and fire pump room. Three electric
roll-up doors shall be provided to facilitate forklift access to the chemical storage areas
and water treatment equipment. A grating covered trench shall be provided in the grade
slab for drain piping. Particular attention shall be focused on sloping floors and adding
drains around equipment to eliminate any pooling of water.
The interior of the water treatment shall provide aisle space to maneuver a forklift truck
and to include a wastewater sump facility. The water treatment building will be an open
area with the exception of an electrical room and chemical laboratory. These rooms shall
be constructed of painted masonry units with a precast concrete roof. The monolithic
concrete floor slab shall have a chemical-resistant epoxy coating in areas exposed to
harsh chemicals. Particular attention shall be focused on sloping floors and adding drains
around equipment to eliminate any pooling of water. Reinforced concrete containment
walls and curbs shall be provided where appropriate to contain potential chemical spills.
The area floor and equipment drains shall be piped to a wastewater sump pit. Truck
access shall be provided for off-loading acid and caustic materials.
The chemical feed/sample panel building shall be sized for the equipment and to provide
storage space for a minimum of 30 days of operation. The building shall be a weather
tight building provided for protection of the HRSG chemical injection equipment and the
sample panel. The monolithic concrete floor slab shall have a chemical-resistant epoxy
coating in areas exposed to harsh chemicals. Reinforced concrete curbs shall be provided
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where appropriate to contain potential chemical spills. The interior shall be an open area.
The exterior wall shall be the interior metal liner panel of the insulated metal siding. The
metal liner panel shall extend the full height of the wall.
Along the outer side of the water treatment area, an oil and chemical storage area shall be
located. This area shall be enclosed with a roof and two sides as a minimum. This area
shall be bermed. The size of the oil and chemical storage area shall be at least 100 square
feet with an 8-foot height.
The fire pumphouse portion of the building will house the one electric fire water pump,
one diesel fire pump, and one jockey pump. Access doors will be provided for
maintenance of the pumps.
9.13.2.5
Cooling Tower Treatment Building
The cooling tower treatment building shall be a single-story, insulated, pre-engineered
metal building supported on a reinforced concrete foundation. The building shall contain
the associated cooling tower treatment equipment, including the cooling tower MCC’s
equipment. Interior wall liners shall be provided to protect the insulation. The circulating
water pumps and the chemical tanks shall be outdoors. A chemical truck unloading area
with appropriate containment shall be provided adjacent to the area.
9.13.2.6
Switchyard Control House
The switchyard control house shall be a single-story, insulated, pre-engineered metal
building supported on a reinforced concrete foundation. The building shall contain the
relay protection panels and associated switchyard equipment and partitioned battery room
with appropriate ventilation. Interior wall liners shall be provided to protect the
insulation. The building shall be provided with double doors sized to allow removal of
equipment. A concrete driveway/parking area shall be provided to facilitate maintenance
access. Personnel access shall be through the switchyard fence side of the building.
9.13.3.
Architectural
All buildings shall be weather tight with insulated metal siding and standing-seam
roofing.
Buildings shall have insulated walls, roof, and ceilings designed to complement the
specific building area use and optimize HVAC system design. For example, air
conditioned areas shall use wallboard and non-air conditioned areas shall use 26 gauge
steel liner panels.
The outside of the exterior building panels shall have a baked-on Kynar 500, or
equivalent, coating system having a minimum of 70% Kynar resin. Wall insulation shall
use a minimum R-13 fiberglass blanket insulation with UL 25 vapor retardant. The wall
panel thickness shall be as required to provide an insulated wall heat transmission
coefficient "U" per ASTM C236 not greater than 0.10 Btu/hr-ft2-F. The pre-fabricated
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modular equipment enclosures shall have the supplier’s standard industrial finish. All
exterior doors shall have weather protection awnings or vestibules.
Roof slopes shall be within the range of 0.5 to 1 inch of rise per 12 inches of run. The
outside of the exterior panel shall have a baked-on Kynar 500, or equivalent, coating
system having a minimum of 70% Kynar resin. Minimum R-19 fiberglass blanket
insulation with UL 25 vapor retardant shall be used and attached to the ceiling with metal
components such that there is no sagging. Roof panel thickness and width shall be as
required to provide a "U" factor of 0.08 or less and gauge and shape of panels shall be
sufficient to withstand all design loadings without excessive deflection or vibration.
All buildings shall be provided with gutters and downspouts, routed to the storm drain
systems.
Suspended lay-in acoustical tile ceilings, vinyl composition floor tile with resilient base,
and recessed fluorescent lighting shall be provided in offices, restrooms, lunch room,
conference room, storage areas, electronics room, and the control room. Partitions in the
administration area will consist of painted gypsum board on each side of 3-5/8” metal
studs. A folding partition shall be installed in the lunchroom. High-bay buildings such as
