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Specification for Pressure Vessels
B01
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Date
Rev
GPO-EN-SPE-46010
B01
Group Instruction for Supply
GIS 46-010
Specification for Pressure Vessels
GPO-EN-SPE-46010
© BP p.l.c.
Page 2 of 2
Rev: B01
BP Internal
Specification for Pressure Vessels
Table of Contents
Page
1
Scope .................................................................................................................................... 7
2
Normative references............................................................................................................. 7
3
Terms and definitions........................................................................................................... 10
4
Symbols and abbreviations .................................................................................................. 12
5
Order of precedence ............................................................................................................ 14
6
Supplier’s responsibilities..................................................................................................... 14
7
Design requirements............................................................................................................ 15
7.1
General..................................................................................................................... 15
7.2
Design loads and load combinations......................................................................... 16
7.3
Wind loading ............................................................................................................. 16
7.4
Seismic loading......................................................................................................... 17
7.5
Snow loading ............................................................................................................ 17
7.6
Motion induced loads ................................................................................................ 17
7.7
Cyclic loading............................................................................................................ 17
7.8
Local loading............................................................................................................. 18
7.9
Wind-induced vibration of vertical vessels................................................................. 18
7.10 Transportation loads ................................................................................................. 19
7.11 Lifting loads............................................................................................................... 19
7.12 Design calculations ................................................................................................... 20
7.13 Shock loading ........................................................................................................... 20
8
Materials requirements ........................................................................................................ 20
8.1
General..................................................................................................................... 20
8.2
Certificates of compliance ......................................................................................... 21
8.3
Certified material test reports .................................................................................... 21
9
Vessel components.............................................................................................................. 21
9.1
Vessel shells and transitions..................................................................................... 21
9.2
Formed heads........................................................................................................... 21
9.3
Connections, nozzles, and manways ........................................................................ 22
9.4
Flanges..................................................................................................................... 25
9.5
Blind flanges and bolted flat heads ........................................................................... 27
9.6
Swing bolt closures ................................................................................................... 27
9.7
Quick-actuating closures........................................................................................... 27
Copyright © 2013 BP International Ltd. All rights reserved.
This document and any data or information generated from its use are classified, as a
minimum, BP Internal. Distribution is intended for BP authorised recipients only. The
information contained in this document is subject to the terms and conditions of the
agreement or contract under which this document was supplied to the recipient's
organisation. None of the information contained in this document shall be disclosed
outside the recipient's own organisation, unless the terms of such agreement or contract
expressly allow, or unless disclosure is required by law.
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Specification for Pressure Vessels
9.8
9.9
9.10
9.11
9.12
9.13
9.14
Supports ................................................................................................................... 27
Anchor bolts.............................................................................................................. 30
Internal attachments ................................................................................................. 31
External attachments ................................................................................................ 32
Removable internals ................................................................................................. 38
External jackets ........................................................................................................ 41
Nameplates............................................................................................................... 42
10
Spares ................................................................................................................................. 42
11
Fabrication requirements ..................................................................................................... 42
11.1 General..................................................................................................................... 42
11.2 Tolerances ................................................................................................................ 43
11.3 Joints ........................................................................................................................ 43
11.4 Welding..................................................................................................................... 44
11.5 Temporary welded attachments ................................................................................ 47
12
Examination requirements ................................................................................................... 47
12.1 General..................................................................................................................... 47
12.2 Preparation ............................................................................................................... 48
12.3 Examination of materials........................................................................................... 48
12.4 Surface examination of welds ................................................................................... 49
12.5 Volumetric examination of welds............................................................................... 49
12.6 Hardness testing ....................................................................................................... 50
12.7 Repair of welding defects.......................................................................................... 50
12.8 Positive materials identification (PMI)........................................................................ 51
12.9 Production control test plates.................................................................................... 51
13
Inspection requirements....................................................................................................... 51
14
Post weld heat treatment ..................................................................................................... 51
15
Pressure test........................................................................................................................ 52
15.1 General..................................................................................................................... 52
15.2 Hydrostatic test ......................................................................................................... 53
15.3 Pneumatic test .......................................................................................................... 54
16
Cleaning, surface preparation, painting, and marking .......................................................... 54
16.1 Cleaning ................................................................................................................... 54
16.2 Surface preparation painting and non-metallic lining ................................................. 55
16.3 Marking..................................................................................................................... 56
17
Preparation for shipment...................................................................................................... 57
17.1 General..................................................................................................................... 57
17.2 Preparations for the vessel ....................................................................................... 58
17.3 Preparations for spares and crated parts .................................................................. 58
17.4 Securing and padding ............................................................................................... 59
17.5 Material safety data sheets ....................................................................................... 59
18
Documentation..................................................................................................................... 59
18.1 Proposal documentation ........................................................................................... 59
18.2 During design and fabrication ................................................................................... 60
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18.3
Final documentation.................................................................................................. 61
19
Quality management............................................................................................................ 63
20
Inspection, test and certification ........................................................................................... 63
20.1 Inspection and test plan ............................................................................................ 63
20.2 Inspection access ..................................................................................................... 63
20.3 Quality assurance ..................................................................................................... 63
21
Packing, preservation, marking and shipping ....................................................................... 64
22
Supplier deliverables............................................................................................................ 64
Annex A (Normative) Supplementary requirements for special services ....................................... 65
A.1
General................................................................................................................................ 65
A.2
Anhydrous ammonia service................................................................................................ 65
A.3
Butane storage .................................................................................................................... 65
A.4
Amine service ...................................................................................................................... 65
A.5
Caustic service .................................................................................................................... 65
A.6
Cyanides service ................................................................................................................. 65
A.7
Cyclic service....................................................................................................................... 66
A.8
Hydrofluoric acid .................................................................................................................. 66
A.9
Hydrogen service................................................................................................................. 66
A.10 Cryogenic service ................................................................................................................ 67
A.11 Propane storage .................................................................................................................. 67
A.12 Sour water, wet H2S, or wet sour service ............................................................................. 67
Annex B (Normative) Supplementary requirements for chrome-moly vessels ............................... 71
B.1
General................................................................................................................................ 71
B.2
Fabrication........................................................................................................................... 72
B.3
Examination requirements ................................................................................................... 72
B.4
1,25Cr-0,5Mo vessels (including Vanadium enhanced) ....................................................... 72
B.5
2.25Cr-1Mo vessels (including Vanadium enhanced) .......................................................... 72
Annex C (Normative) Supplementary requirements for stainless steel vessels ............................. 74
C.1
Fabrication........................................................................................................................... 74
C.2
Welding................................................................................................................................ 74
C.3
Examination requirements ................................................................................................... 74
C.4
Cleaning and surface preparation ........................................................................................ 75
Annex D (Normative) Supplementary requirements for clad plate or weld-overlay construction .... 76
D.1
Design ................................................................................................................................. 76
D.2
Clad plate material............................................................................................................... 78
D.3
Cladding re-instatement....................................................................................................... 78
D.4
Weld overlay ........................................................................................................................ 79
D.5
Welding procedures ............................................................................................................. 80
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D.6
Internal attachments ............................................................................................................ 81
D.7
Examination of weld overlay and clad re-instatement........................................................... 81
D.7.1 UT examination......................................................................................................... 81
D.7.2 PT examination......................................................................................................... 82
D.7.3 Chemical analysis ..................................................................................................... 82
Annex E (Normative) Supplementary requirements for DHT and IPWHT...................................... 83
E.1
Dehydrogenation heat treatment.......................................................................................... 83
E.2
Intermediate post weld heat treatment ................................................................................. 83
Annex F (Normative) Allowable piping loads on nozzles ............................................................... 85
Annex G (Normative) Ladders and platforms ................................................................................ 93
G.1. General................................................................................................................................ 93
G.2. Layout.................................................................................................................................. 93
G.3 Platforms ............................................................................................................................. 93
G.4. Ladders, ladder cages, and safety gates.............................................................................. 96
G.5. Handrailing .......................................................................................................................... 96
List of Tables
Table 1 - Minimum transportation acceleration loadings................................................................ 19
Table 2 - Minimum thickness of nozzles........................................................................................ 23
Table 3 - Quality levels for straight beam examinations from flat surfaces .................................... 26
Table 4 - Skirt vents ...................................................................................................................... 29
Table 5 - Dimensions of light lifting lugs ........................................................................................ 35
Table 6 - Dimensions of heavy lifting lugs ..................................................................................... 36
Table 7 - Tailing lug dimensions.................................................................................................... 37
Table 8 - Mist eliminator dimensions ............................................................................................. 41
Table 9 - Flatness tolerances of gasket contact surface................................................................ 43
Table F.1 - Pipe size forces .......................................................................................................... 86
Table F.2 - De-rating factor ........................................................................................................... 86
Table F.3 - Allowable piping loads on nozzles............................................................................... 87
Table G.1 - Minimum platform clearances..................................................................................... 95
List of Figures
Figure 1 - Skirts on vertical vessels less than 50 mm (2 in) thick or in non-cyclic service .............. 28
Figure 2 - Skirts on vessels ≥ 50 mm (2 in) thick or in cyclic service ............................................. 28
Figure 3 - Opening for skirt access or for piping............................................................................ 29
Figure 4 - Opening for a skirt vent................................................................................................. 29
Figure 5 - Design of light lifting lug ................................................................................................ 35
Figure 6 - Design of heavy lifting lug ............................................................................................. 36
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Figure 7 - Design of tailing lug....................................................................................................... 37
Figure 8 - Mist eliminator used for the full diameter of a vessel ..................................................... 38
Figure 9 - Mist eliminator for an enclosed internal cylinder............................................................ 39
Figure 10 - Mist eliminator for a reduced diameter ........................................................................ 39
Figure 11 - Mist eliminator attachment details ............................................................................... 40
Figure 12 - Mist eliminator support details..................................................................................... 41
Figure 13 - Surface Contours........................................................................................................ 56
Figure 14 - Internal attachments ................................................................................................... 56
Figure D.1 - Typical clad nozzle attachment to shell ..................................................................... 76
Figure D.2 - Attachment of lightly loaded attachment to a clad vessel........................................... 76
Figure D.3 - Attachment of a moderately loaded attachment to a clad vessel ............................... 77
Figure D.4 - Method for cladding a raised face flange ................................................................... 77
Figure D.5 - Method for cladding a ring type joint flange ............................................................... 77
Figure D.6 - Cladding re-instatement at a vessel seam ................................................................. 79
Figure G.1 - Typical column platform and ladder elevations.......................................................... 94
Figure G.2 - Minimum clearances in platform design .................................................................... 95
Figure G.3 - Typical platform at the top of a vessel ....................................................................... 96
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Specification for Pressure Vessels
1
Scope
a.
