Guidelines for the
Mothballing of Process Plants
Other Books by Ronald J. Twigg
Inspection Guidelines for Pressure Vessels and Piping
Volume 1: New Fabrication
MTI Publication No. 40
Inspection Guidelines for Pressure Vessels and Piping
Volume 2: Manual and Pocket Guides
MTI Publication No. 49
Guidelines for the Mothballing
of Process Plants
MTI Publication No. 34
(Third Printing)
Ronald J. Twigg
Glencor Engineering Limited
20GlenbrookWay
Nepean, Ontario K2G 0V2
Canada
Materials Technology Institute
of the Chemical Process
Industries, Inc.
© Copyright 1989, 1998, 2002, by
Materials Technology Institute
of the Chemical Process Industries, Inc.
Library of Congress Catalog Card Number: 89-63607
ISBN 1-877914-00-2
Printed and bound in the United States of America All
rights reserved, including translations
First Edition published for MTI by National Association of Corrosion Engineers (now NACE International)
in softcover in 1989
2nd Printing published by MTI with new title and About MTI pages and new cover design
in softcover in 1998
3rd Printing, 2002
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Executive Director of MTI.
Published by
Materials Technology Institute of the
Chemical Process Industries, Inc.
ABOUT MTI
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founded in 1977, is a unique, not-for-profit technology development organization representing
private industry. It sponsors projects focused on both developing new technology and transferring existing knowledge to day-to-day practice. Practical generic, nonproprietary studies are
conducted on the selection, design, fabrication, testing, inspection, and performance of materials of construction used in the process industries. The scope of work includes evaluation of
metallic and non-metallic materials; optimum design applications; fitness-for-service, mechanical
integrity, and life cycle determinations; and economic factors affecting performance of vessels,
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TABLE OF CONTENTS
Section
Page
ACKNOWLDGMENTS.............................................................................................................................. i
ABSTRACT........................................................................... „ ................................................................ ii
1 GENERAL CONSIDERATIONS.....................................................................................................1-1
2 ECONOMIC CONSIDERATIONS ..................................................................................................2-1
EQUIPMENT CONDITION ............................................................................................................2-1
Internal Inspection ..................................................................................................................2-1
Exterior Inspection ..................................................................................................................2-1
Mechanical Equipment ...........................................................................................................2-1
Electrical Equipment ...............................................................................................................2-1
Structural.................................................................................................................................2-1
Piping ......................................................................................................................................2-1
IDLE PERIOD ................................................................................................................................2-2
EXPERIENCE AT OTHER PLANTS ................................ 2-2
Staff Considerations ...............................................................................................................2-3
Site Requirements ..................................................................................................................2-3
MAJOR COST ITEMS-MOTHBALL PROGRAM ........................................................................2-3
WHAT EQUIPMENT SHOULD BE PROTECTED.........................................................................2-3
Field Erected Equipment ........................................................................................................2-4
Heat Exchangers ....................................................................................................................2-4
Piping ......................................................................................................................................2-4
Fired Heaters ..........................................................................................................................2-4
Boilers and Associated Equipment .........................................................................................2-5
Mechanical Equipment ...........................................................................................................2-5
Reactors, Mixers, Autoclaves.................................................................................................2-5
Electrical Equipment ...............................................................................................................2-5
Flare Systems .........................................................................................................................2-5
EQUIPMENT NOT PROTECTED ..................................................................................................2-5
3 PROTECTION SYSTEMS AND PLANT EXPERIENCE ................................................................3-1
FILM TYPE ....................................................................................................................................3-1
Thin Film .................................................................................................................................3-1
Thick Film................................................................................................................................3-1
Hard Film ................................................................................................................................3-1
Paint, Varnish, Lacquer ..........................................................................................................3-2
Wrapping Materials .................................................................................................................3-2
Cocooning ...............................................................................................................................3-2
GREASES AND OILS ...................................................................................................................3-2
Oils ..........................................................................................................................................3-2
Greases................................................................ ,.................................................................3-2
VOLATILE CORROSION INHIBITORS .........................................................................................3-3
ALTERATION OF THE ENVIRONMENT.......................................................................................3-3
Dehumidification......................................................................................................................3-3
Air Conditioning.......................................................................................................................3-3
Heat ........................................................................................................................................3-3
Desiccants ..............................................................................................................................3-4
Other Drying Media ................................................................................................................3-4
Neutralization ..........................................................................................................................3-4
Antifreeze ................................................................................................................................3-4
INERT ATMOSPHERES ................................................................................................................3-5
MULTICOMPONENT SYSTEMS...................................................................................................3-6
PLANT EXPERIENCE ...................................................................................................................3-6
Plastic Wrap............................................................................................................................3-6
Flanges ...................................................................................................................................3-6
Safety Valves ..........................................................................................................................3-6
4
5
6
Electrical Equipment...............................................................................................................3-6
Storage Yards.........................................................................................................................3-6
Insulation ................................................................................................................................3-6
Equipment Removal ...............................................................................................................3-7
SUMMARY OF PLANT EXPERIENCE..........................................................................................3-7
TESTING OF PROTECTION COMPOUNDS.................................................................................4-1
CORROSION TESTS ....................................................................................................................4-1
Coupon Preparation................................................................................................................4-1
Application of the Preservative ...............................................................................................4-1
Corrosion Test........................................................................................................................4-1
Adherence and Protection Test..............................................................................................4-2
Test Conditions ...................................................................................................................4-2
Test Sequence....................................................................................................................4-2
Chemical Analysis ..................................................................................................................4-2
Elastomers, Gaskets...............................................................................................................4-2
Removal of Preservatives.......................................................................................................4-2
INERT GAS PURGING AND BLANKETING OF EQUIPMENT.....................................................5-1
PURGE AND FILL.........................................................................................................................5-1
CONTINUOUS PURGE.................................................................................................................5-1
MONITORING................................................................................................................................5-1
CAUTION................................................................................................, .....................................5-1
SELECTION OF PROTECTIVE COMPOUNDS ............................................................................6-1
SURFACE PREPARATION ..........................................................................................................6-1
QUALITY CONTROL ....................................................................................................................6-1
CLASS I-SOLVENT TYPE ..........................................................................................................6-1
Application ..............................................................................................................................6-1
Service....................................................................................................................................6-1
Removal..................................................................................................................................6-1
CLASS II—OIL ..............................................................................................................................6-2
Application ..............................................................................................................................6-2
Service....................................................................................................................................6-2
CLASS HI-EMULSION TYPE ......................................................................................................6-2
Application ..............................................................................................................................6-2
Service....................................................................................................................................6-2
Removal..................................................................................................................................6-3
CLASS IV (a)-ANTIFRICTION GREASE ...................................................................................6-3
Application ..............................................................................................................................6-3
Service....................................................................................................................................6-3
CLASS IV (b)-INDUSTRIAL GREASE ........................................................................................6-3
Application ..............................................................................................................................6-3
Service....................................................................................................................................6-3
CLASS V-HARD FILM TYPE .....................................................................................................6-4
Application ..............................................................................................................................6-4
Service....................................................................................................................................6-4
Removal..................................................................................................................................6-4
CLASS VI-VOLATILE CORROSION INHIBITOR FLUID (VCI) ..................................................6-4
Application ..............................................................................................................................6-4
Service....................................................................................................................................6-4
Removal......................................................................................................................., .........6-4
CLASS VII-VOLATILE CORROSION INHIBITOR (VCI)
CRYSTALS, TAPES, EMITTERS, ETC.........................................................................................6-5
Application ..............................................................................................................................6-5
Service....................................................................................................................................6-5
CLASS VIII-MULTICOMPONENT SYSTEMS.............................................................................6-5
Application ..............................................................................................................................6-5
Service....................................................................................................................................6-6
PLASS IX-DESICCANTS ...........................................................................................................6-6
Application ..............................................................................................................................6-6
7
Service ................................................................................................................................... 6-6
CLASS X-INERT ATMOSPHERE.............................................................................................. 6-6
Application.............................................................................................................................. 6-6
Service ................................................................................................................................... 6-6
CLASS IX-PAINTS, LACQUERS, VARNISHES ........................................................................ 6-7
Application.............................................................................................................................. 6-7
Service ................................................................................................................................... 6-7
Removal ................................................................................................................................. 6-7
PROTECTION PROGRAM FOR 1-18 MONTHS.......................................................................... 7-1
SHUTDOWN CONSIDERATIONS ............................................................................................... 7-1
CORROSIVE ENVIRONMENTS................................................................................................... 7-1
WATER LINES ............................................................................................................................. 7-2
INSULATION ................................................................................................................................ 7-2
PIPING, VALVES AND FITTINGS................................................................................................ 7-2
Stainless Steel and Nonferrous Alloys ................................................................................... 7-2
Carbon and Low Alloy Steel Materials................................................................................... 7-2
Lined Low Alloy Steel Pipe .................................................................................................... 7-2
FLARE SYSTEMS........................................................................................................................ 7-3
HEAT TRACING ........................................................................................................................... 7-3
PROCESS VESSELS AND TANKS ............................................................................................. 7-3
Stainless Steel and Nonferrous Alloys ................................................................................... 7-3
Carbon Steel .......................................................................................................................... 7-3
Reactors................................................................................................................................. 7-3
Towers, Spheres, Bullets ....................................................................................................... 7-4
COOLERS AND EXCHANGERS.................................................................................................. 7-4
Cooling Towers...................................................................................................................... 7-4
Spray Coolers ........................................................................................................................ 7-4
Air Coolers, Finned ................................................................................................................ 7-4
Plate Exchangers ................................................................................................................... 7-5
Shell and Tube Exchangers .................................................................................................. 7-5
STORAGE TANKS ....................................................................................................................... 7-5
Six-to-Twelve Months ............................................................................................................ 7-5
Over Twelve Months .............................................................................................................. 7-6
ROTATING EQUIPMENT.............................................................................................................. 7-6
Centrifugal Pumps ................................................................................................................. 7-6
Reciprocating Pumps ............................................................................................................. 7-6
Mechanical Seals and Packing ............................................................................................. 7-6
Bearings—All Equipment........................................................................................................ 7-6
Drives ..................................................................................................................................... 7-6
Couplings ............................................................................................................................... 7-6
Agitators, Centrifuges and Mixers ......................................................................................... 7-7
Hydraulic Systems, Lubricating Oil Systems and
Oil Reservoirs ........................................................................................................................ 7-7
COMPRESSORS.......................................................................................................................... 7-7
Centrifugal or Rotary ............................................................................................................. 7-7
Reciprocating ......................................................................................................................... 7-7
STEAM TURBINES ...................................................................................................................... 7-8
ELECTRICAL EQUIPMENT.......................................................................................................... 7-8
Motors ............................................................................................................................. - .... 7-8
Transformers.......................................................................................................................... 7-8
Switchgear ............................................................................................................................. 7-8
Batteries................................................................................................................................. 7-9
CONTROL DEVICES AND INSTRUMENTATION........................................................................ 7-9
Pneumatic Systems ............................................................................................................... 7-9
Control Valves ....................................................................................................................... 7-9
FIRED HEATERS AND FURNACES............................................................................................ 7-9
DIESEL AND GASOLINE ENGINES.......................................................................................... 7-10
LINED TANKS AND VESSELS.................................................................................................. 7-10
Rubber-Lined Equipment ..................................................................................................... 7-10
Thin or Baked Linings .......................................................................................................... 7-10
For Open Tanks ............................................................................................................... 7-10
Thick or Free-Standing Linings............................................................................................ 7-10
Brick-Lined Vessels ............................................................................................................. 7-10
REFRIGERATION SYSTEMS .................................................................................................... 7-11
CONTROL ROOMS .................................................................................................................... 7-11
EXPANSION JOINTS.................................................................................................................. 7-11
SPRINKLER SYSTEMS ............................................................................................................. 7-11
WAREHOUSE AND STORAGE YARD ...................................................................................... 7-11
Warehouse Items ................................................................................................................. 7-11
Storage Yard........................................................................................................................ 7-12
BUILDINGS ................................................................................................................................ 7-12
8 PROTECTION PROGRAM FOR 19-60 MONTHS ........................................................................ 8-1
SHUTDOWN CONSIDERATIONS ................................................................................................ 8-1
CORROSIVE ENVIRONMENTS .................................................................................................. 8-1
Acid Service.......................................................................................................................... .8-1
Alkaline Service ..................................................................................................................... 8-1
Organic Compounds .............................................................................................................. 8-1
Pyrophoric Materials .............................................................................................................. 8-1
Sulfur-Oxy (Polythionic) Acids ............................................................................................... 8-2
WATER LINES ............................................................................................................................. 8-2
INSULATION ................................................................................................................................ 8-2
PIPING, VALVES AND FITTINGS................................................................................................ 8-2
Carbon and Low Alloy Steel Materials ................................................................................... 8-2
Piping, Valves, Fittings (Underground)................................................................................... 8-3
Austenitic Stainless Steel and Other High Alloys .................................................................. 8-3
Lined Low Alloy Steel Pipe .................................................................................................... 8-3
FLARE SYSTEM .......................................................................................................................... 8-3
HEAT TRACING... ........................................................................................................................ 8-4
PROCESS VESSELS AND TANKS ............................................................................................. 8-4
Stainless Steel and Nonferrous Alloys ............................................................................... ...8-4
Carbon Steel .......................................................................................................................... 8-4
Reactors................................................................................................................................. 8-4
Towers, Spheres, Bullets........................................................................................................ 8-5
COOLERS AND EXCHANGERS.................................................................................................. 8-5
Cooling Towers ...................................................................................................................... 8-5
Spray Coolers ........................................................................................................................ 8-5
Finned Air Coolers ................................................................................................................. 8-6
Plate Exchangers ................................................................................................................... 8-6
Shell and Tube Exchangers .................................................................................................. 8-6
STORAGE TANKS ................................................................................................................... ...8-7
ROTATING EQUIPMENT ............................................................................................................. 8-7
Centrifugal Pumps ................................................................................................................. 8-7
Reciprocating Pumps ............................................................................................................. 8-7
Mechanical Seals and Packing .......................................................................................... ....8-8
Bearings—All Equipment ....................................................................................................... 8-8
Drives ..................................................................................................................................... 8-8
Couplings ............................................................................................................................... 8-8
Agitators, Centrifuges, Mixers ............................................................................................... 8-8
Hydraulic Systems, Lubricating Oil Systems and
Oil Reservoirs ........................................................................................................................ 8-8
COMPRESSORS .......................................................................................................................... 8-9
Centrifugal or Rotary ............................................................................................................. 8-9
Reciprocating ......................................................................................................................... 8-9
STEAM TURBINES .................................................................................................................... 8-10
ELECTRICAL EQUIPMENT........................................................................................................ 8-10
Motors—Field Storage ......................................................................................................... 8-10
9
Motors—Disassembled......................................................................................................... 8-11
Vertical Motors..................................................................................................................... 8-11
Transformers........................................................................................................................ 8-11
Switchgear ........................................................................................................................... 8-11
Batteries............................................................................................................................... 8-12
Cables and Small Field Electrical Devices........................................................................... 8-12
CONTROL DEVICES AND INSTRUMENTATION ..................................................................... 8-12
Pressure Relief Valves ........................................................................................................ 8-12
Temperature Gages ............................................................................................................. 8-12
Liquid Level Gages .............................................................................................................. 8-12
Pressure and Differential Pressure Indicators
and Switches ....................................................................................................................... 8-12
Control Valves ..................................................................................................................... 8-12
Field Panels ......................................................................................................................... 8-13
FIRED HEATERS AND FURNACES.......................................................................................... 8-13
DIESEL AND GASOLINE ENGINES.......................................................................................... 8-13
PROTECTION OF LINED TANKS AND VESSELS .............................................................. .8-14
Rubber-Lined Equipment ..................................................................................................... 8-14
Thin or Baked Linings .......................................................................................................... 8-14
For Open Tanks ............................................................................................................... 8-14
Thick or Free-Standing Linings .................................................................................................. 8-15
Brick-Lined Vessels ............................................................................................................. 8-15
REFRIGERATION SYSTEMS..................................................................................................... 8-15
CONTROL ROOMS .................................................................................................................... 8-15
EXPANSION JOINTS ................................................................................................................. 8-16
SPRINKLER SYSTEMS ............................................................................................................. 8-16
WAREHOUSE AND STORAGE YARD ITEMS .......................................................................... 8-16
Warehouse Items ................................................................................................................. 8-16
Storage Yard........................................................................................................................ 8-17
BUILDINGS ................................................................................................................................ 8-17
PROTECTION PROGRAM BEYOND 60 MONTHS ..................................................................... 9-1
SHUTDOWN CONSIDERATIONS ............................................................................................. ...9-1
CORROSIVE ENVIRONMENTS .................................................................................................. 9-1
Acid Service........................................................................................................................... 9-1
Alkaline Service ..................................................................................................................... 9-1
Organic Compounds .............................................................................................................. 9-1
Pyrophoric Materials .............................................................................................................. 9-1
Sulfur-Oxy Acids (Polythionic Acids).................................................................................... ..9-2
WATER LINES ............................................................................................................................. 9-2
INSULATION ................................................................................................................................ 9-2
PIPING AND VALVES.................................................................................................................. 9-2
Carbon and Low Alloy Steel Piping, Valves and Fittings (Above Ground).......................... ..9-2
Carbon and Low Alloy Steel Piping, Valves, Fittings (Underground) ................................. ....9-3
Austenitic Stainless Steel and Other High
Alloy Lines.............................................................................................................................. 9-3
Lined Low Alloy Steel Pipe .................................................................................................... 9-3
FLARE SYSTEM .......................................................................................................................... 9-3
HEAT TRACING ........................................................................................................................... 9-4
PROCESS VESSELS AND TANKS ............................................................................................. 9-4
Stainless Steel and Nonferrous Alloys ................................................................................... 9-4
Carbon Steel .......................................................................................................................... 9-4
Reactors............................... *................................................................................................ 9-5
Towers, Spheres, Bullets ....................................................................................................... 9-5
COOLERS AND EXCHANGERS .................................................................................................. 9-5
Cooling Towers ...................................................................................................................... 9-5
Spray Coolers ........................................................................................................................ 9-6
Finned Air Coolers ................................................................................................................. 9-6
Plate Exchangers ................................................................................................................... 9-6
Shell and Tube Exchangers .................................................................................................. 9-6
STORAGE TANKS ....................................................................................................................... 9-7
ROTATING EQUIPMENT.............................................................................................................. 9-7
Centrifugal Pumps.................................................................................................................. 9-7
Reciprocating Pumps ............................................................................................................. 9-8
Mechanical Seals and Packing.............................................................................................. 9-8
Bearings—All Equipment........................................................................................................ 9-8
Drives ..................................................................................................................................... 9-8
Couplings ............................................................................................................................... 9-8
Agitators, Centrifuges, Mixers ............................................................................................... 9-8
Hydraulic Systems, Lubricating Oil Systems
and Reservoirs....................................................................................................................... 9-9
COMPRESSORS ..........................................................................................................................9-9
Centrifugal or Rotary ............................................................................................................. 9-9
Reciprocating ......................................................................................................................... 9-9
STEAM TURBINES .................................................................................................................... 9-10
ELECTRICAL EQUIPMENT........................................................................................................ 9-10
Motors—Field Storage ......................................................................................................... 9-10
Motors—Disassembly .......................................................................................................... 9-11
Vertical Motors ..................................................................................................................... 9-11
Transformers........................................................................................................................ 9-11
Switchgear ........................................................................................................................... 9-11
Batteries ............................................................................................................................... 9-12
Cables and Small Field Electrical Devices........................................................................... 9-12
CONTROL DEVICES AND INSTRUMENTATION...................................................................... 9-12
Pressure Relief Valves......................................................................................................... 9-12
Temperature Gages ............................................................................................................. 9-12
Liquid Level Gages .............................................................................................................. 9-12
Pressure and Differential Pressure Indicators
and Switches........................................................................................................................ 9-13
Control Valves...................................................................................................................... 9-13
Field Panels ......................................................................................................................... 9-13
FIRED HEATERS AND FURNACES..........................................................................................9-13
DIESEL AND GASOLINE ENGINES..........................................................................................9-14
PROTECTION OF LINED TANKS AND VESSELS....................................................................9-14
Rubber-Lined Equipment ..................................................................................................... 9-14
Thin or Baked Linings .......................................................................................................... 9-14
For Open Tap.ks ............................................................................................................... 9-15
Thick or Free-Standing Linings............................................................................................ 9-15
Brick-Lined Vessels ............................................................................................................. 9-15
REFRIGERATION SYSTEMS .................................................................................................... 9-15
CONTROL ROOMS .................................................................................................................... 9-16
EXPANSION JOINTS ................................................................................................................. 9-16
SPRINKLER SYSTEMS ............................................................................................................. 9-16
WAREHOUSE AND STORAGE YARD ITEMS .......................................................................... 9-16
Warehouse........................................................................................................................... 9-16
Storage Yards...................................................................................................................... 9-17
BUILDINGS ................................................................................................................................ 9-18
Unheated Buildings.............................................................................................................. 9-18
Heated Buildings............................................................................................. :................... 9-18
All Buildings ......................................................................................................................... 9-18
10 POWER PLANTS FOR 1-18 MONTHS ...................................................................................... 10-1
BOILERS .................................................................................................................................... 10-1
Boiler Water Side-Wet Method ......................................................................................... 10-1
Boiler Water Side—Dry or Cold Method.............................................................................. 10-1
Boiler Fire Side-Wet Method ............................................................................................. 10-2
Boiler Fire Side-Dry or Cold Method................................................................................. 10-2
Boiler Fire Side—Hot Technique ......................................................................................... 10-2
TURBINES ..................................................................................................................................10-2
MOTORS AND GENERATORS..................................................................................................10-3
PUMPS........................................................................................................................................10-3
FANS...........................................................................................................................................10-3
Induced Draft Fans ..............................................................................................................10-3
PIPING ........................................................................................................................................10-4
DEAERATORS, AIR RECEIVERS, INERT GAS TANKS AND OTHER
PRESSURE VESSELS...............................................................................................................10-4
TANKS........................................................................................................................................10-4
HEAT EXCHANGERS, CONDENSERS, EJECTORS, CHILLERS, ETC ..................................10-4
SWITCHGEAR, CIRCUIT BREAKERS, CONTROL CABINETS,
RELAY CABINETS, ETC............................................................................................................10-5
CONVEYORS, HOPPERS AND OTHER HANDLING EQUIPMENT..........................................10-5
SOFTENERS, ION EXCHANGE COLUMNS, ETC.....................................................................10-5
11 POWER PLANTS FOR 19-60 MONTHS ....................................................................................11-1
BOILERS ....................................................................................................................................11-1
Boiler Water Side—Dry Method...........................................................................................11-1
Boiler Fire Side—Dry Method..............................................................................................11-1
TURBINES..................................................................................................................................11-2
Motors and Generators Stored in Place ..............................................................................11-2
Motors and Generators—Disassembled...............................................................................11-2
PUMPS .......................................................................................................................................11-3
Centrifugal Pumps ...............................................................................................................11-3
Reciprocating Pumps...........................................................................................................11-3
FANS ..........................................................................................................................................11-3
Induced Draft Fans ..............................................................................................................11-4
PIPING ........................................................................................................................................11-4
DEAERATORS, AIR RECEIVERS, INERT GAS TANKS AND
OTHER PRESSURE VESSELS..................................................................................................11-4
TANKS........................................................................................................................................11-5
HEAT ECHANGERS, CONDENSERS, EJECTORS, CHILLERS, ETC ....................................11-5
SWITCHEAR, CIRCUIT BREAKERS, CONTROL CABINETS,
RELAY CBINETS, ETC ..............................................................................................................11-5
CONVEYOS, HOPPERS AND OTHER HANDLING EQUIPMENT ............................................11-5
SOFTENERS, ION EXCHANGE COLUMNS, ETC.....................................................................11-5
12 POWER PLANTS OVER 60 MONTHS.......................................................................................12-1
BOILERS ....................................................................................................................................12-1
Boiler Water Side-Dry Method...........................................................................................12-1
Boiler Fire Side—Dry Method..............................................................................................12-1
TURBINES..................................................................................................................................12-2
Motors and Generators Stored in Place ..............................................................................12-2
Motors and Generators—Disassembled...............................................................................12-2
PUMPS .......................................................................................................................................12-3
Centrifugal Pumps ...............................................................................................................12-3
Reciprocating Pumps ...........................................................................................................12-3
FANS ..........................................................................................................................................12-3
Induced Draft Fans ..............................................................................................................12-4
PIPING ........................................................................................................................................12-4
DEAERATORS, AIR RECEIVERS, INERT GAS TANKS AND OTHER
PRESSURE VESSELS...............................................................................................................12-4
TANKS........................................................................................................................................12-5
HEAT EXCHANGERS, CONDENSERS, EJECTORS, CHILLERS, ETC..................................12-5
SWITCHGEAR, CIRCUIT BREAKERS, CONTROL CABINETS, RELAY
CABINETS, ETC .........................................................................................................................12-5
CONVEYORS, HOPPERS AND OTHER HANDLING EQUIPMENT..........................................12-5
SOFTENERS, ION EXCHANGE COLUMNS .............................................................................12-5
13 INSPECTION AND MAINTENANCE...........................................................................................13-1
MANPOWER ..............................................................................................................................13-1
INSPECTION.............................................................................................................................. 13-1
Inspection Equipment .......................................................................................................... 13-1
Inert Gas (Nitrogen) Blankets .............................................................................................. 13-1
Sealed Equipment ............................................................................................................... 13-1
Desiccants ........................................................................................................................... 13-2
Structural Steel and Other Primed Equipment .................................................................... 13-2
Gears, Fans, Couplings, etc................................................................................................ 13-2
Bolts, Nuts, Flanges ............................................................................................................ 13-2
Pumps, Motors, Turbines and Other Rotating Equipment................................................... 13-2
Storage Yards ..................................................................................................................... 13-2
Warehouse .......................................................................................................................... 13-2
Towers, Drums, Spheres, Bullets and Other Pressure Vessels .......................................... 13-2
Heat Exchangers, Condensers, Ejectors, etc...................................................................... 13-3
Boilers, Furnaces, Heaters .................................................................................................. 13-3
Tanks................................................................................................................................... 13-3
Piping................................................................................................................................... 13-3
Special Situations ................................................................................................................ 13-4
MAINTENANCE ......................................................................................................................... 13-4
Pumps, Motors, Turbines, Generators and Other
Rotating Equipment............................................................................................................. 13-4
Sealed Equipment ............................................................................................................... 13-4
Drainage .............................................................................................................................. 13-4
Piping Systems.................................................................................................................... 13-4
Electrical .............................................................................................................................. 13-4
Firewater............................................................................................................................ 13-4
RECORDS.................................................................................................................................. 13-4
14 RECOMMISSIONING A MOTHBALLED PLANT ....................................................................... 14-1
INSPECTION.............................................................................................................................. 14-1
PLANNING ................................................................................................................................. 14-1
RECOMMISSIONING ................................................................................................................. 14-2
WATER LINES........................................................................................................................... 14-2
Piping, Valves and Fittings .................................................................................................. 14-2
Piping and Valves (Underground) ....................................................................................... 14-2
Austenitic Stainless Steel and Other High
Alloys ................................................................................................................................... 14-2
FLARE SYSTEM ........................................................................................................................ 14-2
HEAT TRACING ......................................................................................................................... 14-3
PROCESS VESSELS AND TANKS ........................................................................................... 14-3
Stainless Steel and Nonferrous Alloys ................................................................................ 14-3
Carbon Steel........................................................................................................................ 14-3
Reactors .............................................................................................................................. 14-3
COOLERS AND EXCHANGERS ............................................................................................... 14-3
Cooling Towers ................................................................................................................... 14-3
Spray Coolers...................................................................................................................... 14-4
Finned Air Coolers ............................................................................................................... 14-4
Plate Exchangers ................................................................................................................ 14-4
Shell and Tube Exchangers ................................................................................................ 14-4
STORAGE TANKS..................................................................................................................... 14-4
ROTATING EQUIPMENT ........................................................................................................... 14-5
Centrifugal Pumps............................................................................................................... 14-5
Reciprocating Pumps........................................................................................................... 14-5
Mechanical Seals and Packing ........................................................................................... 14-5
Bearings—All Equipment ..................................................................................................... 14-5
Drives................................................................................................................................... 14-5
Couplings............................................................................................................................. 14-5
Agitators, Centrifuges, Mixers ............................................................................................. 14-6
Hydraulic Systems, Lubricating Oil Systems and
Oil Reservoirs...................................................................................................................... 14-6
Centrifugal or Rotary Compressors......................................................................................14-6
Reciprocating Compressors .................................................................................................14-6
Steam Turbines ................................................................................................................... 14-6
ELECTRICAL EQUIPMENT ....................................................................................................... 14-7
Motors...................................................................................................................................14-7
Transformers ....................................................................................................................... 14-7
Switchgear............................................................................................................................14-7
Batteries ...............................................................................................................................14-7
Control Devices and Instrumentation ...................................................................................14-7
Pressure Relief Valves .....................................................................................................14-7
Temperature Gages..........................................................................................................14-7
Liquid Level Gages ...........................................................................................................14-8
Pressure and Differential Pressure Indicators and Switches ........................................... 14-8
Control Valves ................................................................................................................. 14-8
Field Panels ..................................................................................................................... 14-8
FIRED HEATERS AND FURNACES ......................................................................................... 14-8
DIESEL AND GASOLINE ENGINES ......................................................................................... 14-8
LINED TANKS............................................................................................................................ 14-9
REFRIGERATION SYSTEM ...................................................................................................... 14-9
CONTROL ROOMS ................................................................................................................... 14-9
15 BIBLIOGRAPHY ........................................................................................................................ 15-1
FIGURE 13.1—Sample of a Plant Protection Inspection Procedure Sheet ....................................... 13-5
FIGURE 13.2—Sample of a Maintenance and Inspection Control Sheet .......................................... 13-6
TABLE 3.1-To Avoid Problems with Mothballing............................................................................... 3-8
TABLE 6.1—Types of Preservatives Used in Mothballing................................................................... 6-8
TABLE 6.2—Specifications Used to Identify Mothballing Preservatives.............................................. 6-9
ACKNOWLEDGMENTS
The author would like to thank members of the MTI Resource Group for helpful discussions and
suggestions during the preparation of this document; in particular A. Bisio, G. Kobrin of Du Pont, L. A.
Scribner of Union Carbide, N. Monsour of Polysar and A. S. Krisher of MTI for their review and comments
on the draft report. Special thanks are extended to J. Gutzeit of Amoco who supplied a number of technical
articles on plant experience. J. English of Cain Chemicals also made several helpful suggestions following
his review of the draft report.
Finally the author would like to express his appreciation to the managements of mothballed facilities who
allowed him to draw on his practical experience gained in protecting their plants.
ABSTRACT
Corrosion in an idle process plant may be reduced by the judicious selection and application of
preservatives so that the plant may be recommissioned.
This manual provides information on which to base a mothballing program for a selected shutdown
period at the lowest cost, and with the fewest problems when a plant is returned to service.
Various protective systems and their methods of application are outlined as they have been used in
major facilities of the chemical, petrochemical, refining, power generation and oil exploration industries. The
advantages and disadvantages of each system are given.
Guidelines are presented for the preparation of detailed field instructions to personnel performing
protection work on different types of equipment.
Three other important stages are outlined as well: the inspection and the maintenance of the mothballed
facility and the recommissioning of such a plant.
The protection periods of plant equipment may be classified according to the life expectancy of the
preservatives: short-term (1-18 months), medium-term (19-60 months) and long-term (over 60 months).
Section 6, Selection of Preservatives, is the basis for each of the protection sections (7, 8 and 9 for process
plants, 10, 11 and 12 for power houses).
SECTION 1 GENERAL
CONSIDERATIONS
The shutdown and extended storage of a plant or unit should be treated as a significant event with
extensive planning and budgeting to preserve equipment thai otherwise can suffer rapid deterioration. The
decision to protect a plant should be based on sound economic principles and on the results of an extensive
inspection to establish equipment condition and its ability to withstand the forecast idle period.
If a decision to mothball or protect the equipment is made, a complete study is necessary to determine
the appropriate protective measures, such as the exclusion of moisture, the establishment of inert
atmospheres, and the selection of preservative compounds.
Moisture is the primary cause of deterioration in idle equipment. It may come from condensation, or it
may be present in process streams that have not been completely removed or it may be introduced in some
of the protective compounds selected for the program, particularly in inert gases.
Moisture contributes to pitting and other forms of corrosion which may lead to perforation of equipment,
fouling and gouging of seating surfaces, destruction of electrical contacts, and the deterioration of buildings
and other structures. It can be controlled through the use of a dew point level for the atmospheres inside
equipment so that condensation will not occur even at the lowest ambient temperature the equipment will
experience. For short shutdown periods, frequent draining of equipment may reduce the moisture level
sufficiently to prevent serious corrosion.
Damaged insulation can result in heavy corrosion due to the ingress of moisture from rain or snow.
Proper sealing of insulation is necessary particularly in marine or industrial environments.
Heat tracing on equipment helps to alleviate moisture problems by keeping temperatures above the dew
point and by drying insulation. However, consideration must be given to the effects of heat on stagnant
solutions. Rapid corrosion could result from boiling or concentration of corrosives. In addition, shutdown units
may not have power or steam available so that maintenance of a tracing system would be impossible.
Heating is recommended, of course, for the protection of buildings and of electrical components. In many
instances, electrical equipment has its own heaters which must be continuously energized to prevent
damage.
Inert atmospheres may be employed to preclude the presence of moisture and/or oxygen. The inert
atmosphere must be dry and free from harmful contaminants. Nitrogen is the inert atmosphere most
commonly used. However, its effects on various scales and sludges found in a plant must be assessed.
Sludges and scales found in most plants frequently contain compounds that combine with oxygen or
moisture to produce harmful acids. These acids may promote rapid corrosion and cracking of common
construction materials. Neutralization of these sludges and scales using a gas such as ammonia or a solution
such as sodium carbonate may be necessary. Since short shutdown periods may not require neutralization
it is essential to determine how long a sludge or scale can be exposed to oxygen or moisture before harmful
corrosive compounds are formed.
Oil may be used to protect equipment, particularly in refineries with abundant supplies. The oil should be
free of contaminants, such as hydrogen sulfide, that can promote corrosion. However, provisions must be
made to ensure that the oil is not drained off and sold, particularly during periods of rising oil prices.
There are other oil-based products that can be used to prevent basic atmospheric corrosion. These
include both water repellent oils and emulsifying oils. Intended for short-term protection, these products
generally have a life expectancy of six months outdoors but perform satisfactorily for longer periods in
sheltered locations.
There are a number of coating systems commonly used for plant protection. These usually employ
grease, wax or plastic as the base coat and may require touching up from time to time. All systems require
periodic inspection to ensure that the integrity of the protective envelope is maintained.
The term "protective envelope" also describes membranes that have been used extensively in naval
applications. These include protective plastics of the polyvinyl chloride and polyethylene types that may be
applied over painted structures or used in combination with grease and oils to provide a relatively long-term
system. However, dehumidification is essential to prevent condensation and excessive corrosion within the
envelope. Tests on large towers indicated that some of these protective systems tend to strip under their own
weight, so care in their selection is essential.
Protection systems are selected to prevent corrosion, at the lowest possible cost for the intended
shutdown, yet permit future plant start-up with the fewest possible problems.
These guidelines offer standard protection methods for process plant equipment and are based on
experience gained in the mothballing of major facilities in the chemical, petrochemical, refining, power
generation and oil exploration industries. They have been arranged in sections to reflect the general practice
of equating protection measures with the length of the idle period. Three periods, namely, one-to-eighteen
months, nineteen-to-sixty months, and beyond sixty months, are accepted in industry as realistic divisions or
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categories for protection applications. Consequently, Sections 7, 8 and 9 for process equipment and 10, 11
and 12 for steam plants reflect these three periods. Each section is a general procedure for protecting
equipment for a given time and is intended to be complete in itself.
1-2
SECTION 2 ECONOMIC
CONSIDERATIONS
The decision to shut down an operating facility and protect the idle equipment is never made easily. In
many instances, equipment experiences an extended idle period before a decision to protect it is reached.
Severe deterioration may result due to corrosion from the general environment and from scales or deposits
which can be protective under operating conditions but corrosive during shutdown. Consequently, the sooner
a decision is made to clean and protect, the better the chance of successful restart.
A decision to mothball assumes that the plant equipment is worth preserving in the first place—a
conclusion that depends on the answers to the following questions:
1. What are the financial prospects for the company now and in the future?
2. Is the market for the products likely to recover?
3. Will the cost of preserving the equipment exceed its future replacement cost?
4. Can the unit be protected or does its design preclude any chance of successful protection?
5. Can the equipment last for the duration of the protection period?
EQUIPMENT CONDITION
The condition of the equipment must be determined by a complete and thorough inspection relying on
past history to identify potential problem areas. This inspection should include:
Internal Inspection
A complete visual inspection of the interior of all process equipment and vessels is recommended after
any necessary cleaning. Sweetening, steam cleaning, or other neutralizing steps may be required for vessel
entry.
Any problems found should be identified and repair techniques outlined. Nondestructive evaluation
techniques such as ultrasonics or radiography are useful on a spot basis to verify vessel condition. Sludges
and scales should be analyzed to assess their effect on protection capabilities.
Exterior Inspection
Examination of components for exterior corrosion should be performed, particularly of those that may be
affected by wet insulation. Examination of insulation is necessary to determine whether or not it should be
removed or can be repaired. The condition of heat tracing should be assessed.
Mechanical Equipment
Pumps, compressors, motors, fans, etc. should be examined both internally and externally, as
applicable, to determine their condition and suitability for protection.
Electrical Equipment
Electrical equipment is usually in reasonably good condition. However, this must be established through
thorough inspection.
Structural
Structural members should be thoroughly inspected. This includes such items as tower and exchanger
bases, anchor bolts, pipe racks, cooling towers and all forms of support plus the protection (normally paint)
that has been applied.
Piping
Piping, particularly small diameter components, is perhaps the most difficult item to assess. It is usually
insulated and there are untold miles of it in plants. Inspection frequently involves the complete assessment
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of large diameter members (over 24" is a convenient break point) including removal of insulation, spot
radiography, valve removal to permit internal inspection, and ultrasonic thickness measurements.