the shop and warehouse shall have high-pressure sodium vapor lighting.
For high-moisture areas, such as showers and locker rooms, ceilings shall have moisture
resistant, lay-in tiles. Unglazed ceramic tile shall be used on floors in high moisture areas
such as locker rooms, showers, and toilets.
Steel-troweled, surface-hardened concrete shall be used in unfinished areas. Any
chemical containment areas shall be of concrete construction and use barrier coatings or
linings as required for the chemical environment.
All wall surfaces, ceilings, doors, and frames shall be painted. The color scheme for the
project will be selected by the Purchaser from color samples submitted by the Seller.
Windows shall be manufacturer-standard aluminum, factory tinted, used in commercial
or industrial applications, as appropriate.
Double doors with transoms shall be provided where required for equipment removal and
access.
Doors shall meet the requirements of Steel Door Institute-recommended specifications
100-91, Grade II, Model 2. Doors shall be heavy-duty seamless-composite construction
using 18 gauge galvanized face sheets. Door frames shall be formed of 16 gauge steel to
the sizes and shapes required. Doors for the pre-fabricated modular equipment enclosures
shall be the supplier’s standard for industrial applications.
Doors and frames in the outer limits of environmentally controlled areas shall be fully
insulated. Where fire doors are required, the door, frame, and hardware shall bear a
certification label from Underwriter’s Laboratories for the class of opening and rating.
Doors shall be finished with glass and glazing at the following locations: building entries
and exits, control room, laboratory, hallways, offices, and any other high traffic areas
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where viewing windows will help prevent the doors from being opened into oncoming
traffic. Glass and glazing shall conform to the requirements for glazing materials for
Category II products in accordance with the Safety Standards for Architectural Glazing
Materials 16 CFR 1201, and installed in accordance with the publications of the Flat
Glass Marketing Association.
The Seller shall provide locks on each door and 10 sets of a coordinated master key set
for all lockable panels, hatches, covers, doors, etc.
Rolling steel doors shall be interlocking galvanized steel slats to withstand a wind
pressure of 25 pounds per square foot. Doors shall be motor operated with manual
override and three push-button controls.
The personnel access way to and from buildings shall be provided with canopies or
substantial overhangs to protect personnel from foul weather while entering and leaving
the buildings.
Fire-rated assemblies shall be provided when required by building or fire codes.
Penetrations through partitions shall be provided with fire stops. Insulation shall be used
for sound and thermal control in walls between and around finished rooms and airconditioned areas.
The Seller shall supply all fixtures and appliances for the control/administration/
maintenance building. Seller shall provide commercial-grade carpeting in all areas of the
administration building with the exception of the control room, DCS room,
communications room, restrooms, lunch room, and kitchen areas. The carpet style and
color scheme for the project shall be selected by the Purchaser from samples submitted
by the Seller.
The Seller shall provide interior furnishings for the buildings such as desks and furniture,
bulletin boards, lab furniture or equipment, shop equipment, maintenance tools, or
warehouse storage shelves. A list of furnishings and manufacture catalog number shall be
provided for Purchaser’s approval. Piping and electrical conduit and equipment along the
walls within the warehouse and maintenance area shall be located to maximize the
amount of space available for shelving.
9.13.4.
Furnishings
Administration Building furniture and equipment including the following:
Each staff office: 1 desk with chair; file storage, 1 book case, 1 guest chair, 1 computer
workstation with 1 personal computer and 1 laser jet printer, 1 white board
Manager’s office: 1 desk with chair, 1 credenza, 2 book cases, file storage, 1 small
conference table with 4 chairs, computer workstation with 1 personal computer and 1
laser jet printer, 1 white board.
Conference Room: 1 conference table (no smaller than 4 ft x 8 ft) and chairs (minimum
of 10); credenza; TV, VCR, DVD player, projection screen, and overhead projector.
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Reception/Clerical Area: 1 reception cubicle with chair, file storage, book storage, 1
computer workstation with 1 personal computer and 1 laser jet printer; 4 reception chairs
and 1 table.
Training Room/Library: 1 table (no smaller than 3 ft x 6 ft) and chairs (minimum of
6); Tall book shelves against two walls and several file cabinets and drawing storage
cabinets.
File Room: file storage cabinets
Control Room: 3 Computer workstations including 3 personal computers and 3 printers.
Necessary DCS workstations and printers.
Kitchen: All appliances including 1 refrigerator, 1 microwave oven, 1 oven/stove.
Lunch/Room: 1 table (minimum size 4 ft by 4 ft) and chairs (minimum 4)
Tools and Equipment including the following:
Laboratory: cabinets, bench, and testing equipment necessary to monitor cycle
chemistry and to conduct tests for environmental compliance.
Machine Shop: hand tools and tool boxes (3 sets); shop benches; 1 drill press; 1
hydraulic press; 1 pipe threader machine; 1 band saw; rigging equipment (including an
assortment of slings, chain falls (including two 1 ton, 2 ton, 3 ton and 4 ton), shackles,