b.
2
This Specification provides requirements for the design, materials, fabrication, inspection,
testing, documentation, and preparation for shipment of pressure vessels designed,
fabricated, and certified in conformance to one of the following standards:
1.
ASME Boiler and Pressure Vessel Code, Section VIII, Division 1.
2.
ASME Boiler and Pressure Vessel Code, Section VIII, Division 2.
3.
BSI PD 5500 Specification for Unfired Fusion Welded Pressure Vessels.
4.
EN 13445 Unfired Pressure Vessels.
This specification also provides recommended design requirements for standard vessel
details which may be used if desired by the vessel manufacturer or if specified to be used
on the engineering datasheet in the direct purchase of pressure vessels. The use of other
standard details, such as those provided by the engineering contractor or industry
organisations, is not precluded.
Normative references
The following documents are referenced in one or more requirements in this document. For dated
references, only the version cited applies. For undated references, the latest version of the referenced
document (including any amendments) applies.
Company Documents
GIS 06-602
GIS 18-012
GIS 18-013
GIS 36-025
GIS 36-102
GIS 36-103
GIS 42-300
GIS 42-301
GIS 46-040
GP 36-26
Specification for Coating and Painting of Supplier Equipment
Specification for Procurement, Storage, and Control of Welding
Consumables
Specification for Weld Overlay, Integral Cladding, and Limited Loose
Lining of Pressure Vessels and Other Components
Requirements for Sour Service Materials for Upstream Oil and Gas
Production Systems
Specification for Hardness Testing, Post Weld Heat Treatment, Stress
Relief, and Pickling for Pressure Vessels, Piping, and Other Components
Specification for Positive Materials Identification (PMI) for Pressure
Vessels, Piping, and other Components
Specification for Flange Bolts
Specification for Gaskets
Specification for Internals for Columns
Materials for Sour Service in Refining and Marketing Operations
American Petroleum Institute (API)
API Specification 5L
API Specification Q1
API RP 934-A
Specification for Line Pipe.
Specification for Quality Programs for the Petroleum, Petrochemical and
Natural Gas Industry
Materials and Fabrication of 2 1/4Cr-1Mo, 2 1/4Cr-1Mo-1/4V, 3Cr-1Mo,
and 3Cr-1Mo-1/4V Steel Heavy Wall Pressure Vessels for
High-temperature, High-pressure Hydrogen Service
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API RP 934-C
API RP 934-E
Materials and Fabrication of 1 1/4Cr-1/2Mo Steel Heavy Wall Pressure
Vessels for High-pressure Hydrogen Service Operating at or below 825ºF
(441 ºC)
Closed Recommended Practice for Materials and Fabrication of 1 1/4
CR-1/2 Mo Steel Pressure Vessels for Service above 825ºF (440ºC)
American Society of Mechanical Engineers (ASME)
ASME SA-263
Standard Specification for Stainless Chromium Steel-Clad Plate
ASME SA-264
Standard Specification for Stainless Chromium Nickel Steel Clad Plate
ASME SA-265
Standard Specification for Nickel and Nickel Base Alloy Clad Steel Plate
ASME SA-435/SA-435M Straight-Beam Ultrasonic Examination of Steel Plates
ASME SA-516/SA-516M Standard Specification for Pressure Vessel Plates, Carbon Steel, for
Moderate and Lower Temperature Service
ASME SA-541/SA-541M Quenched and Tempered Carbon and Alloy Steel Forgings for
Pressure Vessel Components.
ASME SA-578/SA-578M Standard Specification for Straight-Beam Ultrasonic Examination of
Rolled Steel Plates for Special Applications
ASME SA-745/SA-745M Ultrasonic Examination of Austenitic Steel Forgings
ASME SA-770/SA-770M Through-Thickness Tension Testing of Steel Plates for Special
Applications
ASME SA-841/SA-841M Steel Plates for Pressure Vessels, Produced by Thermo-Mechanical
Control Process (TMCP)
ASME B16.5
Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch
Standard
ASME B16.47
Large Diameter Steel Flanges: NPS 26 through NPS 60 Metric/Inch
Standard
ASME B31.3
Process Piping
ASME PCC-1
Guidelines for Pressure Boundary Bolted Flange Joint Assembly
ASME PCC-2
Repair of Pressure Equipment and Piping
ASME BPVC VIII-1
ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division
1: Rules for Construction of Pressure Vessels
ASME BPVC VIII-2
ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division
2: Alternative Rules
American Society for Testing and Materials (ASTM)
ASTM A380
ASTM A578
ASTM E112
ASTM E165
Standard Practice for Cleaning, Descaling and Passivation of Stainless
Steel Parts, Equipment, and Systems
Standard Specification for Straight-Beam Ultrasonic Examination of
Rolled Steel Plates for Special Applications
Standard Test Methods for Determining Average Grain Size
Standard Practice for Liquid Penetrant Examination for General Industry
American Society of Civil Engineers (ASCE)
ASCE 7
Minimum Design Loads of Buildings and Other Structures
American Welding Society (AWS)
AWS A4.2
Standard Procedures for Calibrating Magnetic Instruments to Measure the
Delta Ferrite Content of Austenitic and Duplex Austenitic-Ferritic
Stainless Steel Weld Metal
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AWS A2.4
Standard Symbols for Welding, Brazing, and Non-destructive
Examination
British Standards Institute (BSI)
BSI BS EN 1991-1-4 + A1 NA
UK National Annex to Eurocode 1 - Actions on
structures Part 1-4: General actions - Wind actions - AMD 1
BSI PD 5500
Specification for Unfired Fusion Welded Pressure Vessels
European Standards (EN)
EN 1991-1-4 + A1
EN 10028-3
EN 10028-5
EN 10028-6
EN 10160
EN 10164
EN 10228-1
EN 10228-2
EN 10228-3
EN 10228-4
EN 13445
Eurocode 1 - Actions on structures Part 1-4: General actions - Wind
actions
Flat products made of steels for pressure purposes Part 3: Weldable fine
grain steels, Normalised
Flat products made of steels for pressure purposes Part 5: Weldable fine
grain steels, Thermomechanically rolled
Flat products made of steels for pressure purposes. Weldable fine grain
steels, quenched and tempered
Ultrasonic testing of steel flat product of thickness equal or greater than 6
mm (reflection method)
Steel products with improved deformation properties perpendicular to the
surface of the product. Technical delivery conditions
Non-destructive testing of steel forgings. Magnetic particle inspection
Non-destructive testing of steel forgings. Penetrant testing
Non-destructive testing of steel forgings. Ultrasonic testing of ferritic or
martensitic steel forgings
Non-destructive testing of steel forgings. Ultrasonic testing of austenitic
and austenitic-ferritic stainless steel forgings
Unfired pressure vessels
International Organisation for Standardisation (ISO)
ISO 8249
ISO 8573-1
ISO 9001
ISO 15156-1
ISO 15156-2
ISO 15156-3
Welding - Determination of Ferrite Number (FN) in austenitic and duplex
ferritic-austenitic Cr-Ni stainless steel weld metals
Compressed air - Part 1: Contaminants and purity classes
Quality Management System - Requirements
Petroleum and natural gas industries - Materials for use in
H2S-containing environments in oil and gas production - Part 1: General
principles for selection of cracking-resistant materials
Petroleum and natural gas industries - Materials for use in
H2S-containing environments in oil and gas production - Part 2:
Cracking-resistant carbon and low-alloy steels and the use of cast irons
Petroleum and natural gas industries - Materials for use in
H2S-containing environments in oil and gas production - Part 3:
Cracking-resistant CRAs (corrosion-resistant alloys) and other alloys
National Association of Corrosion Engineers (NACE)
NACE MR0103
NACE MR0175
Materials Resistant to Sulfide Stress Cracking in Corrosive Petroleum
Refining Environments
Petroleum, Petrochemical and Natural Gas Industries – Materials for Use
in H2S-containing Environments in Oil and Gas Production (ISO 15156)
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NACE SP0472
Methods and Controls to Prevent In-Service Environmental Cracking of
Carbon Steel Weldments in Corrosive Petroleum Refining Environments
NACE TM0284
Evaluation of Pipeline and Pressure Vessel Steels for Resistance to
Hydrogen-Induced Cracking
NACE TM0177
Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking
and Stress Corrosion Cracking in H2S Environments