Piping less than twenty-four inches in diameter may be completely inspected or may be inspected on a
sampling basis depending on its importance to plant operations. For plants with predominantly small
diameter piping, personnel will inspect everything over two inches in diameter. Piping two inches and less in
diameter is generally abandoned unless it is critical to the operation.
High-alloy piping, lined piping systems, and those constructed of other alloys that may be expensive or
be long delivery items are usually inspected thoroughly, following cleaning and drying.
Small diameter piping is examined on a sampling basis with the critical nature of the line determining the
attention paid to it. Of course, the maximum diameter of the line chosen as a cut-off for complete inspection
varies from plant to plant.
A complete inspection of the plant is therefore the first major cost item to be associated with a
mothballing program. It may represent anywhere from 0.1 to 1.0% of the capital cost of the equipment
depending on the extent to which in-house personnel or contract personnel are used.
IDLE PERIOD
If the equipment is worth preserving, the next step is to determine the probable shutdown period. The
length of this period affects every aspect of planning and costs because the longer the equipment is idle, the
more protection is required. An inaccurate prediction of idle time will affect the cost of maintaining the
equipment and the ability to restart in the future. In fact, underestimating the idle period is not only the most
common complaint associated with mothballing but also is responsible for the greatest deterioration in
shutdown plants.
This is illustrated by the history of a chemical plant that was shut down initially for a three month period.
Market conditions did not improve and the plant shutdown was extended in three month increments for
approximately three years. Short-term protection was applied at the end of each three month period. When
start-up was approved, it was found that the cost of protection and equipment replacement amounted to six
times the anticipated cost of a program designed for a 1 1/2 year-to-five year period.
Plants protected with short-term preservatives almost always remain idle much longer than the original
forecast period. Consequently, a review of market conditions and preservation costs after a one year idle
period is recommended. If start-up is not foreseen for at least another year, upgrading the protection to the
eighteen-to-sixty months program is advisable, particularly on critical or long delivery items.
As mentioned in Section 1, protection programs are generally divided into three categories: 1-18 months,
19 months-to-five years and over five years. Obviously a plant is not going to disintegrate at 19 months;
however, the periods do reflect the life expectancies of various protection methods so that extension beyond
the established time generally involves reapplication of preservatives. A general "rule of thumb" establishes
costs for programs as
1-18 months
19 months-to-five years
greater than five years
—
—
—
1.0
2.5
4.0
Preservatives to be applied for longer protection periods generally require better metal surface
preparation, with sandblasting common. Restrictions on such cleaning methods may dictate the protection
program chosen.
The success of a protection program may depend on the quality and detail of the protection instructions
and procedures. Obviously, the more detailed the procedure the less likely something will be overlooked, e.g.
the thickness of protection coatings.
Considerable engineering time will be spent on the preparation of a protection program once the idle
period has been established. It will be necessary to prepare detailed procedures and field instructions for the
protection of each category of equipment. No detail should be left to interpretation by a contractor. The
procedure for conducting each operation should be described in complete detail, step by step. Acceptance
and rejection criteria must be outlined as well.
Close inspection of the application of the preservatives is necessary. A properly applied compound may
protect for years but a poorly applied one may cover problems which will show up long after the contractor
has left, requiring costly repairs. The importance of responsible supervision of the work cannot be
overemphasized.
EXPERIENCE AT OTHER PLANTS
Based on experience gained at plants being mothballed, a number of problems may be avoided through
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the judicious use of manpower. Some of these considerations are listed below.
Staff Considerations
During short-term shutdown—one lasting six months or less—it is unlikely that personnel would be laid
off. Preservation work may be done by these personnel as they will have a vested interest in maintaining the
plant.
If there is to be a layoff for longer term shutdowns, plant personnel should not be involved in the
protection work as they tend to make the job last as long as possible. Sabotage is quite common as is theft.
Experience indicates that only staff who are to continue at the plant should be involved in its protection.
Otherwise, contract personnel should be hired to do the work while inspection of the application of the
mothball compounds should be done by those responsible for maintaining and inspecting the plant after
shutdown.
Safety aspects must be considered including security guards and sufficient personnel to maintain a fire
crew on site, where required.
Site Requirements
Electricity, heat and water for fire fighting are necessary to maintain certain mothball and safety aspects.
The costs involved must be forecast and form part of any economic evaluation. Similarly, maintenance of an
inert atmosphere will involve replenishment of the gas as leaks are almost inevitable.
Road clearance under winter conditions may be necessary in northern climates. Brush and grass control
will be necessary as well.
Insurance may be a major cost item, particularly if the plant will maintain a large inventory of flammable
products.
MAJOR COST ITEMS-MOTHBALL PROGRAM
1. Complete inspection of plant or unit to establish condition.
2. Selection of preservatives based on predicted idle period.
—cost of equipment preparation —cost of
preservatives and application —cost of
reapplication as necessary
3. Preparation of a comprehensive mothball program.
—preparation of procedures and specifications
4. Application of the protection program.
—contractors or plant personnel
—inspection of the application
5. Monitoring of the system.
—inspection personnel
—2 mechanical/production or process
— 1 electrical
—security (must have adequate fire fighting crew)
—maintenance
6. Other costs.
—insurance
—electricity
—heat
WHAT EQUIPMENT SHOULD BE PROTECTED
Although equipment in a chemical plant or refinery represents a considerable capital investment, it may
be impractical to protect it all during an extended shutdown period. Some equipment is relatively inexpensive
and protection methods can result in considerable expenditures. Nonetheless, in order to maintain an inert
atmosphere it may be necessary to protect some of this equipment to maintain the integrity of the rest of the
plant. Plant personnel will decide what is critical and what is not. The following have been used as general
guidelines during the mothballing of facilities:
2-3
Field Erected Equipment
All major equipment such as towers, crackers, spheres, bullets and storage tanks are generally
considered worth protecting due to the costs involved in building these relatively large structures. The amount
of protection varies with the complexity and value of the item. Storage tanks, for instance, may be protected
simply by draining or they may be coated with oil. Towers and spheres probably will be protected with inert
atmospheres.
Insulation is extremely important on this equipment as considerable time is involved in its application or
removal. Still, if towers and spheres are to be stored beyond three years, insulation removal should be
considered.
Heat Exchangers
Heat exchangers are generally considered as a separate item both because of their numbers in most
plants and because of their complexity. Heat exchanger protection includes cleaning followed by thorough
drying. (These steps are critical to the success of the operation as any deposits or moisture may establish
conditions for accelerated corrosion.) Exchanger geometry such as fixed tubesheets, floating tubesheets,
multiple-pass units, the U-bends in tubes, and even dissimilar metal construction all complicate the protection
equation. As well, the gap between flanges, flange faces and sealing surfaces must be protected to avoid
costly reworking prior to restart.
Most heat exchangers are protected with an inert atmosphere on the inside. Banks of exchangers in a
unit lend themselves readily to this technique. It also permits protection of the interconnecting piping which
is often complicated. In addition, flange faces are protected with gasketing compound to prevent crevice
attack and the gap between flanges may be filled with protective compound although both procedures are
costly and time consuming.
Bolting can be protected in the same manner, although some facilities consider the replacement of all
bolting prior to start-up as routine.
Insulation again is of prime concern for it is rarely moistureproof and without operating temperatures to
keep it dry very rapid attack can result, particularly in climates subject to large temperature variations
between day and night. Insulation removal and exchanger painting is normally suggested for storage of more
than three years.
Austenitic stainless steel construction does afford considerable protection in units of these materials.
Here, the major concerns are crevice corrosion between flanges, stress-corrosion cracking or intergranular
corrosion due to inadequate neutralization, or cracking due to wet insulation. Maintaining heat tracing may
help to alleviate problems related to the insulation but it also may cause increased corrosion due to
concentration effects caused by boiling of solutions. Extreme care must be used if heat tracing is to remain
on.
Piping
-------Piping presents the most difficult protection problem in a plant because of the great quantities, varying
size and the condition of the insulation.
In most plants, large diameter, expensive piping is protected internally with inert atmospheres after
flushing, draining and drying. Smaller diameter piping, unless it is essential to maintain ah inert atmosphere,
is not protected other than to flush it and drain it. Drain valves are generally left open.
The size of pipe that constitutes the cut-off between protection and nonprotection varies from plant to
plant—24" in several facilities, 12" in some and as small as 2" in others. Economics dictate the protection
afforded as it is relatively easy to procure small-diameter, carbon steel pipe although installation can be
expensive.
Underground piping presents additional problems. If it is cathodically protected, the system should be
maintained and inert atmospheres used internally. Buried piping that can be easily replaced is frequently
abandoned.
Piping in trenches presents another problem as trenches tend to fill with water, creating serious external
corrosion. This piping is also frequently abandoned in favor of new construction at start-up.
Pipe insulation is particularly bothersome again due to the sheer volume of it. Moisture ingress at
hangers, flanges or other breaks in covering can promote very rapid corrosion.
Fired Heaters
Fired heaters are generally protected through the use of heat, desiccants, inert atmospheres and
2-4
protective compounds. These heaters are relatively large expense items and their protection is comparatively
easy.
Boilers and Associated Equipment
Boilers which represent a large capital outlay are designed to operate many years. Even very old boilers
can operate efficiently so protection is usually elaborate and complete. Boilers may be stored dry or wet. Dry
storage is usually utilized when the shutdown is to exceed one year while wet is used for shorter periods or
when the boilers may have to be brought back on line relatively quickly.
Dry storage involves the use of desiccants, oils, vapor phase inhibitors and preservation greases. Wet
storage utilizes some heat and oxygen scavengers with or without corrosion inhibitors.
Mechanical Equipment
Most large pumps, compressors, blowers, fans, extruders and their associated seal and lubricating
systems are protected, frequently in place, although they may be disassembled instead. Casings, valves,
rotors, etc. are coated with various protection compounds, and oils are circulated through the systems.
Rotors are usually turned once a month to protect bearings and shaft bearing surfaces.
Reactors, Mixers, Autoclaves
The vessels are the heart of many processes and usually are protected. Many of these items are indoors
so that protection, after cleaning, requires only coating of machined surfaces, and maintaining heat or
providing an inert atmosphere.
Electrical Equipment
Electrical equipment such as motors, switchgear, relays, etc. are generally protected. Motors may have
their heaters activated and the rotors are turned once a month. Desiccants and vapor phase inhibitors are
used in cabinets or relays. Switchgear is generally coated with grease.
Flare Systems
If an inventory of flammable products is maintained in a plant, the flare system remains operational. If no
inventories exist, the flare system is generally protected to the flare drums with an inert atmosphere following
flushing, draining and drying. The stacks may be capped or they may be left open. Some facilities have
attempted an inert atmosphere blanketing of the stacks but gas losses tend to be high.
EQUIPMENT NOT PROTECTED
Small, inexpensive equipment is usually not protected due to the costs involved. This equipment
includes:
1. Inexpensive instrumentation such as small pressure gages, level gages, small control valves, etc.
2. Small motors—experience suggests that it is uneconomical to protect motors of less than 10 hp.
3. Small tanks such as weigh tanks, small atmospheric storage tanks, waste treatment tanks and
other components that can be replaced quickly and inexpensively.
4. Small pumps, blowers and fans that can be replaced readily.
5. Small diameter piping (2" and less) and cast iron lines with the exception of fire water mains, large
cooling water mains and speciality-lined components.
6. Wood stave pipes and small FRP piping systems.
7. FRP tankage that has been thoroughly cleaned and drained.
2-5
2-6
SECTION 3
PROTECTION SYSTEMS AND PLANT EXPERIENCE
Protection compounds, particularly those intended for use with carbon steel, are many and varied. In
general, each is based on some proprietary product reputed to make it more effective than competing
materials. However, product data sheets often refer to simulated field tests and may not reflect the true
response of the material in the particular mothballing situation at hand.
Preservatives may be classified according to their main characteristics, specific basic components, or the
method by which protection is accomplished. Common groupings are:
—film type preservatives
—greases and oils
—volatile corrosion inhibitors
—environment alteration
—inert atmospheres
—combination systems
FILM TYPE
Film type preservatives are, by far, the largest category as they include paints, varnishes, thin film, thick
film, hard film, wrapping paper and tapes, and plastic films used to cover or wrap an entire component
(cocooning).
Thin Film
Thin film materials are usually solvent-based systems that dry through evaporation of the solvent leaving
a thin (10 mils/0.010 inch or less), evenly distributed film. The film is usually self-healing and waterdisplacing. Thin film materials are intended for the short-term protection of freshly machined components,
flange faces and similar items.
Thin film products protect the metal by preventing moisture from contacting the metal surface.
Breakdown of the film results in corrosion of the underlying metal.
Thin films are generally effective for corrosion protection under indoor or sheltered outdoor storage
conditions for periods of one-to-twenty-four months with the average protection being six months. If they are
used to protect equipment that is to be idle over six months they can be high maintenance items as they may
require frequent reapplication.
Thin films may suffer a loss of film integrity as the preservative may flow off the parts, particularly under
conditions of high ambient temperature. However, they can be quite effective between mating flanges.
Thick Film
Thick film material, i.e. a preservative applied at greater than 10 mils (0.010 inch) thickness, also
depends on the integrity of the film to prevent corrosion. Corrosion Inhibitors may be added to the compound
so that small breaks can be tolerated without severe corrosion.
The preservative may dry by solvent evaporation leaving a relatively firm outer surface with a relatively
soft interior thus enabling the coating to expand or contract with the metal. Some manufacturers inaccurately
refer to these thick coatings as industrial greases.
Thick film products may withstand higher temperatures than industrial greases but they are harder to
remove when restarting the unit. Thick films are intended for protection of equipment for twenty-four months
or longer.
In most instances, surface preparation plays an important role in the protective ability of thick films.
Sandblasting may be required although some compounds are intended for use over hand-cleaned surfaces.
Wrapping to protect the film may be necessary.
A well-applied thick film offers good long-term protection but poorly applied material can result in "mud
cracking" or the rupture of the film under gravity due to the weight of the material itself.
Thick film materials tend to be relatively expensive to use in that hand application is the normal method
of coating.
Hard Film
Hard film materials are ususally petroleum-based products that dry by solvent evaporation, leaving a
3-1
hard surface. The degree of protection depends on the integrity of the coating and the cleanliness of the
surface to which it is applied. Breaks or pinholes will result in severe corrosion. These coatings are often
black so that corrosion developing underneath is hidden. Hard films tend to be difficult to remove.
Paint, Varnish, Lacquer
Paints, varnishes and lacquers also depend on the integrity of the film to prevent moisture from
contacting the underlying surface and causing corrosion. Good surface preparation is essential for success.
Paint breakdown is frequent, requiring hand cleaning to permit repairs.
Wrapping Materials
Wrapping tapes and papers are used to protect components, usually critical items, by completely
covering them. The papers or tapes may be impregnated with inhibitors, e.g. vapor phase inhibitors, to
prevent corrosion.
Components may be removed and wrapped or they may be wrapped in place.
Wrapping tends to be a high cost item as it is labor intensive.
Cocooning
Cocooning is the name given to a process of enveloping and protecting with a sprayable plastic coating.
It is generally applied to large structures and is used in combination with another system such as paint,
desiccants or vapor phase inhibitors. The cocoon acts as a vapor barrier; consequently moisture in the
atmosphere inside the cocoon may condense on equipment that is enveloped. Dehumidification, air
conditioning and desiccants are employed to control the moisture.
Cocooning tends to be relatively expensive but it can effectively seal out corrosives provided the seal
remains intact. A cocooning system applied to flanges proved unsuccessful in an industrial application. The
coating which had been sprayed on was torn by the wind and severe corrosion resulted from the ingress of
moisture which remained in close contact with the metal. In addition, tests on insulated towers revealed that
the coating tended to strip off under its own weight.
Cocooning has been used successfully on a large scale even though it tends to be a high maintenance
item. It is intended for long-term shutdowns extending up to ten years or more.
GREASES AND OILS
These products, based on petroleum, are intended not only for lubrication but also for the preservation
of metallic surfaces. They are applied both for short- and long-term idle periods.
Oils
The interior surfaces of vessels, heat exchangers, piping, headers, compressors, pumps and other
closed equipment may be protected with a coat of light oil which may contain corrosion inhibitors. The oil must
have enough viscosity so that it adheres to the walls and does not readily evaporate.
Oil is a popular preservative as it may be applied by many methods, particularly filling and draining, or
spraying. It requires no special technical knowledge for its application and it may require no cleanup upon
restarting.
It is, however, a short-term preservative and may require frequent reapplication. Protection periods range
from three-to-twelve months depending on the oil and the presence of corrosion inhibitors. Some problems
have been encountered with oils containing corrosives such as sulfur and naphtha compounds that convert
to acids in the presence of moisture. Care should be exercised also in using oils containing vapor phase
inhibitors. Some such products have been found to contain sulfuric acid resulting from manufacturing
practices.
Greases
Grease includes both antifriction greases for lubrication of components and the industrial greases
3-2
designed for long-term protection of equipment. These materials contain corrosion inhibitors and are
intended for short- to long-term protection depending on the location.
The industrial greases, similar to thick film materials, harden on the outer surface while retaining a soft
consistency on the inner surface so that they may expand and contract with the metal. Some form of
protection such as wrapping or crating is normally required to prevent mechanical damage to the coating.
Greases tend to be high maintenance items as they may require frequent replacement unless they are
protected by wrapping. High ambient temperatures may result in loss of protection due to running of the
grease. The materials do, however, offer reasonable long-term protection at moderate cost.
VOLATILE CORROSION INHIBITORS
Volatile corrosion inhibitors (VCIs) are self-vaporizing chemical compounds which are supplied as
crystals, pellets, liquids or on VCI-impregnated tapes or foam rubber. Protective vapors are released and are
disseminated throughout an enclosed space until equilibrium is reached. The vapors condense on the metal
surface to form a thin protective film of molecular thickness, particularly in the presence of moisture.
Protection is relatively simple and may be accomplished by placing the inhibitor in the tank, vessel, drum
or other equipment. Openings must be sealed to prevent loss of vapor.
VCIs are temperature sensitive. Heating above 150°F causes excessive vaporization and loss of
protection. In addition, VCIs tend to be combustible and may form explosive mixtures when heated.
VCIs may be selected for many metals and for some combinations of metals. Since some VCIs may
cause deterioration of incompatible materials, consultation with those familiar with their use is recommended
before putting them into service.
ALTERATION OF THE ENVIRONMENT
Corrosion of idle equipment may be controlled primarily by preventing condensation from the atmosphere and/or the ingress of water from rain or snow. Moisture in the atmosphere can be removed by altering
the environmental conditions around the equipment.
Dehumidification
Dehumidification of buildings, the housings of critical equipment such as turbines, and areas containing
electrical switchgear, relay cabinets, etc. generally prevents significant corrosion. Dehumidification is also
used in conjunction with cocooning to prevent condensation beneath the plastic cover. It may be achieved
by using large commercial dryers or even through use of small household units placed in sealed areas such
as control rooms, warehouses and office buildings.
Water removal from the dehumidifiers is essential, particularly from small individual units, to prevent
localized corrosion. Fans are generally required in the enclosed area to ensure complete circulation of the air.
Air Conditioning
Air conditioning may be used to control humidity by preventing condensation. It is particularly effective
with electrical switching and relay equipment. Air conditioning prevents swelling of the organics holding the
electrical contacts. Air conditioning is particularly effective in control rooms, warehouses and other enclosed
storage spaces. Window units are frequently employed but their effectiveness diminishes with distance from
the unit. Fans are usually required to ensure circulation of the air.
Heat
Heat may be employed to prevent condensation and the resulting corrosion. Temperatures 10°F (5.5°C)
above ambient are often maintained in warehouses to prevent corrosion. However, in warm climates this may
create intolerable working conditions. An effective localized method of heating involves the use of an ordinary
light bulb or a heating lamp in each bin of stored components. The heat is usually sufficient to prevent
corrosion. Heat tracing left on equipment may prevent corrosion by drying insulation and preventing
condensation. However, it may also create severe corrosion problems by concentrating corrosives in
stagnant solutions through boiling.
Similarly, boilers stored wet generally benefit from some low heat as the water is circulated.
3-3
Most electrical equipment such as large motors, switchgear, relay and logic cabinets, control consoles,
etc. have their own internal heaters. These are usually continuously energized during storage to prevent
corrosion.
Heating may be necessary as well to prevent freezing of piping and other systems during winter
conditions, particularly during shutdown periods when the systems may not be completely drained. Again,
care must be exercised to prevent boiling of solutions.
Desiccants
Desiccants are used to absorb moisture, thereby preventing corrosion. Silica gel and hydrated lime are
the most common desiccants used.
Silica gel is usually placed in cloth bags and inserted in equipment, particularly in electrical cabinets and
control consoles. The silica gel will absorb moisture and change color so that spent material can be detected
before moisture problems arise.
Silica gel may also be used in certain equipment such as transformers that have receptacles designed
for the product. Loose silica gel is placed in the "see-through" containers and is replaced when the color
indicates a change is necessary.
Hydrated lime (slaked lime) is generally used inside vessels and in the fire boxes of heaters, boilers,
furnaces, etc. It is placed in open, low-sided trays and is often raked to expose fresh material. Replacement
is necessary at fixed intervals, frequently three-to-six months. The lime does not experience a color change
so detection of spent material is difficult.
Both materials are effective in preventing corrosion. However, spent material in contact with equipment
can promote rapid corrosion as it prevents the moisture from evaporating thereby maintaining a continuous
wet environment.
Other Drying Media
Piping systems and equipment may be dried by blowing hot air, inert gas, or even process gases through
the equipment. The air or gas should be hot enough to prevent condensation and should be free of
contaminants that promote corrosion in the presence of moisture such as sulfur compounds, nitrous oxides,
carbon dioxide and other similar acid-forming substances.
The gas is blown through the system while dew point or moisture content is analyzed. When satisfactory
levels are reached, the flow of gas is stopped and the system closed. Other protection such as the insertion
of VCIs or purging with inert gas may be employed as well.
Neutralization
Many items of operating equipment contain deposits, scales or sludges that are protective under
operating conditions but become highly corrosive under shutdown conditions when they absorb air and
moisture. These scales are neutralized through a flow of gas or a wash with a suitable solution. Plant
personnel must choose the neutralizing step suitable to their particular operation.
Perhaps the most familiar neutralization procedure involves the use of ammonia or sodium carbonate
solutions to prevent polythionic acid attack of austenitic stainless steels that have been exposed to hydrogen
sulfide environments. Here ammonia or a solution of 1 -to-2% sodium carbonate is circulated through the
system to neutralize the scales. Where possible, scales are often then flushed from the system followed by
a final drying of components to a low dew point.
Care must be exercised in neutralization particularly if gas lines are involved. These lines may never
have been designed to carry the weight of a liquid flush so that severe damage may occur on flushing.
Antifreeze
Antifreeze compounds may be required in plants where the ambient temperature goes below the freezing
point, even if there is only an occasional dip in a normally warm climate. Damage due to freezing is found
most frequently in piping and in jacketed equipment where draining has been either incomplete or
preservative solutions without antifreeze characteristics have been used.
Antifreeze solutions should contain suitable corrosion inhibitors to prevent attack on the equipment being
protected.
3-4
INERT ATMOSPHERES
Use of inert atmospheres is a relatively inexpensive and effective method of protecting the interior of
equipment and piping systems. Nitrogen is the gas most frequently chosen.
However, the nitrogen used for this purpose is relatively pure and free of moisture, containing a
maximum of 1% oxygen.
Nitrogen is used effectively only if all flanges and other potential leak locations are tightly sealed. The gas
may be introduced through a continuous purge or a fill-and-drain technique until analysis shows an oxygen
level of 1% or less. To prevent condensation and corrosion, a dew point of 0°F (-18°C) is maintained in
systems protected with inert gases.
The inert gas is maintained at a positive pressure to prevent the ingress of air and a program of periodic
monitoring of the system pressure is required. Where applicable, piping connections to vessels or systems
under inert gas protection should be well off the ground to prevent damage during heavy snowfall or severe
storms.
Since the equipment contains an inert atmosphere, all points of personnel entry are labeled with
cautionary signs.
MULTICOMPONENT SYSTEMS
Multicomponent systems generally use a combination of heavy industrial greases or thick film products
covered with some form of wrapping material or tape. The tape is frequently coated with a grease-type
product to promote adherence and to provide extra protection.
The multicomponent system is extremely effective in protecting equipment for long-term storage, and a
ten year life is not unexpected. Such systems tend to be expensive as they are labor intensive with the
wrapping done by hand. Taping machines have been developed for some products but their effectiveness
depends on the skill of the operator.
A variation of a multicomponent system consists of the greasing and crating of equipment to be stored
in the warehouse. Here an industrial grease is applied followed by wrapping with paper or tape impregnated
with VCI. The entire assembly is then placed in a wooden crate for long-term storage.
The main disadvantage of multicomponent systems is the difficulty encountered in removing the
preservative to permit a return to service.
PLANT EXPERIENCE
Many plants and units have been "mothballed" for periods that vary from a few weeks to many years.
These facilities are Jocated in industrial climates varying from tropical marine to inland desert to extreme
northern regions. Despite their locations, a number of common problems in protection are encountered.
These problems usually are the result of a lack of understanding of protection requirements, failure to
recognize potential problem areas, a poor forecast of the idle period, or removal of some equipment from a
protected system thereby exposing the remainder of the system to corrosion.
Plastic Wrap
The misuse of plastic film to wrap components in the field can result in rapid corrosion damaging or
destroying the "protected" parts quite quickly. Plastic sheet is wrapped around valves, valve springs, valve
stems, electrical cabinets, pumps, motors, etc. in the hope of keeping out moisture. Condensation occurring
underneath the plastic film can result in severe corrosion.
To avoid this problem, plastic wrap is used only in conjunction with dehumidification or desiccants unless
the wrapping serves merely as a dust cover. It is wrapped tightly around components only if they are
completely protected from moisture by some other means.
Plastic wrap is placed over relay switching, console cabinets and the like so as to provide at least a two
inch (5 cm) air space at the bottom to allow ventilation. If the plastic wrap is fastened to the floor around the
cabinets, condensation may occur. If the cabinets are protected with desiccants or are in dehumidified areas,
the air gap is not necessary.
Plastic wrap used outdoors to cover equipment may cause corrosion if it touches the metal surface as
condensation can and does occur in these locations.
A gap all around the covering along the bottom is necessary for ventilation. Equipment covered with
plastic wrap should be protected with some other material such as a grease, oil, or VCI as well as the plastic.
3-5
Plastic used to cover open flanges may promote corrosion unless the flange face and associated
hardware are protected with a grease or oil.
Flanges
Corrosion is experienced between mating flanges, particularly carbon steel components. The gap
between the flanges creates a crevice and with no heat on the system, rapid corrosion takes place. In
addition, flange bolting also experiences very rapid attack and may corrode through, permitting the ingress
of moist air into the system.
To avoid these problems, flanges are opened and cleaned of all rust, scale or other contamination and
then coated with a suitable grease or oil and reassembled. The gap between the flanges is covered. On
critical items such as heat exchangers this may involve packing with a grease and covering with a suitable
tape. The heads and nuts of bolts are coated as well to prevent accelerated attack.
Plugs may also present ideal crevice situations, particularly if they are on horizontal surfaces. Here water
and dirt can accumulate keeping the threaded sections of the couplings continuously wet.
Safety Valves
Safety valve springs are often rendered useless by corrosion. If possible, safety valves over four inches
in diameter are removed from the unit and stored indoors in a humidity-controlled environment. The openings
are blanked and the flange faces are protected with a suitable grease.
Electrical Equipment
Electrical cabinets, relay cabinets, console cabinets, motors, etc. with their own heaters keep these units
energized to promote drying. Swelling of organics in these components tends to render them useless in a
relatively short time under moist conditions. Drying out wet components may not restore their integrity.
Silica gel placed in cabinets has been helpful in preventing problems.
Storage Yards
Storage yards are frequently overlooked when a plant or unit is mothballed. Piping is left to corrode as
is spare equipment.
Effective yard care includes: grading to promote drainage, cutting brush and grass, piling piping with a
slope so that the prevailing winds can blow through it and water can drain out, separating lengths of pipe from
one another to prevent build-up in the natural crevices formed between adjacent lengths, and protecting
flange faces with a suitable grease or oil.
Of course, stored material should carry identification which will be maintained, covered (with a clear
lacquer, for example) so it will be intact when the material is needed.
Wood used as bolsters is treated with a preservative to prevent bacteria-induced corrosion where it
contacts steel but care in the selection of the preservative is necessary as some products can corrode
metals.
Insulation
Wet insulation has resulted in severe corrosion in many plants. To prevent this corrosion, insulation is
inspected frequently and any wet material removed. For short shutdowns, consideration can be given to
replacing the wet sections and sealing the insulation against moisture ingress. For shutdowns lasting beyond
three years, it may be decided that all the insulation will be removed until start-up. The exposed equipment
surface is protected by painting or by other suitable methods.
Where only partial removal is possible the insulation left on components requires sealing. Problems with
insulation are frequently found adjacent to flanges, valves, pumps, etc. where ineffective sealing exposes the
insulation to moisture. Due to a wicking action, such moisture will travel along the insulation and may cause
severe corrosion in areas remote from the point of moisture entry.
3-6
Equipment Removal
The removal of equipment for use as spare parts for other plants has resulted in rapid corrosion of the
remaining items, particularly if the system was protected with an inert atmosphere. Scrapping of the
remaining equipment is not uncommon.
If some equipment may be used as spare parts, this is identified before the plant is protected so that
protection methods may be altered to accomodate missing pieces, e.g. spool pieces may be used to by-pass
missing equipment allowing inert atmosphere protection where necessary.
Severe corrosion has been encountered as well in equipment protected by being filled with oil. When oil
prices were attractive, the oil was drained off for sale; the protective oil was not replaced and the equipment
deteriorated rapidly.
SUMMARY OF PLANT EXPERIENCE
When used inappropriately, certain materials and practices have been identified as causing rapid
deterioration of equipment. The following table may be used to avoid potential problems with the different
means of protection.
3-7
TABLE 3.1
To Avoid Problems with Mothballing
Item
Plastic Wrap
Do
Don't
1) Use plastic wrap as
a dust cover only. Air
gap of two inches all
around bottom to permit
ventilation.
1) Use plastic wrap to
cover equipment unless
equipment is protected
with a preservative, dehumidification, or other
suitable system.
2) Use plastic wrap as
a seal when desiccants
are used inside equip
ment such as switch
gear and relay cabi
nets.
2) Cover flanges with
plastic wrap unless
flanges are protected with a
preservative.
3) Use plastic wrap
over a frame to make a
shelter for equipment.
Adequate ventilation
must be provided to
prevent condensation.
3) Use plastic wrap in
place of tapes to seal
flanges or other equip
ment.
4) Use plastic wrap as a
vapor barrier on insula
tion.
4) Use plastic bags to
store small components
in the warehouse.
Components should be
coated with a preser
vative before bags are
sealed.
Insulation
5) Use plastic wrap in
place of VCI paper to
wrap components.
1) Leave wet insulation
on equipment.
1) Seal insulation to
prevent ingress of
moisture.
2) Attempt to dry insula
tion with tracing if
lines contain no flow of
product.
2) Use insulation to
prevent freezing.
3) Consider removing
insulation for idle
periods greater than
three years.
Oil
3) Rely on insulation as
protection against corro
sion.
1) Drain oil without providing alternate protection.
1) Use oil as a preser
vative for short-term
protection.
2) Use oil on interior
surfaces and as a lu
bricant.
3) Use oil containing
corrosion inhibitors.
Heat
1) Keep buildings warm
to prevent condensa
tion.
1) Heat stagnant solu
tions.
2) Heat equipment con
taining inert atmos
pheres.
2) Use light bulbs in
bins to prevent corro
sion in the warehouse.
3) Heat equipment con
taining VCIs.
3) Use heat with
boilers, heaters, fur
naces, etc. to prevent
corrosion.
4) Keep internal heaters
on equipment energized.
3-8
TABLE 3.1 (continued)
To Avoid Problems with Mothbaiiing
Hem
Environment
Do
Dont
1) Use air condition-
1) Use plastic sheet to
ing or dehumidification
to protect electrical
equipment, buildings
and equipment stored
indoors.
make a sealed environment
unless it is dehumidified
as well.
2) Leave spent desiccant
in equipment.
2) Use desiccants Inside electrical cabinets, fired heaters,
critical vessels, etc.
Use desiccants that
change color for ease
of identification of
spent material.
3) Use fans to circulate air in air conditioned or dehumidified buildings.
Inspection
1) Maintain accurate
1) Decrease inspection
and Maintenance
records of what was protected.
and maintenance activities to reduce costs.
2) Maintain accurate
records of what was
inspected, when it
was inspected, how it
was inspected, and
the results of the
inspection.
3) Record each maintenance activity.
Storage
1) Store as much equip-
1) Store critical equip-
ment indoors (in a controlled environment)
as possible.
ment in unheated buildings.
2) Store equipment in
buildings that are not
weatherproof.
2) Dismantle critical
rotating equipment for
indoor storage for idle
periods extending beyond three years.
3) Store equipment close
to the seashore, in the
path of fallout from
operating units, close to
major highways or in
areas affected by flooding due to heavy rains.
3) Erect shelters over
critical equipment in
the field.
4) Grade and fence
storage yards
for drainage protection.
5) Store equipment off
the ground and separated from one another
to prevent the formation of crevices.
Pressure
4) Use absorbent material
between mating flange
faces.
1) Maintain inert
atmospheres at a positive pressure to prevent air inleakage.
1) Overpressure tanks.
3-9
TABLE 3.1 (continued)
To Avoid Problems with Mothbaiiing
Item
Drainage
Do
Don't
1) Drain and dry all
components.
1) Leave moisture from
hydrostatic tests in
equipment.
2) Open valves at all
low areas to facilitate
draining. Drill holes
for drainage only when
no other method is avail
able.
3) Tag drilled holes.
3-10
SECTION 4 TESTING OF PROTECTIVE
COMPOUNDS
Many protective compounds exist. Some effectively protect metals, others offer little protection or can
even, in the extreme, promote corrosion. Most of the protective compounds have been tested under
laboratory conditions, generally in a salt spray cabinet, and while they may be effective in that environment,
they can suffer rapid deterioration in the field. Consequently, it is important to conduct both field and
laboratory tests to ensure that the preservatives chosen will perform as expected. Some relatively simple yet
effective tests are outlined below. Complicated tests invite errors in interpretation.
CORROSION TESTS
Coupon Preparation
Coupons of the metal to be protected may be cut to any practical size; 6" x 6" x 1/4" or 4" x 6" x 1/4"
are popular sizes. A hole is drilled through the coupon near the top center so the sample can be suspended,
preventing contact with surrounding surfaces.
The coupons are cleaned using the method that will be employed on the equipment to be protected. This
may involve sandblasting to a white metal finish, hand cleaning or some other suitable method; sandblasting
of carbon steel coupons permits the most accurate assessment of a preservative's protection capabilities as
even small amounts of rust can be distinguished against the "white" background. Care must be taken to
prevent contamination by grease, dust, oil, scale, fingerprints, etc.
Application of the Preservative
The preservative is applied to the coupons by spraying, brushing, rolling, dipping or any other method
recommended by the product manufacturer. The method of application should approximate what will be done
in applying the product to process equipment. At least two sets of coupons are prepared for each compound
tested. One set is completely covered by the coating; the second has only 50% of its surface area covered.
The preservative is applied to the wet film and/or dry film thickness planned for use in the field. Care is
taken to ensure that the coating is free of pinholes and other defects.
Corrosion Test
The coupons should be suspended so that they form a 60° angle with the vertical and be placed in a
moist, warm environment, indoors for indoor preservatives and outdoors for outdoor material, for a period of
30 days minimum.
Following the 30 day exposure, the coupons are carefully examined for any sign of rust breakthrough,
blistering or other signs of degradation. The 50%-coated coupon is examined for rust undercutting the
coating. The dry film thickness is measured to determine if coat "run-off" has occurred.
If corrosion has occurred under the coating, rust has penetrated the 50%-coated material, or blistering
or thinning of the coating is detected, the material is unsuitable for protection under field conditions.
4-1
Adherence and Protection Test
A simple test devised to assess both adherence and protection of various compounds involves
subjecting coated coupons to a weather cycle as might be experienced under field conditions. Temperature
cycling, particularly freeze-thaw conditions, can destroy a protective layer quickly and, when coupled with the
effects of corrosive rainwater, can result in rapid corrosion of components.
Test Conditions
The test involves freezing in a freezer, then heating with a sun lamp followed by wetting with water
acidified to the pH of the site's rainwater.
Test Sequence
A sequence that has been used involves these steps:
—Freezer for eight hours.
—Sun lamp for four hours.
—Water spray for two hours.
—Sun lamp for four hours.
—Water spray for two hours.
—Sun lamp for four hours.
—Repeat cycle.
The test is conducted for a minimum of 30 days.
A variation of the test involves freezing one end of a sample while using the sun lamp on the other to
produce temperature gradients that may exist under winter conditions in northern climates.
The test may, of course, be altered to reflect local climatic conditions such as cooling but no freezing,
heavy rains, abrasive conditions due to dust storms, the presence of a salt air environment, etc.
Chemical Analysis
Each batch of protective compound is chemically analyzed to ensure that it is not different from other
batches. Samples supplied for testing are chemically analyzed as well to ensure that they are no different
from commercially produced lots.
Compounds containing high levels of sulfur should be viewed with concern as corrosive products may
be formed in moist conditions.
Elastomers, Gaskets
Samples of "O-rings", diaphragms, seals, gaskets, etc. are tested in the protective compounds by
immersion or coating for 30 days. Swelling and general deterioration may result, indicating the preservative
is unsuitable for use with the elastomer.
Removal of Preservatives
In addition to testing preservatives to determine their effectiveness in protecting equipment, tests are
conducted on the method of removal. Most product data sheets list suggested cleaning techniques that are
supposed to be effective in removing the preservatives. Cleaning procedures for all preservatives are
developed at the testing stage to avoid surprises during recommissioning. In any case, one must know the
cleaning techniques in order to forecast the costs associated with reapplication of preservatives for long idle
periods or with recommissioning.