etc.; adequate supply of ladders; 1 A-frame structure on wheels for lifting; portable
hydraulic lift; complete set of pneumatic tools; impact guns (including a ½ inch, ¾ inch,
and 1 inch); oxygen and acetylene cylinder kit; 2 computer workstations including 2
personal computers and 1 shared printer.
I&C shop: shop tools and test equipment including but not limited to the following:
I&C shop benches; 2 computer workstations including 2 personal computers and 1 shared
printer; high voltage tester; clamp-on amp meters; megger; oscilloscope; amps power
station relay tester; Calvin bridge; pneumatic test bench; dead weight tester or decade
box; carbon pile high current breaker tester; analog meters, digital meters; 4-20 mA
generators and receivers; temperature transmitters and receivers; temperature calibrator;
electronic transmitter communicator.
Spare Parts and Inventory Storage: shelving and storage structure; 1 computer
workstation including 1 personal computer and 1 printer.
Computer and telecom equipment including the following:
Drawing management system; maintenance system; local area network; total of 16
personal computers and 14 printers; and telephones for each telephone connection.
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Building Systems
The Facility shall include ventilation and air conditioning for each building. All HVAC
and ventilation systems throughout the plant shall be sized and installed appropriately for
climate and dust control as defined in other sections.
9.14.
Foundations for Equipment and Structures
All equipment foundations and concrete structures shall be designed and built per
manufacturers’ criteria, the soil investigation, and the geotechnical report.
Soil stabilization, remediation, piles, etc. shall be provided as required for all plant
facilities including buried lines and facilities as required by the geotechnical investigation
report.
Foundation analysis and design shall be performed for the gas turbine generator, steam
turbine generator, and HRSG, as recommended by the respective equipment
manufacturers. All foundations designed for rotating equipment shall be adequate, and
shall not be subject to failure due to induced vibration. In addition, foundations for
rotating equipment shall not result in unreasonable vibration levels, consistent with good
engineering practice, or violate OEM guidelines.
Foundation analysis for major equipment shall include the evaluation of total and
differential settlement. At grade, outdoor tank foundations may be ring-type or reinforced
concrete mat design. Tanks, equipment skids, pumps, and supports shall be installed on
raised slabs or pads for corrosion protection.
Dynamic foundation analysis shall be performed for the turbine generators. The design
shall ensure that all foundations for rotating equipment are adequate and shall not be
subject to failure due to induced vibrations. In addition, foundations for rotating
equipment shall not impart unreasonable vibration levels, consistent with normal utility
industry practice, as well as OEM guidelines and specifications, to surrounding
foundations and equipment.
Grade-floor elevations of buildings and the tops of foundations for major outdoor
equipment at grade shall be at a minimum 6 inches above the high point of the finished
grade elevation. All concrete shall be designed per applicable American Concrete
Institute (ACI) standards.
Oil-filled transformer foundations shall have an integral reinforced concrete spill
containment area. Ground wires shall be embedded in foundations and stubbed up at their
final location to prevent a tripping hazard.
9.15.
Concrete Work
Concrete design shall be in accordance with the latest release of ACI codes 318, 350, and
530.
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Concrete design for the cooling tower basin, if required, shall be appropriate for the
design water chemistry inside the basin.
Exposed concrete floors within the administration, control, warehouse, maintenance,
water treatment, chemical feed, and unloading areas are to have a brushed finish and be
sealed to impart chemical resistance where such exposure is possible.
Duct banks that run under roads and maintenance areas shall be adequately reinforced to
withstand anticipated loads.
9.16.
Masonry Work
Structural masonry shall be design in accordance with ACI - 530, “Building Code
Requirements for Masonry Structures.”
9.17.
Steel Work
The steel structure to be used for pipe racks, the gas and steam turbine enclosures, and
warehouse/maintenance area shall be designed, fabricated, and erected in accordance
with American Institute of Steel Construction specification.
Bolts and nuts for galvanized structural steel shall be hot dipped galvanized or zinc
electroplated.
All hoist and monorail support beams shall be clearly marked with their rated capacity.
9.17.1.
Steel Grating and Steel Grating Stair Treads
The steel to be used for grating and grating treads shall conform to either ASTM A 36 or
ASTM A 570. The ITW Ramset/Red Head Grating Disk system, or equivalent, shall be
used for fastening. Stair treads shall be provided with nonslip abrasive nosings. The
treads shall have end plates for attaching to stringers. Grating shall be of the rectangular
type and consist of welded steel construction. Grating shall be hot dip galvanized after
fabrication in accordance with ASTM A 123. Outdoor grating shall have a serrated
surface. Grating shall have at least a 1-inch bearing support and be designed for a
minimum live load of 100 psf. Deflection shall be limited to 1/200 of the span.
Floor or platform openings around the HRSG, pressure vessels, piping, and equipment
subject to expansion shall be protected as follows:

Openings around penetrating objects exceeding 1.5 inches in width shall be
protected by toe plates

Openings around penetrating objects exceeding 8 inches in width shall be
protected by toe plates and handrails
Cutouts required for any type of penetration, including those to be made in the field, shall
be provided in the floor grating. Cutouts smaller than 6 inches shall be banded with bars
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as thick as the bearing bars. Cutouts 6 inches and larger shall be banded with a 0.25-inchthick toe plate projecting 4 inches above the finished floor.
Additional support members for the larger opening will be provided as required.
The direction of bearing bars shall be consistent within the floor framing system, and
they shall be aligned with the adjoining section.
At the joints, the end of one section shall be banded to prevent other sections from
telescoping.
Surfaces on which the galvanized finish has been damaged, scratched, or defaced before
acceptance shall be cleaned and touched up with galvanized repair paint in accordance
with the paint manufacturer's instructions.
9.17.2.
Stairs and Ladders
Stairs shall be provided for the purposes of traveling from one elevation to another.
Vertical ladders may be provided only where personnel access is infrequent. Safety cages
and/or other devices shall be provided for fixed ladders per OSHA, and shall have
landings no further than every 30 feet. Safety cages and ladder openings shall include
self-closing gates.
9.18.
Painting and Coatings
Painting and coating system shall include uniform color coordination for system
designation. All exposed surfaces of the facilities shall receive a protective coating
system. All interior surfaces not coated shall be painted. Concrete shall be coated as
required to protect against environmental conditions and chemical exposure.
All outdoor structural and miscellaneous support steel shall be galvanized in accordance
with ASTM A123, ASTM A153, and ASTM A385. Steel in high moisture areas, grating,
embedded anchor bolts, assemblies, nuts, washers, plates, and assemblies are to be
galvanized. Miscellaneous embedded plates shall also be galvanized.
Indoor structures, such as building columns, and the HRSGs, shall be painted. All paint
coating systems shall consist of surface preparation, a prime coat, and a finish coat. The
Seller shall submit for approval and use high-quality paint products as manufactured by
Ameron, Briner, Carboline, Ceilcote, DuPont, Glidden, Porter, Sherwin Williams,
Tnemec, or ZRC. The primary color for the plant and the color scheme for all buildings
and enclosures shall be determined later by Purchaser for all primary external finish coat,
trim, flashing, gutters, downspouts, louvers, doors, windows frames, roof panels, and
exposed galvanized surfaces. The color of the finish coat shall be selected by the
Purchaser from color samples submitted by the Seller. Surface preparation and paint
system application shall be in accordance with the paint system manufacturer’s
recommendations. The primer, intermediate coat, and finish coat shall be from the same
manufacturer.
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All painting and coating work shall include a final touch-up before turnover.
The following protective coating systems shall be used unless approved otherwise by the
Purchaser:
a.
Exposed structural steel, steel piping, and equipment shall have a surface
preparation as recommended by the paint manufacturer, a primer coat (2-4 mils
DFT) of two-component inorganic zinc and a finish coat (4-6 mils DFT) of semigloss polyurethane paint.
b.
Steel areas where chemical exposures (acidic, neutral, or alkaline) are anticipated
to occur shall have a surface preparation as recommended by the paint
manufacturer, a primer coat (4-6 mils DFT) of polyamide epoxy paint, and a finish
coat (2-3 mils DFT) of acrylic aliphatic polyurethane paint.
c.
Externally exposed metal surfaces with service temperatures of 450F to 750F
shall receive a SSPC SP10 surface preparation, a primer coat (2-2.5 mils DFT) of
inorganic zinc silicate paint, and a finish coat (1.5 mils DFT) of silicone aluminum
paint.
d.
Environmentally controlled areas with interior concrete and concrete masonry
components requiring painting shall have a surface preparation that is clean, dry,
and free of contaminants, a primer coat (thickness rate per paint manufacturer) of
masonry filler, an intermediate coat (2-3 mils DFT) of low-gloss acrylic latex, and
a finish coat (2-3 mils DFT) of low-gloss acrylic latex.
e.
Exterior and non-environmentally controlled areas with concrete and concrete
masonry components requiring painting shall have a surface preparation that is
clean, dry, and free of contaminants, a primer coat (thickness rate as recommended
by the paint manufacturer) of masonry filler, an intermediate coat (2-3 mils DFT)
of water-borne acrylic paint, and a finish coat (2-3 mils DFT) of water-borne
acrylic paint.
f.
All drywall areas shall have a smooth, clean, and dry surface preparation, a primer
coat (0.5 to 3.0 mils DFT) of sealer or thinned finish coat as recommended by the
paint manufacturer, and intermediate coat (1-2 mils DFT) of low-gloss acrylic
latex paint, and a finish coat (1-2 mils DFT) of low-gloss acrylic latex paint.
g.
The interior surfaces of steel tanks for the storage of potable and service water
shall have a SSPC SP5 surface preparation, and two coats of epoxy polyamide
(each coat 4-6 mils DFT) meeting or exceeding the requirements of ANSI/NSF
Standard 61 for potable water tanks.
h.
The interior surfaces of steel tanks for the storage of high purity water shall have a
SSPC SP5 surface preparation, a primer coat (4-6 mils DFT) of two-component
zinc-filled epoxy, and a finish coat (4-6 mils DFT) of alaphatic amine epoxy.
i.
The exterior surfaces of steel tanks shall receive a primer coat (4-6 mils DFT) of
two-coat zinc-filled epoxy and finish coat (4-6mils DFT) of polyurethane paint.
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Building exterior finish coatings shall be applied to all roof and wall panels and decks,
wall louvers, flashings, gutters, trim, and other exposed galvanized surfaces.
9.19.
Design
The design shall conform to relevant aspects of the U.S. Codes and Standards as noted in
Section 7. The design shall be based on the International Building Code 2003 Edition
(IBC), or other applicable local or state building code, the American Concrete Institute
(ACI), and American Institute of Steel Construction (AISC). Where there is conflict
between the building code, city code, or state code, the provisions containing the most
restrictive regulation shall apply and govern. All buildings, structures and equipment
shall be designed and built to required seismic specifications.
Strength design shall generally be employed for reinforced concrete structures, and
allowable stress design or load and resistance factor design employed for steelwork.
Wind, snow, and earthquake loading shall be in accordance with IBC or local
jurisdictional building code, whichever is more stringent.
The design shall take account of all applied loads, including dead, live, impact, thermal,
dynamic, settlement, movement, and seismic, and other loading conditions where
appropriate. Temporary loads during maintenance and erection shall be considered.
Platforms shall be designed for a minimum live load of 100 psf. Platform design shall
employ the use of grating in lieu of checkered plate unless required for containment
purposes. All handrail, toe plate, ladders, cages, gates, etc., shall be in accordance with
OSHA Standard Rules and Regulations.