SSPC SP 5/NACE No. 1 White Metal Blast Cleaning
Other References
Joseph Vellozzi, Ph.D
Brownell and Young
Zick, L.P
Dynamic Response of Tall Flexible Structures to Wind Loading.,
Department of Commerce, National Bureau of Standards, Building
Science Series Number 32, 1966
Process Equipment Design, Wiley & Sons Publishers, 1959
Stresses in Large Horizontal Cylindrical Pressure Vessels on Two Saddle
Supports, Pressure Vessels and Piping: Design and Analysis, A Decade
of Progress. Vol. 2, 1972
Process Industry Practices (PIP)
PIP STE05501
PIP STF05501
PIP STF05520
PIP STF05521
PIP STF05530
PIP STE05535
PIP STF05535
PIP VEFV1100
PIP VEFV1100M
Fixed Ladders and Cages Design Guide
Fixed Ladders and Cages Fabrication Details
Details for Pipe Railing for Walking and Working Surfaces
Details for Angle Railings for Walking and Working Surfaces
Grating Fabrication Details
Vessel Circular Platform Detail Guidelines
Vessel Circular Platform Details
Vessel/S&T Heat Exchanger Standard Details (U.S. Customary Units)
Vessel/S&T Heat Exchanger Standard Details (Metric Units)
Welding Research Council (WRC)
WRC Bulletin 297
WRC Bulletin 368
WRC Bulletin 537
3
Local Stresses in Cylindrical Shells Due to External Loadings on Nozzles
Stresses in Intersecting Cylinders Subjected to Pressure
Precision Equations and Enhanced Diagrams for Local Stresses In
Spherical and Cylindrical Shells Due To External Loadings For
Implementation of WRC Bulletin 107
Terms and definitions
For the purpose of this Specification, the following terms and definitions apply:
ASME Code
ASME Boiler and Pressure Vessel Code.
Certificates of compliance
A document by which the material manufacturer (or seller to the extent that the Code allows) certifies
that the material represented has been produced and tested in conformance to the requirements of the
basic material specification shown on the certificate.
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Certified material test report
A document, or documents, on which are recorded the results of tests, examinations, repairs, or
treatments required by the material specification.
Cladding re-instatement
The process in which areas at joints, nozzles and attachments, that have had cladding removed to
permit welding of the base material, are re-clad by weld overlay.
Company
BP p.l.c., an associate or subsidiary, or other organisation acting as owner, purchaser, or customer as
designated in the Purchase Order.
Company responsible engineer
Company engineer responsible for the technical requirements of the item.
Cyclic service
A service in which fatigue becomes significant due to the cyclic nature of mechanical and (or) thermal
loads.
Fabrication plan
A detailed description of the processes and sequence of the processes to be used to fabricate the
pressure vessel.
Ferritic steel
Steel where the predominant phase is ferrite, such as Carbon, Carbon Manganese, and low alloy steels.
Inspection and test plan
A detailed matrix of quality assurance and inspection activities to be performed. The format of the
document includes provisions to indicate monitoring and witness points.
Manufacturer
An entity performing welding of a pressure vessel or pressure vessel parts. May or may not be the
Supplier.
Quality assurance
Planned and systematic actions required to provide confidence that a product or service satisfies given
requirements for quality.
Quality control plan
The manufacturer’s job specific documented plan for ensuring that all specified technical requirements
shall be followed.
Quality control system
The manufacturer’s documented system for ensuring that all applicable code requirements for the
manufacturing process, including material handling and identification, design, fabrication, inspection
and testing, are followed.
Quality plan
A document setting out the specific quality practices, resources and sequence of activities for a
particular product, service or Purchase Order.
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Reinforcing plate
Reinforcing element as used in ASME Code, compensation plate as used in BSI PD 5500, or
reinforcing plate as used in EN 13445.
Supplier
Entity entering into a Purchase Order with Company to provide materials, goods, supplies, equipment,
or plant and includes the successors and (or) permitted assigns of such entity.
Weldment
Weld, HAZ, and adjacent parent metal.
4
Symbols and abbreviations
For the purpose of this Specification, the following symbols and abbreviations apply:
ASS
Austenitic stainless steel.
CMCL
Corrugated metal with covering layers.
CMTR
Certified material test report.
DHT
Dehydrogenation heat treatment.
DN
Nominal pipe diameter.
FCAW
Flux cored arc welding.
FEA
Finite element analysis.
FN
Ferrite number (per Welding Research Council Bulletin Number 342).
GMAW
Gas metal arc welding.
GTAW
Tungsten inert gas welding.
HAZ
Heat affected zone.
HIC
Hydrogen-induced cracking.
HRB
Rockwell hardness number, B scale, tested with a steel ball.
HBW
Brinell hardness measured by tungsten carbide ball (also referred to as HB and
BHN).
Hv10
Vickers hardness measured with a 10 kgf indenter (also referred to as HV).
IPWHT
Intermediate post-weld heat treatment (also known as ISR Intermediate stress
relief).
ITP
Inspection and test plan.
LWN
Long welding neck.
MAP
Maximum allowable pressure.
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MAWP
Maximum allowable working pressure.
MSDS
Material safety data sheets.
MDMT
Minimum design metal temperature.
MT
Magnetic particle testing.
NDE
Non-destructive examination.
NPS
Nominal pipe size.
PCN
Personnel Certification in Non-Destructive Testing.
PMI
Positive material identification.
PQR
Procedure qualification record.
PT
Liquid or dye penetrant testing.
PWHT
Post-weld heat treatment.
PWHTmin
Shortest time for which the vessel may be heat treated to meet code requirements.
PWHTmax
Longest time for which the vessel may be heat treated.
QA
Quality assurance.
Q+T
Quenched and tempered.
RT
Radiographic testing.
RTV
Room temperature vulcanising.
SAW
Submerged arc welding.
SMAW
Shielded metal arc welding.
SOHIC
Stress orientated hydrogen induced cracking.
SZC
Soft zone cracking.
TMCP
Thermo-mechanical control process.
TOFD
Time of flight diffraction.
UT
Ultrasonic testing.
WFMT
Wet fluorescent magnetic particle testing.
WPQ
Welder or welding operator performance qualification.
WPS
Welding procedure specification.
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Specification for Pressure Vessels
5
Order of precedence
a.
6
The order of precedence of the codes and standards quoted in the specifications shall be:
1.
International and local statutory regulations.
2.
Project data sheets.
3.
Project specifications.
4.
This Specification.
5.
Referenced Company documents.
6.
Referenced national and international codes.
b.
Areas of apparent conflict between documents shall be brought to the attention of
Company for resolution.
c.
In the event of a conflict between this document and a relevant law or regulation, the
relevant law or regulation shall be followed. If the document creates a higher obligation, it
shall be followed as long as this also achieves full compliance with the law or regulation.
d.
Design, engineering, procurement, and construction for equipment shall comply with the
statutory laws and regulations of the final location of the asset. Refer to documents
identified in the Purchase Order for a list of these regulations.
e.
For projects where the final location of the asset is in the EU:
1.
Products supplied shall be confirmed to comply with applicable EU directives.
2.
A Declaration of Conformity shall be provided.
3.
The CE mark shall be affixed to the pressure vessel nameplate.
4.
Components supplied shall be listed together with the EU directives with which they
comply and the rationale by which compliance has been achieved.
5.
A Technical File in compliance with applicable EU directives shall be compiled and
retained for a period of 10 years.
Supplier’s responsibilities
a.
The mechanical design, provision of materials, fabrication, inspection, testing, and quality
of workmanship of pressure vessels which shall be provided in conformance to this
Specification and the following:
1.