4-2
SECTION 5
INERT GAS PURGING AND BLANKETING OF EQUIPMENT
Inert gas purging and blanketing of equipment may be accomplished by one of two methods—purge and
fill or the continuous purge. However, prior to purging the tightness of all joints should be determined. This
is done most easily by filling a vessel with an inert gas (e.g. nitrogen) at a pressure of 14 psig (0.0965 MPa)
and testing all the joints with soap solution. Any leaks should be repaired. Care must be exercised to ensure
that the equipment is capable of retaining the required pressure. Atmospheric tanks are purged by a flow of
gas without raising the pressure.
PURGE AND FILL
1. Pressurize the vessel or system with inert gas to 10 psig (0.069 MPa).
2. Depressurize to 2 psig (0.014 MPa) by opening the top vent valves.
3. Repeat steps 1 and 2 until the oxygen content at all sample points is less than 1% by volume.
4. Measure the dew point of the inert gas in the vessel. If it is greater than 0°F (-18°C), continue the
purge and fill until a satisfactory dew point is reached, less than 0°F.
5. When the oxygen level is less than 1% by volume and the dew point is less than 0°F, pressurize the
vessel to 10 psig (0.069 MPa) minimum and close off all valves.
6. Maintain the vessel under a positive pressure of inert gas of 5 psig (0.034 MPa) minimum, adding
gas as necessary to maintain the pressure.
CONTINUOUS PURGE
1. Purge the vessel or system with inert gas with the top valve open until the oxygen content and the
dew point are below 1% by volume and 0°F (-18°C), respectively.
2. Ensure that the inert gas expanding through the nozzle does not chill carbon steel vessels below
59°F (15°C) to avoid possible brittle fracture.
3. Close the vent valve and pressurize the vessel to 10 psig (0.069 MPa) minimum.
4. Maintain the vessel under a positive pressure of 5 psig (0.034 MPa) minimum, adding inert gas as
necessary.
MONITORING
Each vessel or system maintained under an inert gas blanket is fitted with a pressure gage to permit
periodic monitoring of the pressure. The pressure is monitored, generally on a weekly basis, until no pressure
loss is noted for three consecutive weeks. Monitoring is then performed monthly as long as no loss of the inert
gas blanket occurs.
CAUTION
The use of nitrogen or any other inert atmosphere may present a safety hazard to personnel. It is an
important safety precaution to post warning signs at each manway or other point of entry into equipment and
systems protected with inert atmospheres.
5-1
5-2
SECTION 6
SELECTION OF PROTECTIVE COMPOUNDS
The selection of compounds to protect idle equipment can be extremely difficult due to the vast numbers
of such products available. To help in making a choice, the products available have been divided into groups
or classes based either on the type of protection afforded or on a characteristic of the compound, e.g.
protection by film formation. These classes are outlined in this section along with general instructions for the
application of the preservatives. Table 6.1 lists the material classifications including the life expectancy and
removal method where applicable. Care must be exercised in selecting the preservative best suited for the
type of protection desired.
To aid in the selection of preservatives MIL Specifications or other recognized general standards are
listed in Table 6.2. However, these specifications permit considerable variation in products and are to be
used only as guidelines. Testing of the product is the best approach to establishing a suitable preservative
for a specific protection requirement.
SURFACE PREPARATION
In general, all surfaces to be coated should be thoroughly cleaned of all oil, dust, grease, rust, scale and
other material that may affect the performance of the coating. Cleaning is normally done in accordance with
the Steel Structures Painting Council Manual, Volume 1. However, different techniques may be required for
machined surfaces where tolerances must be preserved, and for the interior of vessels, drums, tanks, heat
exchangers, etc. that are to be protected with oils, inert atmospheres or VCIs.
Preservatives that require sandblasting prior to coating are applied within twelve hours (4-8 hours in
humid environments) of cleaning to prevent flash rusting.
All surfaces to be coated are inspected for cleanliness before the preservative is applied.
QUALITY CONTROL
It is advisable to test all preservatives to ensure that they comply with their specifications. Testing as
described in Section 4 is often performed to determine the adequacy of the preservatives for the planned idle
period.
Coatings or other preservatives are inspected after application to ensure they are free of runs, sags, mud
cracking, pinholes or other defects. Thickness measurements, either wet or dry, may be made to ensure the
coatings are thick enough to provide adequate protection.
CLASS I-SOLVENT TYPE
This material is solvent based. After application, the solvent evaporates as the drying mechanism,
leaving a thin, evenly distributed film. Generally self-healing, the film displaces moisture and inhibits
fingerprint acids on machined surfaces. Consequently, it may be applied to parts that are damp from soluble
cutting oils or atmospheric moisture. It may also be used to dry parts prior to coating them with compatible
compounds from other classes of preservatives. As the film is extremely thin its removal is generally not
necessary before returning equipment to service.
The consistency of material in this class may vary from a thin liquid to a semiviscous liquid depending
on the preservative chosen.
Application
The preservative is applied by spraying, dipping, brushing, swabbing or other suitable method at
temperatures between 50° and 95°F (10°-35°C) to a dry film thickness of 1.0 to 2.0 mils (0.001-0.002 inch).
Service
The material is recommended for the intermediate-term indoor and short-term outdoor protection of
metal surfaces, engines, piping systems and fuel systems. Its expected life is six-to-twenty-four months in
indoor service, three-to-six months in sheltered outdoor service and one-to-three months in unsheltered
outdoor service.
6-1
It is used to protect freshly machined or cleaned components for short-term outages, warehouse stock,
and the interior of critical carbon steel equipment and piping systems. It is seriously limited by its tendency
C
to flow at 100°F (37.8 C), effectively removing the protective film. Components exposed to high ambient
temperatures or strong direct sunlight may lose their protective films quite easily.
Removal
Although removal is generally not necessary, it may be accomplished with hot water, mineral spirits or
hot alkaline cleaning systems.
CLASS II—OIL
This material is a petroleum-based oil of approximately SAE 20 to 3G viscosity (300 SUS to 500 SUS,
at 100°F) which may or may not contain corrosion inhibitors. It is used for the protection of gearboxes,
crankcases, bearings and housings, and other machinery which normally would be lubricated during
operation. The material does not have to be removed from the surfaces when the normal lubricating oil is
reintroduced.
Application
Oil is applied by brushing, spraying, dipping, or filling and draining. Normally the surfaces to be protected
do not require cleaning other than to remove grease and dirt. The material is generally applied as a very thin
film of 0.2 to 0.4 mil (0.0002-0.0004 inch).
Service
The material is intended for use on the internal surfaces of rotating or reciprocating equipment. It is used
on the interior of machinery stored both indoors and outdoors. Openings on the protected equipment are
sealed to prevent leakage and the ingress of air.
It may be used on external surfaces of equipment provided frequent reapplication (probably every few
days) is anticipated.
Oil may also be used on intricate parts and bearings that have been removed for storage in sealed
containers.
A chemical analysis of the oil will ensure that it contains no compounds that might promote corrosion, e.g.
sulfur or naphthenic acid.
CLASS Ill-EMULSION TYPE
This material is a petroleum-based product which forms a very thin, dry skin on the surface while
underneath the product remains soft and sticky. The coating is able to expand and contract with the metal
without cracking. For critical equipment, wrapping may be necessary to prevent mechanical damage.
Chemical analysis prior to use may be necessary to ensure that the product contains no free water since
isolated droplets can cause corrosion on the underlying metal.
Application
The material is applied to prepared surfaces by brush, swab, spray or by dipping. The preferred method
is by brush or spray. Dipping may result in very thick coatings and some form of scraping may be necessary
to remove excess material.
This material is applied at temperatures between 50° to 95°F (10°-35°C) to a dry thickness of 2 to 4 mils
(0.002-0.004 inch). A curing or drying period of two-to-four hours should be allowed following application.
Service
The material is recommended for intermediate-term indoor and short- to intermediate-term outdoor
protection of all metallic surfaces. It is applied to gears, valve stems, bolts, cables, flanges, etc. It is intended
6-2
for both indoor and outdoor service and is applicable to both external and internal surfaces. Mating flange
faces are often protected with the material.
The protection afforded is good as long as the coating is intact but, due to its soft properties, it is easily
damaged. However, dust appears to be absorbed and does not destroy the coating. Wrapping with tape or
paper is recommended for critical equipment. Crating may be necessary for disassembled parts.
The coating is affected by heat and may flow off components under conditions of high ambient
temperature. Temperatures over 300°F (149°C) will result in complete removal of the coating.
Removal
Removal is achieved with petroleum solvent, kerosene, or dry-cleaning fluids. Brushing the softened
product followed by steam cleaning may be required as well.
CLASS IV (a)-ANTIFRICTION GREASE
This material is an antifriction bearing grease containing corrosion inhibitors. It is intended for the
protection of antifriction bearings, pillowblocks and plain bearing assemblies, all with full external protection
or wrapping. The grease may be used when the bearings are put back in service provided it is water-free and
not discolored.
Application
The material is applied with a grease gun, spatula or other suitable method to exclude all air. Thickness
is generally a minimum of 10 mils (0.010 in.) and a maximum of whatever is necessary to fill the cavities.
Service
Antifriction grease is recommended for indoor or sheltered outdoor storage of antifriction bearings or
bearing assemblies that are enclosed or wrapped. The protection period can be up to twenty-four months in
indoor service and six-to-twelve months in outdoor sheltered service.
Removal of the grease may be accomplished with mineral spirits or alkaline cleaners.
CLASS IV (b)-INDUSTRIAL GREASE
Industrial grease is a petroleum-based product whose outer surface hardens while underneath it retains
its original consistency and self-healing properties. The coating is able to expand and contract with the metal
without cracking. Mechanical protection afforded by wrapping or crating is usually necessary for extended
protection.
Application
The material is applied by grease gun, brush, spatula or other method at temperatures between 50° and
95°F (10°-35°C) to a thickness of 10 to 30 mils (0.010-0.030 inch) considerably thicker than Class 111 materials
having similar properties.
Service
The material is recommended for long-term indoor and intermediate-term outdoor protection of all
metallic surfaces. It is applied to gears, valve stems, cables, bolts, etc. It is applicable to both external and
internal surfaces. Mating flange faces are often protected with the material.
The protection afforded is extremely good as long as the coating is intact. The coating is subject to
mechanical damage unless protected by wrapping with tape, paper or other suitable product. Crating of
greased components is also effective in guaranteeing long-term protection.
The coating is affected by heat and may flow off components under conditions of high ambient
temperature; heat resistant grades are available.
The grease is removed with mineral spirits.
6-3
CLASS V-HARD FILM TYPE
Materials of this type are generally petroleum-based products and dry by solvent evaporation leaving a
hard, tough surface which may feel somewhat waxy. The quality of protection depends both on the integrity
of the coating and on the cleanliness of the surface to which it is applied. Breaks or pinholes can result in
rapid corrosion of the underlying metal.
Application
This material is applied by brushing, spraying, swabbing, or with rollers to a dry film thickness of 2 to 4
mils (0.002-0.004 inch). Complete coverage is necessary to avoid peeling.
Service
Materials of this type are intended for the protection of nonprecision parts, flange faces, unpainted
components and other areas requiring long-term protection. The protection period is twelve-to-twenty-four
months in unsheltered outdoor service, twenty-four-to-forty-eight months in indoor service.
Service life depends on the integrity of the coating.
Most of these preservatives contain bitumen, producing a dark-to-black finish. Corrosion underneath the
coating cannot be observed.
This means that careful inspection is required to ensure cleanliness of the surface prior to coating.
Periodic inspection of the coating is required to detect potential problems during the shutdown.
Removal
These products are relatively difficult to remove. Steam and detergents followed by mineral spirits or
possibly sandblasting, in extreme cases, may be necessary.
CLASS VI-VOLATILE CORROSION INHIBITOR FLUID (VCI)
This material is a petroleum oil containing volatile corrosion inhibitor fluids that produce vapors which
form a barrier film when they condense on the internal surfaces of equipment. The protective vapors are
formed generally at temperatures between 80° and 150°F (27°-66°C). Above 150°F (66°C), excessive
vaporization causes loss of protection. Openings in equipment must be sealed to prevent the ingress of air
and dilution of the product.
Application
This material is generally applied by filling equipment with the fluid to the normal operating level and
running the equipment long enough to obtain full circulation. The equipment is then shut down and all
openings sealed.
Alternatively, equipment may be filled and drained, it may be filled and left filled, or the fluid may be
sprayed or fogged into the equipment.
Service
VCI fluid is intended for use in hydraulic systems, circulating oil systems, turbines, pumps, compressors,
gear casings, housings and other similar equipment. The integrity of the seal determines the protection
period. Maximum life expectancy is twenty-four months.
Problems have been encountered with some VCI fluids which were manufactured using sulfuric acid
rather than phosphoric acid. Before use, each batch of fluid may be analyzed for sulfur compounds and
tested for corrosion on freshly sandblasted carbon steel or other appropriate metal.
Removal
VCI fluid is removed by draining.
6-4
CLASS VII-VOLATILE CORROSION INHIBITOR (VCI)
CRYSTALS, CAPSULES, TAPES, EMITTERS, ETC.
Volatile corrosion inhibitors are self-vaporizing chemical compounds. They are sold as crystals, pellets,
capsules or liquids. In addition, tapes, sponges or other absorbing materials may be impregnated with the
compounds and sold as "VCI emitters."
A protective coating of molecular thickness is formed when the vapors condense on the walls of the metal
enclosure. Normally this protection does not have to be removed before the equipment is returned to service.
The compounds are combustible and can produce explosive mixtures when heated. Safety requires that
compounds not be exposed to heat or open flame and that they be removed from equipment prior to welding
or any other heating operation.
In addition, some studies are reputed to equate a high incidence of detached retina with exposure to VCI
compounds. Information is inconclusive but breathing apparatus is recommended for personnel exposed to
vapors on a continuing basis.
Application
The interior of components is protected by placing the crystals, capsules, tape, etc. within twelve inches
of the surfaces to be protected. Crystals may be placed in porous bags; tapes may be strung through the
equipment; crystals may be dissolved in water and the solution sprayed or painted on the areas to be
protected; or crystals or powder may be blown into components to effect protection. Small components may
be wrapped in VCI-impregnated paper. There are several grades of paper available; it is important to choose
one tough enough to withstand the anticipated storage conditions.
For carbon steel components, the amount of VCI is 0.035 oz. (1 gm) for each square foot of surface to
be protected. This level may be increased where high rates of attack are anticipated.
Service
VCI materials are recommended for the internal protection of gear reducers, tanks, bearings, electrical
panels, relay switches, logic cabinets, etc. The protection period depends on the integrity of the sealing and
the amount of inhibitor used. Under normal conditions, life expectancy is about two years. However, it is
important to inspect at fixed intervals, generally every six months. If the crystals are gone or signs of rust
appear, the treatment is repeated.
It is important that all equipment protected with VCI crystals, capsules, etc. is tagged to warn of the
possible explosion hazard upon heating and of potential eye problems.
CLASS VIII-MULTICOMPONENT SYSTEMS
These preservatives involve the application of a paste or protective compound tc carbon steel
components followed by wrapping with tape to seal joints and prevent damage. Two protective compounds
may be used: a paste which is a saturated hydrocarbon (petrolatum) with inert filling and passivating agents
and a mastic which is also a saturated hydrocarbon (petrolatum) with inert filling and vegetable fibers.
The paste is used primarily as a primer or adhesive for a wrapping tape. However, the paste is a release
agent and may cause debonding of the tape if applied too thickly.
Mastic is used to bridge gaps and fill out uneven contours on components where the paste could act as
a release agent. The tape is a nonwoven nylon fabric, impregnated with petrolatum similar to the paste
(except that it is formulated to a harder consistency). The tape is used to wrap or cover components pr^t-vAed
with primer or mastic.
Application
Components are protected by applying either the paste or the mastic to surfaces that have been cleaned
of all loose rust, scale, dirt, grease, etc. by wire brushing. Application is by brush or other suitable means to
produce an even coat of 40 mils (0.040 inch) for a flat surface. Temperature range for the application is 32°
to 100°F(0°-38°C).
Uneven contours or gaps are filled with the mastic ensuring a minimum of 40 mils (0.040 inch) thickness
for flat surfaces.
6-5
Components are then wrapped with the tape. Wrapping involves an overlapping or bandage technique
ensuring that all bubbles are removed by smoothing with bare hands. Tape ends start and finish in the top
quadrant of vertical joints to prevent unwrapping. The tape is worked into the grooves and contours to give
a smooth tight finish.
Service
Multicomponent systems are intended to protect bolts and nuts, heat exchanger and other flanges. They
are removed mechanically before the components are put back in service.
The protection period varies with the quality of the application. A ten year life is normal.
CLASS IX-DESICCANTS
Desiccants are used to ensure moisture removal. Silica gel is the most popular although lime may be
used as well.
Silica gel is a hard, amorphous granular form of hydrated silica that changes color when it absorbs
moisture permitting easy detection of spent material. It may be regenerated by heating to remove moisture.
Application
Silica gel is used on the interior or in enclosed sections of electrical equipment such as transformers,
relay cabinets, switch gear, and of pressure vessels, etc. It may be employed in the fire boxes of heaters,
boilers, etc. although lime trays are often employed in these locations.
The desiccant may be placed in fabric bags and suspended in the components or it may be placed loose
in receptacles designated for that purpose.
Service
The service life of silica gel will vary with the humidity and the amount of exposure. Inspection at
three-to-six month intervals and replacement when it has changed color are done to prevent corrosion.
CLASS X-INERT ATMOSPHERE
Nitrogen is the gas most frequently used for an inert atmosphere. It is important that the gas is dry and
low in contaminants, especially oxygen (no more than 1% oxygen).
A dew point (no more than 0°F or—18°C) is established for nitrogen used as an inert atmosphere.
Application
Nitrogen is used for the purging and blanketing of pressure vessels, heat exchangers, boiler drums,
piping and other components that can be sealed and maintained under a positive pressure. The nitrogen is
utilized either in a continuous purge or in a purge and drain technique until the equipment is filled with
nitrogen containing less than 1% oxygen and a dew point of 0°F (-18°C) maximum. Pressure gages will
permit monitoring so that nitrogen may be added to maintain a positive pressure.
Service
Care is exercised to ensure that the nitrogen does not chill carbon steel vessels below 60°F,(16°C) during
filling since these vessels are subject to brittle fracture. The life expectancy of a nitrogen blanket depends on
maintaining the integrity of the seal.
As mentioned before, all vessels containing nitrogen are tagged at all points of entry with cautionary
signs indicating an inert atmosphere.
6-6
CLASS XI-PAINTS, LACQUERS, VARNISHES
Paints, lacquers, and varnishes normally used in the plant are included in this class of material. Primers
generally consist of zinc-rich material, red lead, zinc chromate, etc.; top coats of alkyds, epoxies, acrylics,
vinyls, urethanes or other suitable materials are used.
Lacquers and varnishes are used for coating motor windings, preservation of material identification and
general purpose maintenance.
Choice of a particular compound depends on plant specifications and preference.
Application
Paint coatings are applied to cleaned surfaces by spraying, dipping, brushing, rolling, swabbing or other
suitable means. Cleaning may involve hand cleaning, power brushing, sandblasting or other suitable
methods. Sandblasting requires care to avoid contaminating components with sand.
Paints are applied to varying dry film thicknesses depending on the system chosen. Two to four mils
(0.002-0.004 inch) per coat is not unusual. A second coat or top coat as required may be applied after a
suitable drying period.
Varnishes applied to motor windings are generally brushed on to prevent damage to associated
components.
Service
In general, paint is applied to all nonmachined metal surfaces to provide a protective barrier. Interior
surfaces of some tanks and vessels may be protected in this manner as well.
Paint systems tend to be a high maintenance item as frequent hand cleaning of blistered and damaged
surfaces to permit repainting is necessary, again depending on the system employed in the plant. Runs, sags
and pinholes are to be avoided as damage to the coating can result in rapid corrosion of the underlying metal.
Removal
Paint applied to vessels and structures is generally suitable for plant operation and is not removed.
6-7
TABLE 6.1
Types of Preservatives Used in Mothballing
N.R. » Not Recommended
6-8
TABLE 6.2
Specifications Used to Identify Mothballing Preservatives
Type
Class
Specification
1
Solvent
MIL-C-16173D Grade II
MIL-P-116Type2
II
Oil
SAE 20-30
III
Emulsion
P.O. Dept. VB-65-1
IV(a)
Grease
MIL-G-23827B
IV (b)
Industrial Grease
MIL-C-11796B-Class III
V
Hard Film
MIL-C-16173D Grade I
MIL-P-116ETypeP-1
Class VI
VCI Fluid
MIL-P-46002A MIL-185062 (AS) MIL-C-16173D
Grade III
Class VII
VCI Crystals,
Tapes, Emitters
MIL-1-22110B Types I and II
Class VIII
Multicomponent
Petrolatum Tape
Class IX
Desiccants
Silica Gel, Slaked Lime
6-9
6-10
SECTION 7 PROTECTION PROGRAM FOR 118 MONTHS
"Mothballing" of a process plant normally involves an idle period which exceeds six months—time
enough to permit ambient temperature fluctuations due to seasonal changes. Shorter idle periods are
considered extended shutdowns and while considerable corrosion may occur, preventive measures tend to
be less stringent due to the imminent restart of the unit or plant.
During extended shutdowns, power, heat tracing, water and other services may remain available.
Manpower also tends to be plentiful so that corrosion prevention techniques that require frequent
reapplication of preservatives prove more economical than those requiring extensive surface preparation.
Inspection frequency may be maintained at a high level to detect deterioration in equipment with limited
protection.
The 1-18 month protection program is intended to maintain a plant or unit in a state of preservation that
is relatively easy both to apply and to remove, permitting a fast and efficient restart. Extended shutdowns
would also use this program.
For longer idle periods, cost savings would require a reduction in manpower and in the utilities charges
for a facility. Consequently, short-term preservatives and those that require frequent reapplication would be
less economical than those requiring more thorough surface preparation.
Protection procedures are matched to the degree of protection required relative to the expected idle
period. However, some precautionary measures would be observed during each equipment shutdown
regardless of the anticipated idle period.
SHUTDOWN CONSIDERATIONS
Certain pieces of equipment require shutdown and start-up procedures. These procedures normally
monitor both temperature and pressure to prevent excessive stresses and possible equipment damage.
Heavy-walled vessels or those likely to contain heavy deposits, catalyst or coke may require a controlled cool
down to prevent rupture.
Controlled cooling may be required also for vessels containing hydrogen or for equipment in which
hydrogen may be present as a corrosion product associated with such functions as sour service. The slow
cooling permits degassing of vessel walls and helps to prevent blistering or cracking.
Lined or coated vessels may require slow cooling allowing trapped gases to diffuse, thereby preventing
blistering of the coating or collapse of the liner.
At high temperature some alloys, particularly some of the higher carbon austenitic stainless steels used
in furnace tubing, develop structures which may be susceptible to brittle fracture at ambient temperatures.
These alloys should not be shock loaded by a sudden cool down as fracture may occur.
CORROSIVE ENVIRONMENTS
Many chemical, petrochemical and refining industry processes produce relatively stable scales on vessel
walls. These scales tend to be protective at operating temperatures but may promote extensive corrosion
when exposed to oxygen and moisture during shutdown. Other scales which may be pyrophoric in nature
when exposed to oxygen present serious safety hazards. The operators of a facility have the experience to
determine the deleterious effects of the various sludges and scales that may be present and the measures
to counteract their negative aspects.
Flushing with water followed by drying with air or nitrogen may be required. In general, equipment that
has been in acid service is flushed with water and drained completely. Neutralizing with an alkaline wash may
be necessary as well. Equipment that has been in alkaline service is usually flushed with water and drained
completely. Equipment that has been exposed to various organic compounds may require special washing
and neutralizing. Pyrophoric materials such as iron sulfides are flushed from the system or maintained under
an inert atmosphere.
Austenitic stainless steels and some non-ferrous alloys may be subject to pitting, stress-corrosion
cracking or other forms of corrosion when exposed to various solutions, in particular, those containing
chlorides and sulfur-oxy-acids. Neutralizing by use of gases such as ammonia or flushing with a sodium
carbonate solution (soda ash) is effective in controlling corrosion and may be necessary even for very short
shutdowns. Many plants flush with sodium carbonate as a routine measure regardless of the length of the
shutdown period.
Sulfur deposits, often occurring in convection sections of boilers, furnaces and heaters and in breeching
and stacks as well, may result in excessive corrosion. These deposits are normally removed for a shutdown.
7-1
WATER LINES
Water lines that are not necessary for the operation of other parts of the plant are drained completely and
blown dry with air or nitrogen. Holes may have to be drilled in low points or in complicated shapes where
valves do not exist to permit drainage. The holes would be tagged so they may be repaired before start-up.
However, the drilling of holes in equipment is used only if there is no other way of removing the water
completely.
INSULATION
Insulation is thoroughly inspected. Wet insulation is then removed and replaced for short-term protection
periods. Any damage to the insulation covering is repaired to prevent the ingress of water.
PIPING, VALVES AND FITTINGS
In general, piping two inches (5 cm) or less in diameter is not protected unless it is associated with a
critical component or system. Costs associated with protecting small diameter lines are usually prohibitive.
Stainless Steel and Nonferrous Alloys
1. Neutralize if necessary.
2. Flush, clean and dry the lines. Open valves, break open flanges and drill holes at low points if
necessary. Tag holes for repair before start-up.
3. Dry the lines with air or nitrogen.
4. Check insulation. Replace wet insulation, particularly on austenitic stainless steel and repair the
insulation covering as required.
5. If plant is in a marine or heavy industrial environment, coat joints, crevices, etc. of piping twelve
inches and over in diameter with Class II or Class III material to prevent the ingress of airborne
contaminants.
Carbon and Low Alloy Steel Materials
1. Flush and drain all lines.
2. Break flanges and open valves at all low points to permit draining. Drilled holes may be necessary
in critical areas or with complicated shapes.
3. Dry lines by blowing with dry air or nitrogen.
4. Examine insulation. Remove and replace wet insulation repairing leaks as necessary. Repair
damaged insulation.
5. Touch up primer on bare pipe as necessary.
6. Lubricate valves.
7. Cover exposed valve stems with Class IV (a) grease. Consider removing valves over 12" in
diameter, spraying the inside with Class II material and reinstalling them (for a shutdown of more
than twelve months).
8. Tag areas where holes have been drilled to permit repair.
9. Spray Class II oil between flanges of critical lines to prevent corrosion. In a marine environment, oil
spray may be used on all flanges as deemed necessary.
10. Coat exposed threads of small drain and vent valves with Class I or Class III material. Class III is
used for shutdowns beyond twelve months.
Lined Low Alloy Steel Pipe
1. Flush and drain all lines.
2. Break flanges and open valves at low points.
3. Dry lines with warm air.
4. Remove and replace wet insulation.
5. Cover exposed valve stems with Class IV (a) grease.
6. Spray Class II oil (provided it is compatible with pipe lining material) between flanges of critical lines
7-2
to prevent corrosion. In a marine environment, oil may be used on all flanges as deemed necessary. 7.
Coat exposed threads of small drain and vent valves with Class I or Class III materials. Use Class III
for shutdowns extending beyond twelve months.
FLARE SYSTEMS
The flare system remains operational if flammable products are left in tanks or used as preservatives,
e.g. filling with oil. The headers and stack are maintained under a nitrogen purge.
If the flare system is to be shut down, the headers and drums are flushed and drained. They are then
dried with nitrogen and maintained under a nitrogen purge.
HEAT TRACING
1. Shut down steam tracing.
2. Flush and drain the lines, then blow them dry with dry air leaving them open or, alternatively, filling
them with antifreeze of suitable composition for the ambient temperatures.
3. Traps may be removed to promote draining and drying.
4. Disconnect electrical tracing.
NOTE: If process fluids are maintained in some systems for an extended shutdown, heat tracing may be
necessary to prevent freezing or coagulation.
PROCESS VESSELS AND TANKS
Stainless Steel and Nonferrous Alloys
1. Neutralize as necessary.
2. Flush, clean and dry with air or nitrogen.
3. Seal all openings.
4. Check insulation and insulation covering. Replace wet insulation and repair covering as required.
5. If a plant is located in a marine or heavy industrial environment, coat all joints, crevices, etc. with
Class II or Class III material to prevent the ingress of airborne contaminants.
Carbon Steel
1. Neutralize as necessary removing such deposits as pyrophoric sludges.
2. Flush and drain completely.
3. Blow dry with air or nitrogen.
4. Coat bolting with Class III material.
5. Coat open flange faces with Class II or Class III material after cleaning.
6. Cover open flanges, pipe ends and other openings with a waterproof barrier and then cover with a
blank where possible.
For critical equipment the following steps may be added to the above:
7. Insert Class VII VCI and seal all openings.
8. Purge with nitrogen ensuring that no leaks exist at flanges when tested with a soap solution.
9. Maintain the vessel under a positive nitrogen pressure. Otherwise, exhaust the air replacing it with
nitrogen at atmospheric pressure.
NOTE: All vessels maintained under a 5-10 psig (0.034-0.069 MPa) inert gas blanket should be capable
of withstanding that pressure. Atmospheric equipment should be filled but not pressurized.
Reactors
1. Determine whether or not the catalyst should be removed.
7-3
2. Purge with nitrogen and maintain at a positive pressure of 5-10 psig (0.034-0.069 MPa) ensuring that
all openings are sealed.
3. Drain all jackets where applicable and blow with dry air or nitrogen. Fill the jacket with inhibited
antifreeze to the strength required for expected ambient temperatures. Vessels inside heated
buildings require no antifreeze and the jacket is left open after draining and drying.
4. Flush, drain and dry heating coils, then fill them with inhibited antifreeze as necessary.
5. Disconnect electric tracing.
Towers, Spheres, Bullets
1. Flush and clean equipment following neutralizing where applicable. Drain.
2. Purge vessels with nitrogen ensuring that all openings are sealed and leak free.
3. Maintain under a positive pressure of 5-10 psig (0.034-0.069 MPa) of nitrogen.
4. Replace wet insulation and repair insulation covering as required.
5. Coat areas between flanges with Class II or Class III material (seal gaps with tape in marine or heavy
industrial environments).
COOLERS AND EXCHANGERS
Cooling Towers
The materials of construction of a cooling tower will determine the protective measures necessary. For
instance, it is important to consider the potential fire hazard of dry wood in an idle unit. For a shutdown period
of less than three months, cooling towers require little in the way of protection other than normal maintenance
activities. For shutdowns beyond three months, the tower will require preservation.
1. Open and drain all piping.
2. Drain the water from the basin and flush the basin clean.
3. Block open the basin drain valves.
4. Make all necessary repairs to tower components.
5. Grease and/or oil all fans, gearboxes, etc. as per the normal maintenance schedule using Class IV
(a) or Class II material as applicable.
6. Operate fans for 5 to 10 minutes once per month.
7. Continuously wet any wood material as prevention against fire and deterioration, or spray wood with
a preservative and suitable fire retardant.
Spray Coolers
Spray coolers require protection due to the moist environment they encounter.
1. Close and blank the water inlet valve.
2. Drain and clean the water trough.
3. Blank the product inlet line after flushing and draining.
4. Clean and prime bare metal components as necessary.
5. Drain and clean the concrete basin; block open the drain valves.
Air Coolers, Finned
Finned air coolers may be extremely difficult to protect depending on the amount of debris accumulated
on the fins and on the effort necessary to clean the tubes.
1. Drain all product from the tubes and blow them dry with nitrogen or dry air depending on the process
stream. (Neutralization may be necessary before drying.)
2. Blow the fins clean with dry air.
3. Pump oil through carbon or low alloy steel tubes or purge them with nitrogen, maintaining them under
a positive pressure of 5-10 psig (0.034-0.069 MPa), if nitrogen is used. Dry high alloy tubes with
nitrogen.
4. Grease and/or oil the fans, fan motors, and gear reducers with Class IV (a) or Class II material as
applicable.
5. Spray the exterior of metal fans with Class II material (in a severe industrial or marine environment).
7-4
6. Clean and reprime bare structural steel.
7. Coat the threads of plugs with Class II material.
NOTE: Alloy plugs are coated to prevent crevice corrosion. For very high nickel alloys, this may not be
necessary.
Plate Exchangers
Perform normal washing, chemical cleaning or mechanical cleaning prior to protection.
1. Disassemble plates to ensure complete cleaning and drying.
2. For storage periods over twelve months, coat the rubber sealing rings with a suitable compound to
promote ease of removal.
3. Reassemble plates.
4. Leave drain valves open.
5. Reprime frame materials as necessary.
6. Coat bolts and nuts with Class II or Class III material.
Shell and Tube Exchangers
Shell and tube heat exchangers are manufactured from many alloys and combinations of alloys.
Protection methods are generally those that are required to protect the alloy most prone to corrosion.
Austenitic stainless steel tubes in carbon steel shells are protected as if they were carbon steel. Higher alloy
materials may require little in the way of protection other than cleaning and drying.
The normal washing, chemical cleaning, mechanical cleaning or neutralizing that would be used during
a routine shutdown should be performed.
1. Flush, drain and neutralize as applicable.
2. Remove bundle (floating head installations) and thoroughly clean the shell and bundle.
3. Thoroughly dry components with warm air.
4. Coat flange faces to the edges with Class II or Class III material.
5. Reinstall bundle and purge exchangers with nitrogen. Maintain under a positive pressure of 5-10 psig
(0.034-0.069 MPa) nitrogen.
6. For fixed tube bundles, open heads and clean tubes and channels.
7. Flush shell side and dry with warm air or nitrogen.
8. Reassemble and purge with nitrogen. Maintain under a positive pressure of 5-10 psig (0.034-0.069
MPa) nitrogen.
9. Coat insides of flanges out to flange edges with Class II or Class III material.
10. For all exchangers, touch up primers as necessary and inspect all insulation. Replace wet insulation
and repair insulation cover to prevent ingress of moisture. Coat all drain valves, sample valves, etc.
with Class III material.
NOTE: For extended shutdowns, some companies prefer to flush and drain exchangers and then purge
them with nitrogen. A nitrogen blanket at 5-10 psig (0.034-0.069 MPa) is maintained until start-up. If the
shutdown is to extend beyond six months, the gap between flanges is cleaned of all rust and scale and
sprayed with Class II oil.
It is assumed that the exchangers are capable of being pressurized to 5-10 psig (0.034-0.069 MPa)
nitrogen. If not, they may be filled with nitrogen just to displace the air.
STORAGE TANKS
Six-to-Twelve Months
1. If the inventory is to remain in tanks, carry out normal maintenance procedures. If the tanks are
drained, flush and clean them of scales and sludges.
2. Empty tanks may be coated by spraying with Class II material. If damage due to high winds is a
possibility, partially fill the tanks with inhibited water at pH 8.5-9.5.
3. Floating roof drains are left open and the roofs lowered to rest on the legs of empty tanks.
7-5
Over Twelve Months
1. Drain and clean tanks, removing scales and sludges where applicable.
2. Coat interior with Class II material.
3. In areas of high winds, fill or at least partially fill tanks with inhibited water at pH 8.5-9.5.
4. Open roof drains as applicable.
5. Remove agitators where applicable and seal openings with gasketed covers.
6. Touch up primers as necessary.
ROTATING EQUIPMENT
Rotating equipment may be classified as to the material of construction. Items of austenitic stainless
steels or non-ferrous alloys are generally neutralized, flushed and cleaned, dried thoroughly and sealed.
Ferritic alloy components require more extensive protection.
Centrifugal Pumps
1. Drain the casing and the bearing housing.
2. Flush to clean and dry with air.
3. Fill the pump casing with Class II material and rotate the pump shaft to ensure complete coverage.
4. Rotate the pump shaft once a month.
5. Spray pump shafts with Class II material. Repeat as necessary.
6. Fill shaft couplings with Class IV (a) grease as applicable.
Reciprocating Pumps
1. Open all vents and drains on both ends of the pump.
2. Fill both sides of the pump with Class II material.
3. Move pistons back and forth to ensure coverage with oil.
4. Drain oil from system and seal all openings.
5. Fill lubricators with Class II material.
Mechanical Seals and Packing
1. Flush the seal and operate the pump a minimum of two minutes once a month.
2. On packed equipment, remove and discard the packing.
3. Clean the seal cavity in the stuffing box and coat with Class IV (a) grease.
Bearings—All Equipment
1. Pump greased bearings full of Class IV (a) grease.
2. Drain oil-filled bearings, then fill with Class II material.
Drives
1. Drain gear cases and fill to the operating level with Class II material.
2. Run for 5 to 10 minutes to ensure that all surfaces are coated.
3. Seal with oil-resistant tape to prevent leakage.
4. Open gears, sprockets, screws and chain drives and coat with Class IV (a) if mechanism is covered
or Class IV (b) if mechanism is outdoors and uncovered.
5. On V-belt drives, remove the belts and store indoors. Coat the sheaves with Class IV (a) grease.
Couplings
1. Clean and coat couplings with Class IV (a) grease if indoors or sheltered, or with Class IV (b) grease
if outdoors and unsheltered.
7-6
2. Fill oil-lubricated couplings with Class II material.
3. Fill grease-lubricated couplings with the normal grease used in normal operation.
Agitators, Centrifuges and Mixers
1. Neutralize, clean and dry equipment as necessary.
2. Place Class VII material on the inside of vessels and seal all openings.
3. Purge critical vessels with nitrogen, in addition to using Class VII material, and maintain under a
positive pressure of 5-10 psig (0.034-0.069 MPa) nitrogen.
4. Clean flanges and coat with Class II or Class III material depending on the length of shutdown.
5. Coat bolts and nuts with Class II or Class III material, again depending on the length of shutdown.
Hydraulic Systems, Lubricating Oil Systems and Oil Reservoirs
1. Drain systems and fill to the operating level with Class II material.
2. Operate the systems until the oil has been circulated completely.
3. Seal the systems with oil-resistant tape.
4. On critical items, Class VI fluid may be substituted for Class II.
COMPRESSORS
Compressors, regardless of the alloy, are protected as if they were of carbon steel due to their high
capital cost.