Pre-engineered building rafters shall be designed for the appropriate collateral loading
from roof supports, HVAC ducts, cable tray, and piping.
Grade slabs (turbine equipment laydown) shall be designed, at a minimum, for 300 psf.
Ground floor slabs for areas and auxiliary buildings shall be designed, at a minimum, for
150 psf. Storage areas will be designed for actual weight of material but no less than
150 psf.
Snow, wind, and earthquake loading shall be in accordance with the IBC or local
jurisdictional building code, whichever is more stringent.
All work shall be produced in accordance with the laws, regulations, and rules applicable
to Professional Engineers practicing in the state where the facility is located, using due
standards of care, skill, and diligence. All design drawings and specifications produced
shall be sealed by a Professional or Structural Engineer licensed to practice in the state
where the facility is located.
Vendor-generated structural steel details, concrete reinforcing details, and erection
drawings are to be reviewed and approved by the Seller’s Professional Engineer,
registered in the state where the facility is located.
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Access doors and hand rails shall be designed and located for easy access for
maintenance and inspections. Adequate hand railing and fall protection barriers shall be
installed for maintenance activities.
9.20.
Construction
All materials, workmanship, and testing shall be in accordance with the appropriate
specifications, standards, and codes of practice. Methods of quality control shall be
clearly established and documented.
Working methods shall ensure the construction of stable structures able to withstand all
applied loadings during construction and for the design life of the Facility without
collapse, failure, or excessive deformation such as to cause any damage, loss of function,
or durability problems.
A permanent Facility benchmark shall be established on the Facility site by the Seller
based upon USGS vertical datum. Settlement monitoring points shall be provided, with a
minimum of four points for each CTG, HRSG, and STG foundation. The existing
elevation at each point shall be inscribed on an embedded brass marker before setting of
equipment.
All welding shall be performed by welders qualified in accordance with AWS D1.1,
using only procedures qualified in accordance with AWS D1.1.
9.21.
Testing and Inspections
A program for testing soils during earthwork and when underground utilities and
foundations are installed shall be utilized.
The minimum moisture and density testing requirements for structural fill shall be one
test per 75 cubic yards with at least one test under each foundation greater than 15 square
feet.
In-place representative field density tests shall be performed, preferably at the
frequencies specified below in accordance with ASTM D 1557. The following
frequencies shall be increased in areas where apparent difficulties exist:
Fill Class
Testing Area
Frequency
Cubic Yards per Test
A
Structural Foundations
250 (or 1600 ft2 of each lift or
once per work shift, whichever is
more frequent)
B
Backfill Surrounding
Structures
(Same as Class A)
B
Roads, Shoulders, and
Parking Lots
650
C
General Backfill
1800
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If a compacted area fails to meet the specified compaction requirements, two additional
tests shall be performed for that area. If the results of either of the two additional testsprove unsatisfactory, the area shall undergo additional compaction and testing until test
results meet the minimum compaction requirements.
Records of inspection and testing of soils to ensure compliance with design assumptions
shall be turned over to Purchaser and shall comply with good engineering and
construction practices as well as the requirements of the local authority regarding
notification and inspection. If pile-supported foundations are to be used, the Seller shall
conduct a pile load test program. The trial pile-testing program shall be submitted to the
Purchaser for review at least two weeks before the start of the pile testing.
Testing and inspections of structures shall be in accordance with the California Building
Code and other licensing requirements.
Concrete test cylinder sets shall be taken at the minimum rate of one set per day but not
less than once for each 150 cubic yards for slabs, foundations, or walls. Concrete test
cylinder sets for paving shall be taken at the minimum rate of 1 set per day but not less
than once for each 150 cubic yards, nor less than once for every 5,000 square feet. As a
minimum, one set of cylinders shall be taken for each equipment foundation, with
exception that one set of cylinders may be made for each concrete truck load where
multiple small foundations are poured from a single load. Test procedures shall be in
accordance with the appropriate ASTM standards. Copies of test data shall be provided to
the Purchaser.
The Seller shall utilize a system to validate type and grade of high-strength bolts by
sampling and metallurgical testing.
A testing program of high-strength bolts and nuts shall be conducted by the Seller to
ensure that each bolt shipment meets the appropriate ASTM standards for dimensional
tolerances and material quality.
All structural welds shall be subject to inspection in accordance with weld quality
requirements provided in AWS D1.1. Critical welds shall be inspected as required, and
all other welds shall be subject to random inspection.
10.
DOCUMENT SUBMITTALS
As part of its work scope, the Seller shall submit detailed documentation to the Purchaser
to demonstrate the facility’s conformance with all specification requirements. This
documentation shall include, but not be limited to, progress reports, specifications, design
criteria, calculations, drawings, manuals, and schedules. The Seller shall submit this
documentation for all areas of work to enable the Purchaser to fully understand the
proposed design and to review it for compliance with the specification. A schedule for
the submission of documentation defined below shall be agreed with the Purchaser. The
individual submissions shall be provided to allow at least two weeks for the Purchaser's
review before any commitment. In addition to the hard copies, documentation shall be
provided in common electronic formats generally using Microsoft Office. Generally, all
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drawings shall be provided in AutoCAD or Microstation format, and Vendor drawings
shall be in AutoCAD or Microstation format.
All documents shall be in English. Units of measurement shall be US customary.
10.1.
Documents To Be Submitted For Purchaser Review and Comment
Critical documents that define the overall conceptual design of the facility are required to
be submitted for Purchaser review and comment following initial issue and each
subsequent revision. Other documents shall be submitted for information upon initial
issue, issue for construction, and final record.
Purchaser 's comments shall be forwarded to the Seller within 10 working days of the
date documents are received in the Purchaser's offices (receipt of email notification of
document transmittal and availability of document at the designated FTP site).
The drawings and documents in the types and quantities indicated on the following table
shall be provided by Seller to Buyer. After the first drawing or document submittal,
submitted revisions shall be provided in the same quantities indicated for the first
submittal, except where otherwise indicated on the table. The column headings are
described below:

Buyer Review refers to drawing or document review, comment, and review as
described in the contract. The stages are as follows:
—
A = Buyer’s review, hold until release from Buyer
—
I = For Information Only
—
R = Buyer Review and Comments

First Issue refers to the type of issue of the referenced document to be submitted
to the Buyer as the first formal submittal. Subsequent issues of “A” category
drawing shall be provided to Buyer until last project issue for drawings issued for
Buyer’s review and hold. Seller is not required to provide subsequent revisions of
“I” and “R” category drawings, but Seller must provide the final version of “R”
category drawings for review by Buyer before Last Project Issue.

Last Project Issue refers to the issuing of the final issue of the drawings for
construction or the as-shipped drawings for manufactured equipment. Seller shall
update lists to conform to Subsystem Turnover Package records, and the Last
Project Issue drawings supplied by equipment Subcontractors shall correspond to
the as-shipped condition.

As Built refers to a formal record or as-built design drawing issued by the
Contractor or Seller revised to indicate all documented design modifications made
during construction.
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PACIFIC GAS AND ELECTRIC COMPANY
PURCHASE AND SALE AGREEMENT
Technical Specifications: Appendix N2
Combined Cycle
Last
Project
Issue
As Built
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
R
R
I
X
X
X
X
X
X
X
X
X
X
X
I
I
R
I
I
I
I
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Control Design Drawings – Power Block and BOP
Local Logic Diagrams
DCS Logic Diagrams
DCS Graphics Drawings
DCS Program Logic Diagrams
Typical Installation Details
R
R
R
R
I
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Civil and Architectural Drawings
Site Grading and Drainage Drawings
Foundation Location and Elevation Drawings
Composite Underground Utilities Drawings
Foundation Drawings
Concrete Floor Drawings
Road Paving and Location Drawings
Typical Detail Drawings
Structural Steel Drawings (including pipe racks)
Building Architectural Drawings
A
R
I
I
I
R
I
I
A
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
LISTS
Equipment List
Valve List
Pipeline List
Electrical Load List
Cable Schedule
Control Instrument and Device List
I/O List
Contractor Drawing List
List of Vendor Drawings
Lubricants Schedule
I
I
I
I
I
I
I
I
I
R
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Description
DESIGN DRAWINGS
Mechanical Design Drawings
Plant Arrangement Drawings
Piping & Instrument Diagrams
Large Bore Piping Isometrics
Composite Underground Piping Arrangements Dwgs
Installation Detail Drawings
HVAC Drawings
Heat Balance Diagrams
Water Balance Diagrams
Electrical Design Drawings
Single Line Diagrams
Three Line Diagrams
Elementary Diagrams
Interconnecting Wiring Diagrams or Termination
Details
Composite Raceway Drawings
Cable Tray Layout Drawings
Lighting Drawings for Control Rm. & Offices
Lighting Drawings – Other
Installation Detail Drawings
Grounding and Lightning Protection Drawings
Duct Bank Duct Number Drawings
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Buyer
Review
First
Issue
A
R
I
R
I
R
A
A
X
X
X
X
X
X
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PACIFIC GAS AND ELECTRIC COMPANY
PURCHASE AND SALE AGREEMENT
Technical Specifications: Appendix N2
Combined Cycle
Last
Project
Issue
Buyer
Review
First
Issue
R
R
I
I
X
X
X
R
X
X
(Changes
Only)
R
X
Grounding Calculations
R
X
Cable Sizing Calculations
R
X
Short Circuit Calculations for Switchyard
R
X
Select Civil/Structural Calculations (foundations, etc.)
R
X
Equipment Sizing Calculations
Select Mechanical Calculations (BFP sizing, sample
system sizing calculations, etc.)
Electrical Relay and Coordination Calculations
R
X
R
X
X
(Changes
Only)
X
(Changes
Only)
X
(Changes
Only)
X
(Changes
Only)
X
(Changes
Only)
X
(Changes
Only)
X
(Changes
Only)
R
X
I/R
X
I
X
Description
REPORTS
Plant Auxiliaries Electrical Load Flow and Fault Study
Electrical Relay Settings
Geotechnical Report
Cathodic Survey Study
CALCULATIONS
Main Power Equipment Sizing
Transformer
Isolated Phase Bus
Circuit Breakers
Short Circuit Study and Load Flow Calculations
MISCELLANEOUS
Design Basis/Criteria
Vendor Drawings & Information
List of documents to be provided for review. Selected
drawings will be requested such as for BFP,
Condensate pumps, condenser, cooling tower, water
treatment, generator circuit breakers, HV breakers,
transformers, etc.
Unpriced Equipment Purchase Orders and/or
Specifications
Soil Resistivity Tests
Operation & Maintenance Manual(s)
Vendor Test Reports
Ground Grid Resistance Tests
Cathodic Protection Soil Tests
Flow Nozzle Tests
Metering Tests
Interconnection Design Information
Pipe Stress Reports (High Energy)
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I
R
I
I
I
I
I
I
I
As Built
X
X
E
X
X
X
X
X
(Changes
Only)
X
X
X
X
X
X
X
X
X
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PACIFIC GAS AND ELECTRIC COMPANY
PURCHASE AND SALE AGREEMENT
Technical Specifications: Appendix N2
Combined Cycle
Seller shall furnish drawings, lists, calculations, test reports, and miscellaneous
information in accordance with the table in this Appendix necessary for review of design
and construction by the Buyer and for maintenance and operation of the Facility. All
transmittals shall be accomplished via a secure FTP or project internet site, and shall be
transferred by electronic files, in Word or Excel or in PDF, or Microstation formats. Any
paper copies of drawings shall be provided by the recipient of the files.
Where equipment subcontractor-supplied drawings, calculations, test reports, or
miscellaneous information includes the above information, the Seller is not required to
redraw them, provided they indicate the information required and are properly crossreferenced to other information.
Plant arrangement drawings shall indicate the location of all-major mechanical
equipment, major electrical equipment and panels, and major control and process control
panels (including roll-out space or other maintenance access as appropriate). A site plant
arrangement drawing shall also be provided showing the location of all buildings, major
equipment, and plant roads. Equipment identification on these drawings shall match the
equipment identification on the Equipment List.
Piping and instrument diagrams (P&ID) shall be provided for each plant system. These
diagrams shall indicate all process piping, except vents and drains, regardless of size,
with each line identified by size, specific line number, and piping class designation. All
control valves and valves 2.5 inches and larger, equipment, mechanical devices (such as
orifice plates), and instruments and control devices shall be identified.
Large bore piping isometrics shall be provided for each system indicating location,
arrangement, and fabrication. Large bore pipe is pipe 2.5 inches and larger.
In lieu of single-line diagrams for panel boards, the Supplier may supply panel board lists
with load descriptions for each panel circuit breaker. Lighting circuits will not require
circuit numbers.
Three-line diagrams shall be provided for the following:

Generator step-up transformers, and station auxiliary transformers, including
potential and current transformer circuits.

Medium-voltage switchgear, including potential and current transformer circuits,
but excluding load circuits.
Elementary diagrams shall be provided for equipment and systems with hard-wired
controls.
Interconnecting wiring diagrams or termination details shall be provided for controls and
instrument circuits and will include the following:

Terminal point connection wiring

Circuit number

Both circuit ends or cross reference drawing number for unshown circuit end
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PURCHASE AND SALE AGREEMENT
Technical Specifications: Appendix N2
Combined Cycle
Raceway drawings shall indicate cable tray in single-line or other form, wireway, and
conduits 2.5 inches and larger. These drawings will include all cable tray, wireway, and
conduit numbers, where applicable.
Supplier shall provide logic diagrams that will indicate logic control and configurations
and interlocks.
Composite underground utilities drawings shall include information included on the site
arrangement drawing (simplified where required for clarity).
Concrete floor drawings shall include design loads.
Electrical relay settings shall be provided in report form for all relays down to the 480
volt secondary unit substation breakers.
Subsystem turnover packages shall include pertinent construction data, the work required
to place subsystems in service, and pertinent subsystem drawings.
10.2.
Performance Curves
For operating conditions that are different from either International Organization for
Standardization (ISO) conditions or guaranteed site rating conditions, the Seller shall
supply the Purchaser with expected performance curves and correction factors to cover
the range of site conditions. This information shall cover the expected range of variation
of the following: shaft speed, power output, compressor inlet temperature, atmospheric
pressure, inlet and exhaust pressure losses, and effect of variations in fuel properties.
Performance parameters indicated shall be power, fuel flow, water/steam flow rate, and
heat rate (lower heating value). The following types of performance curves shall be
provided:

Curves showing generator kVA output against field current through the entire
power factor range

Curves showing reactive capability versus kilowatt load

Decrement curves for three-phase, line-to-line, and line-to-line to ground short
circuits, including effect of voltage regulator

Regulation curve with excitation and speed constant

Curves showing correction to heat rate vs. condenser vacuum (100 to 500 mm Hg
Abs. in increments of 100 mm HgA) at specified loads

Exciter load versus exciter voltage curves showing drooping characteristic

Curve or data on the excitation and voltage regulation system characteristics
showing generator stator, field, and exciter per unit amperes vs. time. Specify
which excitation system model type is representative of the equipment shall be
specified.