Comply with local jurisdictional requirements.
2.
The required design code shall be as specified on the data sheets.
3.
Pressure equipment directive when specified on the data sheets.
4.
Other codes and standards referenced in this Specification.
5.
Additional requirements listed on the data sheets.
b.
Vessels shall conform to the specified design code, including the application of code stamp
or certificate of conformity.
c.
Vessels designed in conformance to the ASME Code shall be registered with the National
Board.
d.
Design of a vessel or a vessel component furnished by Company shall not relieve the
Supplier of their responsibility to conform to the requirements of this Specification and
other Purchase Order documents.
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7
7.1
e.
Company’s review and agreement of Supplier documentation shall not relieve the Supplier
of their responsibility to conform to the requirements of this Specification and other
Purchase Order documents.
f.
Company shall be allowed shop access for inspecting materials and activities during vessel
fabrication for conformance to this Specification. Work or materials not conforming shall
be cause for rejection.
g.
Data sheets, drawings, quality control records, and other items which assist in determining
the acceptability of a vessel for inspection shall be made available to Company.
h.
Release for shipment by Company inspector shall not relieve the Supplier of their
responsibility to conform to the requirements of this Specification and Purchase Order
documents.
i.
The Supplier shall be responsible for assuring that subcontracted fabrication work is in
conformance to this Specification and Purchase Order documents, however no portion of
vessel construction, such as plate forming, welding, heat treatment, non-destructive
examination, painting, shall be subcontracted without prior written agreement from
Company.
Design requirements
General
a.
Vessel design shall be in conformance to the applicable design code, this Specification,
and all Purchase Order documents.
b.
Computer calculations shall show input and output data, clearly state assumptions made,
and specify program name and version number.
c.
The maximum design temperature rating shall be increased to the highest temperature
permitted in conformance to the Code without affecting the minimum required thickness of
the shell or heads and without changing the pressure class of the flanges.
d.
A vessel may be designed and stamped for more than one condition of pressure and
coincident metal temperature.
e.
Unless otherwise specified on the data sheets, vessels shall be assumed to operate
completely filled with process fluid having a minimum specific gravity of 1,0.
f.
MAWP shall be calculated based on actual construction unless otherwise specified on data
sheets.
g.
For vessels constructed to ASME BPVC VIII-1, the coincident ratio used for calculating
the MDMT of the vessel shall not be less than 1,0.
h.
The supplementary requirements for special services shall conform to Annex A of this
Specification if specified on data sheet.
i.
Standard details provided by Supplier are not precluded, but details in this Specification
shall be used and fabricated as shown if specified on data sheets.
j.
Document numbers PIP VEFV1100 and PIP VEFV1100M contain standard drawings,
prefixed ‘PIP VEFV’ in U.S. customary units and metric units respectively. This
Specification will reference metric standard drawing numbers only but it shall be
interpreted as also referring to the metric standard drawing (with suffix M) and equivalent
standard drawing in U.S. customary units (without suffix M).
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7.2
Design loads and load combinations
7.2.1
Design load classifications and definitions
The following definitions shall apply for the load case combinations specified in 7.2.2:
7.2.2
a.
Dead load (L1) is the installed weight of the vessel, including internals, catalyst or
packing, refractory lining, platforms, insulation fireproofing, piping, and other permanent
attachments. This does not include the weight of process liquid or catalyst contents.
b.
Operating live load (L2) is the weight catalyst plus the weight of process liquid at the
design liquid level, including that on trays.
c.
Pressure load (L3) is the MAWP (internal or external at the coincident temperature)
considering the pressure variations through the vessel.
d.
Thermal load (L4) is the load caused by the restraint of thermal expansion and interaction
of vessel and its supports.
e.
Test load (L5) is the weight of test water.
f.
Wind load (L6) shall be determined in conformance to 7.3.
g.
Seismic load (L7) shall be determined in conformance to 7.4.
h.
Piping and superimposed equipment loads (L8) are loads caused by piping (based on
Annex F loadings), and loads caused by superimposed equipment. See 9.3.6.
Load conditions
Vessels and their supports shall satisfy all of the following load conditions:
a.
Erected condition with full wind load (L1 + L6).
b.
Design condition with wind load (L1 + L2 + L3 + L4 + L6 + L8).
1.
c.
Design condition with seismic load (L1 + L2 + L3 + L4 + L7 + L8).
1.
d.
e.
7.3
Both full and zero pressure loads (L3) shall be included for check of maximum
longitudinal tensile and compressive stress.
Both full and zero pressure loads (L3) shall be included for check of maximum
longitudinal tensile and compressive stress.
Future (corroded) pressure test (L1+ test pressure + L5 + 0,25*L6).
1.
Vessels shall be designed to permit application of a full hydraulic test in their
operating positions and 25% design wind load.
2.
The general primary membrane tensile stress under this load condition in the corroded
condition shall not be greater than either of the following:
a)
For hydrostatic testing, 90% of the specified minimum yield strength at 38°C
(100°F), in both circumferential and longitudinal directions.
b)
For pneumatic testing, 80% of the specified minimum yield strength at 38°C
(100°F), in both circumferential and longitudinal directions.
Lift condition
1.
See data sheets and 7.11.
2.
Erection load shall be total erection weight of vessel multiplied by an impact factor as
specified in data sheet.
Wind loading
a.
Unless otherwise specified on the data sheets:
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1.
7.5
a)
Importance factor shall be Category III.
b)
Velocity pressure exposure coefficient and gust response factors shall be
Exposure C for inland and coastal installations and Exposure D for offshore
installations.
2.
For EU sites, wind loading shall conform to EN 1991-1-4 + A1.
3.
For sites in the UK, wind loading shall conform to EN 1991-1-4 + A1, used in
conjunction with BSI BS EN 1991-1-4 + A1 NA.
4.
Wind load for other locations shall conform to data sheets and comply with local
regulatory requirements.
b.
Allowable deflection at any location on a vertical vessel in the corroded condition shall not
exceed 150 mm per 30 m (6 in per 100 feet) of vessel height.
c.
Projected area of vessel accessories such as platforms, ladders, piping, and other
equipment attached to the vessel shall be included in the wind load calculation.
d.
Vessels fitted with spoilers:
e.
7.4
For US sites, wind load shall conform to ASCE 7 and governing local jurisdictional
requirements. The following shall be used in calculations:
1.
Column projected area shall be calculated using the projected diameter taken at the
outside edge of the spoilers multiplied by the height of the section under
consideration.
2.
Column projected area normal to wind and corresponding force coefficient, for the
column height shall be used in the design of vessel and supporting structure to
calculate the overturning load.
Wind induced moment and shear forces at the base of the vessel shall be specified on
Supplier drawings.
Seismic loading
a.
Unless otherwise specified on the data sheets, seismic loads shall be determined in
conformance to ASCE 7 and governing local jurisdictional regulations.
b.
Pressure vessel, supporting structures and foundation bolts shall be evaluated using the
allowable stress design method.
c.
Vertical columns shall be considered as “cantilevered column systems” if they are
anchored to a foundation at grade.
d.
Seismic induced moment and shear forces at the base of the vessel shall be specified on
Supplier drawings.
Snow loading
Unless otherwise specified on the data sheets, the snow load shall be determined in
conformance to ASCE 7 and governing local jurisdictional regulations.
7.6
Motion induced loads
The motion induced loads listed on the data sheets shall be applied to all load cases listed in 7.2.
7.7
Cyclic loading
a.
The rules in ASME BPVC VIII-2, Paragraph 4.1.1.4, shall be used as a basis for
establishing further action if a data sheet specifies a vessel is in cyclic service.
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b.
7.8
Local loading
a.
b.
7.9
A fatigue analysis shall be performed for agitator mounting nozzles and their attachment to
the vessel.
Local stresses in vessel shell, heads and nozzles shall be evaluated using either
WRC Bulletin 297, 537 and 368 procedures, BSI PD 5500 annex G, or other local stress
analysis procedures agreed by Company based on:
1.
The allowable imposed loads and moments on nozzles specified in Annex F of this
Specification.
2.
The loads and moments imposed on attachments from piping and platforms.
For loads evaluated using WRC Bulletins 297, 537 and 368:
1.
The allowable stresses for local nozzle loads and pressure at design temperature shall
be 1,5S for local primary membrane stress and 3S for primary membrane plus
secondary bending stress at nozzles.
2.
The allowable stresses for attachment local loads at ambient temperature shall be 1,0S
and 1,5S respectively.
c.
S is the Code allowable or design stress.
d.
For local loads evaluated in conformance to BSI PD 5500 annex G, the allowable stresses
at ambient and design temperature shall conform to the code.
Wind-induced vibration of vertical vessels
a.
Vessels with a height to diameter ratio of either the entire vessel or the top third of the
vessel is greater than or equal of 15 shall be evaluated for dynamic behaviour from wind
excitation as described in Dynamic Response of Tall Flexible Structures to Wind Loading
or by other similar proven evaluation methodology.
b.