Centrifugal or Rotary
Compressors of this type are generally protected in several ways:
1. Close the suction and discharge valves.
2. Purge with nitrogen and maintain under a nitrogen blanket of 5-10 psig (0.034-0.069 MPa).
3. Bump over the compressor. Circulate the fluids in lubricating and seal-oil systems by hand once a
month.
4. Coat external, machined surfaces with Class III material.
- or 1. Fill casing with Class II material and then drain.
2. Place bags of Class VII crystals inside.
3. Purge with nitrogen and seal all openings.
4. Coat exposed machined surfaces with Class III material.
- or 1. Spray Class VI material into the suction line as the machine is rotated slowly.
2. Next place bags of Class VII crystals in the suction and discharge lines.
3. Close and seal the system.
4. Rotate the shaft 2 1/3 turns once a month.
5. Coat all exposed machined surfaces with Class III material.
Reciprocating
- or -
1. Disconnect the suction and discharge piping from process lines.
2. Fabricate a short circuit pipe between suction and discharge nozzles.
3. Operate the compressor against open suction and discharge for 10 minutes.
4. Install short circuit pipe and apply 5-10 psig (0.034-0.069 MPa) nitrogen at the media side.
5. Drain cooling system and dry with hot air or nitrogen.
6. Operate compressors 10 minutes per month. All lubricating and seal-oil systems must be operated
5 minutes before and after each compressor operation.
7. Coat all exposed machined surfaces with Class III material.
8.Drain tanks and receivers. Insert Class VII material and seal all openings.
1. Drain crankcase and refill it with Class VI fluid.
7-7
2. Operate the compressor for 10 minutes then seal the crankcase.
3. Purge cylinders with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069
MPa).
4. Drain the cooling system and fill with an inhibited antifreeze mixture suitable to the climate.
5. Coat all exposed machined surfaces with Class III material.
6. Drain tanks and receivers. Insert Class VII material and seal all openings.
NOTE: For breathing air and instrument air compressors, protection with an inert atmosphere is
preferable to prevent possible contamination.
STEAM TURBINES
1. Dry the steam spaces with warm air or nitrogen.
2. Fog the steam spaces with Class VII material, turning the rotor as the material is blown in.
3. Seal the turbine casing closing all openings leading to the steam spaces.
4. Protect bearings as outlined previously in this section under Rotating Equipment.
5. Pack gears or other drive mechanisms with Class IV (a) grease.
6. Fill the shaft coupling with Class IV (a) grease and wrap it.
7. Install a space heater in housings if none is provided and keep energized.
8. Dehumidify inside of any housing or enclosure.
9. Protect lubricating and seal oil systems as described under Rotating Equipment.
ELECTRICAL EQUIPMENT
All electrical equipment should be stored indoors or otherwise protected from rain and high humidity.
Moisture may cause excessive swelling of organic compounds used in the construction of many electrical
devices and drying may not be sufficient to recover equipment exposed to high moisture.
Motors
1. Blow-dry open motors with air or nitrogen.
2. Heat open motors of 50 hp or larger that do not contain heaters by installing auxiliary heaters or by
maintaining reduced voltage in the stator windings.
3. Where applicable, continuously energize the heaters of open motors.
4. Drain oil-lubricated bearings and fill them with Class II oil. Rotate the shaft once a month.
5. Fill grease-type bearings with normal operating grease and rotate the shaft monthly.
6. Uncouple motors of less than 50 hp. Operate them for two hours once a month.
7. Where commutators or collector rings are accessible on large motors, remove or at least lift the
brushes, for shutdowns extending beyond twelve months, so that wax-free greaseproof insulation
paper may be placed under them to prevent etching.
8. Coat exposed shafts with Class II or Class III material.
Transformers
1. De-energize transformers not required to maintain service.
2. Maintain heat on transformers through installed heaters or through space heaters in the control
housings.
3. Install Class IX silica gel in receptacles or other locations to prevent moisture damage.
4. Inspect monthly for oil leaks and desiccant degradation.
5. Check oil dielectric strength yearly.
Switchgear
1. Place bags of Class IX silica gel in the cabinets of switchgear and motor controls located in buildings.
Maintain heat in the buildings. Dehumidification may be necessary.
2. Continuously energize any heaters of equipment.
3. Protect outdoor controls with Class VII material and seal the cases. If plastic film is placed over the
7-8
cabinets, a two inch gap is left around the bottom. 4.
Main buses generally remain energized.
Batteries
1. Remove dry cell batteries from emergency lighting.
2. Disconnect wet cell batteries from the power supply.
3. Float batteries left in service (as in a 125-volt switchgear station) at 129 volt charge; equalize at 140
volts once a month.
4. Store rectifiers indoors in a heated location.
CONTROL DEVICES AND INSTRUMENTATION
All instruments and control devices with the exception of field electronic equipment are left in place.
1. Inspect field control devices once a month for signs of damage. Repair damage and touch up primers
as necessary.
2. Continuously energize field control panels. If no heaters exist, install space heaters.
3. Leave power on for all field instruments.
4. Instruments not protected by housings may be removed and stored in an indoor, heated location or
they may be protected by building shelters over them.
Pneumatic Systems
1. Disconnect and blow-dry air lines at the instrument housing.
2. Plug all air inlets, vents and openings.
3. Space heaters or even electric light bulbs may be used in an enclosed area to prevent moisture
damage. Bags of desiccant may be used in conjunction with heaters.
4. Seal all enclosure doors.
Control Valves
1. Inspect control valves externally. Remove any showing signs of damage for internal inspection and
repairs.
2. Touch-up primers as necessary.
3. Consider the removal of critical devices in order to store them indoors in a heated building. Seal all
openings.
FIRED HEATERS AND FURNACES
1. Clean the exterior of tubes to remove combustion products and other deposits.
2. Clean convection sections to remove such contaminants as sulfur.
3. Clean the inside of tubes, decoking as necessary. Drain tubes, drilling holes at low points if
necessary, and remove catalyst where applicable. Tag all drilled holes for repair before start-up.
4. Neutralize inside and/or outside of tubes as necessary.
5. Dry tubes with warm air or nitrogen.
6. Clean headers and close them.
7. Place lime trays in each fire box. Lime should be thoroughly raked once a month and replaced after
six months.
8. Place a cap on all stacks. The cap prevents entry of rain but is open enough to provide a positive
draft.
9. Cap the duct openings
10. Grease all door and other opening hinges with Class IV (a) material.
11. Shut and seal doors and other openings.
12. Grease and/or oil all moving parts associated with burners. Some burners may be protected in place
by wrapping with VCI-impregnated paper. Others may require removal for indoor storage. Seal
burner openings.
13. Touch-up primers as necessary.
DIESEL AND GASOLINE ENGINES
1. Run the engine until it is thoroughly heated.
2. Stop the engine and drain all lubricating oil from the system.
3. Fill the lubricating oil system with Class II oil.
4. On diesel engines, drain the fuel system and fill it with kerosene. Prime the fuel system.
5. Drain and flush the cooling system.
6. Fill the cooling system with inhibited antifreeze appropriate for the lowest anticipated temperature.
7. Spray Class II oil into the manifold as the engine is barred or turned over.
8. Seal all openings.
9. Reprime exterior surfaces and coat exposed machined surfaces with Class II oil or Class IV (b)
grease.
LINED TANKS AND VESSELS
Protection of lined equipment may be complicated due to the variety of materials used. For shutdowns
beyond twelve months, the manufacturer should be consulted for recommendations. Care must be exercised
to prevent a cold wall effect with the resultant blistering of coatings.
Rubber-Lined Equipment
- or -
1. Flush and drain the vessels.
2. Dry with warm air or nitrogen.
3. Install space heaters or light bulbs to keep the lining warm.
4. Reprime exterior surfaces as necessary.
1. Fill with a 5-10% sodium carbonate solution (or other solution recommended by liner manufacturer)
leaving a small vapor space.
2. Close all openings,
3. Store in a heated location or provide freeze protection.
Thin or Baked Linings
1. Drain tank or vessel and flush clean.
2. Blow-dry with warm air or nitrogen.
3. Purge critical vessels with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain under a positive
pressure.
4. To avoid the cold wall effect, keep vessels warm with space heaters, light bulbs or by maintaining
heat in the building.
For Open Tanks
1. Flush to remove all deposits.
2. Drain and dry.
3. Fit tanks with cover.
Thick or Free-Standing Linings
1. Flush and drain tanks.
2. Seal gaps between liner and shell at the top of tank.
3. Install heater or light bulb to keep lining warm.
Brick-Lined Vessels
1. Drain and flush vessel.
2. Thoroughly dry with warm air or nitrogen.
7-10
3. Insert lime trays or silica gel, raking lime once a month and replacing it after six months. Replace
silica gel when it turns color.
4. Seal openings and coat bolting with Class II oil or Class III material.
REFRIGERATION SYSTEMS
1. Drain water and other fluids from the system.
2. Remove the refrigerant from the system and store in tanks or auxiliary cylinders as necessary.
3. Blow the lines and equipment dry with nitrogen.
4. Protect pumps, compressors, chillers, condensers, etc. as outlined previously in this section.
5. For shutdowns longer than twelve months, purge system with 5-10 psig (0.034-0.069 MPa) nitrogen
and maintain under a positive pressure.
CONTROL ROOMS
1. Place bags of silica gel in each cabinet ensuring that cabinets are sealed.
2. Dehumidify the control room or install air conditioners if none exist.
3. Install portable fans in the control room to ensure complete circulation of air.
4. Cover all control panels loosely with plastic film to prevent dust contamination. Leave a two inch air
gap between the bottom of the plastic sheet and the floor to permit air circulation.
EXPANSION JOINTS
Expansion joints are often treated as separate items during protection. In general, the bellows are
constructed of austenitic stainless steels or higher alloys so that protection methods attempt to prevent
cracking that might occur in the highly stressed areas. Consult the expansion joint manufacturer for
recommendations concerning storage.
1. Flush, drain and dry the joints taking care to remove water from the bellows' convolutions.
2. Clean the outside of the bellows wherever possible.
3. Install tie-down bolts where possible to prevent distortion of the bellows. Tag bolts to ensure their
removal prior to start-up.
4. Coat end rings, retaining rings and associated hardware with Class II or Class III material.
5. Coat areas of dissimilar metal contact, e.g. bellows to end rings, bellows to pipe nipple, with Class
II or Class III material.
6. On flanged joints, open and clean the flanges and coat with Class II or Class III material.
SPRINKLER SYSTEMS
Sprinkler systems may remain operational under short-term idle conditions and would be maintained in
the normal manner. If the sprinkler system is not required for fire protection:
1. Drain all lines, open valves and break flanges where applicable.
2. Blow the lines dry with air and leave the system open.
3. Cover heads with loose fitting plastic or cloth bags for dust protection. The bags are left open at the
bottom to permit air circulation.
WAREHOUSE AND STORAGE YARD
Warehouse Items
Warehouse components are best stored under warm, dry conditions. Heat is normally left on in buildings
and air conditioning or humidity control may be employed.
1. Coat all machined surfaces on carbon and low alloy steel components with Class II material.
2. Light bulbs may be used in storage bins to prevent condensation and corrosion.
3. Mating low alloy flanges bolted face-to-face are separated, coated with Class II or Class III material
and reassembled.
7-11
CAUTION: An absorbent material such as cloth or burlap should not be placed between mating parts.
4. Grease all gears, shafts, etc. with Class IV (a) material.
5. Coat flange faces of valves, pumps, etc. with Class II or Class III material and cover with hard
material such as plywood.
6. Store components in racks or in bins with the identification clearly indicated in each storage area.
7. Place desiccant and Class VII material in electrical cabinets, relay cabinets, etc. Cover the cabinets
with plastic sheeting as a dust cover leaving a two inch gap all around the bottom for ventilation.
8. Grease and/or oil all valves, valve stems and similar components with Class IV (a) or Class II
material.
Storage Yard
1. Locate storage yards away from operating plants, the seacoast or other environments likely to
produce corrosion.
2. Grade and maintain storage yard to promote drainage and control weeds, brush, etc.
3. Store components such as pipe, vessels, etc. on a slope to promote drainage. Store piping and
fittings so that the prevailing wind will blow through the equipment to dry it.
4. Store components a minimum of six inches off the ground. Wooden bolsters used for storage are
treated to prevent rotting. However, care in selection of the preservative is necessary as some of
these products can promote the corrosion of various metals.
5. Store fittings with the open ends down to prevent them from filling with water.
6. If fittings are stored on wooden platforms, drill holes in the platforms to permit drainage.
7. Pipe, fittings and other equipment stored in piles can suffer rapid corrosion in the groove formed by
adjoining members. Separate the pipe lengths, etc. to eliminate such crevices.
8. Coat all flange faces and other machined surfaces with Class III material. Cover flange faces and
other openings with plywood or similar covers.
9. Remove plugs from couplings, coat plugs and coupling threads with Class III material and reinstall
plugs.
10. Open all flanges on equipment, clean and protect with Class III material before reassembling for
storage.
11. Tape flanges on austenitic stainless steel or other high alloy components to prevent the ingress of
moisture.
12. Snow removal may be necessary in certain areas. Deicing salts are not recommended due to
possible equipment damage.
BUILDINGS
Buildings are best protected by maintaining heat and air conditioning systems wherever practical.
Sprinkler systems generally remain active as well to control potential fire damage.
1. Maintain buildings above 50°F (10°C). Space heaters may be substituted for central heating systems
if the latter are decommissioned.
2. Dehumidify either through air conditioning or through dehumidification systems.
3. Run water through plumbing fixtures, sinks, toilets, etc. once a month if these systems remain
operational.
4. If the plumbing is shut down, drain the system and blow-dry with warm air. Leave some taps open
to promote drainage should leakage occur.
5. Shut off all but essential lighting.
6. Install Class VII material in switch panels, etc. along with bags of desiccant.
7. Laboratory services such as gas, water, etc. are normally drained, flushed and dried with warm air.
8. Clean fume hoods and seal against the ingress of moisture and air. Oil all pumps, motors, fans, etc.
9. Books, drawings, specifications and miscellaneous paper are generally stored in fire resistant
locations such as a vault, heated warehouse, etc. Sprinkler systems may cause damage should they
accidentally open so documents are stored in fire resistant cabinets that provide some water
resistance as well.
10. In areas subject to high snow loads, provision is made for snow removal from roofs either through
use of electric tracing or periodic shoveling.
11. In areas subject to high rainfall, provision is made for inspection of all roof drains, roof vents, etc.
after each storm.
7-12
12. Windows may require protection through boarding or covering with other materials.
13. Screening of roof vents helps to prevent birds from entering buildings.
7-13
7-14
SECTION 8 PROTECTION PROGRAM FOR 1960 MONTHS
With the imposition of a longer idle period, protection requirements for process plants become more
extensive and costly to ensure both plant integrity and a successful return to service. Insulation removal may
be necessary as plants have experienced extensive corrosion under wet insulation during an eighteen month
idle period. In addition, crevices tend to fill with debris keeping moist material in contact with components for
long periods. Perforation of thin sections due to the resulting corrosion is not uncommon.
Power, heat tracing, water and other services may be shut down, so careful planning is required to make
these available as necessary to the mothballed plant. Manpower may also prove to be a restriction,
particularly if the plant is in a remote location. Personnel responsible for maintaining and inspecting the
mothballed facility could gain valuable experience by first participating in the application of preservatives.
Although protection procedures are matched to the length of the idle period, certain shutdown
procedures need to be observed, regardless of the length of the idle period, to prevent serious equipment
damage.
SHUTDOWN CONSIDERATIONS
As indicated in Section 7 (page 7-1), certain pieces of equipment require controlled start-up and
shutdown procedures to prevent damage. Heavy-walled vessels, those containing thick deposits or catalyst,
and vessels that may contain hydrogen generally require controlled cooling.
Similarly, lined or coated vessels or alloys that may experience structural changes producing brittleness
need to be cooled slowly to prevent damage.
All such equipment should be shut down or started up using the normal procedures designed for the
particular operation.
CORROSIVE ENVIRONMENTS
Because of the many and varied scales produced in chemical, petrochemical and refining industry
processes, operators of each facility need to determine the deleterious effects of the various sludges during
the long-term shutdown of equipment. In general, scales and sludges tend to be hygroscopic, thereby
creating serious corrosion problems in low alloy materials and serious cracking problems in both low and high
alloy materials.
Removal of potentially harmful sludges and scales is extremely important to ensure the protection of
equipment that is to be shut down beyond eighteen months.
Acid Service
1. Flush equipment that has been in acid or potentially acidic service with fresh water.
2. Drain the equipment thoroughly.
3. Neutralize with a suitable alkaline solution.
4. Drain and dry with warm air or nitrogen.
Alkaline Service
1. Flush with fresh water; drain completely and dry with warm air or nitrogen.
Organic Compounds
1. Special washing or neutralizing may be required. It is best to follow guidelines established by the
individual plant or unit.
Pyrophoric Materials
1. Neutralize if appropriate.
2. Flush with fresh water and keep the material moist.
8-1
3. Remove all loose material.
4. Dry with nitrogen.
Sulfur-Oxy (Polythionic) Acids
1. Neutralize with ammonia or wash with soda ash.
2. Flush with fresh water and drain completely.
3. Remove all sludges and scales.
4. A second ammonia or soda ash wash may be necessary.
5. Dry with nitrogen.
Remove other deposits such as sulfur, fly ash or any combustion products from all equipment to prevent
corrosion.
WATER LINES
1. For water lines that are not necessary for the operation of other parts of the plant, drain completely
and blow dry with air or nitrogen. Holes may have to be drilled in low points or in complicated shapes
where valves do not exist to permit drainage. Tag these holes so they may be repaired before
start-up. (Holes are drilled only if draining cannot be accomplished any other way.)
2. Inspect insulated lines, removing insulation where leaks or other points of water ingress are
suspected. Repair insulation covering. Seal and/or caulk around hangers.
3. Spray exterior surfaces of valves with Class II oil.
4. Remove valves on lines over twenty-four inches in diameter and coat the internals with Class III
material. Fill bonnets of gate valves with Class VI material.
5. Coat exposed valve stems with Class IV (b) grease.
6. On large-diameter critical lines, purge with 5-10 psig (0.034-0.069 MPa) nitrogen and leave under a
positive pressure of nitrogen.
7. Coat all bolts and nuts with Class III material.
INSULATION
1. Remove all wet insulation. Clean and reprime all steel surfaces that have been damaged by wet
insulation.
2. Wet insulation removed from critical or large vessels may or may not be replaced depending on the
length of shutdown.
3. For insulation left in place, repair the weather barriers to prevent the ingress of moisture.
4. Examine insulation at flanges, valves, control valves, etc. The ends are frequently left open to the
weather. The ingress of moisture can cause rapid deterioration. Seal all exposed insulation.
PIPING, VALVES AND FITTINGS
In general, piping two inches (5 cm) or less in diameter is not protected unless it is associated with critical
components or systems.
Carbon and Low Alloy Steel Materials
1. Flush and drain all lines, neutralizing as necessary. Ensure sludge has been flushed from lines.
2. Open flanges and valves at all low points to permit draining. Drill holes as necessary at low points
or in piping with complicated shapes to permit draining. Tag all drilled holes.
3. Dry lines with nitrogen.
4. Examine insulation. Remove wet insulation and replace if desired. Repair damaged insulation
covering. Seal insulation edges at all valves, flanges, etc.
5. Touch up primers on bare steel.
6. Lubricate valves.
7. Cover exposed valve stems with Class IV (b) material.
8. Remove valves over 12" (30 cm) in diameter and spray the insides with Class III material. Reinstall
8-2
valves. Fill bonnets or other cavities with Class VI fluid. 9. Clean and coat flange
faces out to the edges with Class III or Class VIM material.
10. In marine or heavy industrial environments, cover flange edges with Class VIII tape.
11. Coat all exposed bolts and nuts with Class III material.
12. Coat small drain and vent valves with Class III material.
13. Coat hangers and pipe supports with Class III material.
14. For critical lines or large diameter lines, purge with 5-10 psig (0.034-0.069 MPa) nitrogen and
maintain under nitrogen pressure. (Lines must be capable of retaining this pressure.)
Piping, Valves, Fittings (Underground)
1. Flush, neutralize and drain the lines as necessary.
2. Dry the lines with nitrogen.
3. Purge critical lines with nitrogen and maintain them under a positive pressure of 5-10 psig
(0.034-0.069 MPa) nitrogen (provided the piping can withstand this pressure).
4. Maintain cathodic protection if appropriate.
Austenitic Stainless Steel and Other High Alloys
1. Flush lines with fresh water. Neutralize as necessary.
2. Drain lines by opening valves and/or by breaking open flanges at low points if necessary.
3. Dry the lines with warm air or nitrogen.
4. Check insulation. Remove wet insulation and clean the outside of the piping. The insulation may be
replaced or, preferably, left off.
5. Seal all insulation edges; caulk around hangers and other openings.
6. In marine or heavy industrial environments, cover the gap between flanges with Class VIII tape.
7. Coat exposed threads of drain and vent valves with Class III material.
Lined Low Alloy Steel Pipe
1. Flush and drain all lines. Break open flanges and open valves as required at all low points. Leave
drain valves open.
2. Dry lines with warm air or nitrogen.
3. Remove wet insulation, replacing it or leave it off as preferred.
4. Cover exposed valve stems with Class III or Class IV (b) material.
5. Spray Class II or Class III material (provided it is compatible with the pipe lining material) between
the flanges of critical lines to prevent corrosion. In a marine environment, all flanges may be coated
as deemed necessary.
6. Coat exposed threads of small drain and vent valves with Class III material.
FLARE SYSTEM
Flare systems usually remain operational if flammable products are maintained in the plant or are used
as preservatives, e.g. if oil is used. Maintain the headers and stack under a nitrogen purge or as per normal
operation procedures. If the flare system is shut down proceed as follows:
1. Flush all headers, drums and lines, neutralizing as necessary.
2. Dry all lines with nitrogen.
3. Open and clean all drums.
4. Clean and coat all flange faces out to the edges with Class III material and reassemble. In marine
or severe industrial environments cover gap between flanges with Class VIII tape.
5. Blank off the flare stack. Blanks are designed to withstand the purge pressure.
6. Purge the flare system with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 MPa).
7. Touch up all bare steel as necessary.
8. Inspect and replace any damaged or wet insulation. Repair the insulation cover, and caulk and seal
all openings.
9. Cap the stack to prevent the ingress of rain.
8-3
HEAT TRACING
1. Shut down steam tracing and remove unions at low points to promote draining.
2. Flush the lines and blow-dry with air.
3. Leave the lines open or fill them with inhibited antifreeze of suitable composition for the lowest
anticipated ambient temperature.
4. Disconnect electrical tracing.
PROCESS VESSELS AND TANKS
Stainless Steel and Nonferrous Alloys
1. Neutralize as necessary.
2. Flush, clean and dry with air or nitrogen.
3. Seal all openings.
4. Check insulation and insulation covering. Remove wet insulation and wash underlying metal with low
chloride water. High pressure washing may be necessary to remove insulation residue. Dry metal
and replace insulation if desired. Repair insulation covering and seal openings.
5. If the plant is located in a marine or heavy industrial environment, coat all flange faces out to the
flange edges and any other crevices with Class III material and cover with Class VIII tape.
6. Consider coating bare austenitic stainless steel equipment with a suitable paint to prevent pitting in
salt environments.
Carbon Steel
1. Neutralize as necessary removing such deposits as pyrophoric sludges and other contaminants.
2. Flush and drain completely.
3. Blow-dry with air or nitrogen.
4. The inside of the vessels may be coated with Class II oil by spraying or filling and draining. However,
it is important to take into account the process conditions and streams as oil may cause severe
upsets or excessive foaming when service is restored. If oil may pose a problem, eliminate it.
5. Install desiccants in all major vessels either as bags of silica gel or as lime trays.
6. Coat all gasketing surfaces and flange faces with Class III material and close all openings. Cover
gaps between flanges with Class VIM tape (outdoor locations).
7. Purge vessels with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069 MPa)
(vessels must be capable of maintaining this pressure).
8. Remove insulation from one vessel of each type and inspect for corrosion damage. If damage has
occurred, strip other vessels in damage locations.
9. Remove all corrosion scabs and reprime as necessary.
10. Drill holes to prevent standing water in such items as structural steel, insulation rings, ete.
11. Inspect all other insulation and repair as necessary.
12. Remove safety valves and blank openings (bolted valves only). Store valves indoors in a heated
location.
13. Coat bolts and nuts with Class III material.
Reactors
1. Remove catalyst where applicable.
2. Clean, ensuring complete removal of sludges. Neutralize as necessary.
3. Dry with nitrogen.
4. Purge with nitrogen and maintain at a positive pressure of 5-10 psig (0.034-0.069 MPa), ensuring
that all openings are sealed.
5. Clean all flange faces out to the edge and coat with Class III material.
6. Cover the gap between flanges (outdoor location) with Class VIII tape.
7. Remove wet insulation and clean underlying metal. Replace and/or seal insulation to prevent ingress
of moisture.
8. Reprime bare steel as necessary.
8-4
9. Drain all jackets where applicable, and blow-dry with air or nitrogen.
10. Fill the jackets with inhibited antifreeze of sufficient strength to resist lowest anticipated ambient
temperature. Vessels inside heated buildings require no antifreeze, the jacket being left open after
draining and drying.
11. Flush, drain and dry any heating coils and fill with inhibited antifreeze as necessary.
12. Disconnect electric tracing.
Towers, Spheres, Bullets
1. Flush and clean vessels following neutralizing where applicable. Drain completely.
2. Dry with air or nitrogen.
3. The insides of these vessels may be coated with Class II oil by spraying or filling and draining.
However, the nature of process conditions and streams must be considered as oil may cause severe
upsets or excessive foaming when service is restored. If oil may pose a problem eliminate it.
4. Install desiccants—bags of silica gel or lime trays—in all major vessels.
5. Coat all gasketing surfaces and flange faces with Class II or Class III material and close all openings.
6. Purge vessels with nitrogen at 5-10 psig (0.034-0.069 MPa), checking all flange areas for leakage
with soap solution.
7. Seal gap between flanges and all other openings with Class VIII tape.
8. Maintain vessels under a positive pressure of nitrogen of 5-10 psig (0.034-0.069 MPa).
9. Remove insulation from one vessel of each type, where applicable, and inspect for corrosion
damage. If damage has occurred, strip other vessels in similar locations.
10. Remove all corrosion scabs and reprime as necessary.
11. Drill holes to prevent standing water in such items as structural steel, insulation rings, etc.
12. Inspect all other insulation and repair as necessary.
13. Remove safety valves and blank openings (bolted valves only). Store valves indoors in a heated
location.
14. Coat bolts and nuts with Class III material.
15. Inspect bases and foundations. Coat anchor bolts with Class IV (b) material.
COOLERS AND EXCHANGERS
Cooling Towers
The material of construction of the cooling towers will determine the protection measures. A large
inventory of dry wood from an idle unit presents a considerable fire hazard.
1. Open and drain all piping.
2. Drain the water from the basin and flush the basin clean.
3. Block open the basin drain valves.
4. Inspect and replace damaged structural components, warped or missing slats, and tighten loose
bolting.
5. Remove the fan drive motor and protect it as per the section on Electrical Equipment.
6. Drain the oil from the gear reducer housing and refill it with Class II material.
7. Clean the exterior of the gear reducer housing and reprime it as necessary.
8. Coat with Class III material exposed portions of shafts and wrap with VCI-impregnated waterproof
paper.
9. Remove the gear reducer and store in an indoor heated area.
10. Clean the fans and reprime the blades as necessary.
11. Coat the fan drive gears with Class IV (a) material and wrap with a VCI-impregnated waterproof
paper.
12. Secure the fan blades to prevent rotation.
13. Spray all wood with fire retardant chemical and a biocide.
Spray Coolers
1. Close and blank the water inlet valves.
2. Drain and clean the water trough.
3. Flush and drain the product inlet line.
8-5
4. Blank the product inlet valve.
5. Blank all process and product lines.
6. Clean and prime bare metal components.
7. Cover the water troughs with a watertight cover.
8. Drain and clean the concrete basin.
9. Block open the drain valves.
Finned Air Coolers
1. Drain all product from the tubes and blow them dry with nitrogen or dry air. Neutralization may be
necessary before drying.
2. Blow the fins clean with dry air.
3. Pump oil through the tubes or purge them with nitrogen, maintaining them under a positive pressure
of 5-10 psig (0.034-0.069 MPa) if nitrogen is used.
4. Coat the threads of plugs with Class III material and reinstall.
5. Remove the fan drive motors and protect them as per the Electrical Equipment section.
6. Drain the oil from the gear reducers and refill them with Class II material.
7. Clean the exterior of the gear reducer housings and reprime them as necessary.
8. Coat the exposed portions of shafts with Class III material and wrap with VCI-impregnated
waterproof paper.
9. Remove the gear reducers and store them in a heated indoor location.
10. Clean the fans and reprime the blades as necessary.
11. Coat the fan drive gears with Class IV (a) material and wrap with a VCI-impregnated waterproof
paper.
12. Secure the fan blades to prevent rotation.
13. Reprime structural steel members as necessary.
Plate Exchangers
The normal washing, chemical cleaning or mechanical cleaning is performed prior to protection.
1. Disassemble plates to ensure complete cleaning and drying.
2. Store plates flat in crates, properly shimmed to prevent warpage, or store plates vertically, properly
shimmed to prevent metal-to-metal contact.
3. Clean and inspect rubber sealing rings discarding any that display damage.
4. Store sealing rings in sealed packages.
5. Coat all valving with Class III material and store indoors.
6. Reprime frame materials as necessary.
7. Coat bolts and nuts with Class III material and store in frames or in crates.
Shell and Tube Exchangers
Shell and tube exchangers are manufactured from many alloys and combinations of alloys. Protection
methods are generally those that are required to protect the alloy most prone to corrosion. Austenitic
stainless steel tubes in carbon steel shells are protected as if they were carbon steel. Higher alloy materials
may require little in the way of protection other than cleaning and drying.
Perform the normal washing, chemical cleaning, mechanical cleaning or neutralizing that would be used
during a routine shutdown.
1. Flush, drain and neutralize as applicable.
2. Remove bundles (floating head installations) and thoroughly clean all components. Remove sludge,
deposits and all other debris.
3. Thoroughly dry all components with warm air or nitrogen.
4. Coat flange faces out to flange edges with Class III material and seal all gaps with Class VIII tape.
5. Plants with an inventory of oil may choose to coat bundles and shells with oil to which VCIs have
been added. Other facilities may prefer to purge the reassembled exchangers with nitrogen and
maintain them under a positive nitrogen pressure of 5-10 psig (0.034-0.069 MPa).
6. For fixed tube bundles, open the heads and clean the tubes, channels and heads.
7. Flush the shell side; neutralize as necessary, and dry with warm air or nitrogen.
8. Reassemble and purge with nitrogen, maintaining the exchangers under a positive nitrogen pressure
8-6
of 5-10 psig (0.034-0.069 MPa) after coating inside of flanges.
9. Coat inside of flanges out to flange edges with Class III material and seal all gaps with Class VIM
tape.
10. For all exchangers, touch up primers as necessary and inspect all insulation. Replace wet insulation
and repair insulation cover to prevent the ingress of moisture. Coat all drain valves, sample valves,
etc. with Class III material. Remove insulation from one exchanger in each bank. If serious corrosion
damage is found, remove insulation from other equipment until no further problems are found. Clean,
reprime and reinsulate as necessary.
11. Coat anchor bolts with Class III material.
STORAGE TANKS
1. Drain and clean tanks, removing all scales and sludges.
2. Touch up interior primers as necessary.
3. Facilities with oil inventories may prefer to coat tank interior with oil by spraying or by filling and
draining. Other facilities may prefer to spray tank interiors with Class VI fluids, or if tanks can be
sealed and are able to withstand the pressure, to purge them with nitrogen to 5-10 psig (0.034-0.069
MPa) and maintain this pressure throughout the storage period.
4. In areas of high winds, fill or partially fill the tanks with inhibited water at pH 8.5-9.5. A nitrogen purge
may be used in conjunction with the water to prevent corrosion in the vapor space.
5. Open roof drains as applicable.
6. Remove agitators where applicable, and seal the openings with gasketed covers.
7. Maintain vacuum breakers to prevent collapse of tanks when draining.
8. Coat all flange faces out to the edges with Class III material.
9. In marine or severe industrial environments, cover all gaps at flanges or other openings with Class
VIM tape.
10. Touch up primers as necessary.
ROTATING EQUIPMENT
Pumps, mixers, etc. may represent a significant capital cost so the protection afforded them may be
extensive. In general, components made from austenitic stainless steels or non-ferrous alloys are
neutralized, flushed and cleaned, dried thoroughly and sealed.
Centrifugal Pumps
1. Drain the casing and the bearing housing. Neutralize as necessary.
2. Flush the casing and bearing housing and dry with air or nitrogen.
3. Disconnect and blank off the suction and discharge lines.
4. Fill the pump casing with Class VI oil and rotate the pump shaft to ensure complete oil coverage.
Pumps may be operated for ten minutes every month. Operate lubricating and seal-oil systems
during the ten minute period and for five minutes before and after. Ensure that the pump drain
connections are open during any operating period.
5. Plug the bearing housing drains and fill the housings with Class VI oil fluid. Close all vents.
6. Coat the exposed pump shafts and other machined surfaces with Class III material and cover with
Class VIM tape.
7. Fill the shaft couplings with Class IV (a) grease as applicable.
8. Remove wet insulation, clean the exposed surfaces and paint them as applicable.
Reciprocating Pumps
1. Open all vents and drains on both ends of the pump.
2. Break all pipe connections and blank off all suction and discharge lines.
3. Fill both sides of the pump with Class VI oil fluid. Valves are removed to permit filling, then are
reinstalled.
4. Move pistons back and forth to ensure complete coverage with oil.
5. Drain the oil from the system and seal all openings.
6. Coat all valves and covers with Class III material.
8-7
7. Coat exposed rods and other machined surfaces with Class III material and wrap with Class VIII
tape.
8. Fill all lubricators with Class VI oil fluid.
9. Remove wet insulation if applicable. Clean the exposed surfaces and paint them.
Mechanical Seals and Packing
1. For single seals, pack the seal with Class IV (a) grease.
2. Retighten (lightly) the seal gland.
3. For double seals, drain the stuffing box, and flush it, ensuring that the pump operates a minimum of
two minutes before shutting it down.
4. Plug the lower stuffing box drain and fill the stuffing box with Class II oil or Class IV (a) grease.
5. For conventional packing, loosen the packing gland and remove the packing.
6. Coat the interior of the stuffing box with Class IV (a) grease.
7. Leave packing out or repack the pump with nonmetallic packing, tagging the pump to ensure
replacement of the operating packing for a restart.
Bearings—All Equipment
1. Pump greased bearings full of Class IV (a) material.
2. Drain oil-filled bearings and refill with Class II oil. Replace the oil at two year intervals.
Drives
1. Drain gear cases and fill to the operating level with Class II oil.
2. Run for 5 to 10 minutes to ensure that all surfaces are coated.
3. Seal with Class VIII tape to prevent leakage.
4. Replace oil at two year intervals.
5. Open gears, sprockets, screws and chain drives. Coat with Class IV (a) grease if mechanism is
covered or Class IV (b) if mechanism is outdoors and uncovered.
6. On V-belt drives, remove the belts and store indoors. Coat the sheaves with Class IV (b) material.
Couplings
1. Clean and coat couplings with Class IV (a) grease.
2. Wrap couplings with VCI-impregnated waterproof paper.
3. Drain oil-filled couplings and refill with Class II oil.
4. Drain and refill couplings every two years.
5. Fill grease-lubricated couplings with the normal grease used in operation.
Agitators, Centrifuges, Mixers
1. Neutralize, flush and drain all equipment as necessary.
2. Dry with air or nitrogen.
3. Place Class VII material on the insides of vessels and seal all openings.
4. Purge critical vessels with nitrogen, in addition to using the Class VII material.
5. Maintain critical vessels under a positive pressure of 5-10 psig nitrogen if vessels are capable of
withstanding this pressure.
6. Clean flanges and coat with Class III material.
7. Coat bolts and nuts with Class III material.
Hydraulic Systems, Lubricating Oil Systems and Oil Reservoirs
1. Drain systems and fill to the operating level with Class II oil or Class VI oil-based fluids.
2. Operate the system until the oil has circulated completely.
3. Seal the system with oil-resistant tape.
8-8
4. Drain and replace the oil every two years.
5. Operate pumps and circulate oil once every three months.
COMPRESSORS
Compressors, regardless of the alloy, are protected as if they were of carbon steel due to their high
capital cost.
Centrifugal or Rotary
Compressors of this type may be protected in several ways.
1. Close the suction and discharge valves.
2. Purge with nitrogen and maintain under a nitrogen blanket of 5-10 psig (0.034-0.069 MPa).
3. Fill all lubricating and seal-oil systems with Class VI oil fluid.
4. Bump the compressor over each month. Operate all lubricating and seal-oil systems for five minutes
both before and after, as well as during the time the compressor is operated.
5. Coat external, machined surfaces with Class III material.
6. Erect a shelter over outdoor installations.
- or 1. Fill the casing with Class VI material and drain.
2. Purge the casing with nitrogen and seal all openings.
3. Coat exposed machined surfaces with Class III material.
4. Erect a shelter over outdoor installations.
For shutdowns to extend beyond three years, the following may be considered:
1. Remove the rotor, bearings, seals, etc.
2. Clean and coat the components with Class III material and wrap with VCI-impregnated waterproof
paper.
3. Store the components in an indoor heated location in wooden crates. Block the rotor to prevent
bowing or hang it vertically in storage.
4. Blank off all lines.
5. Fill the casing and oil systems with Class VI oil fluid.
6. Coat any exposed machined surfaces with Class III material.
7. Erect a shelter over outdoor installations.
Reciprocating
1. Disconnect the suction and discharge piping from the process lines.
2. Fabricate a short circuit pipe between suction and discharge nozzles.
3. Operate the compressor against open suction and discharge for 10 minutes.
4. Install a short circuit pipe and apply 5-10 psig (0.034-0.069 MPa) nitrogen at the media side. Maintain
the nitrogen pressure.