All applicable performance degradation curves, recoverable and non-recoverable
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PURCHASE AND SALE AGREEMENT
10.3.
Technical Specifications: Appendix N2
Combined Cycle

A curve of turbine heat rate versus turbine load (for steam turbine as provided by
steam turbine supplier)

NOx emission level versus load

Cooling tower performance curves

Curve of condenser performance at turbine maximum continuous rating (TMCR)
and varying circulating water temperatures
Purchaser’s Right to Receive Additional Documents for Information
The intent of this request is to enable the Purchaser to be cognizant of the engineering
progress and to validate the work to be performed under the Contract.
In general, documents normally generated while performing engineering and design on
this Project shall be available to the Purchaser for information. Typical documents
expected to be produced include the following:

Equipment foundation design drawings

Rebar placement drawings

Area paving and drainage drawings

Structural steel plan, section, and detail drawings

Structural steel shop drawings

Building architectural drawings

Electrical duct bank, cable tray, conduit layout, and grounding and lighting
drawings

Electrical load lists

Electrical cable and conduit lists

Electrical panel schedules

Plant switchyard drawings

Control panel internal wiring drawings

Instrument cabinet layout drawings

Instrument installation details

Control panel layout drawings

Piping isometric drawings

Underground piping and drains composite layout drawings

Valve lists

Line lists

Consolidated instrument index
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PACIFIC GAS AND ELECTRIC COMPANY
PURCHASE AND SALE AGREEMENT
10.4.
Technical Specifications: Appendix N2
Combined Cycle

Pipe hanger and support drawings

Protective relaying logic diagrams

Operating and maintenance manuals for all engineered equipment

Design studies

Stress analysis reports

Water hammer study for the circulating water system

Dynamic foundation analysis for combustion turbine generator and steam turbine
generator

Short circuit analysis and voltage drop studies

Unpriced purchase orders

Operating instructions, including freeze protection plan.

Final purchase order, drawing, and vendor drawing lists

Instrument data sheets

Functional control logic diagrams

Completed control settings, to include both tolerance and actual values

Valve data sheets

Complete control system configuration documents and DCS I/O database

Setpoint for instruments (if not included in instrument index)

Vendor drawings, including detailed wiring diagrams

Final grounding and cathodic protection survey reports

Field electrical test reports

Geotechnical and foundation investigation

Relay settings and associated bills of materials and documentation sheets

Equipment and system startup records

Inspection certificates

Startup testing and procedures manuals

Critical civil/structural detailed design calculations. Specifically, steam and
combustion turbine generator foundations, HRSG and stack foundations,
condenser foundations, intake structure, and design criteria or calculations for the
pipe rack
Documents To Be Submitted Before Turnover of Facility
Before Project completion, Seller shall update design drawings and other design
documents as shown in Section 10.1 to reflect as-built information and provide electronic
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PURCHASE AND SALE AGREEMENT
Technical Specifications: Appendix N2
Combined Cycle
and hard copies to the Purchaser. Before submittal of these as-built documents, Seller
shall provide the Purchaser access to field markup drawings and other documents
required to support the Purchaser 's O&M requirements.
Isometrics shall be provided from the “as designed” 3D CAD model. Piping composite
layout drawings may be provided for the aboveground plant facilities. Underground
composites shall be provided. Operational documents, which shall be as-built, include
P&IDs, loop diagrams, one-lines, equipment lists, and interconnecting wiring drawings.
As-built construction drawings for steel detail, pipe supports, rebar drawings, etc. shall be
provided as requested by Purchaser. All shop-fabricated pipe 2.5 inches or above shall be
modeled. Non-CAD drawings can be scanned for submittal on CD ROM.
10.5.
Drawings and Lists
Drawings submitted shall conform to the following:
Size shall be as follows (metric sizes also acceptable):

A – 8.5 inches x 11 inches

B – 11 inches x 17 inches

D – 24 inches x 36 inches

E – 34 inches X 44 inches
The title block shall be in the lower right-hand corner of the drawing, and the drawing,
when submitted, shall be folded to A size with the complete title visible. The title block
shall contain the following minimum information:

Project name

Manufacturer's name

Manufacturer's drawing number

Brief title (clearly defining content of drawing)

Revision number and revision date

Scale and scale bar (when applicable)

Plant and equipment identification number
A space approximately 2 inches x 3 inches near the title block shall be left blank for
approval stamps. A revision column adjacent to the title block shall define briefly the
revisions made for each revision number.
10.6.
Instruction Books and Operating Manuals
The Seller shall furnish the Purchaser with five bound sets and one electronic version
using Microsoft Office for text and AutoCAD, Microstation, or Adobe format for
drawings of complete clearly readable operating manuals. These instructions shall be in
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PACIFIC GAS AND ELECTRIC COMPANY
PURCHASE AND SALE AGREEMENT
Technical Specifications: Appendix N2
Combined Cycle
addition to instruction manuals prepared by individual equipment vendors and shall
provide a brief description of how each system is put into service and normally operates
and shall identify abnormal operating conditions likely to be encountered, along with a
description of corrective actions that should be taken. These manuals are intended for use
in familiarizing new employees with the facility and are not to provide detailed operating
guidelines or procedures.
The equipment instruction books (operating and maintenance manuals) shall be issued
before equipment shipment and shall include the following:

Equipment identification by equipment number, station name, and unit number and
by function name

Final reduced general arrangement and cross section drawings, warranted
performance data, design data sheets, and performance curves for all equipment

Complete installation/operation, troubleshooting, and maintenance instructions

Part lists shall be complete in every respect with parts identified by the original
manufacturer's part number as well as by identification number
Instruction books shall be specific to equipment supplied. The instruction book manuals
and equipment instruction books shall be thoroughly reviewed by Seller before submittal,
to verify that the instruction books apply to the specific equipment purchased.
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