Critical wind velocities shall be determined for every change in vessel outer diameter.
c.
Vessel critical wind velocities (first and second modes) shall be less than 7 m/s (15 mph)
or greater than 27 m/s (60 mph).
d.
For a vessel with critical wind velocities between 7 m/s (15 mph) and 27 m/s (60 mph):
1.
A means of either preventing vortex formation (e.g., by spoilers, piping, ladders, or
platforms) or vibration dampening shall be provided.
2.
Wind spoilers shall be added to the vessel in conformance to one of the following
methods if it is established that a vessel may vibrate and the attachments of the vessel
cannot be changed to put the vessel in a range where vibration cannot occur. The
method used to deter wind-induced vibration shall be agreed by Company.
a)
b)
Helical spoilers
1)
A three-start system of spoilers in a helical pattern shall be provided on top
third of the vessel.
2)
Exposed width of the spoilers beyond insulation shall be 0,09D and a pitch
of 0,5D, where D is the diameter of the top third of the vessel.
3)
Spoiler system may be interrupted to provide clearance at vessel
appendages.
Short vertical spoilers
1)
A three-start system of short vertical spoilers arranged in a helical pattern
shall be provided on the top-third of the vessel.
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7.10
2)
Exposed width beyond insulation of the spoilers shall be 0,09D and the
height of one helical wrap between 0,5D and 0,11D.
3)
A minimum of eight spoilers shall be provided over the pitch distance (i.e.,
each complete helical wrap) and a minimum of 1,5 helical wraps over the
top-third of the vessel.
4)
Spoiler system may be interrupted to provide clearance at vessel
appendages.
Transportation loads
a.
Vessels subject to transportation loadings shall be analysed for the following conditions:
1.
Bending between supports.
2.
General primary membrane tensile stress.
3.
Bending and compressive stress at supports and fixture attachment points.
b.
Calculated general primary membrane tensile stress shall not exceed that listed in 7.11e.
c.
Vessels shall be analysed for actual vertical, lateral, and longitudinal loadings.
d.
Minimum acceleration loadings for different modes of transportation shall be as shown in
Table 1.
e.
Vessel shall be designed for the most severe vertical, lateral, and longitudinal loading
condition if erection loadings are greater than the transportation loadings.
Table 1 - Minimum transportation acceleration loadings
Transportation Mode
Downward
Vertical acceleration
Upward
Lateral
acceleration
Longitudinal
acceleration
Truck (highway speeds)
1,7∙g
0,5∙g
0,3∙g
1,8∙g
Truck (<11,1 m/s (25 mph)
or multi-wheel transporter)
1,3∙g
0,2∙g
0,2∙g
0,2∙g
Rail
2∙g
2∙g
2∙g
3∙g
Inland barge
1∙g
0,2∙g
0,75∙g
0,4∙g
Oceangoing ship or barge
2∙g
2∙g
0,75∙g
0,4∙g
Notes:
1. If multiple modes of transportation are used, the most severe condition shall be used for
evaluation.
2. 1,0∙g is a load equal to the shipping weight of the vessel.
7.11
Lifting loads
a.
Lift weight shall include the weight of all components, such as trays, ladders, platforms,
insulation, additional piping with insulation.
b.
An impact factor, as specified on the data sheet, shall be applied to the lift weight for the
design of lifting devices and vessel shell bending calculations.
c.
Local stresses in the vessel shell, head, skirt and base rings from lifting lugs and trunnions
loads shall be determined using WRC Bulletins 297 or 537,BSI PD 5500 annex G, or other
accepted local stress analysis procedures agreed with Company. Allowable stress values
shall be as specified in 7.8b or 7.8d.
d.
Shear stresses for fillet welds on the lifting attachments to vessel shell or head shall not be
greater than 0,55 times the Code-allowable stress at 38ºC (100ºF) for the material selected.
e.
Lifting stress calculations shall be performed for vertical vessels with height-to-diameter
ratios greater than 8 and lift weight exceeding 11 300 kgf (25 000 pounds) as follows:
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7.12
7.13
1.
Bending stresses in the vessel shell and skirt from the loadings imposed during the lift
from horizontal to vertical position.
2.
Calculated general primary membrane tensile stress shall not be greater than 80% of
the material’s specified minimum yield strength at 38ºC (100ºF).
3.
Calculated compressive stress shall not be greater than 1,2 times the allowable
compressive stress.
Design calculations
a.
Calculations satisfying the pressure vessel code of construction requirements shall be
performed using COMPRESS, PVElite, or Finglow software packages.
b.
Design calculation reports, including finite element analysis reports, shall be submitted for
review and agreement by Company.
c.
The following vessel components shall be subject to analysis and the results submitted for
review and agreement by Company:
1.
Thermal and stress analysis of vessel and skirt attachment region, if specified on data
sheets.
2.
Localised stress analysis of internal and external attachments to the shell.
3.
Localised stress analysis of nozzles subject to piping loads.
4.
Thermal analysis of nozzles, skirt, and appurtenances for thermal gradients induced
into shell, if specified on data sheets.
a)
Information from this analysis shall be used to determine the need for a fatigue
evaluation.
b)
Results of the thermal analysis exempting a vessel from fatigue evaluation shall
be included in the calculations.
d.
For pressure vessels designed to ASME BPVC VIII-1, if a rule for the design of a vessel or
vessel component subject to pressure does not exist in ASME BPVC VIII-1 then, in
conformance to ASME BPVC VIII-1 Paragraph U-2(g), the design shall be evaluated by
rules of ASME BPVC VIII-2.
e.
Calculations evaluated to EN 13445-3 Annex B shall be submitted for review and
agreement by Company.
Shock loading
Vessels shall be checked for dynamic effects if the data sheet indicates the possibility of the
process applying a shock loading such as a slug flow which results in an increased force on the
vessel shell or internals.
8
8.1
Materials requirements
General
a.
Pressure vessel materials shall be as specified on data sheets.
b.
Materials shall conform to the following additional requirements in this Specification when
specified on data sheets:1.
Annex B-supplementary requirements for chrome-moly vessels.
2.
Annex C-supplementary requirements for stainless steel vessels.
3.
Annex D-supplementary requirements for clad plate or weld overlay construction.
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8.2
8.3
9
c.
Materials shall be new and unused.
d.
Material substitutions shall not be made without Company agreement.
e.
Steel plates shall be made in an open-hearth, basic-oxygen, or electric-arc furnace.
f.
Charpy V-notch impact tests for carbon and low alloy steel plates shall conform to design
code unless specified otherwise in Purchase Order.
g.
Records of Charpy V-notch impact tests for steel plates shall record the percent shear
fracture and the lateral expansion for each specimen.
h.
Impact test values shall be reported in the CMTR.
i.
Materials shall be stamped with low stress (round bottom) stamps.
Certificates of compliance
a.
Records of compliance with the requirements of material specifications shall be
maintained.
b.
Certificates of compliance shall include reports or test results required by the material
specification or Purchase Order.
Certified material test reports
a.
Supplementary or special requirements, in addition to the requirements of the material
specification, as required by the Purchase Order shall be included on the CMTR.
b.
The specification of the material being represented, year of issue and material heat number
shall be included on the CMTR.
c.
All such documents shall identify the applicable material specification and shall be
identified to the material represented.
Vessel components
The following clauses contain design, fabrication, and examination requirements for components of
pressure vessels as specified on the data sheets.
9.1
Vessel shells and transitions
a.
Shells shall be fabricated from rolled plate, pipe or forgings.
b.
Transitions shall be made with knuckle and flare if any of the following conditions apply:
c.
1.
Vessel is in cyclic or hydrogen service.
2.
Section is subject to a major support reaction (for example, skirt-to-cone attachment).
3.
Transition thickness or attached shell thickness is over 30 mm (1,25 in).
4.
All loadings per ASME BPVC VIII-1 Appendix 1-5 or 1-8, whichever is applicable,
are not available.
Minimum thickness of shells and transitions shall not be less than 6 mm (1/4 in).plus the
greater of corrosion allowance and the forming allowance.
9.2
Formed heads
9.2.1
General
a.
Heads shall be supplied as one of the following as specified on the data sheets:
1.
Hemispherical.
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9.2.2
9.2.3
2.
2:1 Semi-elliptical.
3.
ASME flanged and dished.
4.
Toriconical.
b.
Dished head construction shall preferably be seamless.
c.
Minimum thickness of heads shall not be less than 6 mm (1/4 in).plus the greater of
corrosion allowance and the forming allowance.
d.
Heads and head nozzles supporting agitators shall be reinforced to withstand the agitator
dynamic loadings in conformance to requirements of 9.3.6a and 9.3.6b.
e.
Head design shall be agreed with the agitator manufacturer and Company before the head
is ordered.
f.