;
5. Drain the cooling system and dry with hot air or nitrogen. Fill with Class VI oil fluid.
6. Fill lubricating and seal-oil systems with Class VI oil fluid.
7. Operate the compressor ten minutes per month. All lubricating and seal-oil systems are operated for
five minutes both before and after, as well as during, each compressor operation.
8. Coat all exposed machined surfaces with Class III material.
9. Drain all tanks and receivers. Dry and insert Class VII material. Seal all the openings.
10. Erect a shelter over outdoor installations.
- or 1. Drain the crankcase and refill it with Class VI oil fluid.
2. Operate the compressor for 10 minutes then seal the crankcase.
3. Purge the cylinders with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069
MPa).
4. Drain the cooling system; dry the system with hot air or nitrogen.
5. Purge the cooling system with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 MPa).
6. Coat all exposed machined surfaces with Class III material.
8-9
7. Drain all tanks and receivers. Dry them with warm air or nitrogen. Insert Class VII material and seal
all openings.
8. Erect a shelter over outdoor installations.
For shutdowns extending beyond three years:
1. Drain the crankcase and refill it with Class VI oil fluid.
2. Drain the cooling system; dry the system with hot air or nitrogen.
3. Purge the cooling system with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 MPa).
4. Remove all piston rod packing rings and oil wiper rings; clean them and coat them with Class III
material. Wrap the rings in VCI-impregnated waterproof paper and store indoors in a heated location.
5. Remove the inlet and discharge valves from the cylinders; clean, then coat valves with Class III
material. Wrap the valves with VCI-impregnated waterproof paper and store in an indoor heated
location in wooden crates.
6. Remove the pistons and rods; clean them and coat them with Class III material. Wrap the pistons
and rods in VCI-impregnated waterproof paper and store in an indoor heated location in wooden
crates.
7. Spray the valve bores with Class VI oil fluid.
8. Fill the crankcase with Class VI oil fluid.
9. Rotate the engine to thoroughly coat all components with the Class VI fluid.
10. Seal all nozzles.
11. Coat any exposed machined surfaces with Class III material.
12. Erect a shelter over outdoor installations.
NOTE: For breathing air and instrument air compressors, protection with an inert atmosphere is
preferable to prevent possible contamination with oil.
STEAM TURBINES
1. Dry the steam spaces with warm air or nitrogen.
2. Fog the steam spaces with Class VII material, turning the rotor as the material is blown in.
3. Seal the turbine casing, closing all openings leading to the steam spaces.
4. Protect bearings as outlined previously under Bearings in Reciprocating Equipment in this section.
5. Pack all drive mechanisms and gears with Class IV (a) grease.
6. Fill the shaft couplings with Class IV (a) grease and wrap them with VCI-impregnated waterproof
paper.
7. Install space heaters in housings if none are provided and keep them energized.
8. Dehumidify inside of any housing or enclosure.
9. Coat any exposed machined surfaces with Class III material.
10. Erect shelters over outdoor installations, if necessary.
11. Protect all lubricating and seal oil systems as described under Hydraulic Systems, Lubricating Oil
Systems and Oil Reservoirs.
ELECTRICAL EQUIPMENT
All electrical equipment intended for indoor or covered operation is stored indoors or otherwise protected
from rain and high humidity. Moisture may cause excessive swelling of organic compounds used in the
construction of many electrical devices. Drying may not be sufficient to restore equipment damaged by
moisture.
Motors—Field Storage
1. Blow open motors dry with air or nitrogen.
2. On open motors of 50 hp or larger that do not contain heaters, heat by installing auxiliary heaters or
by a reduced voltage in the stator windings.
3. Continuously energize heaters in open motors if they are so equipped.
4. Drain oil-lubricated bearings and fill with Class VI oil fluid. The shaft should be turned once a month.
5. Fill grease-type bearings with Class IV (a) grease and rotate the shaft once a month.
8-10
6. Uncouple motors of less than 50 hp and run them once a month for two hours. Motors less than 10
hp need not be protected.
7. On large motors, the brushes of commutators or collector rings are removed or lifted so that
wax-free, greaseproof insulation paper may be placed under them to prevent etching.
8. If motor windings are accessible, apply a coat of insulating varnish.
9. Measure the winding insulation resistance once a year, repairing shorts as identified.
10. Coat exposed shafts with Class III material. Wrap the shafts of large or critical motors with
VCI-impregnated waterproof paper.
11. Erect a shelter over large, critical motors.
Motors—Disassembled
Motors removed from the field are stored in the following manner.
1. Clean all exterior surfaces and blow dry with air.
2. Disassemble the motor.
3. Steam clean all components except those containing windings.
4. Clean windings with a suitable solvent.
5. Test the motor for shorts by "megging" and repair as necessary.
6. Apply a coat of insulation varnish to the motor windings.
7. Clean, check and replace bearings as necessary.
8. Reassemble the motor.
9. Coat all shafts with Class III material and wrap with VCI-impregnated waterproof paper.
10. Measure the winding insulation once a year, repairing shorts as identified.
11. For horizontal motors with sleeve bearings, shim the rotor symmetrically in the stator bore.
12. Reassemble the motor, retaining the air gap shimming but store the upper bearing halves
separately.
13. Coat all exposed surfaces with Class III material.
14. Cover with plastic sheeting as dust protection.
Vertical Motors
1. Jack up rotors 10-20 mils (0.010-0.020 inch) using a crossbar and jacking screw.
2. Fill the bearings with Class II oil or Class IV (a) grease as applicable.
3. Coat exposed machined surfaces with Class III material.
4. Coat accessible motor windings with insulation varnish.
5. Measure the winding insulation once a year, repairing shorts as identified.
Transformers
1. De-energize transformers not required to maintain services.
2. Maintain heat on transformers through installed heaters or through space heaters in the control
housings.
3. Install Class IX silica gel in receptacles or other locations to prevent moisture damage.
4. Inspect monthly for oil leaks and desiccant degradation.
5. Check oil dielectric strength yearly.
Switchgear
1. Install bags of Class IX silica gel in the cabinets of switchgear and motor controls located in buildings.
Maintain heat in the buildings. Air conditioning and dehumidifying may be used to control building
environments and fans may be necessary to circulate air.
2. Place Class VII crystals, tapes or emitters inside each section of the cabinets.
3. Continuously energize heaters in components so equipped.
4. Outdoor controls are protected as in 2 and 3 above.
5. In addition, plastic film is draped over all cabinets leaving a two inch air gap between the bottom edge
of the plastic and the floor.
6. Main buses remain energized to eliminate moisture damage.
7. Breakers and starters are left in the open position.
8-11
Batteries
1. Remove dry cell batteries from emergency lighting.
2. Disconnect wet cell batteries from the power supply.
3. Allow batteries left in service (as at 125 volt switchgear stations) to float at 129 volt charge but
equalize them at 140 volts once a month.
4. Rectifiers are stored indoors in a heated location.
Cables and Small Field Electrical Devices
1. Visually inspect these items once a month, checking paint, and looking for rust breakthrough on
galvanized components, cable sheathing, etc.
2. Inspect cable trays twice a year to ensure structural integrity.
CONTROL DEVICES AND INSTRUMENTATION
In general, control devices are removed from the unit and stored indoors in a heated building. In systems
under a nitrogen blanket, control valves remain in place with exterior protection as per other valves.
Pressure Relief Valves
1. Clean removable valves and after repairing them if necessary, store in a heated building.
2. Coat springs with Class II oil.
3. Coat flange faces with Class III material and cover with wooden blanks.
4. Spray valve cavities with Class VI oil fluid.
5. Gently close valves.
Temperature Gages
1. Clean and repair as necessary.
2. Store indoors in a heated building.
3. Fit plugs coated with Class III material into couplings in the field.
4. Inspect transmitters, elements, indicators and switches at six month intervals.
Liquid Level Gages
1. These devices may be removed and stored indoors or left installed. Partial dismantling is practiced
frequently with all sensing devices and transmitters for remote sensing being stored inside a heated
building.
Pressure and Differential Pressure Indicators and Switches
1. Remove, clean and test all field-mounted units before storing inside a heated building.
2. Remove pressure gages and DP cells and store inside a heated building.
Control Valves
1. Remove control valves fitted with instrumentation such as positioners, limit switches, electronic
converters, solenoid valves, etc.
2. Clean valve bodies.
3. Open hard-seated bodies and coat all seating surfaces with Class III material. Soft-seated bodies
require no coating.
4. Open globe-type valves slightly if they are fitted with a handjack or piston actuator. Otherwise, close
them gently.
5. Store ball valves and butterfly valves fully closed, except for valves that "fail open." These are stored
open.
8-12
6. Coat the bores of the valves, the flange faces, weld preparation areas, other machined surfaces and
body cavities with Class III material.
7. Sea! the ports with plugs or wooden blanks. If blanks cannot be fitted, wrap the valves in plastic
sheeting after inserting bags of Class IX desiccant.
8. Reprime the outside surfaces as necessary.
9. Piston actuators should be filled to 5% of volume with Class VI oil fluid by pouring oil into both sides.
10. Stroke the actuator to coat all surfaces.
11. Drain the oil from the actuator and plug all entry ports.
CAUTION: Rubber-lined butterfly valves or other components require no internal protection, except on
exposed metallic portions.
Field Panels
1. Where practical, remove all switches and measuring instruments from the panels and place in a
heated building.
2. Insert bags of Class IX desiccant in the panels.
3. Insert Class VII crystals, tapes or emitters in the panels.
4. Close the panels and seal them.
5. Cover the panels with plastic sheets leaving a two inch gap at the bottom to permit the circulation of
air.
FIRED HEATERS AND FURNACES
1. Clean the exterior of tubes to remove combustion products and other deposits.
2. Clean convection sections to remove such contaminants as sulfur.
3. Clean the inside of the tubes, decoking as necessary. Drain the tubes, drilling holes at low points if
necessary.
4. Neutralize the inside and/or outside of the tubes as necessary.
5. Dry tubes with warm air or nitrogen.
6. Purge tubes with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain under a positive nitrogen
pressure.
7. Clean headers; dry and purge with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain under a
positive nitrogen pressure.
8. Place lime trays in each fire box. Lime trays should be raked thoroughly once a month. Lime should
be replaced at six month intervals.
9. Cap all stacks. Caps should prevent rain entry but be open enough for a positive draft.
10. Cap duct openings after coating ducts with Class VI oil fluid.
11. Grease all door and other opening hinges, pins, etc. with Class IV (a) material.
12. Shut and seal doors and other openings.
13. Grease and/or oil all moving parts associated with the burners. Some burners may be protected in
place by wrapping with VCI-impregnated waterproof paper. Others require removal for heated,
indoor storage.
14. Seal all burner openings.
15. Touch up primers as required.
16. Grease any stack guy wires or replace as per normal maintenance procedures.
DIESEL AND GASOLINE ENGINES
1. Run the engine until it is thoroughly heated.
2. Stop the engine and drain all lubricating oil from the system.
3. Fill the lubricating oil system, the oil filter housing and the lubricating pump housing with Class VI oil
fluid.
4. For diesel engines, drain the fuel from the system and fill it with kerosene. Prime the fuel system.
5. Drain and flush the cooling system.
6. Refill the system with an inhibited antifreeze suitable to the lowest anticipated ambient temperature.
7. Run the engine for 15 minutes at idling speed, increasing to top speed a few times. Stop the engine.
8. For diesel engines, leave the fuel lines full of kerosene. Leave the fuel injectors in place.
8-13
9. After the engine has cooled, disconnect the inlet and exhaust manifold. Spray the manifolds with
Class VI oil fluid, turning the engine over as the oil is sprayed in to ensure complete coverage.
10. Seal all openings. Coat flanges with Class III material before sealing.
11. Reprime exterior surfaces as necessary. Coat machined surfaces with Class III material and wrap
with VCI-impregnated waterproof paper.
PROTECTION OF LINED TANKS AND VESSELS
Protection of lined equipment can be relatively complicated because of the large number of coatings and
linings that may be in service. Protective compounds that may prevent deterioration with one lining may
promote degradation in another. Consequently, the lining manufacturer should be consulted for recommendations regarding his product.
For coatings and linings it is essential that the cold wall effect be controlled or prevented. Otherwise,
blistering of linings and the cracking of brick may occur. Auxiliary space heaters placed inside large critical
vessels are often used to prevent the cold wall effect.
Heat tracing left on at low settings may be effective as well. However, it is important to prevent
overheating and subsequent destruction of the lining.
Rubber-Lined Equipment
In general, rubber-lined equipment is stored under moist conditions, preferably in a heated, indoor
location. Shelters may be erected around outdoor facilities to permit heating. The following procedures have
been effective in storing rubber-lined equipment for over nine years.
1. Fill vessel one quarter full with 25% sodium chloride solution.
2. Close all openings.
3. Seal flange edges with tape.
4. Seal telltale holes with rubber plugs.
5. Prime exterior surfaces as necessary or repair insulation.
- or 1. Fill vessel with a 5-10% solution of sodium carbonate leaving a small vapor space to accommodate
fluid expansion.
2. Close all openings and seal with tape.
3. Plug telltale holes with rubber plugs.
4. Reprime exterior as necessary or repair insulation.
5. Store in an indoor, heated location.
Thin or Baked Linings
Due to the many varieties of linings such as epoxies, phenolics, cross-linked epoxy-phenolics and the
like, vessels are best protected with an inert atmosphere.
1. Drain tank or vessel and flush clean.
2. Blow-dry with warm air or nitrogen.
3. Open flanges and clean exposed steel.
4. Coat exposed steel with Class III material. Tape edges of lining on flanges to make sure Class III
material does not come in contact with the lining.
5. Coat bolts and nuts with Class III material and reassemble flanges.
6. Remove agitators and seal openings as applicable.
7. Purge vessels capable of withstanding the pressure with 5-10 psig (0.034-0.069 MPa) nitrogen and
maintain under a positive nitrogen pressure. Otherwise fill and then drain the vessels to expel air.
8. Reprime external surfaces or repair insulation as necessary.
For Open Tanks
1. Flush tanks to remove all deposits.
2. Dry tanks thoroughly.
3. Fit tanks with cover.
4. For large tanks a small heater or even a light bulb suspended inside should prevent the cold wall
effect in indoor storage. For outdoor storage a small heater is preferred.
8-14
Thick or Free-Standing Linings
1. Flush tanks to remove all deposits.
2. For free-standing liners, drill holes through the shell in the lower parts of the tank to permit moisture
drainage from behind the liner. Exercise care to avoid drilling through the liner.
3. Seal all gaps between tank liner and shell at the top of the tank to prevent ingress of moisture.
4. For indoor storage install a heater or light bulb to keep the tank warm avoiding the cold wall effect;
a heater is preferred for outdoor storage.
Brick-Lined Vessels
1. Thoroughly drain vessel.
2. Flush the vessel clean and dry with warm air or nitrogen.
3. For vessels that can be sealed, insert lime trays or bags of silica gel.
4. Seal the vessel and if the vessel can take the pressure, purge with 5-10 psig (0.034-0.069 MPa)
nitrogen and maintain under a positive nitrogen pressure.
5. For vessels that cannot be sealed, install lime trays, raking the lime once a month.
6. Replace silica gel at two year intervals and/or lime at six month intervals.
7. Coat steel flange surfaces with Class III material.
8. Coat bolts with Class III material.
9. Reprime exterior and/or repair insulation if necessary.
REFRIGERATION SYSTEMS
Protection of refrigeration systems is no different from that of other plant systems. Heat exchangers,
evaporators and chillers, pumps and compressors are protected in the same manner as process equipment
of the same type.
1. Drain water and other fluids from the system.
2. Remove refrigerant.
3. Blow the lines and all equipment dry with nitrogen.
4. Plug all inlets and outlets using blanks as necessary and purge system with nitrogen.
5. Maintain under a positive nitrogen pressure.
6. If applicable, blow all chiller coils free of dirt and spray with Class VI fluid compatible with the alloy.
7. Protect exchangers, chillers, condensers and evaporators as per Coolers and Exchangers.
8. Protect pumps, compressors and turbines as outlined under Rotating Equipment, Compressors and
Steam Turbines respectively.
9. Cold boxes are frequently protected by placing space heaters inside them to prevent condensation.
Coils are purged with nitrogen and maintained under a positive pressure.
10. Coat bolts, studs and nuts with Class III material.
11. Insulation is removed where leaks or excessive condensation may have damaged the underlying
metal. The insulation may be replaced or the edges of the remaining insulation are sealed to prevent
the ingress of moisture.
CONTROL ROOMS
1. Seal all openings into the control room, particularly around cables, ductwork and other points of entry
to panels and control consoles.
2. Place bags of silica gel in each section of each cabinet.
3. Install VCI tapes, emitters or bags of crystals in each cabinet.
4. Dehumidify the control room or install air conditioners if none exist.
5. Operate air conditioners or dehumidification systems for five working days just prior to covering
cabinets and panels.
6. Install portable fans in the control room to ensure complete circulation of air.
7. Cover all control panels loosely with plastic film to prevent dust contamination. To provide air
circulation, leave a two inch air gap between the bottom of the plastic film and the floor.
8. Continuously energize the heaters of components so equipped.
9. Space heaters may be required to keep the control room temperature above 50°F (10°C).
10. Replace silica gel and VCI protection every two years.
8-15
EXPANSION JOINTS
Expansion joints are often treated as separate items for protection. Since the bellows are generally
constructed of high alloy material, protection methods attempt to prevent the cracking that may occur in
highly stressed areas. Consult the expansion joint manufacturer for advice concerning storage.
1. Flanged expansion joints that are bolted into process lines are frequently removed from the system
and stored indoors in a heated area. Flexible hoses are used to replace the joints if the systems are
to be protected with inert atmospheres or if circulation of fluids through the system is necessary.
2. Flush, drain and dry the joints taking care to remove water from the bellows' convolutions. Neutralize
if applicable.
3. Clean the outside of the bellows if applicable.
4. Install tie-down bolts where possible to prevent distortion. Tag bolts to ensure removal prior to
start-up.
5. Coat end rings, retaining rings and associated hardware with Class III or Class IV (b) material.
6. Coat areas of dissimilar metal contact, e.g. bellows to end rings or bellows to pipe nipple, with Class
III or Class IV (b) material.
7. On flanged joints remaining in place, open the flanges and clean them. Coat the flanges with Class
III or Class IV (b) material and reassemble.
8. In severe industrial or marine environments, cover flange gaps with Class VIM tape or use the Class
VIM protection system.
SPRINKLER SYSTEMS
Sprinkler systems may remain operational or they may be shut down if they are not required for long-term
storage. If the system remains operational, maintain as per normal operating procedures. If it is shut down,
proceed as follows:
1. Drain all lines, opening valves and breaking flanges where applicable.
2. Blow the lines dry with warm air or nitrogen.
3. Leave drain valves open.
4. Install blanks at the main or header.
5. Spray heads with Class VI (water base) material and cover with loose-fitting plastic bags.
6. Touch up primer where required.
WAREHOUSE AND STORAGE YARD ITEMS
Warehouse Items
Warehouse components are best stored under warm, dry conditions. Heat is normally left on in buildings
and air conditioning or humidity control may be employed.
1. Coat all machined surfaces on carbon and low alloy steel components with Class II or Class Ml
material.
2. Place light bulbs in storage bins to prevent condensation and corrosion.
3. Small components may be stored in drums filled with Class II or Class VI material or they may be
placed in oil-filled plastic bags.
4. Separate carbon and low alloy steel flanges; coat the flange faces with Class III or Class IV (b)
material and reassemble.
CAUTION: Do not use absorbent material such as cloth or burlap between mating parts.
5. Grease all gears, shafts, etc. with Class IV (a) material. Coat critical shafts and gears with Class III
material and wrap with VCI-impregnated paper.
6. Coat flange faces of pumps, valves, etc. with Class III or Class IV (b) material and cover with a hard
material such as plywood.
7. Store components in racks or bins with identification clearly marked.
8. Place desiccant and Class VII material in electrical, relay and other cabinets. Cover the cabinets with
plastic sheeting as a dust cover, leaving a two inch air gap all around the bottom for ventilation.
9. Coat all valves, valve stems and similar components with Class III or Class IV (b) material.
8-16
10. Cover all electrical motors with plastic sheeting as a dust cover, leaving a two inch air gap all around
the bottom for ventilation.
Storage Yard
1. Locate storage yards away from operating plants, the seacoast or other environments likely to
produce corrosion.
2. Grade the storage yard to promote drainage. A gravel pad is helpful for long-term storage. Clear all
brush and keep weeds, grass, etc. cut.
3. Store equipment such as pipe or vessels on a slope to promote drainage. Store pipe and fittings so
that prevailing winds will blow through the equipment to dry it; the higher end of the pipe is the
upstream side except if the prevailing wind is from the south. In that case the higher end is to the
north.
4. Store equipment a minimum of six inches off the ground. Treat wooden bolsters used for storage with
a wood preservative to prevent rotting. However, care in the selection of the wood preservative is
necessary as some of these products can promote corrosion of various metals.
5. Store fittings with the open ends down to prevent them from filling with water. Store fittings in such
a manner that the edges do not dig into wooden bolsters or other supporting members. If fittings are
stored on wooden platforms, drill holes at critical points in the platforms to promote drainage.
6. Pipe, fittings and other equipment stored in piles may suffer rapid corrosion in the groove formed
between adjoining members. Separate the pipe lengths, etc. to eliminate these crevices.
7. Coat all flange faces and other machined surfaces with Class III or Class IV (b) material. Cover
flange faces and other openings with plywood or similar covers.
8. Consider coating the inside of large diameter piping and of long delivery items of carbon and low
alloy steels with Class III material and covering the ends with end caps.
9. Remove plugs from couplings, coating plugs and coupling threads with Class III material and
reinstalling them in the couplings. Fill any gaps with Class III material.
10. Open all flanges on equipment; clean and coat them with Class III material, then reassemble. Cover
the flange gaps with Class VIII tape. For critical vessels, protect flanges with the Class VIII system.
11. Tape flanges on austenitic stainless steel or other high alloy components to prevent ingress of
moisture.
12. On carbon and low alloy steels, clean around the stamped identification and coat over the area with
clear lacquer. Apply a top coat as necessary. If possible, stamp identification on materials and
components that are not so identified (note: some material or alloys may be unsuitable for stamping).
13. Prepare a drawing of the storage yard showing the location and identification of each piece of
equipment or group of items. The number of pieces of flanges, fittings, pipe lengths, etc. in each
location is listed as well.
14. Snow removal may be necessary in certain areas. Deicing salts are not recommended due to
possible equipment damage by corrosion.
BUILDINGS
Buildings are best protected by maintaining heat and air conditioning systems wherever practical.
Sprinkler systems may remain active for fire control or be shut down and protected.
1. Maintain buildings above 50°F (10°). Space heaters may be substituted for central heating systems
if the latter are decommissioned.
2. Dehumidify through either the air conditioning or the dehumidification systems. Small portable units
may be used but, to avoid spills due to oversight, automatic draining is recommended. Fans are
generally required to circulate air in buildings, particularly if equipment is stored in them.
3. Run water through plumbing fixtures, sinks, toilets, etc. once a month if these systems remain in
operation.
4. If the plumbing is shut down, drain the system and blow-dry with warm air or nitrogen. Leave taps
and drain valves open.
5. If a building is not heated drain plumbing systems and blow-dry with air. Fill the system including
toilets, catch basins, etc., with inhibited antifreeze.
6. Again, if a building is not heated drain the air conditioning and dehumidification systems and
blow-dry with air. Fill the systems with inhibited antifreeze.
7. Shut off all but essential lighting.
8. Install Class VII materials and bags of desiccant in switch panels, etc.
8-17
9. Drain, flush and dry with warm air all laboratory services such as gas and water.
10. Clean fume hoods and seal against the ingress of air. Oil all pumps, motors, fans, etc., repainting
where necessary.
11. Books, drawings, specifications and miscellaneous papers are stored in fire resistant locations such
as a vault, heated warehouse, etc. Documents are stored in water resistant and fire resistant
cabinets to prevent damage from accidental discharge of sprinkler systems.
12. Snow removal from roofs is necessary in areas subject to high snow loads. Electric tracing or
periodic shoveling may be used.
13. Roof drains, rain gutters, roof vents, etc. are maintained to prevent building damage. Inspection
normally takes place after severe storms.
14. Windows may require protection by boarding or covering them with other materials.
15. Screens are applied over roof vents and other openings to keep out birds.
16. Screens are placed over sewers and other points of entry to keep out rodents.
8-18
SECTION 9 PROTECTION PROGRAM BEYOND
60 MONTHS
A protection program for a predicted idle period greater than five years is very similar to that for a five
year period (Section 8) except that more extensive protection is applied in areas where high rates of
corrosion might be expected. In addition, reapplication of most preservatives will be required as they are
generally not intended to maintain protection indefinitely.
Structural deterioration in foundations and supports may affect the ability to restart. Personnel changes
over the extended period may jeopardize continuity of protection and records. Mounting costs of maintaining
idle equipment may lead to decisions to abandon protection, reduce maintenance and sell off components
for spare parts. However, extensive initial preparation and a high degree of protection may alleviate some of
these complications and ensure the success of the mothball operation.
SHUTDOWN CONSIDERATIONS
As pointed out in Sections 7 and 8 appropriate shutdown procedures must be followed for certain
equipment to prevent cracking or other damage. These procedures, required under normal operations, will
most probably be followed during the initial shutdown but may be ignored for start-up due to a change of
personnel. Therefore, it is important that all such procedures be identified on inspection and maintenance
records. In addition, equipment requiring special start-up procedures could be identified with metal tags at all
points of entry.
CORROSIVE ENVIRONMENTS
It is important to remove from equipment all scales, sludges and deposits, including sulfur and fly ash,
that may produce corrosive conditions when exposed to air and/or moisture. Plant personnel are best
equipped to determine the method of removal. On some critical vessels, sandblasting (provided the sand can
be removed without damaging surrounding equipment) might be considered. This would provide a clean
surface making protection relatively easy. The expense may not be justified if other cleaning methods would
be effective.
Acid Service
1. Using fresh water, flush equipment that has been in acid or potentially acidic service.
2. Drain the equipment thoroughly.
3. Neutralize with a suitable alkaline solution.
4. Drain and dry with warm air or nitrogen.
Alkaline Service
1. Flush with fresh water and drain completely.
2. Dry with warm air or nitrogen.
Organic Compounds
1. Special washing or neutralizing may be required. Plant personnel would probably be most
knowledgeable about the necessary procedures.
Pyrophoric Materials
1. Neutralize, if applicable.
2. Flush with fresh water and keep material moist.
3. Remove all loose material.
4. Dry with nitrogen.
9-1
Sulfur-Oxy Acids (Polythionic Acids)
1. Neutralize by washing with a solution containing 1.5-2.0% sodium carbonate and 0.5% sodium nitrite
(soda ash). Critical vessels may have to be filled and left for three-to-seven days to ensure complete
neutralization.
CAUTION: Vessels and piping must be capable of supporting the weight of the solutions.
2. Flush with fresh water and drain completely.
3. Remove all sludges and scales.
4. Rewash with the soda ash solution.
5. Flush and drain completely.
6. Dry with nitrogen.
WATER LINES
1. Drain water lines that are not necessary for the operation of other parts of the plant.
2. Blow the lines dry with air or nitrogen. It may be necessary to drill holes in low points or in
complicated shapes where valves do not exist to permit drainage but holes are drilled only if no other
draining method is possible. Tag the holes so they may be repaired before start-up.
3. Remove insulation from large, critical lines and prime the steel. On noncritical lines, remove wet
insulation and do not replace it. Seal the edges of the remaining insulation.
4. Coat the exterior surfaces of valves with Class III material.
5. Remove valves on lines over twenty-four inches in diameter and coat the internals with Class III
material. Fill the bonnets of gate and globe valves with Class VI oil fluid. The same protection may
be applied to valves on smaller lines if desired.
6. Coat exposed valve stems with Class IV (b) grease.
7. On large diameter, critical lines, purge with 5-10 psig (0.034-0.069 MPa) nitrogen and leave under
a positive pressure of nitrogen.
8. On lines over twenty-four inches in diameter, open the flanges, clean the flange faces and coat with
Class III material. Reassemble the flanges and protect with the Class VIII system. Again, smaller
diameter lines may be protected in the same manner.
9. Coat all bolts and nuts with Class III material.
INSULATION
1. Remove insulation wherever possible. Clean and reprime all steel surfaces.
2. Repair the weather barrier on any remaining insulation to prevent the ingress of moisture.
3. Seal all insulation edges, particularly at valves, pumps, etc.
4. Caulk all openings, such as at hangers.
PIPING AND VALVES
Carbon and Low Alloy Steel Piping, Valves and Fittings (Above Ground)
In general piping two inches and less in diameter is not protected if it is not associated with a critical
component or system.
1. Flush and drain all lines, neutralizing as necessary. Ensure sludge has been flushed from lines.
2. Break flanges and open valves at all low points to permit draining. Drill holes only if necessary in low
points or in piping with complicated shapes to permit draining. Tag all drilled holes.
3. Remove insulation wherever possible. If insulation is not removed, replace wet material and repair
damaged covering. Seal insulation edges at all valves, flanges, etc.
4. Touch up primers on bare steel.
5. Lubricate valves.
6. Cover exposed valve stems with Class IV (b) material.
7. Remove valves over 12" in diameter and spray the inside with Class III material. Reinstall valves. Fill
bonnets or other cavities with Class VI fluid.
9-2
8. Clean and coat flange faces out to the edges with the Class VIII system for piping 12" and over.
Under 12", coat with Class III material and cover gap between flanges with Class VIII tape (see note
below).
9. Coat all exposed bolts and nuts with Class III material.
10. Coat small drain and vent valves with Class III material.
11. Coat hangers and pipe supports with Class III material.
12. For critical lines or large diameter lines, purge with 5-10 psig (0.034-0.069 MPa) nitrogen and
maintain under nitrogen pressure.
NOTE: Customarily, twelve inches is the size at which the protective method changes. Individual plants
may prefer to use either method for smaller or larger diameter lines.
Carbon and Low Alloy Steel Piping, Valves, Fittings (Underground)
1. Flush, neutralize and drain the lines as necessary.
2. Dry the lines with nitrogen.
3. For critical lines purge the lines with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 MPa) nitrogen.
4. If applicable, maintain cathodic protection.
Austenitic Stainless Steel and Other High Alloy Lines
1. Flush the lines with fresh water. Neutralize as necessary.
2. Drain the lines by opening valves and breaking flanges open at low points if necessary.
3. Dry the lines with warm air or nitrogen.
4. Break open the flanges on large diameter or critical lines and coat flange faces out to the edge with
Class III material.
5. Cover gap between the flanges with Class VIII tape.
6. Remove wet insulation and clean the outside of the piping, removing adhering material. The
insulation may be replaced now although it is more economical to replace it just prior to start-up.
7. Seal all insulation edges. Caulk around hangers and other openings.
8- Coat exposed threads of drain and vent valves with Class III material.
9. On bare pipe, coat pipe hangers, pipe shoes, etc. with Class III material. (Ensure Class III is
compatible with the material used in the pipe shoes and other supports.)
Lined Low Alloy Steel Pipe
1. Flush and drain all lines. Break open flanges and open valves at all low points. Leave drain valves
open.
2. Dry lines with warm air or nitrogen.
3. Remove wet insulation and reprime pipe. Seal remaining insulation edges.
4. Cover exposed valve stems with Class III or Class IV (b) material.
5. Break open flanges, clean and coat metallic portions with Class III material. (Ensure that Class III
material does not cover the liner if they are not compatible.)
6. On critical lines, cover the gap between flanges with Class VIII tape.
7. Coat small drain and vent valves with Class III or Class IV (b) material.
8. Coat pipe hangers and supports with Class III material.
9. Coat all exposed, low alloy steel bolts and nuts with Class III material.
FLARE SYSTEM
Generally, flare systems remain operational if flammable products are to remain in the plant or are used
as preservatives, e.g. filling a vessel with oil. The headers and stack are maintained under a nitrogen purge
or as per normal operating procedures. If the flare system is shut down the following is suggested:
1. Flush all headers, drums and lines, neutralizing as necessary.
2. Dry all lines with nitrogen.
3. Open and clean all drums.
9-3
4. Clean and coat all flange faces out to the edges with the Class VIII system, sealing the gap with the
tape.
5. Close off the flare stack with blanks designed to take the pressure of a nitrogen purge at 5-10 psig
(0.034-0.069 MPa).
6. Purge the flare system with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 MPa).
7. Touch up all bare steel as necessary.
8. Remove insulation and paint the steel as required.
9. Cap the stack to prevent the ingress of moisture. Some plants prefer to seal the stack but others like
to allow a positive draft which will promote drying.
HEAT TRACING
1. Shut down steam tracing. Remove unions at low points to promote draining.
2. Flush the lines and blow them dry with air.
3. Keep the lines open or fill them with inhibited antifreeze of suitable composition for the lowest
anticipated ambient temperature.
4. Disconnect electrical tracing.
PROCESS VESSELS AND TANKS
Stainless Steel and Nonferrous Alloys
1. Neutralize as necessary.
2. Flush, clean and dry with air or nitrogen.
3. Seal all openings.
4. Remove all insulation if equipment is outdoors. As necessary, repair insulation on indoor
installations.
5. If the plant is located in a marine or heavy industrial environment, coat all flange faces out to the
flange edges and any other crevices with Class III material, then cover with Class VIII tape.
6. For salt environments, consider coating bare austenitic stainless steel equipment with a suitable
paint to prevent pitting.
Carbon Steel
1. Neutralize as necessary removing such contaminants as pyrophoric sludges.
2. Flush and drain completely.
3. Blow-dry with air or nitrogen.
4. The inside of the vessels may be coated by spraying, or by draining then filling with Class II oil.
However, process conditions and streams must be considered by operating personnel as oil may
cause severe upsets or excessive foaming when service is restored. If oil may pose a problem,
eliminate it.
5. Install desiccants in all major vessels either in the form of bags of silica gel or as lime trays. Lime has
to be raked monthly and replaced every six months (for vessels that are not sealed).
6. Clean all flange faces and protect with the Class VIII system.
7. Purge vessels with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069 MPa)
if the vessel is capable of withstanding that pressure.
8. Remove insulation wherever possible and paint the vessels.
9. Drill holes to prevent standing water in structural steel, insulation rings, etc.
10. Caulk friction joints to prevent the ingress of water.
11. Inspect all remaining insulation and repair as necessary.
12. Remove safety valves and blank the openings (bolted valves only). Store valves indoors in a heated
location.
13. Coat bolts and nuts with Class III material.
14. Inspect bases, foundations and supports. Coat anchor bolts with Class IV (b) material.
9-4
Reactors
1. Remove catalyst where applicable.
2. Clean, ensuring complete removal of sludges. Neutralize as necessary.
3. Dry with nitrogen.
4. Purge with nitrogen and maintain at a positive pressure of 5-10 psig (0.034-0.069 MPa) ensuring that
all openings are sealed.
5. Clean all flange faces out to the edge and coat with Class VIII material.
6. Cover the gap between flanges (outdoor location) with Class VIII tape.
7. Remove insulation (outdoors) and clean underlying steel. Seal insulation left in place to prevent the
ingress of moisture.
8. Reprime bare steel as necessary.
9. Drain all jackets where applicable and blow-dry with air or nitrogen.
10. Fill the jackets with inhibited antifreeze of sufficient strength to resist the lowest anticipated ambient
temperature. Vessels inside heated buildings require no antifreeze, and their jackets are left open
after draining and drying.
Towers, Spheres, Bullets
1. Flush and clean vessels following neutralizing, where applicable. Drain completely.
2. Dry with air or nitrogen.
3. The inside of the vessels may be coated with Class II oil by spraying or filling and draining. However,
process conditions and streams must be considered as oil may cause severe upsets or excessive
foaming when service is restored. If oil may pose a problem avoid its use.
4. Install bags of desiccant (silica gel) in all major vessels.
5. Protect all flanges with the Class VIII system.
6. If they can withstand the pressure, purge vessels with nitrogen at 5-10 psig (0.034-0.069 MPa),
checking all flange areas for leakage with soap solution.
7. Seal gap between flanges and all other openings with Class VIM tape.
8. Maintain pressure vessels under a positive pressure of nitrogen of 5-10 psig (0.034-0.069 MPa).
9. Remove insulation wherever possible.
10. Remove all corrosion scabs and reprime as necessary.
11. Drill holes to prevent standing water in such items as structural steel, insulation rings, etc.
12. Inspect all other insulation and repair as necessary. Seal the insulation and caulk all openings.
13. Remove safety valves and blank the openings (bolted valves only). Store the valves indoors in a
heated location.
14. Coat bolts and nuts with Class III material.
15. Inspect bases and foundations. Coat anchor bolts with Class IV (b) material.
COOLERS AND EXCHANGERS
Cooling Towers
The materials of construction used for the cooling towers will determine the protection measures. Large
amounts of dry wood in an idle unit present a considerable fire hazard.
1. Open and drain all piping.
2. Drain the water from the basin and flush the basin clean.
3. Block open the basin drain valves.
4. Inspect and replace damaged structural components, warped or missing slats, and tighten loose
bolting.
5. Remove the fan drive motor and protect it as described in this section under Electrical Equipment.
6. Drain the oil from the gear reducer and refill it with Class VI oil fluid.
7. Clean the exterior of the gear reducer housing and reprime it as necessary.
8. Coat exposed portions of shafts with Class III material and wrap with VCI-impregnated waterproof
paper.
9. Remove the gear reducer and store in an indoor heated area.
10. Clean the fans and reprime the blades as necessary.
9-5
11. Coat the fan drive gear with Class IV (a) material and wrap it with VCI-impregnated waterproof
paper.
12. Secure the fan blades to prevent rotation.
13. Spray all wood with a fire retardant chemical and a biocide.
Spray Coolers
1. Close and blank the water inlet valves.
2. Drain and clean the water trough.
3. Flush and drain the product inlet line.
4. Blank the product inlet valve.
5. Blank all process and product lines.
6. Clean and prime bare metal components.
7. Cover the water troughs with a watertight cover.
8. Drain and clean the concrete basin.
9. Block open the drain valves.
Finned Air Coolers
1. Drain all product from the tubes and blow them dry with nitrogen or dry air. Neutralization may be
necessary before drying.