Carbon steel and C-Mn steels, cold-formed heads shall be normalised or stress-relieved
prior to welding to the shell.
Joints in formed heads
a.
Joints in formed heads shall be full penetration.
b.
Joints in formed heads shall be fully radiographed before forming.
c.
Joints in formed heads shall be ground flush with the plate surfaces before forming.
d.
Spin hole which remains after forming and final construction shall be repaired with a metal
plate butt-welded in place and given full volumetric examination.
e.
After forming, all joints in formed head shall receive 100% surface examination on both
sides.
Intermediate heads
a.
Intermediate heads shall:
1.
Be designed with a corrosion allowance applied to both sides.
2.
Be fitted so that the internal head OD equals the shell ID.
3.
Have a continuous fillet weld from the end of the head plate to shell.
4.
Have the attachment welds magnetic particle or liquid penetrant examined.
9.3
Connections, nozzles, and manways
9.3.1
General
a.
b.
9.3.2
Connections shall not be made with:
1.
Threaded coupling.
2.
Socket weld fitting.
3.
Single fillet welds.
4.
Tapped or threaded openings.
Nozzles shall be flanged unless otherwise specified on the data sheets.
Design
a.
MAWP shall not be limited by nozzle reinforcement or nozzle neck thickness.
b.
MAP shall not be limited by nozzle reinforcement or nozzle neck thickness.
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9.3.3
c.
Nozzles with internal projections shall not include the internal projection in reinforcement
calculations.
d.
Nozzles in dished heads shall be positioned such that the nozzle, reinforcing pads, and
attachment welds are not within the knuckle region of the dished head.
Construction details
a.
Nozzles shall be set-in type.
b.
Nozzle to parent component weld shall be full penetration.
c.
Nozzles DN 300 (NPS 12) and larger shall be made from forgings, rolled plate, or
seamless pipe.
d.
Nozzles smaller than DN 300 (NPS 12) shall be constructed using forgings or seamless
pipe.
e.
Nozzles DN 50 (NPS 2) or smaller shall be constructed using either:
1.
LWN or heavier forgings if the forging length is 400 mm (16 in) or less.
2.
Welding stub welded to seamless pipe if the nozzle length is greater than 400 mm
(16 in).
f.
Flange rating of connections DN 50 (NPS 2) or smaller shall be minimum class 300.
g.
Rolled plate used as nozzle necks shall have full volumetric examination prior to
attachment to other components. Acceptance criteria shall be in conformance to the design
code for full NDE.
h.
Minimum pipe schedule used for nozzles shall be as shown in Table 2 or applicable design
code, whichever is greater.
Table 2 - Minimum thickness of nozzles
Material
Size DN (NPS)
Minimum pipe schedule (1)
Carbon steel and low alloy,
clad steels
50 (2)
Schedule 160
High alloy and
non-ferrous materials
Larger than 50 (2)
Schedule XS
50 (2)
Schedule 80S
Larger than 50 (2)
Schedule STD
Note:
1. Pipe wall thickness designations per ASME B36.10M.
9.3.4
i.
Nozzles not directly connected to internals shall be flush with the inside surface of the
vessel wall.
j.
Nozzle with an internal projection shall have a fillet weld at the inside corner.
k.
Inside edges of manways and nozzle neck shall be rounded to 3 mm (1/8 in) minimum
radius unless requirements in 16.2i.3 apply.
Reinforcing pads
a.
Reinforcing pads shall be external to the vessel.
b.
Reinforcing pads shall not be used on internal heads.
c.
Reinforcing pads shall not be used if any of the following conditions apply:
1.
Operating temperature exceeds 300°C (572°F).
2.
Operating partial pressure of hydrogen exceeds 7 bar(a) (100 psia) and operating
temperature exceeds 230°C (450°F).
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9.3.5
Design is for non-intrusive inspection.
4.
Parent wall thickness exceeds 50 mm (2 in).
5.
Ferritic vessels if operating temperature is lower than -50°C (-58°F).
6.
Cyclic service.
d.
Reinforcing pad thickness shall not exceed the parent wall thickness to which the nozzle is
attached.
e.
Reinforcing pads shall be full penetration welded to the nozzle.
f.
Design of multi-segmental reinforcing pad elements shall conform to ASME BPVC VIII-1
Paragraph UG-37(h).
g.
Each pad segment shall have one American Standard Taper Pipe Thread (NPT) 1/4 inch
(6 mm) telltale hole for testing purposes. Each hole shall be left open during welding of
pad and PWHT and located near the lowest point of a pad with the vessel in its operating
position to permit drainage.
h.
See 15.1f for testing of reinforcing pads.
i.
Reinforcing pads that are not circular shall have rounded corners of 75 mm (3 in)
minimum radius.
Nozzle external projection
a.
9.3.6
3.
Minimum projection from the outside of the vessel wall or external insulation to the nozzle
face shall be:
1.
Nozzles less than or equal to DN 200 (NPS 8): 200 mm (8 in).
2.
Nozzles larger than DN 200 (NPS 8): 250 mm (10 in).
b.
The dimension from the face of the nozzle to the vessel centreline or reference line shall be
rounded up to the next greater 10 mm (1/2 in) increment.
c.
Projection of flanged nozzles with external piping attached shall permit removal of bolting
from either side without removal of insulation.
d.
Nozzles shall be extended to ensure flanges and bolting are outside vessel insulation.
e.
Projections of nozzles and manways shall be established by applying the following:
1.
Clearance shall be provided for removing flange stud bolts from between the flange
and vessel and for accessing flange stud nuts.
2.
Clearance shall be provided for flange studs and nuts if nozzles penetrate insulation or
platforms.
Nozzle loading
a.
Nozzles supporting agitators, pumps, or other mechanical equipment shall be evaluated to
withstand the mechanical loadings specified by the equipment manufacturer and piping
loads derived from Table F.3 in Annex F. Nozzle reinforcement as determined by nozzle
reinforcement calculations shall be used in the evaluation.
b.
If, following evaluation, the vessel shell or head is overstressed, Supplier shall not increase
reinforcement on nozzle but shall submit the calculations for review by Company
responsible engineer.
c.
Dynamic loading shall be evaluated for an infinite number of stress reversals using the
applicable stress concentration factor as follows:
1.
5 for as welded attachment welds.
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2.
3,5 for contoured and blend ground nozzle attachment welds.
d.
Nozzles supporting pressure relief devices shall be evaluated to withstand the thrust
reaction by using piping loads derived from Table F.3 in Annex F. Nozzle reinforcement
as determined by nozzle reinforcement calculations shall be used in the evaluation and
shall conform to requirements of 9.3.6b.
e.
Gussets shall not be used to strengthen, stiffen, or reinforce nozzles, unless demonstrated
by calculations to be designed for the specified cyclic life and thermal condition, and the
dimensional requirements, such as tolerances, of the device as furnished by the device
manufacturer are considered.
9.4
Flanges
9.4.1
General
a.
Flanges welded on a nozzle shall be weld neck type unless otherwise specified on data
sheets.
b.
Dimensions and pressure-temperature ratings of standard flanges for nozzles and manways
DN 600 (NPS 24) and smaller shall conform to ASME B16.5.
c.
Dimensions and pressure-temperature ratings of standard flanges for nozzles and manways
larger than DN 600 (NPS 24) shall conform to ASME B16.47 to the series specified on
data sheets.
d.
Vessel shell flanges and head flanges with covers not conforming to sizes in ASME B16.5
or ASME B16.47 shall be weld neck type and designed in conformance to the design code.
e.
The following shall apply if studded nozzle pads are used:
1.
Studded pad holes and studs shall be machined in conformance to drawing number
PIP VEFV1129M.
2.
Indicator type studs for studded pads shall be in conformance to ASME PCC-1
Figures 1 and 2.
3.
Studded pads shall be checked to ensure the full thread depth holes conforms to
specified design code.
f.
Bolt holes in all fixed flanges and studded pads shall straddle the natural centrelines.
g.
For vessels supported on a skirt, the flanges of nozzles in bottom head shall be located
outside the skirt.
h.
Except for standard flanges conforming to ASME B16.5 and B16.47, all carbon, low-alloy,
and high-alloy steel forgings greater than 75 mm (3 in) thick shall be examined
ultrasonically in conformance to ASME SA-745/SA-745M and the following:
1.
Quality levels for straight beam examinations from flat surfaces shall conform to
Table 3.
2.
Quality level for straight beam examinations from curved surfaces shall be QL-5.
3.
Quality level for all angle beam examinations shall be QA-1. Notch depth shall
conform to QA-1 or 6 mm (0,25 in), whichever is less.
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Table 3 - Quality levels for straight beam examinations from flat surfaces
9.4.2
9.4.3
Quality level
75 (3) < t ≤ 200 (8)
200 (8) < t ≤ 300 (12)
t > 300 (12)
QL-2
QL-3
QL-4
Flange facing and surface finish
a.
Splice welds on gasket contact surfaces of a lap ring or flange shall not be used.
b.
Flanges shall have one of the following configurations:
1.
Raised face.
2.
Ring type joint.
3.
A construction that provides outer confinement to the gasket if specified on data
sheets.
c.
The height of a raised face shall be in conformance to ASME B16.5 or ASME B16.47
unless otherwise specified on the data sheets.
d.
Except for flanges conforming to ASME B16.5 and ASME B16.47, the gasket contact
surface flatness tolerance for flanges and shop-fabricated lap rings shall conform to the
following:
1.
0,150 mm (0,006 in) total indicator reading in both the radial and circumferential
directions.
2.
The total circumferential tolerance shall not occur in less than 20 degrees arc.
3.
Measurement shall be made using a dial indicator after all other operations, including
fabrication and heat treatment of flange or lap ring, and attachment to the shell or
nozzle neck, affecting flatness tolerance have been completed.
e.
Flange facings shall be machined in conformance to ASME B16.5 and ASME B16.47.
f.
Flange facings shall be protected from damage during fabrication, heat treatment, and
shipping.
Flange bolting
a.
9.4.4
Forging thickness (t)
mm (in)
Flanged joints shall be designed to enable the use of hydraulic bolt tensioners on the
following:
1.
Joints with nominal bolt diameter 50 mm (2 in) and over.
2.
Duties where the nominal bolt diameter is 40 mm (1,5 in) and over, and the flanges
are either on hydrogen service or are PN 110 (Class 600) or over.
3.
If specified on the data sheets for nominal bolt diameter 25 mm (1 in) and over.
b.
Bolts for bolt tensioning shall be extended by the length of one nut and provided with a cap
for protection during service.
c.
Nozzles adjacent to shell girth flanges or horizontal vessel saddles shall be located with
clearance such that bolt tightening equipment can be used on the girth flange bolts.
d.
Flange bolting, including coating requirements, shall be as specified on data sheets and
conform to GIS 42-300.
Gaskets
a.
Gaskets shall be as specified on data sheets and conform to GIS 42-301.
Page 26 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
9.5
9.6
b.
Pressure and leak test gaskets shall conform to 15.1j.
c.
Spare gaskets shall conform to 10b.1.
Blind flanges and bolted flat heads
a.
Except for blind flanges conforming to ASME B16.5 and B16.47, rolled plate for flat
covers and blind flanges greater than 75 mm (3 in) thick shall be examined in conformance
to ASME SA-578/SA-578M acceptance standard - Level B after cutting to final size.
b.
Nozzles shall not be welded to blind flanges conforming to ASME B16.5 or
ASME B16.47 and weld neck reducing flanges shall be used unless the applicable ASME
blind flange standard specifically allows such an opening while keeping the pressure and
temperature rating.
c.
Vessel manways and flanges fitted with blind flanges shall be supplied with bolting and
gaskets.
Swing bolt closures
Swing bolts shall be of one-piece construction without welding. Hinge pins shall be solid and of
the same material as the swing bolts.
9.7
Quick-actuating closures
a.
Quick-actuating closures shall be designed per ASME BPVC VIII-1 Paragraph UG-35.2 or
ASME BPVC VIII-2 Paragraph 4.8 and Annex 4.B.
b.
Procedures for the operation or maintenance of quick-actuating closure shall be submitted
for review and agreement by Company.
9.8
Supports
9.8.1
Skirts
a.
Vertical vessels shall be self-supporting without guys or braces.
b.
Unless otherwise specified on data sheets skirt supports shall conform to one of the
following standard drawings:
1.
PIP VEFV1107M - Type A skirt base plate with gussets only
2.
PIP VEFV1108M - Type B with cap plate and gussets
3.
PIP VEFV1109M - Type C with cap plate and offset gussets
4.
PIP VEFV1110M - Type D with top ring and gusset
c.
A hot box shall be provided at the junction between the skirt and shell for vessels with a
design temperature of 345°C (650°F) and above.
d.
Material at the top of the skirt for vertical vessels constructed from materials other than
carbon steel shall be the same material specification and grade as the vessel plate to which
it is attached for a length at least equal to the greater of the following:
1.
2,5 * √(skirt radius * skirt thickness).
2.
600 mm (24 in).
Page 27 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure 1 - Skirts on vertical vessels less than 50 mm (2 in) thick or in non-cyclic service
Figure 2 - Skirts on vessels ≥ 50 mm (2 in) thick or in cyclic service
Forging Option
Weld Buildup Option
Shell
Shell
Head
Head / skirt
forging
Weld buildup (with
ultrasonic examination)
Upper skirt section (same
material as vessel shell)
Lower skirt section (Carbon steel)
e.
Skirts on vessels 2 m (6 ft) diameter or less shall have at least one access opening. Vessels
over 2 m (6 ft) diameter and skirt heights over 2,5 m (8 ft), two access openings shall be
provided in the skirt.
f.
Minimum skirt access opening shall be 600 mm (24 in) diameter or 450 mm x 900 mm
(18 in x 36 in) obround.
g.
Openings for skirt access and piping shall conform to Figure 3. Additional strengthening
may be provided by increasing the thickness of sleeve.
h.
Unless specified otherwise on data sheets, a minimum of two 50 mm (2 in) radius
semi-circular drain holes 180 degrees apart shall be located at the vessel skirt to base ring
attachment weld. The drain holes shall be staggered 90 degrees from the skirt vent holes.
In applications where the inside of the skirt will be open or grated, the drain opening shall
be omitted.
i.
Skirt openings for piping shall have a 13 mm (1/2 in) maximum clearance between the
pipe outside diameter, including insulation, and skirt opening if inside of skirt is not
fireproofed.
j.
Openings for pipe vents shall conform to Figure 4.
k.
Refer to Table 4 for quantities of skirt vents.
Page 28 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure 3 - Opening for skirt access or for piping
6mm (1/4 in)
6mm (1/4 in)
SLEEVE
MINIMUM SLEEVE
THICKNESS OF t sk
76mm (3 in) MIN
76mm (3 in) MIN
t sk
BASE RING
ACCESS OPENING OR PIPE
Where tsk is skirt thickness
Figure 4 - Opening for a skirt vent
6mm (1/4 in)
OD 114.3mm T8.8mm (NPS 4 SCH. 80)
PIPE SLEEVE
76mm (3 in) MIN
76mm (3 in) MIN
Table 4 - Skirt vents
Vessel Diameter at Skirt Attachment
9.8.2
Number of
mm
in
Skirt Vents
< 900
< 36
2
> 900 to 1 500
> 36 to 60
4
> 1 500 to 2 400
> 60 to 96
6
> 2 400 to 4 500
> 96 to 180
8
> 4 500
> 180
12
Legs or column supports
a.
Leg supports shall not bear on the knuckle or crown of formed heads but conform to one of
the following standard drawings unless otherwise specified on data sheets:
1.
PIP VEFV1112M - Angle type leg without pad
2.
PIP VEFV1113M - Angle type with reinforcing pad
b.
Leg-type supports shall not be used on vessels greater than 1 524 mm (5 ft) diameter or
6 100 mm (20 ft) tan. to tan.
c.
Structural calculations shall be provided to verify adequacy of leg design.
d.
Stress analysis of legs on spheres shall be submitted for review and agreement by
Company.
Page 29 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
9.8.3
Saddles
a.
Unless otherwise specified on data sheets welded saddles shall conform to one of the
following standard drawings:
1.
PIP VEFV1104M - Small horizontal vessel saddle supports
2.
PIP VEFV1105M - Horizontal vessel saddles supported on concrete
3.
PIP VEFV1106M - Horizontal vessel saddles supported on structural steel
b.
Horizontal vessels shall be investigated for buckling and local stresses. The method of L.P.
Zick may be used for this investigation.
c.
Horizontal vessels shall be supported on two saddles only.
d.
Slots shall be provided for the anchor bolts in one saddle to allow for thermal expansion.
e.
The saddle support that is “fixed” and the support that is “sliding” (slotted) shall be
indicated on the fabrication drawings.
f.
Saddles shall be continuously welded to the shell.
9.9
Anchor bolts
9.9.1
General
9.9.2
9.9.3
a.
Calculations determining quantity and size of anchor bolts shall be based on referenced
PIP standard details, and specified on fabrication drawings.
b.
Supply of anchor bolts is not in Supplier’s scope of supply.
c.
Anchor bolts shall not be less than 19 mm (3/4 in) diameter.
d.
Unless data sheets specify high-strength anchor bolts the following shall apply:
1.
Anchor bolts (such as carbon steel, ASTM F1554-36, etc.) shall have an allowable
stress of 138 MPa (20 000 psi) based on the tensile stress area of the threaded portion.
2.
Maximum anchor bolt diameter shall be 76 mm (3 in).
e.