2. Blow the fins clean with dry air.
3. Pump oil through the tubes or purge them with nitrogen, maintaining a positive pressure of 5-10 psig
(0.034-0.069 MPa).
4. Coat the threads of plugs with Class III material and reinstall.
5. Remove the fan drive motors and protect them as in Electrical Equipment.
6. Drain the oil from the gear reducers and refill them with Class VI oil fluid.
7. Clean the exterior of gear reducer housings and reprime as necessary.
8. Coat the exposed portions of shafts with Class III material and wrap with VCI-impregnated
waterproof paper.
9. Remove the gear reducers and store them in a heated indoor location.
10. Clean the fans and reprime the blades as necessary.
11. Coat the fan drive gears with Class IV (a) material and wrap with a VCI-impregnated waterproof
paper.
12. Secure the fan blades to prevent rotation.
13. Reprime structural steel members as necessary.
Plate Exchangers
The normal washing, chemical cleaning, or mechanical cleaning is performed prior to protection.
1. Disassemble plates to ensure complete cleaning and drying.
2. Store plates flat in crates, properly shimmed to prevent warpage, or store plates vertically, again
properly shimmed to prevent metal-to-metal contact.
3. Clean and inspect rubber sealing rings, discarding any that display damage.
4. Store sealing rings in sealed packages.
5. Coat all valving with Class III material and store indoors.
6. Reprime frame materials as necessary.
7. Coat bolts and nuts with Class III material and store in frames or in crates.
Shell and Tube Exchangers
Shell and tube exchangers are manufactured from many alloys or combinations of alloys. Protection
methods are generally those required to protect the alloy most prone to corrosion. Austenitic stainless steel
tubes in carbon steel shells are protected as if they were carbon steel. Higher alloy materials may require little
in the way of protection other than cleaning and drying.
The normal washing, chemical cleaning, mechanical cleaning or neutralizing that would be used during
a routine shutdown is carried out.
1. Flush, drain and neutralize as applicable.
9-6
2. Remove bundles (in floating head installations) and thoroughly clean all components. Remove
sludge, deposits and all other debris.
3. Thoroughly dry all components with warm air or nitrogen.
4. Coat flange faces out to the edges with Class VIII material and seal all gaps with Class VIII tape.
5. Plants with an inventory of oil may choose to coat bundles and shells with oil to which VCIs have
been added. Other facilities may prefer to purge the reassembled exchangers with nitrogen and
maintain them under a positive nitrogen pressure of 5-10 psig (0.034-0.069 MPa).
6. For fixed tube bundles, open the heads and clean the tubes, channels and heads.
7. Flush the shell side, neutralize as necessary and dry with warm air or nitrogen.
8. Reassemble and purge with nitrogen, maintaining the exchangers under positive nitrogen pressure
of 5-10 psig (0.034-0.069 MPa).
9. Coat flange faces out to the edges with Class VIII material and seal all gaps with Class VIII tape.
10. For all exchangers, remove insulation where possible. Where insulation is not removed, repair the
insulation cover to prevent ingress of moisture.
11. Coat all drain valves, sample valves, etc. with Class IV (b) material.
12. Clean and reprime steel.
13. Coat anchor bolts with Class IV (b) material.
STORAGE TANKS
1. Drain and clean tanks, removing all scales and sludges.
2. Touch up interior primers as necessary.
3. Facilities with oil inventories may prefer to coat tank interiors with oil by spraying or by filling and
draining. Other facilities prefer to spray tank interiors with Class VI fluids, or if the tanks can be
sealed and pressured, to purge them with nitrogen to 5-10 psig (0.034-0.069 MPa) and maintain this
pressure throughout the storage period.
4. In areas of high winds, fill or partially fill the tanks with inhibited water at pH 8.5-9.5. A nitrogen purge
may be used in conjunction with the water to prevent corrosion in the vapor space.
5. Open roof drains as applicable.
6. Remove agitators where applicable, and seal the openings with gasketed covers.
7. Maintain vacuum breakers to prevent collapse of tanks when they are drained.
8. Coat all flange faces out to the edges with Class III material.
9. In marine or severe industrial environments, cover all gaps at flanges or other openings with Class
VIII tape.
10. Touch up exterior primers as necessary.
ROTATING EQUIPMENT
Pumps, mixers, etc. may represent a significant capital cost so the protection afforded them may be
extensive. In general, components made from austenitic stainless steels or non-ferrous alloys are
neutralized, flushed and cleaned, dried thoroughly and sealed.
Centrifugal Pumps
1. Drain the casing and the bearing housing. Neutralize as necessary.
2. Flush the casing and bearing housing and dry with air or nitrogen.
3. Disconnect and blank off the suction and discharge lines.
4. Fill the pump casing with Class VI oil and rotate the pump shaft to ensure complete oil coverage.
Pumps may be operated for ten minutes every month. Operate lubricating and seal-oil systems
during the ten minute pump operation and for five minutes before and after. Keep the pump drain
connections open during any operating period.
5. Coat the exposed pump shafts and other machined surfaces with Class IV (b) material and cover
with Class VIII tape.
6. Coat the exposed pump shafts and other machined surfaces with Class III material and cover with
Class VIII tape.
7. Fill the shaft couplings with Class IV (a) grease, as applicable.
8. Remove wet insulation; clean the exposed surfaces and paint them.
9-7
Reciprocating Pumps
1. Open all vents and drains on both ends of the pump.
2. Break all pipe connections and blank off all suction and discharge lines.
3. Fill both sides of the pump with Class VI oil fluid. Remove valves to permit filling. Reinstall valves.
4. Move pistons back and forth to ensure complete coverage with oil.
5. Drain the oil from the system and seal all openings.
6. Coat all valves and valve covers with Class III material.
7. Coat exposed rods and other machined surfaces with Class IV (b) material and wrap with Class VIII
tape or protect with the Class VIII system.
8. Fill all lubricators with Class VI oil fluid.
9. Remove any wet insulation; clean the exposed surfaces and paint them.
Mechanical Seals and Packing
1. For single seals, pack the seal with Class IV (a) grease.
2. Retighten (lightly) the seal gland.
3. For double seals, drain the stuffing box and flush it ensuring that the pump operates for a minimum
of two minutes before shutting it down.
4. Plug the lower stuffing box drain and fill the stuffing box with Class II oil or Class IV (a) grease.
5. For conventional packing, loosen the packing gland and remove the packing.
6. Coat the interior of the stuffing box with Class IV (a) grease.
7. Leave the packing out or repack the pump with nonmetallic packing, tagging the pump to ensure
replacement of the operating packing for a restart.
Bearings—All Equipment
1. Pump greased bearings full of Class IV (a) material. Replace the grease at two year intervals.
2. Drain oil-filled bearings and refill with Class VI oil fluid. Replace the oil at two year intervals.
Drives
1. Drain gear cases and fill to the operating level with Class VI oil fluid.
2. Run for 5 to 10 minutes to ensure that all surfaces are coated.
3. Seal with Class VIII tape to prevent leakage.
4. Replace the oil at two year intervals.
5. Open gears, sprockets, screws and chain drives. Coat with Class IV (a) grease if the mechanism is
covered or Class IV (b) if it is outdoors and uncovered.
6. On V-belt drives, remove the belts and store indoors. Coat the sheaves with Class IV (b) material.
Couplings
1. Clean and coat couplings with Class IV (a) grease.
2. Wrap couplings with VCI-impregnated waterproof paper.
3. Drain oil-filled couplings and refill with Class VI oil fluid.
4. Drain and refill couplings every two years.
5. Fill grease lubricated couplings with the normal grease used in operation. Replace at two year
intervals if required.
Agitators, Centrifuges, Mixers
1. Neutralize, flush and drain all equipment as necessary.
2. Dry with air or nitrogen.
3. Place Class VII material on the inside of vessels and seal all openings.
4. Purge critical vessels with nitrogen, in addition to using the Class VII material.
5. Maintain critical pressure vessels under a positive pressure of 5-10 psig (0.034-0.069 MPa) nitrogen.
6. Clean flanges and coat with Class III material.
9-8
7. Coat bolts and nuts with Class III material.
Hydraulic Systems, Lubricating Oil Systems and Reservoirs
1. Drain systems and fill to the operating level with Class VI oil-based fluids.
2. Operate the system until the oil has circulated completely.
3. Seal the system with oil resistant tape.
4. Drain and replace the oil every two years.
5. Operate pumps to circulate the oil every three months.
COMPRESSORS
Compressors, regardless of the alloy, are protected as if they were of carbon steel due to their high
capital cost.
Centrifugal or Rotary
Compressors of this type may be protected in one of the following ways:
1. Close the suction and discharge valves.
2. Purge with nitrogen and maintain under a nitrogen blanket of 5-10 psig (0.034-0.069 MPa).
3. Fill all lubricating and seal-oil systems with Class VI oil fluid.
4. Bump the compressor over each month. Operate all lubricating and seal-oil systems for five minutes
both before and after the compressor is bumped over.
5. Coat external, machined surfaces with Class IV (b) material.
6. Erect a shelter over outdoor installations.
- or 1. Fill the casing with Class VI material and drain.
2. Purge the casing with nitrogen and seal all openings.
3. Coat exposed machined surfaces with Class IV (b) material.
4. Erect a shelter over outdoor installations.
- or 1. Remove the rotor, bearings, seals, etc.
2. Clean and coat the components with Class IV (b) material and wrap with VCI-impregnated
waterproof paper.
3. Store the components in an indoor heated location in wooden crates. Block the rotor to prevent
bowing or hang it vertically in storage.
4. Blank off all lines.
5. Fill the casing and oil systems with Class VI oil fluid.
6. Coat any exposed machined surfaces with Class IV (b) material.
7. Erect a shelter over outdoor installations.
Reciprocating
1. Disconnect the suction and discharge piping from the process lines.
2. Fabricate a short circuit pipe between suction and discharge nozzles.
3. Operate the compressor against open suction and discharge for ten minutes.
4. Install a short circuit pipe and apply 5-10 psig (0.034-0.069 MPa) nitrogen at the media side. Maintain
the nitrogen pressure during the shutdown period.
5. Drain the cooling system and dry with hot air or nitrogen. Fill with Class VI oil fluid.
6. Fill lubricating and seal-oil systems with Class VI oil fluid.
7. Operate the compressor ten minutes per month. Operate all lubricating and seal-oil systems for five
minutes before and after, as well as during, each compressor operation.
8. Coat all exposed machined surfaces with Class IV (b) material.
9. Drain all tanks and receivers. Dry and insert Class VII material. Seal all the openings.
10. Erect a shelter over outdoor installations.
- or 1. Drain the crankcase and refill it with Class VI oil fluid.
2. Operate the compressor for ten minutes, then seal the crankcase.
9-9
- or -
3. Purge the cylinders with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069
MPa).
4. Drain the cooling system then dry it with hot air or nitrogen.
5. Purge the cooling system with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 psig).
6. Coat all exposed machined surfaces with Class IV (b) material.
7. Drain all tanks and receivers. Dry them with warm air or nitrogen. Insert Class VII material and seal
all openings.
8. Erect a shelter over outdoor installations.
1. Drain the crankcase and refill it with Class VI oil fluid.
2. Drain the cooling system; dry the system with hot air or nitrogen.
3. Purge the cooling system with nitrogen and maintain under a positive pressure of 5-10 psig
(0.034-0.069 psig).
4. Remove all piston rod packing rings and oil wiper rings, clean them and coat them with Class III
material. Wrap the rings in VCI-impregnated waterproof paper and store indoors in a heated location.
5. Remove the inlet and discharge valves from the cylinders; clean the valves and coat them with Class
III material. Then wrap the valves with VCI-impregnated waterproof paper and store in an indoor
heated location in wooden crates.
6. Remove the pistons and rods, clean them and coat them with Class III material. Wrap the pistons
and rods in VCI-impregnated waterproof paper and store in an indoor heated location in wooden
crates.
7. Spray the valve bores with Class VI oil fluid.
8. Fill the crankcase with Class VI oil fluid.
9. Rotate the engine manually or through operation to thoroughly coat all components with the Class
VI fluid.
10. Seal all nozzles.
11. Coat any exposed machined surfaces with Class IV (b) material.
12. Erect a shelter over outdoor installations.
NOTE: For breathing air and instrument air compressors, protection with an inert atmosphere is
preferable to prevent possible contamination with oil or other compounds.
STEAM TURBINES
1. Dry the steam spaces with warm air or nitrogen.
2. Fog the steam spaces with Class VII material, turning the rotor as the material is blown in.
3. Seal the turbine casing, closing all openings leading to the steam spaces.
4. Protect bearings as outlined previously.
5. Pack all drive mechanisms and gears with Class IV (a) grease.
6. Fill the shaft couplings with Class IV (a) grease and wrap them with VCI-impregnated waterproof
paper.
7. Install space heaters in housings or enclosures if none are provided and keep them energized.
8. Dehumidify the inside of any housing or enclosure.
9. Coat any exposed machined surfaces with Class IV (b) material.
10. Erect shelters over outdoor installations, if necessary.
ELECTRICAL EQUIPMENT
All electrical equipment intended for indoor or covered operation is stored indoors to protect it from rain
and high humidity. Moisture may cause excessive swelling of organic compounds used in the construction
of many electrical devices. Drying may not adequately recover equipment damaged by moisture.
Motors—Field Storage
Consideration should be given to disassembly of motors for complete cleaning and storage as outlined next
under Motors—Disassembly. However, field storage as described below is possible. 1. Blow-dry open
motors with air or nitrogen.
9-10
2. Heat open motors of 50 hp or larger that do not contain heaters by installing auxiliary heaters or
through reduced voltage in the stator windings.
3. Continuously energize heaters in open motors so equipped.
4. Drain oil-lubricated bearings and fill them with Class VI oil fluid. Turn the shafts once a month.
5. Fill grease-type bearings with Class IV (a) grease and rotate the shafts once a month.
6. Uncouple motors of less than 50 hp and run them once a month for two hours. Motors of less than
10 hp are not protected.
7. On large motors, remove the brushes of commutators or collector rings or lift them so that wax-free,
greaseproof insulating paper may be placed under them to prevent etching.
8. If motor windings are accessible, apply a coat of insulating varnish.
9. Measure the winding insulation resistance once a year, repairing shorts as identified.
10. Coat exposed shafts with Class IV (b) material. Wrap the shafts of large or critical motors with
VCI-iuipregnated waterproof paper.
11. Erect a shelter over large, critical motors.
Motors—Disassembly
Store motors removed from the field in the following manner:
1. Clean all exterior surfaces and blow-dry with air.
2. Disassemble the motor.
3. Steam clean all components except those containing windings.
4. Clean windings with a suitable solvent.
5. Test the motor for shorts by "megging" and repair as necessary.
6. Apply a coat of insulation varnish to the motor windings.
7. Clean, check and replace bearings as necessary.
8. Reassemble the motor.
9. Coat all shafts with Class IV (b) material and wrap with VCI-impregnated waterproof paper.
10. Measure the winding insulation resistance once a year, repairing shorts as identified.
11. For horizontal motors with sleeve bearings, shim the rotor symmetrically in the stator bore.
12. Reassemble the motor retaining the air gap shimming but omitting the upper bearing halves.
13. Coat all exposed surfaces with Class IV (b) material.
14. Cover the motor with plastic sheeting as dust protection but leave a two inch gap around the bottom
to promote ventilation.
Vertical Motors
1. Jack up rotors 10-20 mils (0.010-0.020 inch) using a crossbar and jacking screw.
2. Fill the bearings with Class VI oil fluid or Class IV (a) grease as applicable.
3. Coat exposed machined surfaces with Class IV (b) material.
4. Coat accessible motor windings with insulation varnish.
5. Measure the winding insulation resistance once a year, repairing shorts as identified.
Transformers
1. De-energize transformers not required to maintain services.
2. Maintain heat on transformers with installed heaters or with space heaters in the control housing
3. Install Class IX silica gel in receptacles or other locations to prevent moisture damage.
4. Inspect monthly for oil leaks and desiccant degradation.
5. Check oil dielectric strength yearly.
6. Purge the air space above the oil with nitrogen and maintain a positive pressure.
7. Reprime external surfaces as necessary.
8. Fasten fans to prevent rotation.
Switchgear
1. For switchgear and motor controls located in buildings install bags of Class IX silica gel in the
cabinets. Maintain heat in the buildings. Air conditioning and dehumidifying may be used to control
building environments. Fans may be necessary to circulate air.
9-11
2. Place Class VII crystals, tapes or emitters inside each section of the cabinets.
3. Continuously energize the heaters of equipment if so equipped.
4. Protect outdoor controls in a similar manner.
5. Drape plastic film over all cabinets leaving a two inch air gap around the bottom between the plastic
and the floor.
6. Keep main buses energized to eliminate moisture damage.
7. Maintain breakers and starters in the open position.
8. Protect small equipment such as relays, circuit breakers, push buttons, etc. by placing them in plastic
bags, inserting Class VII material and sealing the bags.
Batteries
1. Remove dry cell batteries from emergency lighting.
2. Disconnect wet cell batteries from the power supply.
3. Allow batteries left in service (as in 125 volt switchgear stations) to float at 129 volt charge and
equalize them at 140 volts once a month.
4. Store rectifiers indoors in a heated location.
Cables and Small Field Electrical Devices
1. Inspect visually once a month checking paint, rust breakthrough on galvanized components, cable
sheathing, etc.
2. Inspect cable trays twice a year to ensure structural integrity.
3. On overhead power lines, inspect pole hardware, groundwires, brackets, tower legs, etc. once a
year, repairing as necessary.
4. On tower legs and bases protected by cathodic systems, maintain normal operating procedures to
verify that the system is satisfactory.
5. On underground lines that are de-energized, maintain cathodic protection systems, if applicable.
Inspect lines by "megging" before start-up.
CONTROL DEVICES AND INSTRUMENTATION
In general, control devices are removed from the unit and stored indoors in a heated building. Control
valves in systems under a nitrogen blanket remain in place with exterior protection as per other valves.
Pressure Relief Valves
1. Removable valves are cleaned, repaired and stored in a heated building.
2. Coat springs with Class II oil.
3. Coat flange faces with Class IV (b) material and cover with wooden blanks.
4. Spray valve cavities with Class VI oil fluid.
Temperature Gages
1. Clean and repair as necessary.
2. Store indoors in a heated building.
3. Fit plugs coated with Class IV (b) material into couplings in the field.
4. Inspect transmitters, elements, indicators and switches at six month intervals.
Liquid Level Gages
1. These devices may be removed and stored indoors or left installed. Frequently, partial dismantling
is practiced, with all remote sensing devices and transmitters stored inside a heated building.
9-12
Pressure and Differential Pressure Indicators and Switches
1. Remove all field mounted units; clean, test and store them inside a heated building.
2. Remove pressure gages and DP cells and store them inside a heated building.
Control Valves
1. Remove control valves fitted with instrumentation such as positioners, limit switches, electronic
converters, solenoid valves, etc.
2. Clean valve bodies.
3. Open hard-seated bodies and coat all seating surfaces with Class III material. Soft-seated bodies
require no coating.
4. Leave globe-type valves open slightly, if they are fitted with a handjack or piston actuator. Otherwise,
close them gently.
5. Store ball valves and butterfly valves fully closed, except for valves that fail in an open position.
These should be stored open.
6. Coat the bore of the valves, the flange faces, weld preparation areas and other machined surfaces
and body cavities with Class III material.
7. Seal the ports with plugs or wooden blanks. If blanks cannot be fitted, wrap the valve in plastic
sheeting after inserting bags of Class IX desiccant.
8. Reprime the outside surfaces as necessary.
9. Fill piston actuators to 5% of volume with Class VI oil fluid by pouring into both sides.
10. Stroke the actuator to coat all surfaces.
11. Drain the oil from the actuator and plug all entry ports.
CAUTION: Rubber-lined butterfly valves or other valve components require no internal protection, except
for exposed metallic portions.
Field Panels
1. Where practical, remove switches and measuring instruments from the panels and place in a heated
building.
2. Insert bags of Class IX desiccant in the panels.
3. Insert Class VII crystals, tapes or emitters in the panels.
4. Close the panels and seal them.
5. Cover the panels with plastic sheets leaving a two inch gap at the bottom to permit the circulation of
air.
FIRED HEATERS AND FURNACES
1. Clean the exterior of tubes to remove combustion products and other deposits.
2. Clean convection sections to remove such contaminants as sulfur.
3. Clean the inside of the tubes, decoking as necessary. Drain the tubes, drilling holes at low points if
necessary (only if no other adequate method of draining is available). Tag holes for future repair.
4. Neutralize the inside and/or outside of the tubes as necessary.
5. Dry tubes with warm air or nitrogen.
6. Purge tubes with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain under a positive nitrogen
pressure.
7. Clean headers; dry and purge with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain under a
positive nitrogen pressure.
8. Place lime trays in each fire box. Rake lime trays thoroughly once a month. Replace the lime every
six months.
9. Cap all stacks. Caps prevent the entry of rain but are open enough for a positive draft.
10. Cap duct openings after coating ducts with Class IV oil fluid.
11: Grease all door and other opening hinges, pins, etc. with Class IV (a) material.
12. Shut and seal doors and other openings.
13. Grease and/or oil all moving parts associated with the burners. Some burners may be protected in
9-13
place by wrapping with VCI-impregnated waterproof paper. Others require removal for heated indoor
storage.
14. Seal all burner openings.
15. Touch up primers as required.
16. Grease any stack guy wires or replace as per normal maintenance procedures.
DIESEL AND GASOLINE ENGINES
1. Run the engine until it is thoroughly heated.
2. Stop the engine and drain all lubricating oil from the system.
3. Fill the lubricating oil system, the oil filter housing and the lubricating pump housing with Class VI oil
fluid. Coat exposed machined surfaces with Class III material and wrap with Class VIII tape or
VCI-impregnated waterproof paper.
4. For diesel engines, drain the fuel from the system and fill with kerosene. Prime the fuel system.
5. Drain and flush the cooling system.
6. Refill the system with an inhibited antifreeze suitable for the lowest anticipated ambient temperature.
7. Run the engine for 15 minutes at idling speed, increasing to top speed a few times. Stop the engine.
8. For diesel engines, leave the fuel lines full of kerosene. Leave the fuel injectors in place.
9. After the engine has cooled, disconnect the inlet and exhaust manifold. Spray the manifolds with
Class VI oil fluid, turning the engine over as the oil is sprayed in to ensure complete coverage.
PROTECTION OF LINED TANKS AND VESSELS
Protection of lined equipment can be relatively complicated because of the large number of coatings and
linings that may be in service. Protective compounds that may prevent deterioration with one lining may
promote degradation with another. Consequently, it is suggested that the lining manufacturer be consulted
for recommendations regarding his product.
For coatings and linings it is essential that the cold wall effect be controlled or prevented. Otherwise,
blistering of linings and cracking of brick may occur. Auxiliary space heaters placed inside large critical
vessels are often used to prevent the cold wall effect.
Heat tracing left on at low settings may be effective as well. However, exercise care to prevent
overheating and subsequent destruction of the lining.
Rubber-Lined Equipment
In general rubber-lined equipment is stored under moist conditions, preferably in a heated, indoor
location. Shelters may be erected around outdoor facilities to permit heating. The following procedures have
proven effective in storing rubber-lined equipment for over nine years:
1. Fill vessel one quarter full with 25% sodium chloride solution.
2. Close all openings.
3. Seal flange edges with tape.
4. Seal telltale holes with rubber plugs.
5. Prime exterior surfaces as necessary or repair insulation.
- or 1. Fill vessel with a 5-10% solution of sodium carbonate leaving a small vapor space to accomodate
fluid expansion.
2. Close all openings and seal with tape.
3. Plug telltale holes with rubber plugs.
4. Reprime exterior as necessary or repair insulation.
5. Store in an indoor, heated location.
Thin or Baked Linings
Due to the many varieties of linings such as epoxies, phenolics, cross-linked epoxy-phenolics and the
like, these vessels are best protected with an inert atmosphere.
1. Drain tank or vessel and flush clean.
2. Drain tank or vessel and blow-dry with warm air or nitrogen.
3. Break flanges and clean exposed steel.
9-14
4. Coat exposed steel with Class IV (b) material. Tape edge of lining on flanges to make sure Class IV
(b) material does not come in contact with the lining.
5. Coat bolts and nuts with Class IV (b) material and reassemble flanges.
6. Remove agitators and seal openings as applicable.
7. Purge pressure vessels with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain under a positive
nitrogen pressure. Nonpressure tankage may be purged with a low flow of gas.
8. Reprime external surfaces or repair insulation as necessary.
For Open Tanks
1. Flush tanks to remove all deposits.
2. Dry tanks thoroughly.
3. Fit tanks with covers.
4. For large tanks a small heater or even a light bulb suspended inside prevents the cold wall effect in
indoor storage. In outdoor storage, a heater is preferable.
Thick or Free-Standing Linings
1. Flush tanks to remove all deposits.
2. Drill holes through shell in lower parts of tank to permit moisture drainage from behind freestanding
liners. Exercise care to prevent drilling through the liner.
3. Seal all gaps between tank liner and shell at the top of the tank to prevent ingress of moisture.
4. Install a heater or light bulb to keep the tank warm, preventing a cold wall effect, in indoor storage.
Install a heater or erect a shelter around components stored outside.
Brick-Lined Vessels
1. Thoroughly drain vessel.
2. Flush the vessel clean and dry with warm air or nitrogen.
3. For vessels that can be sealed, insert trays or bags of silica gel.
4. Seal the vessel and if it is a pressure vessel, purge with 5-10 psig (0.034-0.069 MPa) nitrogen and
maintain under a positive nitrogen pressure. Otherwise, displace the air, replacing with nitrogen at
atmospheric pressure.
5. For vessels that cannot be sealed, install lime trays, raking the lime once a month.
6. Replace silica gel at two year intervals and/or lime at six month intervals.
7. Coat steel flange surfaces with Class IV (b) material.
8. Coat bolts with Class IV (b) material.
9. Reprime exterior or repair insulation as necessary.
REFRIGERATION SYSTEMS
Protection of refrigeration systems is no different from that of other plant systems. Heat exchangers,
evaporators and chillers are protected in the same manner as process heat exchangers. Pumps and
compressors are protected in the same manner as process equipment of the same type.
1. Drain water and other fluids from the system.
2. Remove refrigerant.
3. Blow the lines and all equipment dry with nitrogen.
4. Plug all inlets and outlets using blanks as necessary and purge system with nitrogen.
5. Maintain under a positive nitrogen pressure.
6. If applicable, blow all chiller coils free of dirt and spray with Class VI fluid compatible with the alloy.
7. Protect exchangers, chillers, condensers and evaporators as in the section on Coolers and
Exchangers if applicable.
8. Protect pumps, compressors and turbines as described under Rotating Equipment earlier in this
section.
9. Cold boxes are protected frequently by placing a space heater inside to prevent condensation. Coils
are purged with nitrogen and maintained under a positive pressure.
10. Coat bolts, studs and nuts with Class III material.
11. Insulation is removed where leaks or excessive condensation may have damaged the underlying
9-15
metal. The insulation may be replaced or the edges of the remaining insulation sealed to prevent the
ingress of moisture.
CONTROL ROOMS
1. Seal all openings into the control room, particularly around cables, duct work and other entry points
to panels and control consoles.
2. Place bags of silica gel in each section of each cabinet.
3. Install VCI tapes, emitters or bags of crystals in each cabinet.
4. Dehumidify the control room or install air conditioners if none exist.
5. Operate air conditioners or dehumidification systems for five working days prior to covering cabinets
and panels.
6. Install portable fans in the control room to ensure complete circulation of air.
7. Cover all control panels loosely with plastic film to prevent dust contamination. Leave a two inch air
gap between the bottom of the plastic film and the floor to permit air circulation.
8. Continuously energize the internal heaters of components so equipped.
9. Space heaters may be required to keep the control room temperature above 50°F (10°C).
10. Replace silica gel and VCI protection every two years.
EXPANSION JOINTS
Expansion joints are often treated as separate items during protection. In general, the bellows are
constructed of high alloy material so protection methods attempt to prevent cracking that may occur in highly
stressed areas. Consult the expansion joint manufacturer for advice concerning storage.
1. Flanged expansion joints are frequently removed for long-term protection and are stored indoors in
a heated building. Flexible hoses or piping spool pieces may be installed to permit inert atmosphere
protection or fluid circulation in units from which expansion joints have been removed.
2. Flush, drain and dry joints taking care to remove water from the bellows' convolutions. Neutralize if
applicable.
3. Clean the outside of the bellows, if accessible.
4. Install tie-down bolts where possible to prevent distortion. Tag bolts to ensure their removal prior to
start-up.
5. Coat end rings, retaining rings and associated hardware with Class III or Class IV (b) material.
6. Coat areas of dissimilar metal contact, e.g. bellows to end rings or bellows to pipe nipples, with Class
III or Class IV (b) material.
7. On flanged joints remaining in place, open the flanges and clean them. Coat the flanges with Class
III or Class IV (b) material and cover the gap with Class VIII tape. Alternatively, protect the flanges
with the Class VIII system.
8. Coat hinge pins and other hardware with Class III or Class IV (b) material, as applicable.
SPRINKLER SYSTEMS
Sprinkler systems are normally shut down for long-term storage. If they do remain operational, maintain them
as per normal operating procedures. For shutdown systems:
1. Drain all lines, opening valves and breaking open flanges at low points where applicable.
2. Blow the lines dry with warm air or nitrogen.
3. Leave drain valves open.
4. Blank off mains and headers.
5. Purge headers with nitrogen and maintain under a slight positive pressure if feasible.
6. Spray heads with Class VI water-based material and cover with plastic bags containing Class VI or
Class VII material. Fasten bags tightly around heads, excluding as much air as possible.
7. Reprime base metal as necessary.
8. Coat exposed valve stems with Class III material.
WAREHOUSE AND STORAGE YARD ITEMS
Warehouse
Warehouse components are best stored under warm, dry conditions. Heat is normally left on in buildings
9-16
and air conditioning or humidity control may be employed. However, for long-term storage warehouse stock
is often sold as protection costs become prohibitive.
1. Coat all machined surfaces on carbon steel and low alloy steel components with Class III material.
2. Place light bulbs in storage bins to prevent condensation and corrosion.
3. Store small items in drums filled with Class II or Class VI oils. They may be stored as well in oil-filled
plastic bags from which air has been removed prior to heat sealing.
4. Separate carbon steel and low alloy steel flanges; coat the flange faces with Class III or Class IV (b)
material, reassemble and store indoors in a heated location. Flanges stored in unheated areas are
coated completely with Class III or Class IV (b) material.
CAUTION: Do not use absorbent material such as cloth or burlap between mating parts.
5. Coat all gears, shafts, etc. with Class III material. Wrap critical items with VCI-impregnated paper
and store in crates.
6. Coat the flange faces of pumps, valves, etc. with Class III or Class IV (b) material, then cover them
with hard material such as plywood.
7. Store components in racks or in bins with identification clearly marked.
8. Place desiccant and Class VII material in electrical cabinets, relay cabinets, etc. Cover the cabinets
with plastic sheeting leaving a two inch air gap between sheet and floor for ventilation.
9. Coat all valves, valve stems and similar components with Class III or Class IV (b) material.
10. Cover all electric motors with plastic sheeting as a dust cover, leaving a two inch air gap all around
the bottom between the plastic and the floor for ventilation.
Storage Yards
1. Locate storage yards away from operating plants, the seacoast or other environments likely to cause
corrosion.
2. Grade the storage yard to promote drainage. A gravel pad is generally necessary for long-term
storage. Clean up all brush and keep weeds, grass and brush cut.
3. Store components by type and specification, e.g. carbon steel components in one area, stainless
steel in another.
4. Prepare a detailed plan of the storage yard showing the location and identification of each piece of
equipment or group of items. The number of items such as flanges, fittings, pipe lengths along with
applicable specifications (such as SA 181 for flanges) included on drawings helps to inventory for
future sale or use upon restart.
5. Store equipment such as pipe or vessels on a slope to promote drainage. Store pipe and fittings so
that the prevailing winds will blow through the equipment to dry it; the higher end of the pipe is at the
upstream side except if the prevailing wind is from the south. In that case the higher end is to the
north.
6. Store equipment a minimum of six inches off the ground. Treat wooden bolsters used for storage with
a wood preservative to prevent rotting. Care in the selection of the wood preservative is necessary
as some of these products can promote corrosion of various metals.
7. Store fittings with the open ends down to prevent them from filling with water. Store fittings so that
the edges do not dig into wooden bolsters or other supporting members. If fittings are stored on
wooden platforms, drill holes in the platforms to permit drainage.
8. Erect a shelter over critical items.
9. Pipe, fittings and other equipment stored in piles may suffer rapid corrosion in the groove formed by
adjoining members. Separate pipe lengths, etc. to eliminate these crevices.
10. Coat all flange faces and other machined surfaces with Class III or Class IV (b) material. Cover
flange faces and other openings with plywood or similar covers.
11. Coat the inside of large diameter piping or long delivery items of carbon and low alloy steels with
Class III material and cover the ends of the pipe lengths with pipe caps, plywood covers or some
other suitable cover.
12. Remove plugs from couplings, coat plugs with Class III material and reinstall in the couplings. Fill any
gaps with Class III material.
13. Open all flanges on equipment, clean and coat them with Class III material. Reassemble the flanges
and cover the gaps with Class VIII tape. For critical equipment of carbon or low alloy steels, protect
the flanges with the Class VIII system.
14. Tape flanges on austenitic stainless steel or other high alloy components to prevent the ingress of
moisture.
9-17
15. On carbon and low alloy steels, clean around stamped identification and coat over the area with clear
lacquer. Apply a top coat if necessary. Stamp identification on materials and components that are not
so identified, if possible. (Some material or alloys may be unsuitable for stamping.)
16. Snow removal may be necessary in certain areas. Deicing salts are not recommended due to
possible equipment damage by corrosion.
BUILDINGS
Buildings are best protected by maintaining heat and air conditioning systems wherever practical.
Sprinkler systems may remain active for fire control or be shut down and protected.
Unheated Buildings
1. Drain plumbing systems and blow them dry with air or nitrogen.
2. Fill the systems with an inhibited antifreeze.
3. Place inhibited antifreeze in toilets, catch basins and other fixtures that may crack upon freezing.
4. Caulk and seal all openings.
5. Drain air conditioning and dehumidification systems. Blow them dry and fill them with inhibited
antifreeze.
6. Shut off all but essential lighting.
7. Install Class VII materials and bags of silica gel in switch panels, etc.
Heated Buildings
1. Maintain the building above 50°F (10°C). Space heaters may be substituted for central heating
systems if these have been decommissioned.
2. Dehumidify either through air conditioning or through dehumidification systems. Small portable units
may be used but automatic draining is recommended. Fans are generally required to circulate air in
buildings, particularly if equipment is stored in them.
3. Run water through plumbing fixtures, sinks, toilets, etc. once a month, if these systems remain
operational.
4. If the plumbing is shut down, drain the system and blow it dry with warm air or nitrogen. Leave taps
and drain valves open or close the system and fill it with inhibited antifreeze.
5. Shut off all but essential lighting.
6. Install Class VII materials and bags of silica gel in switch panels, etc.
7. Clean fume hoods and seal against the ingress of air. Oil all pumps, motors, fans, etc., repainting
where necessary.
8. Books, drawings, specifications and miscellaneous paper are stored in fire resistant locations such
as a vault, heated warehouse, etc. Documents are stored in water and fire resistant cabinets to
prevent damage from accidental sprinkler system discharges.
All Buildings
1. Snow removal from roofs is necessary in areas subject to high snow loads. Electric tracing or
periodic snow shoveling is required.
2. Maintain roof drains, rain gutters, roof vents, etc. to prevent damage to the buildings. Inspection
normally is performed after heavy rain, snow, wind or hail storms.
3. Board up windows that require protection or cover with other materials.
4. Apply screens over roof vents, sewers and other openings to keep out birds and rodents.
9-18
SECTION 10
POWER PLANTS FOR 1-18 MONTHS
The protection of power plant equipment is not vastly different from that for equipment in process plants.
However, as power plants may require a quick return to service, precautions to prevent corrosion and/or
freeze-up may require special attention. The following is intended as a typical guideline, but may have to be
modified to suit specific climatic or operational aspects.
BOILERS
Boilers may be stored wet or dry. The wet method is used for short-term shutdowns or when the boiler
might have to be returned to service on relatively short notice. Ensure that proper circulation and freeze
protection are employed with the wet method.
Boiler Water Side-Wet Method
Soften and deaerate water used for lay-up. Use large amounts (150 ppm sodium sulfite or the equivalent)
of an oxygen scavenger, e.g. sodium sulfite or hydrazine to prevent oxygen pitting.
1. Fill the boiler to the normal operating level, light off the unit and raise the pressure to 25 psig (0.17
MPa). Be sure the drum vents and outlet superheater drains remain open.
2. Fire the boiler until satisfactory pH and oxygen scavenger levels are reached throughout (pH 9.5
minimum and 100 ppm sodium sulfite or equivalent).
3. Discontinue firing of the unit. Establish one of the following controls:
—
Before the pressure drops to zero add softened, deaerated water to the boiler until
flow is
established from the drum vent and the superheater outlet header vent.
—Allow water to circulate continuously through the highest vent on the unit.
- or —Provide a head tank of adequate size (minimum 50 gallons).
—Connect the head tank to the highest vent and at an elevation above the vent.
—
Fill the unit as in Items 1 and 2 above, until the head tank is filled with chemically treated
water.
—Add treated water as needed to keep head tank filled.
- or —Connect a nitrogen supply to the highest vent on the unit.
—After the firing outlined in Item 2 above has stopped and the pressure on the boiler has dropped
to 10 psig (0.069 MPa), feed nitrogen through the vent. As the boiler cools, the nitrogen will replace
the steam above the water level.
—Maintain the nitrogen pressure at 5 psig (0.034 MPa) minimum throughout the shutdown. —
Maintain water at the normal operating levels.
Boiler Water Side—Dry or Cold Method
The dry or cold method is recommended when a boiler is to be idle for an extended period (greater than
six months) or when a wet layup might lead to extensive problems.
1. After the fires are extinguished and the pressure has dropped to one half operating pressure or 25
psig (0.17 MPa) minimum depending on the system, blow down the water drum, water glass,
continuous blow down, lower drum blow down valves and all waterwall header drain valves for
approximately 30 seconds each.
2. Close the nonreturn valve and the stop valve at the main steam header. Open drain valves between
the closed valves to prevent leakage back from the main header.
3. Acid clean the boiler if necessary.
4. When the pressure reaches 10 psig (0.069 MPa), open the vent valve and the superheater outlet
drain valve.
5. Drain the boiler through all blow down and header drain valves.
6. When the pressure reaches atmospheric, open all manholes and the hand holes in the lower
waterwall header. Clean all surfaces removing sludge and deposits by flushing.
7. Remove all water from tubes and drums by blowing with dry air, by vacuuming or other suitable
means. Holes may have to be drilled in nondrainable low spots. However, these holes will have to
be tagged to permit future repairs. Nondrainable superheaters are frequently drained in this manner.
8. Place bags of desiccant (silica gel preferred) inside each drum. Bags are suspended from distributor
piping or other suitable locations along the length of each drum.
9. Close boiler drums and all hand holes. Purge the drums with dry nitrogen at a pressure of 5-10 psig
(0.034-0.069 MPa). Maintain the drums under a positive nitrogen pressure of 5 psig (0.034 MPa)
minimum.
10. Blank off all lines connected to the boiler.
11. Remove safety valves if possible and store indoors in a heated location. Blank openings with blanks
protected with Class III or Class IV (b) material. Clean safety valves that are welded in; coat them
with Class II or Class III material and cover them loosely with a weather barrier.
12. Drain pressure gage, sight glass and level alarm lines. Blow-dry with dry air.
Boiler Fire Side-Wet Method
1. Flush the tubes with fresh water of neutral pH.
2. Clean the fire side with a high pressure alkaline rinse as necessary.
3. Dry the fire side with warm air or with a small fire.
4. If the fire side is to be left open, it should be kept dry by circulating warm air through it. If it is to be
closed up, place trays of lime or silica gel in the fire box, changing the material at six month intervals
or more frequently as indicated by changes in color (if using silica gel).
Boiler Fire Side—Dry or Cold Method
1. Operate all soot blowers several times to remove as much deposit and fly ash as possible. For the
last operating sequence, start withthe soot blower at the furnace and follow the flue gas path to the
blower nearest the stack. Air lances may be employed as well.
2. After the boiler has cooled to 140°F (6Q°C), the boiler, economizer, and air heater are washed down
on the flue gas side. Carry out the final washing, working from top to bottom, while the boiler is still
warm. A wash with neutral pH water followed by an alkaline high pressure water cleaning may be
necessary.
3. Dry the boiler with a light refiring.
4. Coat all metal surfaces with Class I, Class II or Class VII material by spraying or fogging.
5. Place lime trays or silica gel in the fire box. Lime requires raking once a month and replacement after
six months. Silica gel is replaced when it changes color.
6. Close all openings, sealing as necessary.
7. Cap the stack in such a manner that a positive draft is created but the ingress of rainwater is
prevented.
8. Reprime structural steel as necessary.
Boiler Fire Side—Hot Technique
Some package boilers cannot be cleaned and coated with rust inhibitors on the gas side without
extensive disassembly. These units may be preserved under hot conditions as follows:
1. The temperatures in the boiler are maintained above 170°F (77°C). This temperature may be
maintained by circulating water as in Boiler Water Side—Wet Method (Section 10, item 3), or by light
controlled firing.
2. If circulating water is used, the flue gas duct and/or the air supply are blanked. If firing is used,
blanking is not necessary.
3. Continuous burning pilots have been useful for protection in the hot mode.
TURBINES
Turbines are protected in such a manner that vapors do not leak into the turbine or the condenser,
depending on the unit.
1. Clean all deposits from the system before shutdown using standard plant procedures.
2. Blank all steam lines leading to or connected to the turbine.
3. Drain the oil reservoir and clean it.
4. Fill the oil reservoir with Class II or Class VI material.
5. Circulate the oil through the system with the auxiliary pump. Repeat monthly.
10-2
6. On the exchangers, disconnect all water lines, clean the units and dry with air or nitrogen.
7. Maintain the units under a positive pressure of nitrogen of 5-10 psig (0.034-0.069 MPa).
8. Seal turbine housing or shelter doors to prevent the ingress of moisture. Place Class VII tapes or
emitters within the housing or shelters prior to sealing the doors.
MOTORS AND GENERATORS
1. All motors less than 10 hp may be left without protection depending on replacement deliveries.
2. Open motors are blown dry with air or nitrogen.
3. For all equipment with heaters, energize the heaters continuously. Space heaters or even light bulbs
may be used to maintain a temperature high enough to prevent condensation.
4. Oil-lubricated bearings are drained and filled with Class II material. The shaft is rotated a minimum
of 2 1/3 turns once a month.
5. Grease type bearings are filled with the normal operating grease and the shaft rotated a minimum
of 2 1/3 turns once a month.
6. Motors less than 50 hp are uncoupled and run once a month for two hours.
7. Dismantled motors are raised off the bearings and supported on shims.
8. Where commutators or collector rings are accessible on large motors for shutdowns extending
beyond twelve months, the brushes are removed or at least lifted so that wax-free, greaseproof
insulating paper may be placed under them to prevent etching.
9. Exposed shafts are coated with Class II or Class III material.
10. Exposed couplings are packed with Class IV (a) grease and covered with Class VIII tape.
11. Motors over 10 hp and generator winding insulation are megged after one month in storage and then
at six month intervals using a 500 VDC megohmmeter. The minimum resistance should equal the
rated voltage/1000 + 1 megohms.
PUMPS
Fire water and other critical pumps may continue in service and be maintained with normal operating
procedures. Protect pumps to be shut down as follows:
1. Disconnect and blank off suction and discharge from the piping.
2. Neutralize and clean pumps as required.
3. Purge critical pumps with 5-10 psig (0.034-0.069 MPa) nitrogen.
4. Fill lube and seal-oil systems with Class II oil.
5. Operate pumps for 10 minutes every month. Operate lubricating and seal-oil systems during this 10
minute period and for 5 minutes before and after shutdown. Ensure that the pump drains are open
during any operating period.
6. Coat machined surfaces with Class I, II or III material based on the length of shutdown and the
storage location.
7. Erect weatherproof structures over critical outdoor installations.
FANS
1. Thoroughly clean the fan blades and coat with Class II or Class III material.
2. Clean both internal and external casings or housings and coat with Class II or Class III material.
3. Close the inlet and outlet dampers.
4. Drain and flush bearings with Class II or Class VI material.
5. Drain the jackets of water cooled bearings and then flush them with Class VI material followed by
blowing them dry with air. Flush the water lines and disconnect them at the header. Flush the header
with Class VI material, then drain and blow it dry.
Induced Draft Fans
1. Remove all fly ash from the casing and ducts.
2. Blank the duct at the stack.
3. Drain the gearboxes and oil systems. Clean the systems and fill with Class II or Class VI material.
4. Clean couplings and coat them with Class II or Class IV (a) material depending on the type of
coupling.
10-3
PIPING
1. Drain and flush all piping. Holes may be drilled in hard-to-drain areas but tagging for future repair is
essential.
2. Dry the lines with air or nitrogen.
3. Keep critical lines under a positive pressure of nitrogen of 5-10 psig (0.034-0.069 MPa).
4. Seal the remaining lines to prevent the ingress of moisture from a potentially warm building.
5. Inspect insulated outdoor lines and repair the insulation as necessary.
6. Open flanges on large diameter outdoor lines; clean and coat them with Class II or Class III material
and then reassemble them.
DEAERATORS, AIR RECEIVERS, INERT GAS TANKS AND OTHER PRESSURE VESSELS
1. Blank all inlet and outlet lines.
2. Open the system to drain it, as applicable.
3. Flush to remove all sludge, as applicable.
4. Dry with warm air or nitrogen.
5. Place bags of silica gel in such components as the deaerator and major receiver tanks.
6. Disassemble flanges, clean and coat with Class II or Class III material out to the flange edge and
reassemble.
7. Purge the deaerator with 5-10 psig (0.034-0.069 MPa) nitrogen and maintain at a positive pressure
of 5 psig (0.034 MPa).
8. Insert Class VII material in all other vessels and seal all openings.
9. Inspect and repair insulation on outdoor vessels.
TANKS
1. Clean chemical tanks and neutralize them as applicable. Dry the tanks with warm air or nitrogen.
2. Insert Class VII material (metallic tanks) in critical tanks and seal all openings. Fiber glass or other
noncorroding materials are dried and left open.
3. Large outdoor tanks may require some ballast to prevent wind damage. Inhibited water is normally
used.
4. Touch up structural steel is required.
HEAT EXCHANGERS, CONDENSERS, EJECTORS, CHILLERS, ETC.
Perform normal washing, chemical cleaning, mechanical cleaning or neutralizing that would be used
during a routine shutdown.
1. Flush, drain and neutralize, as applicable.
2. Remove the bundle (floating head installations) and thoroughly clean the shell and bundle.
3. Thoroughly dry components with warm air.
4. Coat flange faces out to the flange edges with Class II or Class III material.
5. Reinstall bundle and purge exchanger with nitrogen. Maintain under a positive pressure of 5-10 psig
(0.034 0.069 MPa) nitrogen.
6. For fixed tube bundles, open heads; clean tubes, channels and heads.
7. Flush the shell side and dry with warm air or nitrogen.
8. Reassemble and purge with nitrogen. Maintain under a positive pressure of 5-10 psig (0.034-0.069
MPa).
9. Coat flange faces out to the edges with Class II or Class III material.
10. On all exchangers in a marine or heavy industrial environment, cover all openings between flanges
with Class VIM tape.
11. Touch up primers as necessary and inspect all insulation. Replace wet insulation and repair
insulation cover to prevent the ingress of moisture.
12. Coat all drain valves, sample valves, etc. with Class III material.
NOTE: For extended shutdowns (six months or less), some companies prefer to flush and drain
exchangers and then purge them with nitrogen without any further operation. A nitrogen blanket at 5-10 psig
(0.034-0.069 MPa) is maintained until start-up. If the shutdown is extended beyond six months, more
10-4
extensive work including coating the.flanges takes place.
SWITCHGEAR, CIRCUIT BREAKERS, CONTROL CABINETS, RELAY CABINETS, ETC.
1. Continuously energize the heaters in equipment fitted with them. Seal all cabinet openings.
2. Suspend bags of silica gel in each section of the cabinets.
3. Place Class VII emitters in each section of the cabinets.
4. Cover cabinets with loose plastic or tarpaulins to keep out dirt. Leave a minimum of a two inch (5 cm)
gap between the floor and the bottom of the plastic sheets to prevent condensation.
CONVEYORS, HOPPERS AND OTHER HANDLING EQUIPMENT
1. Clean elements, removing dirt and debris.
2. Grease rollers and other drive mechanisms with the normal operating grease.
3. Spray inside of hoppers, etc. with Class II oil.
4. Coat bolts and nuts with Class II oil or Class III material.
SOFTENERS, ION EXCHANGE COLUMNS, ETC.
1. Drain softeners and columns.
2. Regenerate resins or exchange media as applicable.
3. Provided the equipment can withstand the pressure, purge with nitrogen and maintain under a
positive pressure of 5-10 psig (0.034-0.069 MPa). Otherwise, evacuate the air, replacing it with
nitrogen at atmospheric pressure.
10-5
10-6
SECTION 11
POWER PLANTS FOR 19-60 MONTHS
The medium- to long-term protection methods for a power plant are very similar to those established for
process units and involve the complete removal of water to prevent corrosion and/or freezing. Wet storage
methods are not recommended for boilers or other equipment since it is unlikely that a quick return to service
will be necessary.
BOILERS
Boilers are completely drained and dried for protection periods extending beyond eighteen months.
Costs associated with wet storage and the potential for corrosion increase dramatically in proportion to the
length of the idle period.
Boiler Water Side—Dry Method
1. After the fires are extinguished and the pressure has dropped to one half operating pressure or 25
psig (0.17 MPa) minimum depending on the system, blow down the water column, water glass,
continuous blow down, lower drum blow down valves and all waterwall header drain valves for
approximately 30 seconds each.
2. Close nonreturn valves and stop valves at the main steam header. Open drain valves between the
closed valves to prevent leakage back from the main header.
3. Acid clean the boiler.
4. When the pressure reaches 10 psig (0.069 MPa), open the vent valves and the superheater outlet
drain valves.
5. Drain the boiler through all blow down and header drain valves.
6. When the pressure reaches atmospheric open all manholes in the lower waterwall header. Clean all
surfaces, removing sludge and deposits, by flushing.
7. Remove all water from the tubes and drums by blowing with dry air or nitrogen, by vacuuming or by
other suitable means. Holes may have to be drilled in nondrainable low spots. The holes will have
to be tagged to permit future repairs. Nondrainable superheaters are frequently drained in this
manner.
8. Place bags of desiccant (silica gel) inside each drum. Bags are suspended from distributor piping or
other suitable locations along the length of each drum.
9. Close boiler drums and all hand holes.
10. Purge the drums with dry nitrogen at a pressure of 5-10 psig (0.034-0.069 MPa) until the oxygen
content is 1% or less.
11. Maintain the drums under a positive nitrogen pressure of 5 psig (0.034 MPa) minimum. (Holes drilled
for drainage in generator or superheater sections will have to be plugged.)
12. Blank off all lines connected to the boiler.
13. Remove safety valves if possible and store indoors in a heated location. Blank openings with blanks
protected with Class IV (b) material. Clean safety valves that are welded in and coat them with Class
III material and cover loosely with a weather barrier.
14. Drain pressure gages, sight glasses; level alarm lines and blow-dry with nitrogen.
Boiler Fire Side—Dry Method
1. Operate all soot blowers several times to remove as much deposit and fly ash as possible. For the
last operating sequence start with the soot blower at the furnace and follow the flue gas path to the
blower nearest the stack. Air lances may be employed as well.
2. After the boiler has cooled to 140°F (60°C), wash down the boiler, economizer and air heater all on
the flue gas side. Perform the final washing from top to bottom finishing while the boiler is still warm.
3. Wash with neutral pH water and follow with a high pressure cleaning with water of pH 10.5 minimum.
4. Dry the boiler by a light refiring.
5. Coat all metal surfaces with Class VI material by spraying or fogging.
6. Place lime trays or silica gel in the fire box. Lime trays require raking once a month and replacement
after six months. Silica gel is replaced when it changes color.
7. Close all openings, sealing as necessary.
11-1
8. Cap the stack in such a manner that a positive draft is created but the ingress of rainwater is
prevented.
9. Reprime structural steel as necessary.
TURBINES
Turbines are protected in such a manner that vapors do not leak into the turbine or the condenser,
depending on the unit.
1. Clean all deposits from the system before shutdown using standard plant procedures.
2. Blank all steam lines leading to or connected to the turbine.
3. Drain the oil reservoir and clean it.
4. Fill the oil reservoir with Class VI oil-based fluid.
5. Circulate the Class VI fluid through the system with the auxiliary pump. Repeat monthly.
6. Drain and refill the oil reservoir with Class VI oil-based fluid every two years.
7. On the exchangers, disconnect all water lines and clean the units, flushing with fresh water.
8. Dry the exchangers with nitrogen.
9. Purge the exchangers with nitrogen to less than 1% oxygen.
10. Maintain the exchangers under a positive nitrogen pressure of 5-10 psig (0.034-0.069 MPa).
11. For outdoor installations with housings or shelters that can be sealed, seal door or other points of
entry.
12. Place Class VII tapes or emitters within the shelters or housing. Replace at two year maximum
intervals.
13. Fill the shaft couplings, as applicable, with Class IV (a) grease and wrap with VCI impregnated
waterproof paper.
14. Install a space heater if none is provided and keep it energized.
15. Coat any exposed machined surfaces with Class III material.
Motors and Generators Stored in Place
1. All motors less than 10 hp may be left without protection depending on replacement deliveries.
2. Blow open motors dry with nitrogen.
3. Continuously energize the heaters on all equipment fitted with them. Space heaters may be used to
maintain a temperature high enough to prevent condensation.
4. Drain oil-lubricated bearings and fill them with Class VI oil fluid. Rotate the shaft a minimum of 2 1/3
turns once a month.
5. Fill grease type bearings with Class IV (a) grease and rotate the shaft once a month.
6. Uncouple motors less than 50 hp and run them once a month for two hours.
7. On large motors, remove the brushes of commutators or collector rings, or lift them, so that wax-free,
greaseproof insulating paper may be placed under them to prevent etching.
8. If motor windings are accessible, apply a coat of insulating varnish.
9. Meg motors over 10 hp and generator winding insulation after one month in storage, then at six
month intervals after that using a 500 VDC megohmmeter. The minimum resistance should equal the
rated voltage/1000 + 1 megohms.
10. Coat exposed shafts with Class III material. Wrap the shafts of large or critical motors with
VCI-impregnated waterproof paper.
11. Pack exposed couplings with Class IV (a) grease and wrap with VCI-impregnated waterproof paper.
12. Erect shelters over large critical motors and generators.
Motors and Generators—Disassembled
1. Clean all exterior surfaces and blow-dry with air.
2. Disassemble the components.
3. Steam clean all components except those containing windings.
4. Clean windings with a suitable solvent.
5. Test the windings for shorts by megging and repair as necessary.
6. Apply a coat of insulation varnish to the windings.
7. Clean, check and replace bearings as necessary.
8. Reassemble motors or generators.
11-2
9. Coat all shafts with Class III material and wrap with VCI-impregnated waterproof paper.
10. Meg motors over 10 hp and generator winding insulation after one month in storage and then at six
month intervals using a 500 VDC megohmmeter. The minimum resistance should equal the rated
voltage/1000 + 1 megohms.
11. For horizontal equipment with sleeve bearings, shim the rotor symmetrically in the stator bore.
12. Reassemble the motor retaining the air gap shimming and omitting the upper bearing halves.
13. Coat all exposed surfaces with Class III material.
14. Cover loosely with plastic sheeting as dust protection.
For generators and critical motors for shutdowns to extend beyond three years, the following may be
necessary:
1. Remove the rotors, bearings, etc.
2. Clean the windings with a suitable solvent and steam clean the remaining components.
3. Apply a coat of insulation varnish to all windings.
4. Coat all exposed shafts and machined surfaces with Class III material and wrap with VCIimpregnated waterproof paper.
5. Store the components in an indoor heated location in wooden crates. Block the rotor to prevent
bowing or store it vertically.
PUMPS
Fire water and other critical pumps may continue in service and be maintained with normal operating
procedures. Protect pumps to be shut down as follows:
Centrifugal Pumps
1. Drain the casing and bearing housing. Neutralize as necessary.
2. Flush the casing and bearing housing and dry with air or nitrogen.
3. Disconnect and blank off the suction and discharge lines.
4. Fill lube and seal-oil systems with Class VI oil fluid.
5. Fill the pump casing with Class VI oil fluid and rotate the pump shaft to ensure complete oil coverage.
Pumps may be operated for ten minutes every month. Operate lubricating and seal-oil systems
during the ten minute running period and for five minutes before and after this period. Leave the
pump drain connections open during any operating period.
6. Plug the bearing housing drains and fill the housing with Class VI oil fluid. Close all vents.
7. Coat the exposed shafts and other machined surfaces with Class III material and cover with Class
VIII tape.
8. Fill the shaft couplings with Class IV (a) grease, as applicable.
Reciprocating Pumps
1. Open all vents and drains on both ends of the pump.
2. Break all pipe connections and blank off all suction and discharge lines.
3. Fill both sides of the pump with Class VI oil fluid. Valve removal is used to permit filling.
4. Move pistons back and forth to ensure complete oil coverage.
5. Drain the oil from the system and seal all openings.
6. Coat all valves and valve covers with Class III material.
7. Coat exposed rods and other machined surfaces with Class III material and wrap with Class VIM
tape.
8. Fill lube and seal-oil systems with Class VI oil fluid.
9. Erect weatherproof structures over critical outdoor installations.
FANS
1. Protect fan drive motors as outlined previously in this section.
2. Drain the oil from the gear reducer and refill it with Class VI oil fluid.
3. Clean the exterior of the gear reducer housing and reprime it as necessary.
11-3
4. Coat exposed portions of shafts with Class III material. On critical equipment, wrap the coated shafts
with VCI-impregnated waterproof paper.
5. Clean fan blades and coat with Class III material.
6. Clean the internal and external surfaces of the fan housing and coat with Class III material.
7. Drain and flush the bearings with Class VI oil fluid.
8. Secure fan blades to prevent rotation.
9. Drain the water jackets of water-cooled bearings and then flush them with Class VI water-based
material, drain, blow-dry and seal.
Induced Draft Fans
1. Remove all fly ash from the casing and ducts.
2. Blank the duct at the stack.
3. Drain the gearboxes and oil systems. Clean the systems and fill with Class VI oil fluid.
4. Clean couplings and coat them with Class VI or Class IV (a) material, depending on the type of
coupling.
5. Clean the fan blades and coat with Class III material.
6. Coat casing and ducts with Class VI oil fluid or Class VII material by spraying or fogging.
7. Secure blades to prevent rotation.
PIPING
In general steam headers are protected like boiler drums with an inert atmosphere. However, some
operators prefer to treat headers as piping and protect them accordingly.
1. Drain and flush all piping. Holes may be drilled in hard-to-drain areas but be sure to tag the holes for
future repairs.
2. Dry all lines. Air may be used on noncritical lines; nitrogen is recommended for critical installations.
3. Purge steam headers and critical lines with nitrogen until less than 1% oxygen is reached at all
sampling points.
4. Maintain the headers and critical lines under a positive nitrogen pressure of 5-10 psig (0.034-0.069
MPa).
5. For outdoor installations, steam lines and other critical lines, open the flanges and clean the flange
faces. Coat the flange faces out to the edges with Class III material and reassemble.
6. Cover gaps between flanges with Class VIII tape.
7. Coat carbon steel and low alloy steel bolts and nuts with Class III material. Austenitic stainless steel
bolts are coated in marine or heavy industrial environments.
8. Noncritical lines, after being flushed and blown dry, are sealed to prevent the ingress of moisture.
Seal the gap between flange faces with Class VIII tape and coat bolting with Class III material.
9. Inspect insulation. Remove wet insulation and seal the gaps. Reinstall the insulation at start-up.
DEAERATORS, AIR RECEIVERS, INERT GAS TANKS AND OTHER PRESSURE VESSELS
1. Blank all inlet and outlet lines.
2. Open the system and drain it, as applicable.
3. Flush to remove all sludges.
4. Dry with warm air or nitrogen.
5. Place bags of silica gel in such things as the deaerator and major receiver tanks.
6. Disassemble flanges, clean the flange faces and coat out to the edges with Class III material;
reassemble.
7. In outdoor environments, cover the gap between flanges with Class VIII tape.
8. Purge the deaerator with nitrogen and maintain a positive pressure of 5-10 psig (0.034-0.069 MPa).
9. Insert Class VII crystals, tapes or emitters in all other vessels and seal all openings.
10. Inspect and repair insulation on outdoor vessels.
11. On outdoor installations, remove safety valves and blank openings. Store valves in a heated
building.
12. Coat bolts and nuts with Class III material.
11-4
TANKS
1. Clean chemical tanks, neutralize them as applicable, and dry them with warm air or nitrogen.
2. Touch up interior primers as necessary.
3. Protect critical tanks by inserting Class VII material (for metallic tanks) and sealing all openings.
Tanks of fiber glass or other noncorroding materials may be drained, neutralized, flushed clean,
dried and left open.
4. Large outdoor tanks may require ballast to prevent wind damage. Partially fill tanks with inhibited
water at pH 8.5-9.5. A nitrogen purge may be used in conjunction with the water to prevent corrosion
in the vapor space. In cold climates a suitably inhibited antifreeze may be necessary.
5. Cover all gaps at flanges or other openings with Class VIII tape.
6. Touch up exterior primers as necessary.
HEAT EXCHANGERS, CONDENSERS, EJECTORS, CHILLERS, ETC.
The normal washing, chemical cleaning, mechanical cleaning or neutralizing procedures that would be
followed during a routine shutdown should be utilized.
1. Flush, drain and neutralize, as applicable.
2. Remove bundles (floating head installations) and thoroughly clean all components. Remove sludge,
deposits and all other debris.
3. Thoroughly dry all components with warm air.
4. Clean all flange faces and coat them out to the edges with Class III material. Seal all gaps between
flanges with Class VIII tape.
5. Reinstall bundles and purge the exchangers with nitrogen. Maintain exchangers under a positive
pressure of 5-10 psig (0.034-0.069 MPa) nitrogen.
6. For fixed tube bundles, open heads, clean tubes, channels and heads.
7. Flush shell side and dry with warm air or nitrogen.
8. Reassemble and purge with nitrogen. Maintain under a positive nitrogen pressure of 5-10 psig
(0.034-0.069 MPa).
9. Coat flange faces out to the edges with Class III material.
10. Cover all gaps between flanges with Class VIII tape.
11. Coat all bolts, nuts, drain valves, sample valves, etc. with Class III material.
12. Remove wet insulation, clean and reprime shells as necessary. Seal edges of remaining insulation
and replace insulation at start-up.
13. Touch up primers as necessary and coat anchor bolts with Class III material.
SWITCHGEAR, CIRCUIT BREAKERS, CONTROL CABINETS, RELAY CABINETS, ETC.
1. Continuously energize the heaters of all components so equipped.
2. Suspend bags of silica gel in each section of the cabinets.
3. Install Class VII crystals, tapes or emitters in each section of the cabinets.
4. Cover cabinets with loose plastic or tarpaulins to keep out dirt. Leave a minimum of a two inch (5 cm)
gap between the floor and the bottom of the plastic sheets to prevent condensation.
5. Leave breakers and starters in the open position.
CONVEYORS, HOPPERS AND OTHER HANDLING EQUIPMENT
1. Clean all elements to remove dust, dirt and other debris.
2. Grease rollers and other drive mechanism components with Class IV (a) material.
3. Reprime surfaces as necessary.
4. Drill holes in low areas to prevent standing water. Tag for future repair.
5. Spray the inside of hoppers, etc. with Class II oil.
6. Coat bolts and nuts with Class III material.
SOFTENERS, ION EXCHANGE COLUMNS, ETC.
1. Drain softeners and columns.
11-5
or -
2. Regenerate resins or exchange media as applicable.
3. Dry with nitrogen.
4. Purge with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069 MPa), if the
vessels are able to withstand that pressure, otherwise replace air with nitrogen.
1. Remove dried resins or exchange media.
2. Purge vessels with nitrogen and maintain under a positive pressure of 5-10 psig (0.034-0.069 MPa).
11-6
SECTION 12
POWER PLANTS OVER 60 MONTHS
The long-term protection methods for a power plant are very similar to those established for process units
and involve the complete removal of water to prevent corrosion and/or freezing. Wet storage methods are not
recommended for boilers or other equipment as it is unlikely that a quick return to service will be necessary.
BOILERS
Drain and dry boilers completely for protection periods extending beyond eighteen months. Costs
associated with wet storage and the potential for corrosion increase dramatically with the length of the idle
period.
Boiler Water Side—Dry Method
1. After the fires are extinguished and the pressure has dropped to one-half operating pressure or 25
psi (0.17 MPa) minimum, depending on the system, blow down the water column, water glass,
continuous blow down, lower drum blow down valves and all waterwall header drain valves for
approximately 30 seconds each.
2. Close nonreturn valves and stop valves at the main steam header. Open drain valves between the
closed valves to prevent leakage back from the main header.
3. Acid clean the boiler.
4. When the pressure reaches 10 psig (0.069 MPa), open the vent valves and the superheater outlet
drain valves.
5. Drain the boiler through all blow down and header drain valves.
6. When the pressure reaches atmospheric, open all manholes and the hand holes in the lower
waterwall header. Clean all surfaces, removing sludge and deposits, by flushing.
7. Remove all water from the tubes and drums by blowing with dry air or nitrogen, by vacuuming or by
other suitable means. Holes may have to be drilled in nondrainable low spots. Tag these holes to
permit future repairs. Nondrainable superheaters are frequently drained in this manner.
8. Place bags of desiccant (silica gel) inside each drum. Bags are suspended from distributor piping or
other suitable locations along the length of each drum.
9. Close boiler drums and all hand holes.
10. Purge the drums with dry nitrogen at a pressure of 5-10 psig (0.034-0.069 MPa) until the oxygen
content is 1% or less.
11. Maintain the drums under a positive nitrogen pressure of 5 psig (0.034 MPa) minimum. (Holes drilled
for drainage in generator or superheater sections will have to be plugged.)
12. Blank off all lines connected to the boiler.
13. Remove safety valves if possible and store indoors in a heated location. Blank openings with blanks
protected with Class IV (b) material. Clean safety valves that are welded in, coating them with Class
IV (b) material and covering loosely with a weather barrier.
14. Drain pressure gages, sight glasses and level alarm lines and blow-dry with nitrogen.
Boiler Fire Side—Dry Method
1. Operate all soot blowers several times to remove as much deposit and fly ash as possible. Start the
last operating sequence with the soot blower at the furnace and follow the flue gas path to the blower
nearest the stack. Air lances may be employed as well.
2. After the boiler has cooled to 140°F (60°C), wash down the boiler, economizer, and air heater on the
flue gas side. Carry out the final washing from top to bottom completing it while the boiler is still
warm.
3. Wash with a neutral pH water and follow with a high pressure cleaning with water of pH 10.5
minimum.
4. Dry the boiler with a light refiring.
5. Coat all metal surfaces with Class VI material by spraying or fogging.
6. Place lime trays or silica gel in the fire box. Lime trays require raking once a month and replacement
after six months. Silica gel is replaced when it changes color.
7. Close all openings, sealing as necessary.
12-1
8. Cap the stack in such a manner that a positive draft is created but the ingress of rainwater is
prevented.
9. Reprime structural steel as necessary.
TURBINES
Turbines are protected in such a manner that vapors do not leak into the turbine or the condenser,
depending on the unit.
1. Clean all deposits from the system before shutdown using standard plant procedures.
2. Blank all steam lines leading to or connected to the turbine.
3. Drain the oil reservoir and clean it.
4. Fill the oil reservoir with Class VI oil fluid.
5. Circulate the Class VI fluid through the system with the auxiliary pump. Repeat monthly.
6. Drain and refill the oil reservoir with Class VI oil fluid every two years.
7. On the exchangers, disconnect all water lines and clean the units, flushing with fresh water.
8. Dry the exchangers with nitrogen.
9. Purge the exchangers with nitrogen to less than 1% oxygen.
10. Maintain the exchangers under a positive nitrogen pressure of 5-10 psig (0.034-0.069 MPa).
11. For outdoor installations with housings or shelters that can be sealed, seal the doors and other points
of entry.
12. Place Class VII tapes or emitters within the shelters or housing. Replace at two year maximum
intervals.
13. Fill the shaft couplings, as applicable, with Class IV (a) grease and wrap with VCI-impregnated
waterproof paper.
14. Install a space heater if none is provided and keep it energized.
15. Coat any exposed machined surfaces with Class IV (b) material.
Motors and Generators Stored in Place
1. All motors less than 10 hp may be left without protection depending on replacement deliveries.
2. Blow open motors dry with nitrogen.
3. For all equipment with heaters, energize the heaters continuously. Space heaters may be used to
maintain a temperature high enough to prevent condensation.
4. Drain oil-lubricated bearings and fill with Class VI oil fluid. Rotate the shaft a minimum of 2 1/3 turns
once a month.
5. Fill grease type bearings with Class IV (b) grease and rotate the shaft once a month.
6. Uncouple motors less than 50 hp and run them once a month for two hours.
7. On large motors, the brushes of commutator or collector rings are removed or lifted so that wax-free,
greaseproof insulating paper may be placed under them to prevent etching.
8. If motor windings are accessible, apply a coat of insulating varnish.
9. Meg motors over 10 hp and generator winding insulation after one month in storage and then at six
month intervals after that using a 500 VDC megohmmeter. The minimum resistance should equal the
rated voltage/1000 + 1 megohms.
10. Coat exposed shafts with Class IV (b) material. Wrap the shafts of large or critical motors with
VCI-impregnated waterproof paper.
11. Exposed couplings are packed with Class IV (a) grease and wrapped with VCI-impregnated
waterproof paper.
12. Erect shelters over large, critical motors and generators.
Motors and Generators—Disassembled
1. Clean all exterior surfaces and blow-dry with air.
2. Disassemble the components.
3. Steam clean all components except those containing windings.
4. Clean windings with a suitable solvent.
5. Test the windings for shorts by megging and repair as necessary.
6. Apply a coat of insulation varnish to the windings.
7. Clean, check and replace bearings as necessary.
12-2
8. Reassemble motors or generators.
9. Coat all shafts with Class IV (b) material and wrap with VCI-impregnated waterproof paper.
10. Meg motors over 10 hp and generator winding insulation after one month in storage and then at six
month intervals using a 500 VDC megohmmeter. The minimum resistance should equal the rated
voltage/1000 + 1 megohms.
For horizontal equipment with sleeve bearings:
11. Shim the rotor symmetrically in the stator bore.
12. Reassemble the motor retaining the air gap shimming and omitting the upper bearing halves.
13. Coat all exposed surfaces with Class IV (b) material.
14. Cover loosely with plastic sheeting as dust protection.
For generators and critical motors the following may be necessary.
1. Remove the rotors, bearings, etc.
2. Clean the windings with a suitable solvent and steam clean the remaining components.
3. Apply a coat of insulation varnish to all windings.
4. Coat all exposed shafts or machined surfaces with Class IV (b) material and wrap with VCIimpregnated waterproof paper.
5. Store the components in an indoor heated location in wooden crates. Block the rotor to prevent
bowing or store it vertically.
PUMPS
Fire water and other critical pumps may continue in service and be maintained with normal operating
procedures. Protect pumps to be shut down as follows:
Centrifugal Pumps
1. Drain the casing and bearing housing. Neutralize as necessary.
2. Flush the casing and bearing housing and dry with air or nitrogen.
3. Disconnect and blank off the suction and discharge lines.
4. Fill the lube and seal-oil system with Class VI oil fluid.
5. Fill the pump casing with Class VI oil fluid, and rotate the pump shaft to ensure complete oil
coverage. Pumps may be operated for ten minutes every month. Operate lubricating and seal-oil
systems during this ten minute period and for five minutes before and after operation. Keep the pump
drain connections open during any operating period.
6. Plug the bearing housing drains and fill the housing with Class VI oil fluid. Close all vents.
7. Coat the exposed shafts and other machined surfaces with the Class VIII system.
8. Fill the shaft couplings with Class IV (a) grease as applicable.
Reciprocating Pumps
1. Open all vents and drains on both ends of the pump.
2. Break all pipe connections and blank off all suction and discharge lines.
3. Fill both sides of the pump with Class VI oil fluid. Valve removal is used to permit filling.
4. Move pistons back and forth to ensure complete oil coverage.
5. Drain the oil from the system and seal all openings.
6. Coat all valves and valve covers with Class IV (b) material.
7. Coat exposed rods and other machined surfaces with the Class VIII system.
8. Fill lube and seal-oil systems with Class VI oil fluid.
9. Erect weatherproof structures over critical outdoor installations.
FANS
1. Protect fan drive motors as outlined previously in this section.
2. Drain the oil from the gear reducer and refill it with Class VI oil fluid.
3. Clean the exterior of the gear reducer housing and reprime it, as necessary.
12-3
4. Coat exposed portions of shafts with Class IV (b) material. For critical equipment, wrap the coated
shafts with VCI-impregnated waterproof paper.
5. Clean fan blades and coat metallic blades with Class IV (b) material.
6. Clean the internal and external surfaces of the fan housing and coat with Class IV (b) material.
7. Drain and flush the bearings with Class VI oil fluid.
8. Secure fan blades to prevent rotation.
9. Drain the water jackets of water-cooled bearings and then flush them with Class VI water-based
material. Blow them dry.
10. Flush water lines and disconnect them at the header. Flush the header with Class VI water-based
material; drain, blow-dry and seal.
Induced Draft Fans
1. Remove all fly ash from the casing and ducts.
2. Blank the duct at the stack.
3. Drain the gearboxes and oil systems. Clean the systems and fill with Class VI oil fluid.
4. Clean couplings and coat them with Class VI or Class IV (a) material, depending on the type of
coupling.
5. Clean the fan blades and coat with Class IV (b) material.
6. Coat casing and ducts with Class VI oil fluid or Class VII material by spraying or fogging.
7. Secure blades to prevent rotation.
PIPING
In general steam headers are protected with an inert atmosphere similar to boiler drums. However, some
operators prefer to treat headers as piping and protect accordingly.
1. Drain and flush all piping. Holes may be drilled in hard-to-drain areas; tag them for future repairs.
2. Dry all lines. Air may be used on noncritical lines; nitrogen is recommended for critical installations.
3. Purge steam headers and critical lines with nitrogen until less than 1% oxygen is reached at all
sampling points.
4. Maintain the headers and critical lines under a positive nitrogen pressure of 5-10 psig (0.034-0.069
MPa).
5. For outdoor installations, steam lines and other critical lines, open the flanges and clean the flange
faces. Coat the flange faces out to the edges with Class VIM material, then reassemble.
6. Cover gaps between flanges with Class VIII tape.
7. Coat all carbon steel and low alloy steel bolts and nuts with Class IV (b) material. Coat austenitic
stainless steel bolts in marine or heavy industrial environments.
8. Noncritical lines, after being flushed and blown dry, are sealed to prevent the ingress of moisture.
Seal the gap between flange faces with Class VIII tape and coat bolting with Class IV (b) material.
9. Inspect insulation. Remove wet insulation and seal the gaps. Reinsulate at start-up. On critical lines
and headers located outdoors remove the insulation and paint the steel.
DEAERATORS, AIR RECEIVERS, INERT GAS TANKS AND OTHER PRESSURE VESSELS
1. Blank all inlet and outlet lines.
2. Open the system and drain it, as applicable.
3. Flush to remove all sludges.
4. Dry with warm air or nitrogen.
5. Place bags of silica gel in such items as the deaerator and major receiver tanks.
6. Disassemble flanges; clean the flange faces and coat out to the edges with Class VIII material;
reassemble.
7. In outdoor environments, cover gaps between flanges with Class VIII tape.
8. Purge the deaerator with nitrogen and maintain a positive pressure of 5-10 psig (0.034-0.069 MPa).
9. Insert Class VII crystals, tapes, or emitters in all other vessels and seal all openings.
10. Inspect and repair insulation on outdoor vessels.
11. On outdoor installations, remove safety valves and blank openings. Store valves in a heated
building.
12. Coat bolts and nuts with Class IV (b) material.
12-4
TANKS
1. Clean chemical tanks; neutralize as applicable, and dry them with warm air or nitrogen.
2. Touch up interior primers as necessary.
3. Protect critical tanks by inserting Class VII material (for metallic tanks) and seal all openings. Tanks
of fiber glass or other noncorroding materials are drained, neutralized, flushed clean, dried and left
open.
4. Large outdoor tanks may require ballast to prevent wind damage. Partially fill tanks with inhibited
water of pH 8.5-9.5. A nitrogen purge may be used in conjunction with the water to prevent corrosion
in the vapor space. In cold climates, a suitable antifreeze is added to the water ballast.
5. Cover all gaps at flanges or other openings with Class VIII tape.
6. Touch up exterior primers as necessary.
HEAT EXCHANGERS, CONDENSERS, EJECTORS, CHILLERS, ETC.
The normal washing, chemical cleaning, mechanical cleaning or neutralizing procedure that would be
followed during a routine shutdown is utilized.
1. Flush, drain and neutralize, as applicable.
2. Remove bundles (floating head installations) and thoroughly clean all components. Remove sludge,
deposits and all other debris.
3. Thoroughly dry all components with warm air.
4. Clean all flange faces and coat them out to the edges with Class VIII material. Seal all gaps between
flanges with Class VIII tape.
5. Reinstall bundles and purge the exchangers with nitrogen. Maintain exchangers under a positive
pressure of 5-10 psig (0.034-0.069 MPa) nitrogen.
6. For fixed tube bundles, open heads, clean tubes, channels and heads.
7. Flush shell side and dry with warm air or nitrogen.
8. Reassemble and purge with nitrogen. Maintain under a positive nitrogen pressure of 5-10 psig
(0.034-0.069 MPa).
9. Coat flange faces out to the edges with Class VIII material.
10. Cover all gaps between flanges with Class VIII tape.
11. Coat all bolts, nuts, drain valves, sample valves, etc. with Class IV (b) material.
12. Remove wet insulation; clean and reprime shell as necessary. Seal edges of remaining insulation
and replace removed insulation only at start-up.
13. Touch up primers as necessary and coat anchor bolts with Class IV (b) material.
SWITCHGEAR, CIRCUIT BREAKERS, CONTROL CABINETS, RELAY CABINETS, ETC.
1. For all equipment with heaters energize the heaters continuously.
2. Suspend bags of silica gel in each section of the cabinets.
3. Install Class VII crystals, tapes, or emitters in each section of the cabinets.
4. Cover cabinets with loose plastic sheets or tarpaulins to keep out dirt. Leave a gap, a minimum of
two inches (5 cm), between the floor and the bottom of the plastic sheets to prevent condensation.
5. Leave breakers and starters in the open position.
CONVEYORS, HOPPERS AND OTHER HANDLING EQUIPMENT
1. Clean all elements to remove dust, dirt and other debris.
2. Grease rollers and other drive mechanism components with Class IV (a) material.
3. Reprime surfaces as necessary.
4. Drill holes in low areas to prevent standing water. Tag holes for future repair.
5. Spray the inside of hoppers, etc. with Class VI oil fluid.
6. Coat bolts and nuts with Class IV (b) material.
SOFTENERS, ION EXCHANGE COLUMNS
1. Remove resins or softening media.
12-5
or -
2. Recharge the resins or softening media, as applicable, and store indoors in a heated location.
3. Flush softeners and ion exchange columns with fresh water.
4. Dry vessels with air or nitrogen.
5. Fog the inside of the softeners or exchange columns with Class VII material and seal all openings,
1. Purge vessels with nitrogen and maintain under a positive nitrogen pressure of 5-10 psig
(0.034-0.069 MPa). (Vessels must be able to withstand this pressure.)
2. Seal flange gaps with Class VIII tape.
3. Touch up primers as necessary.
12-6
SECTION 13
INSPECTION AND MAINTENANCE
The inspection and maintenance of a mothballed plant involve periodic examination of all equipment and
repairs as necessary.
MANPOWER
Manpower requirements for both inspection and maintenance will vary according to plant size and
complexity. In general, at least one person is employed full time for inspection with additional help provided
as workload and/or problems dictate.
Ideally, personnel who will be inspecting the mothballed plant will monitor the application of all
preservatives during the mothballing phase so they can become familiar with the products and their
application. Similarly, maintenance personnel will participate in the mothball operation to gain experience in
the repair techniques required to keep the protection in good condition.
Maintenance generally involves at least three trades: a millwright, an electrician and a painter. Other
personnel may be required depending on the volume of work and local labor requirements. Boilermakers and
a welder may be required to open vessels and make repairs.
INSPECTION
Inspection of a mothballed plant is conducted on a regular schedule to detect changes in the protection
applied. These changes may include the loss of inert gas, paint damage, wet insulation and other signs that
corrosion may be taking place.
Most inspections entail a visual examination to detect deterioration. However, nondestructive evaluation
techniques, most commonly ultrasonic thickness measurements, can be used to augment the visual
examination.
Inspection Equipment
Inspection equipment frequently used in mothballed plants includes the following:
1. micrometers
2. pit gage
3. mirrors
4. hand lenses
5. ultrasonic thickness gage
6. soap solution or an ultrasonic leak detector
7. holiday detector
8. scraper
9. camera
In addition, boroscopes, fiberscopes, radiography, and eddy current instruments may be used to assess
the condition of critical equipment should the need arise.
Inert Gas (Nitrogen) Blankets
All pressure gages are monitored on a weekly basis for the first month to verify that leaks have not
developed. If the inert gas pressure falls below 5 psig (0.034 MPa), inert gas is added to bring the pressure
above this level. If the pressure is consistently low, leak checks with soap solution are performed until the leak
is located and repaired.
After four consecutive weekly inspections confirming that the gas pressure is above 5 psig (0.034 MPa)
and no leaks have occurred, the inspection frequency may be changed to monthly. On critical equipment,
inspection at two week intervals throughout the shutdown period may be advisable.
Sealed Equipment
Equipment that has been sealed and contains desiccant (silica gel) and/or VCI is examined once a month
13-1
to ensure that the sealing is intact. If signs of moisture are found the equipment is opened, dried out, and
reprotected.
Plastic sheeting draped over electrical panels, switchgear, control consoles, etc. is examined once a
month for moisture collecting under them. Sheets showing moisture are removed to promote drying; the
cabinets are opened and then the protection is reapplied.
Desiccants
Equipment with desiccant in visible reservoirs is checked once a month. Silica gel that has changed color
or lime that has formed lumps would be replaced.
As well, sealed equipment containing desiccant is checked once a month to ensure integrity of the seal.
If the seal is broken, the equipment would be opened, the desiccant replaced and the protection reapplied.
Structural Steel and Other Primed Equipment
All painted steel is inspected once a month in warm climates or twice a year in temperate climates. Paint
breakthrough should be repaired, probably by hand cleaning and reapplication of the paint. Anchor bolts,
caulked joints, concrete bases, etc. are inspected yearly.
Gears, Fans, Couplings, etc.
These items are inspected at one month intervals. Any loss of grease is recorded and the protection
restored.
Bolts, Nuts, Flanges
These items are examined once a month in warm climates and quarterly in temperate climates to ensure
that the protection is intact. Large diameter flanges on critical equipment should be inspected once a month
regardless of climate.
Pumps, Motors, Turbines and Other Rotating Equipment
Equipment containing heaters is checked once a week to ensure that the heaters are energized. After
four consecutive periods showing continuous operation, the inspection period may be increased to once a
month.
Turning of rotors is witnessed on a sampling basis. Each new rotor position is marked to ensure that it
is moved the next time. Critical items such as turbines, generators and large pumps are monitored on each
maintenance operation.
Storage Yards
Storage yards are inspected at three month intervals to ensure that the equipment is in good condition
and is draining properly.
Warehouse
Components stored in warehouses are examined, on a sampling basis, at six month intervals. If damage
is found, a complete visual inspection takes place to identify the source of the problem.
Towers, Drums, Spheres, Bullets and Other Pressure Vessels
A visual inspection is made on the exterior of these items monthly for the first three months under
mothball conditions. If no problems are noted, only critical items need be inspected monthly, the remainder
at three month intervals. Inert gas pressure, if applicable, is monitored weekly until it has been determined
13-2
that no leaks exist [four consecutive weeks with the pressure above 5 psig (0.034 MPa)]. Monthly intervals
may then be used.
Flange protection is inspected at three month intervals.
Insulation is inspected at three month intervals.
For protection periods extending beyond three years, one vessel of each type (tower, sphere, bullet, etc.)
is opened and given a complete internal inspection after three years' shutdown. If problems are found,
additional equipment would be inspected. If no problems are found, the same vessel and an additional one
would be opened and inspected internally after five years' shutdown. If no problems are found an internal
inspection is made on the same two vessels at subsequent five year intervals.
For shutdowns extending beyond twelve months, ultrasonic thickness measurements are made yearly at
selected locations on all vessels. Windows may be cut in insulation to facilitate the testing. Testing locations
are chosen to reflect areas that might experience condensation and corrosion.
CAUTION: All windows cut in the insulation must be sealed after each test period.
Heat Exchangers, Condensers, Ejectors, etc.
An external inspection of equipment is made monthly for the first three months. If no problems are noted,
only critical items are inspected monthly; the remainder are inspected at three month intervals.
If inert gas is used, pressure gages are monitored weekly until four consecutive periods reveal no
pressure loss. The inspection frequency is then increased to monthly.
Flange protection is inspected at three month intervals.
Insulation is inspected at three month intervals, as well.
For protection periods extending beyond three years, one exchanger of each type is opened after three
years for a complete internal inspection. With floating head construction, the bundle would be removed from
the shell for inspection. Tubes are examined for pitting, particularly under baffles. If problems are found,
additional exchangers are inspected. If no problems are found, the same exchanger is inspected at three
year intervals.
For fixed tube bundles, a fiberscope may be used on the shell side as well as in the tubes to detect
possible damage.
Boilers, Furnaces, Heaters
Any components with inert gas are monitored weekly until four consecutive inspections reveal no loss of
pressure. The inspection interval may then be increased to monthly.
Boiler drums are opened to permit an internal inspection once a year (assuming dry shutdown).
Desiccant may be replaced at this time.
Refractory is inspected to detect corrosion on the underlying steel. Such features as bulges, cracks, rust
spots or damp spots are indications of possible damage.
The protection on the boiler and/or furnace tubes is inspected yearly and reapplied as necessary.
Ultrasonic thickness readings are performed on tubes, particularly in low spots or at bends where moisture
might accumulate. A sampling technique is used to select the tubes to be tested: 10-20% of carbon and low
alloy steel tubes are tested but 1-5% of high alloy materials.
Desiccant in fire boxes is inspected once a month for the first three months and then quarterly thereafter
if no problems are noted.
Tanks
Large storage tanks are inspected quarterly to ensure that drainage occurs and that corrosion is not
taking place. Ultrasonic thickness monitoring of selected locations is performed yearly. After three years'
shutdown, large storage tanks are inspected internally then and at three year intervals thereafter.
Piping
Piping is inspected at six month intervals unless it is used to maintain an inert atmosphere on other
equipment. Under these circumstances, monthly inspection is advisable.
For above ground piping, ultrasonic thickness measurements are performed yearly on representative
13-3
areas. Readings are taken around the entire pipe circumference. Monitoring points are selected in areas that
may be hard to drain and where condensation might occur.
Flanges and bolting protection are monitored at three month intervals.
Insulation on piping is inspected at three month intervals.
Cathodic protection systems on buried piping are monitored according to normal plant procedures. If
applicable, inert gas pressure is monitored monthly.
Special Situations
It is advisable to examine all equipment—particularly large storage tanks and tall towers—after heavy
rain storms or after high winds. Erosion, particularly during dust storms, may damage corrosion protection.
It is advisable to remove standing water from equipment and buildings.
MAINTENANCE
Apart from general plant maintenance to ensure safe conditions, standard maintenance activities for a
shutdown plant include the following:
Pumps, Motors, Turbines, Generators and Other Rotating Equipment
Elements are rotated on a monthly basis at least 2 1/3 turns and heaters are maintained to ensure that
they are continuously energized.
Oil levels in reservoirs are checked and topped up as necessary. Lubrication systems are operated as
required, on a monthly basis.
Sealed Equipment
Periodic examination will ensure that the seals are intact. Equipment is opened for inspection and
replacement of the protection system as required.
Drainage
All drainage systems are inspected to ensure that they are functioning properly. Pits and trenches are
pumped out as needed.
Piping Systems
Inert gas systems are maintained and any leakage found is repaired.
Pipe supports and hangers are monitored with grease applied as necessary to prevent corrosion.
Insulation is maintained in good repair.
Electrical
The plant is properly lighted for safety.
Fire Water
Ensure that fire water systems and monitors are operational and in good repair. Fire water pumps are
tested monthly.
RECORDS
Records of all inspection and maintenance activities are maintained on forms such as those in Figures
13.1 and 13.2 to produce a complete history of all work and/or repairs.
13-4
FIGURE 13.1
Sample of a
Plant Protection Inspection Procedure Sheet
Description of Component
Part - Material
Actual Specified Protection Method/Compound
Exterior
Protection
Thick.
Mils
Interior
Protection
Thick.
Mils
ADDITIONAL PROTECTION REQUIREMENTS
Protection Appeared:
Recommendation Action:
Suitable
Not Suitable
Inspect Now
Review Protection
Prepared by:
Date:
Reviewed by:
Date:
Approved by:
Date:
Reprotect
13-5
FIGURE 13.2
Sample of a
Maintenance and Inspection Control Sheet
MAINTENANCE REQUIREMENTS
Description of
Component Part
Material
Interval,
Months
Maintenance
Activity
Rq.
Man
Hrs.
Interval,
Months
Inspection
Method
Acceptance/
Rejection Criteria
TOTAL MAN
HOURS PER UNIT
TOTAL MAN HOURS PER UNIT
MAINTENANCE:
SAFETY REQUIREMENTS:
INSPECTION:
COMMENTS BY:
Equipment
Requirements
13-6
COMPANY:
Rq.
Man
Hrs.
SECTION 14 RECOMMISSIONING A
MOTHBALLED PLANT
Recommissioning a plant that has been idle for an extended period either in a shutdown mode or
mothballed state can be complicated or relatively simple depending on the completeness and accuracy of the
records compiled during the idle period. If the plant has been inspected carefully on an ongoing basis, it is
probable that the equipment is in good condition. Conversely, if little inspection or maintenance has occurred,
the chances of starting the plant without extensive repairs and/or expense are poor.
INSPECTION
The first step in recommissioning a plant is a thorough inspection of all equipment both externally and
internally, relying on the inspection and maintenance history over the shutdown period to identify potential
problem areas. Care must be exercised in the inspection as many vessels will contain inert atmospheres.
The inspection is designed to gather certain information:
1. Verify the type of protection applied to vessels and the best method of removal.
2. Establish the condition of vessels, particularly the internal surfaces of pressure components,
identifying areas to be repaired. Nondestructive evaluation techniques such as ultrasonic thickness
measurements, ultrasonic flaw detection and radiography may be required to verify vessel condition.
3. Locate all holes drilled for drainage and ensure they are identified for repairs.
4. Identify all components that have been disassembled and locate all parts or items.
5. Identify areas requiring insulation repairs or reinsulation.
6. Identify all vessels and/or components requiring the removal of desiccants such as lime trays.
7. Identify components requiring the draining of oil, replacement of grease, etc.
8. Identify small piping that has to be replaced.
CAUTION: During the inspection phase, protection is removed from equipment. If the equipment is left
unprotected while the plant is being recommissioned, serious corrosion may result. Therefore, the inspection
is followed immediately by the application of at least short-term protection. Inert atmospheres are used
frequently at this stage to protect any equipment that can be sealed against leakage and can be maintained
at a low positive pressure.
Water used for hydrostatic testing can create serious corrosion problems if left in equipment and piping
while other sections of the plant are recommissioned. Therefore, remove all water after testing and
thoroughly dry the equipment.
At this time studs and nuts, particularly those in heat exchangers and large diameter piping, often corrode
to the point that they must be replaced. Frequent spraying with oil can prevent the deterioration.
PLANNING
A recommissioning manager is designated, particularly when more than one unit is involved. This
manager has total responsibility for the entire start-up, not just for one area.
Thorough planning, necessary to ensure a successful return to operation, commences well before the
actual recommissioning. Prior to the detailed inspection a rough recommissioning plan is established,
complete with a timetable for such steps as the isolation of equipment if sandblasting is necessary to remove
coatings. The results of the inspection are then used to complete the recommissioning plan.
Mobilization of personnel will be necessary if a plant has been mothballed for long periods. If lab^' !^ws
allow, operating personnel may be employed to recommission the plant. Allow time for the work force to
become familiar with the methods to remove preservatives.
Recommissioning follows a logical pattern through the plant or unit. Most often it follows the path of
process streams starting and/or fininshing at battery limits. Flow diagrams are a useful aid with various colors
identifying trades and work completed as a section is finished. Even more helpful are isometrics, particularly
if complicated piping systems are involved.
Care is exercised to ensure that interbattery facilities are recommissioned on time. This is an area
frequently overlooked as are utilities within battery limits and safety systems. Check lists established prior to
the start of work and verified by a "dry run" through the plant help to identify potential problems. It is advisable
that check lists be signed off by area supervisors, foremen or responsible trade-group leaders as each
function is completed. The information is then transferred to a master check list and to drawings maintained
by the recommissioning manager's staff.
14-1
RECOMMISSIONING
Recommissioning is relatively simple if one remembers that it is simply the reverse of the protection
procedure. Cleaning may be easier because there are no corrosive scales, sludges or deposits to be
removed. However, depending on the length of shutdown, there may be organic compounds to remove and
flush out of systems.
Plants that have been in an extended shutdown or in a short-term mothball mode may require very little
in the way of recommissioning as most short-term preservatives are compatible with operating conditions and
generally do not require removal other than by flushing. Plants shut down beyond twelve months usually
require a recommissioning program.
The following pages in this section give a general outline for recommissioning the various systems in a
plant.
WATER LINES
1. Repair any holes that have been drilled for drainage.
2. Remove valves over twenty-four inches in diameter that have been protected with Class III material
and remove the preservative. Reinstall valves.
3. Drain any fluids that have been put into valve cavities.
4. Remove Class VIII systems where applicable.
5. Reinsulate where necessary.
6. Hydrostatically test lines, repairing leaks and replacing bolts as necessary. Drain water from lines
and dry if delays in start-up are anticipated.
Piping, Valves and Fittings
1. Repair any holes that have been drilled for drainage.
2. Flush lines.
3. Clean Class III and Class IV (b) material off valve stems where applicable.
4. Drain all fluids from valve body cavities.
5. Remove and clean valves that have been coated internally with Class III material.
6. Remove Class III or Class VIII material from all flange faces. Bolting may be left coated if operating
c
temperatures are below 150°F (66°C). If above 150 F (66°C), remove the coating.
7. Hydrostatically test the lines, repairing leaks as necessary.
8. Drain water from lines and dry to prevent corrosion damage while the rest of the plant is
recommissioned.
Piping and Valves (Underground)
1. Flush lines.
2. Hydrostatically test lines and repair leaks as necessary.
3. Drain and dry lines following testing.
4. Test cathodic protection system and repair as necessary.
Austenitic Stainless Steel and Other High Alloys
1. Remove any flange gap coverings, tape and protection between flanges.
2. Flush lines with fresh water or compatible process fluids.
3. Hydrostatically test lines, repairing as necessary.
4. Drain and dry lines following testing.
FLARE SYSTEM
1. Remove Class III or Class VIII material on flanges.
2. Flush drums and lines.
3. Hydrostatically or pneumatically test system.
4. Remove stack cap.
14-2
5. Grease or replace guy wires on stack if applicable.
6. Replace safety valves if removed or remove valves for cleaning and testing, as applicable.
7. Fill water seal.
8. Purge system with nitrogen.
9. Reinsulate where necessary.
HEAT TRACING
1. Inspect all steam tracing lines, replacing material where necessary.
2. Replace any traps or unions removed for drainage.
3. Drain antifreeze and flush lines, repairing any leaks.
4. Connect system and flush lines, repairing any leaks.
5. Reconnect electrical tracing and test for shorts. Replace damaged sections as necessary.
PROCESS VESSELS AND TANKS
Stainless Steel and Nonferrous Alloys
1. Remove any flange protection that was applied.
2. Replace insulation as necessary.
3. Flush vessels and blow-dry with air or nitrogen.
4. Hydrostatically test critical vessels, then drain and dry them.
5. Replace safety valves that were removed or clean and test those left in place.
Carbon Steel
1. Remove all flange protection.
2. Remove all desiccants or other foreign substances.
3. Vessels protected internally with oil may require steam cleaning.
4. Flush vessels to remove any deposits (nitrogen protection tends to leave a very thin, fine rust film).
5. Replace safety valves or clean and test valves remaining in place.
6. Reprime steel as necessary and reinsulate where necessary.
7. Remove protection from bolting if operating temperature will be above 150°F (66°C).
8. Remove any blanks installed in lines.
9. Replace instrumentation such as temperature probes, level gages, etc.
10. Hydrostatically test vessels, then drain and dry them.
Reactors
1. Drain any preservation liquids, antifreeze, etc. from the reactor jackets, heating coils, etc., as
applicable.
2. Clean reactors to remove any dirt, rust, desiccant, etc.
3. Check catalyst supports to ensure there is no damage.
4. Install catalyst where applicable.
5. Remove all flange and bolt protection.
6. Replace safety valves or clean and test valves that remained in place.
7. Remove any blanks installed.
8. Hydrostatically or pneumatically test as applicable.
9. Replace insulation where applicable.
COOLERS AND EXCHANGERS
Cooling Towers
1. Clean any debris from the basin.
2. Replace any damaged or missing slats and tighten bolts
14-3
3. Close all valves.
4. Clean and reassemble fan drive motor, gear reducer, etc. replacing preservative oils and greases
with normal operating ones.
5. Remove protection on shafts.
6. Remove wrapping from the fan drive gear.
7. Remove the fan blade fastenings to permit rotation.
8. Fill the cooling basin.
9. Wet the wood and keep wet until operation is restored.
Spray Coolers
1. Remove the cover on the water troughs where applicable.
2. Clean troughs and the concrete basin.
3. Remove all blanks and blocks.
4. Flush all process and product lines.
5. Blow the lines dry.
Finned Air Coolers
1. Remove plugs and clean the tubes as per normal procedures, removing any oil that was added.
2. Clean Class III material from the plugs.
3. Blow fins clean with dry air.
4. Hydrostatically or pneumatically test, as applicable.
5. Reinstall fan drive motors after removing protection. Remove all preservation oils and replace with
operating fluids where necessary.
6. Remove wrappings from all shafts.
7. Remove the blade fastenings to permit rotation.
Plate Exchangers
1. Reassemble as necessary; replace rubber sealing rings as required.
2. Hydrostatically test if applicable.
Shell and Tube Exchangers
1. Remove all Class III, Class IV (b) or Class VIII material that has been applied to flanges.
2. Drain all oil or other fluids that may have been placed in shells or bundles.
3. Remove bundles from floating head assemblies and clean as required.
4. Flush fixed tube bundles, drain and blow-dry.
5. Remove any blanks that were installed and replace all gaskets.
6. Remove plugs, clean and reinstall.
7. Replace insulation as necessary.
8. Reinstall safety valves if removed.
9. Hydrostatically test units as required to detect leaks.
STORAGE TANKS
1. Drain all water that was used as ballast.
2. Examine and clean all roof drains as necessary.
3. Flush tanks that were coated internally with oil or other fluids.
4. Reinstall agitators, mixers, etc.
5. Test vacuum breakers to ensure proper operation.
6. Grease all pivots, pins, etc.
7. Remove any protection that was added to flanges.
8. Replace insulation as necessary.
14-4
ROTATING EQUIPMENT
1. Replace the filters on all pumps, mixers, compressors and other mechanical equipment.
2. Drain or remove all oil and grease and replace them, except for short-term storage in which the
normal operating materials have been used. Even then complete replacement might be considered
to prevent possible contamination.
Centrifugal Pumps
1. Drain and flush the casing and the bearing housing.
2. Remove all the blanks and reconnect lines.
3. Drain and flush the lubricating and seal-oil system.
4. Remove protection from shafts and other machined parts.
5. Drain fluids from lubricating and seal-oil systems.
6. Fill lubricating and seal oil systems with the proper operating fluids.
7. Reinstall valves that were removed during protection.
8. Run pump in.
Reciprocating Pumps
1. Drain all fluids from the system.
2. Remove blanks from all lines and reconnect the lines.
3. Remove preservatives from valves and valve covers.
4. Remove preservatives from rods and other machined surfaces.
5. Drain fluids from lubricators and seal-oil systems.
6. Fill lubricating and seal-oil systems with the proper operating fluids.
7. Replace valves that were removed during protection.
8. Run pump in.
Mechanical Seals and Packing
1. For single seals, remove the Class IV (a) grease.
2. Install the appropriate operating grease and retighten seal gland.
3. For double seals, unplug and drain the stuffing box or remove the grease, as applicable.
4. Flush the stuffing box ensuring that the pump is running properly.
5. Fill the stuffing box with the normal operating oil.
6. For conventional packing, remove the Class IV (a) grease from the stuffing box.
7. Remove storage packing and repack with the operating packing.
Bearings—All Equipment
1. Remove the Class IV (a) grease or the oils that have been used for protection.
2. Repack or refill the bearings with the normal operating grease or oil.
Drives
1. Drain gear cases and fill to operating level with the normal operating oil.
2. Remove all tape used for sealing.
3. Open gears, sprockets, screws and chain drives. Remove the Class IV materials and replace with
the regular operating greases.
4. On V-belt drives, remove the preservative grease from the sheaves. Inspect the belts and reinstall.
Couplings
1. Drain oil-filled couplings and remove grease from grease-filled couplings.
2. Refill couplings with normal operating oils and greases.
14-5
3. Remove any protective coverings.
Agitators, Centrifuges, Mixers
1. Remove all material placed in equipment.
2. Flush all systems or clean shafts, blades, etc.
3. Remove flange protection where applicable.
4. Remove bolting protection if operating temperature will be above 150T (66°C).
Hydraulic Systems, Lubricating Oil Systems and Oil Reservoirs
1. Drain all oil or fluids from the systems.
2. Replace all filters.
3. Flush all systems with normal operating fluids.
4. Replace filters after the flushing operation.
5. Refill system with normal operating fluids.
Centrifugal or Rotary Compressors
1. Remove preservatives from external, machined surfaces.
2. Drain fluids from casing if applicable.
3. Drain fluids from lubricating and seal-oil systems.
4. Replace all filters.
5. Flush casings and oil systems.
6. Replace all filters after the flushing operation.
7. If rotor, bearings, seals, etc. were removed, thoroughly clean them before reinstalling.
8. Remove all blanks.
9. Run compressor in as per the original operating instructions.
Reciprocating Compressors
1. Remove any short circuit piping installed.
2. Change any cooling system filters.
3. Drain and flush the cooling system.
4. Replace the cooling system filters.
5. Replace the lubricating and seal-oil filters.
6. Drain and flush the lubricating and seal-oil systems.
7. Replace the lubricating and seal-oil system filters.
8. Remove all protection applied to machined surfaces.
9. Remove materials placed in tanks and receivers.
10. Flush and dry all tanks and receivers.
11. Drain the crankcase and refill it with the normal operating oil.
12. If the compressor has been disassembled, remove protection from all piston rods, packing rings, oil
wiper rings, pistons and valves.
13. Reinstall all components.
14. Run in the compressor as per the original operating instructions.
Steam Turbines
1. Remove any material that might be in the steam spaces.
2. Remove all blanks and seals.
3. Remove bearing protection.
4. Remove grease from all mechanisms and gears and replace with the normal operating grease.
5. Remove all shaft coupling protection.
6. Remove space heater if applicable.
7. Remove dehumidification equipment.
8. Remove protection from machined surfaces.
14-6
9. Run in the turbine as per original operating instructions.
ELECTRICAL EQUIPMENT
In general, all ground systems and attachments are examined to ensure they are in good condition.
Motors
1. On motors over 50 hp, meg the windings to ensure they are in good condition.
2. Remove all auxiliary heaters.
3. Drain all bearings and fill with the normal operating oil or grease.
4. Replace commutator or collector ring brushes or remove paper as applicable.
5. Remove shaft protection.
6. For motors that have been shimmed, remove shims and assemble shafts in bearings.
7. Return vertical motors to operating levels.
Transformers
1. Check dielectric strength of oil. Replace if necessary.
2. Remove desiccants. Replace desiccants in transformers equipped with receptacles.
3. Remove auxiliary heaters.
4. Clean fans, coils, etc. and ensure fans are rotating freely.
Switchgear
1. Remove plastic film.
2. Remove desiccant.
3. Remove VCI crystals, tapes or emitters.
4. Test breakers and starters.
Batteries
1. Replace dry cells in emergency lighting.
2. Reconnect wet cells, recharging as necessary.
3. Reinstall rectifiers.
Control Devices and Instrumentation
Identify control devices needed for operation; locate them in storage and install them.
Pressure Relief Valves
1. Test all valves to ensure they are set properly.
2. Remove any oils or greases from springs.
3. Remove preservatives from flange faces.
4. Remove preservatives from valve cavities.
5. Install valves.
Temperature Gages
1. Remove plugs from couplings and clean preservative from coupling threads or flange faces as
applicable.
2. Reinstall gages in equipment.
3. Connect transmitters, elements, indicators and switches as applicable.
14-7
Liquid Level Gages
1. Examine gages that were left in place and replace as necessary.
2. Reinstall remote sensing devices as applicable.
Pressure and Differential Pressure Indicators and Switches 1.
Reinstall all equipment as applicable.
Control Valves
1. Remove all seating surface, valve bore, and flange face protection from the valve bodies.
2. Remove plugs, blanks or plastic wrapping as necessary.
3. Drain fluid from actuators, flush and fill with normal operating fluids.
4. Remove and clean the insides of valves left in the field.
5. Reinstall valves that have been removed from systems or removed for cleaning.
6. Test valves to ensure proper functioning.
Field Panels
1. Uncover the panels and open them.
2. Remove the bags of desiccant and VCI crystals, emitters or tapes.
3. Reinstall all switches and measuring instruments as applicable.
FIRED HEATERS AND FURNACES
1. Open fire box and remove lime trays.
2. Uncap stack ancUduct openings.
3. Remove all protection on burners and grease all moving parts.
4. Reinstall burners, flame scanners, etc. as applicable.
5. Remove all blanks and connect fuel and process lines.
6. Inspect brick work, repairing damage as necessary.
7. Inspect all tubing for signs of damage, particularly at supports or hangers. Repair any drilled holes.
8. Remove nitrogen from headers and tubes.
9. Warm brick by a light firing or by installing a space heater to drive off any accumulated moisture.
10. Cool heaters and inspect for damage, particularly near the base of the stack and in the duct
work.
11. Return heater to service.
DIESEL AND GASOLINE ENGINES
1. Remove all preservative compounds from flanges and other machined surfaces.
2. Drain the lubricating oil system, the oil filter housing and the lubricating pump housing.
3. Replace all lubricating filters.
4. Flush the lubricating system with the normal operating oil.
5. Change all lubricating filters.
6. Fill the lubrication system, oil filter housing and lubricating pump with the normal operating oil.
7. Drain the cooling system and change all filters.
8. Flush the cooling system with the normal operating fluids.
9. Change the cooling system filters.
10. Fill the cooling system with the normal operating fluids.
11. Reconnect all manifolds.
12. Drain the fuel system and replace the filters.
13. Flush the fuel system with the normal operating fuel.
14. Replace the fuel filters.
15. Check exhaust systems for blockage.
16. Tune the engine.
17. Lubricate all components as necessary.
14-8
18. Start engine as per the original operating procedures.
LINED TANKS
1. Remove all solutions, inert atmospheres and other preservatives.
2. Remove all preservatives, including isolating tape applied to flanges.
3. Remove lime trays or other desiccant as applicable.
4. Repair holes that were drilled for drainage by fitting threaded plugs.
5. Flush tanks and vessels to remove any salt residues, as applicable.
6. Reinstall agitators, mixers, etc.
7. Warm brick-lined vessels for several days with space heaters to drive off any moisture. Remove
heaters and place vessels in service.
8. Follow normal start-up procedures to prevent lining damage.
REFRIGERATION SYSTEM
1. Recommission exchangers, chillers and evaporators in the same manner as described in the section
on Coolers and Exchangers.
2. Recommission pumps, compressors or turbines in accordance with the Rotating Equipment section,
as applicable.
3. Remove any heaters from cold boxes.
4. Replace insulation as necessary.
5. Purge system with normal operating refrigerant to remove nitrogen.
6. Refill systems with water or other fluids as applicable.
7. Pressure systems to 5-10 psig (0.034-0.069 MPa) and examine for leakage.
8. Start up system as per normal operating procedures.
CONTROL ROOMS
1. Remove plastic covering on all equipment.
2. Reconnect power supply as applicable.
3. Remove desiccant and VCI protection as applicable.
4. Reactivate control panels and instrumentation according to normal operating procedures.
14-9
14-10
SECTION 15
BIBLIOGRAPHY
American Petroleum Institute, Guide for Inspection of Refinery Equipment. Third Edition, Washington,
DC, April 1982.
American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code. Sections VI and
VII, New York, NY.
Beecher, Jesse, Guidelines for Lay-Up of Boilers and Their Auxiliaries. 42nd Annual Meeting International Water Conference, Pittsburgh, PA, 1981.
Block, Heinz, "Protecting Idle Rotating Equipment Takes on New Urgency." Power, V130 (No. 5), May
1976, pp 51-52, 56-57.
Bly, Robert L, "Getting Mothballed Equipment Back to Work." Pit and Quarry, V76 (No. 4), October
1983, pp 76-78.
Braunton, P.N., Flatley, M.J., Longster, M.J., Middleton, W.R., and Streatfield, R.E., "New Results of the
CEGB in the Protection of Power Plants During Shutdown by Controlling the Influence of the Chemical
Environment." VCG Kraftwerkstechnik V60, (No. 1), January 1980, pp 47-52, translated by Sunlone Inc.
Bursik, A., "Possibilities for the Protection of Power Plant Units During Shutdown." VGB Kraftwerkstechnik V57 (No. 4), April 1977, pp 255-259, translated by Sunlone Inc.
Cocoon Holland, B.V., "Increasing the Effectiveness of the Lay-Up Option." Dredging and Port
Construction, V11 (No. 11), November 1982, p 15.
Defense Supply Agency, Departments of the Army, the Navy, and the Air Force, Preservation Packaging,
and Packing of Military Supplies and Equipment. December 1963.
Dinsmore, Oliver R., "Protection Problems Encountered in Storing Military Equipment." Materials
Performance V1 (No. 1), January 1962, pp 66-68, 70-73.
Donato, S., "Mothballing." Energy Processing Can., V77 (No. 2), November-December 1984, p 28.
Featherby, Sydney F., Holdup, Edwin D., Procedures Used in "Mothballing" Thunder Bay Generating
Station for Three Years. Canadian Electrical Association, Thermal and Nuclear Power Station Conference,
Montreal, Quebec, March 1969.
Garrison, William G., "Idled Refineries Require Safety Measures." Oil and Gas Journal, V79 (No. 49),
December 7, 1981, pp 128-130.
Hays, Robert L, Cain, Carl Jr., Proceedings of the American Power Conference. Volume 47, Illinois
Institute of Tech, Chicago, IL, 1985.
Hopkins, B.E., Villasmil, G., Mothballing of Refinery Process Equipment. CORROSION/87, Paper 192,
San Francisco, CA, March 1987.
Meyers, Gene A., Guidelines for Plant Mothballing. 46th Mid Year Refining Meeting, API Operating
Practices Subcommittee on Facilities and Maintenance, Chicago, IL, May 1981.
Miksic, B.A., Inhibited Polymeric Coatings Basic Principles and Future Perspectives. CORROSION/76,
Paper 70, Houston, TX, March 1976.
Ministry of Defence, Defence Guide DG-8, Treatments for the Protection of Metal Parts of Service Stores
and Equipment Against Corrosion. London, April 1963.
Parker, W.D., Yeigh, W.H., "Petrolatum Coated Tapes for Marine Use." Materials Protection and
Performance, V11 (No. 11), November 1972, pp 31-33.
Parker, W.D., "Petrolatum Coated Tapes." Fluid Handling, (No. 158), March 1963, pp 68-73.
Probst, Wolfgang, Shannon, James E., Protecting Cooling Circuits During Plant Mothballing Operations.
CORROSION/85, Paper 162, Boston, MA, March 1985.
Reid, William T., "Protecting Standby Equipment, Corrosion Control, During Equipment Shutdown."
Materials Protection, V6 (No. 7), July 1967, pp 42-44.
Robertson, W.S., "Temporary Corrosion Preventatives in Industry." Industrial Lubrication, V20 (No. 10),
October 1968, pp 366-341.
Runyon, C.V., Vaughan, L.H., "Corrosion Protection of Boilers and Equipment in Idle Periods." National
Engineer, V75 (No. 11), November 1971, pp 14-18.
Twigg, R.J., "Mothballing" in Process Industries. CORROSION/85, Paper 163, Boston, MA, March 1985.
15-1
NOTES
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