Design loadings for anchor bolts embedded in concrete shall be determined by either the
simplified method (i.e., neutral axis of bolt pattern at centreline of vessel) or the shifted
neutral axis method in conformance to Process Equipment Design.
f.
Unless otherwise specified on data sheets, the design concrete bearing stress shall be
11,4 MPa (1 658 psi) for vessels on concrete foundations.
High-strength anchor bolts
a.
High strength anchor bolts may be used only if specified on the data sheets.
b.
Unless otherwise specified on the data sheets, high-strength anchor bolts (such as
ASTM F1554-105) shall have an allowable stress of 207 MPa (50 000 psi).
Vertical vessel anchor bolts
a.
Anchor bolts shall straddle normal centrelines.
b.
Anchor bolt configuration shall provide radial clearance for a bolt tensioning device.
c.
The number of anchor bolts shall be a multiple of four (4).
d.
All parts of the base ring support system (base ring, chairs, compression ring, gussets,
skirt, etc.) shall accommodate a pretension force on the anchor bolts equal to 75% of the
allowable anchor bolt stress.
Page 30 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
9.10
Internal attachments
9.10.1
General
a.
Internal attachments welded to shells and heads shall be located to permit full visual
inspection of attachment and attachment weld.
b.
Welding of internal attachments to the pressure boundary shall be continuous on all
surfaces to eliminate corrosion pockets.
c.
Internal attachments welded directly to the pressure vessel envelope shall be fabricated
from the same material as the vessel.
d.
Internal attachments shall be naturally draining.
e.
Size of welds shall include the corrosion allowance specified for vessel.
f.
Weld spatter on downcomer bolting bars shall be removed to ensure a flush seal with
downcomer.
g.
If the downcomer does not form a continuous seal with the bolting bars, the downcomer
shall be reassembled with gasket supplied by tray Manufacturer.
h.
Baffles, partitions, and supporting beams shall be designed to accommodate thermal
expansion of vessel shell. Internals, such as mist pads, shall be bolted to support
attachments, not directly welded to shell.
i.
Minimum thickness of welded internal attachments shall be 5 mm (3/16 in) plus corrosion
allowance for each wetted side.
j.
Minimum fillet weld size shall be 5 mm (3/16 in) in the corroded condition.
k.
Seams and corner joints shall be sealed.
l.
Internal attachments shall be designed and installed to satisfy one of the following
requirements:
m.
9.10.2
9.10.3
1.
The distance between the weld-toe of the attachment is not within 50 mm (2 in) of a
pressure boundary weld toe.
2.
The portion of the pressure boundary weld that is covered by the attachment shall be
ground flush and given 100% volumetric examination before internal attachment is
made.
3.
The attachment shall be coped or notched to clear all weld area and each weld-toe by
at least 25 mm (1 in).
The stresses in the attachment and attachment weld shall be checked to ensure they are
within allowable limits of the code of construction.
Manway grab rungs
a.
Manways in vessels shall be supplemented with rungs attached to the inside of the vessel
shell if other internal fixtures do not afford safe footing and handholds for persons entering
or leaving the vessel.
b.
Internal ladder rungs for vertical and horizontal vessels shall conform to drawing number
PIP VEFV1125M unless otherwise specified on data sheets.
c.
Ladder rungs may be extended upwards from the grab rung on vertical vessels if specified
on data sheets.
Vortex Breakers
Vortex breakers shall conform to drawing number PIP VEFV1124M unless otherwise specified
on data sheets.
Page 31 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
9.11
External attachments
9.11.1
General
9.11.2
a.
External attachments welded to shells and heads shall be located to permit full visual
inspection of attachment and attachment weld.
b.
Ladders, platforms and clips shall conform to Annex G unless otherwise specified on data
sheets.
c.
Pipe segments shall not be directly attached to a pressure boundary and used as supports
for ladders, platforms, piping, etc.
d.
Welding of external attachments to the pressure boundary shall be continuous on all
surfaces to eliminate corrosion pockets.
e.
All components welded directly to the pressure vessel envelope shall be fabricated from
the same material as the vessel.
f.
External attachments shall be designed and constructed to prevent the channelling and hold
up of rainwater.
g.
Minimum thickness of welded external attachments shall be 5 mm (3/16 in).
h.
Minimum fillet weld size shall be 5 mm (3/16 in).
i.
Seams and corner joints shall be sealed.
j.
External attachments shall be designed and installed to satisfy one of the following
requirements:
1.
The distance between the weld-toe of the attachment is not within 50 mm (2 in) of a
pressure boundary weld toe.
2.
The portion of the pressure boundary weld that is covered by the attachment shall be
ground flush and given 100% volumetric examination for the length of the overlap
plus at least 50 mm (2 in) on each side before the attachment is made.
3.
The attachment shall be coped or notched to clear all weld area and each weld-toe by
at least 25 mm (1 in).
k.
Stresses in the attachment and attachment weld shall be checked to ensure they are within
the allowable limits of the code of construction.
l.
Galvanised clips or attachments shall not be welded to a vessel.
Insulation supports
a.
Insulation supports shall comprise flat rings, rods, or lengths of angle attached to vertical
vessels in conformance to drawing number PIP VEFV1123M.pages 1, 2 and 5, unless
otherwise specified on data sheets.
b.
Vertical vessel shell insulation shall be supported by one of the following methods:
1.
Support rings which shall conform to the following details and locations shown in
drawing number PIP VEFV1123M:
a)
Type 2 or 3 intermediate ring supports in conformance to detail “J”.
b)
Support rings for vessels with skirts located below the bottom tangent line in
conformance to details “E”, “G” or “H”.
c)
Ring spacing shall be between 3 000 mm (10 ft) and a maximum of 3 700 mm
(12 ft) with the exception of upper support ring which shall be a maximum of
2 400 mm (8 ft) from top tangent line.
Page 32 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
9.11.3
9.11.4
9.11.5
c.
Top heads of vessels insulation shall be supported by a floating ring and type 1 support
ring fitted to the vessel in conformance to details “A” and “J” of drawing number
PIP VEFV1123M.
d.
Insulation for bottom heads of vertical vessels shall be supported by one of the following
methods:
1.
A floating ring and anchor ring fitted to vessels with skirts in conformance to details
“E”, “G” or “H” of drawing number PIP VEFV1123M.
2.
A floating ring and type 1 support ring fitted to vessels without skirts in conformance
to detail “J” of drawing number PIP VEFV1123M.
e.
Rings welded to vertical shell or skirt shall be discontinuous or perforated to prevent the
accumulation of moisture.
f.
Insulation for heads on horizontal vessels shall be supported by a floating ring and anchor
ring fitted to the vessel in conformance to details on page 2 of drawing number
PIP VEFV1122M.
g.
Horizontal vessels with shells 2 450 mm (96 in) diameter or larger shall have longitudinal
supports fitted in conformance to drawing number PIP VEFV1122M.
Fireproofing supports
a.
Fireproofing supports shall be provided and installed on skirts and saddles if concrete
fireproofing is specified on the data sheets.
b.
Fireproofing supports for concrete fireproofing shall conform to details in drawing number
PIP VEFV1123M.
Nameplate brackets
a.
Unless otherwise specified on data sheets vessel nameplate brackets shall conform to
drawing number PIP VEFV1101M.
b.
Nameplate brackets shall be located near a manway and shall not be obstructed if the
manway is open.
c.
For insulated vessels:
1.
Two nameplate brackets shall be provided.
2.
Design code required nameplate shall be installed on a bracket designed to be totally
encased under the vessel insulation.
3.
An additional nameplate bracket and duplicate nameplate shall be attached to the
vessel support, not pressure vessel shell, and project beyond the insulation or
fireproofing material.
Manway davits and hinges
a.
Manways shall be provided with davits or hinges which conform to the following standard
drawings unless otherwise specified on data sheets:
1.
PIP VEFV1116M - Vessel manway hinge
2.
PIP VEFV1117M - Vessel vertical manway davits
3.
PIP VEFV1118M - Vessel horizontal manway davits
b.
Davit and hinge dimensions for manway sizes and (or) flange ratings not listed shall be
determined and design included in calculations for review and agreement by Company.
c.
Selection of davits or hinges shall be as specified on the data sheets.
Page 33 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
9.11.6
d.
Manways orientated at an angle other than 0 degrees or 90 degrees from the horizontal
plane shall be designed with a hinge which opens in the horizontal plane.
e.
Stops shall be provided to prevent damage to vessel shell or insulation from the
over-rotation of the manway hinge or davit.
f.
Eyebolts used in manway davit designs shall be one-piece forgings.
Vacuum stiffening rings
a.
Vacuum stiffening rings shall be designed as a flat bar type and made from plate matching
the vessel plate material specification and grade.
b.
Vacuum stiffening rings shall be continuous fillet welded on the top and bottom of the
ring.
c.
Vessels subject to thermal cycling, such as coke drums, shall not use vacuum stiffening
rings.
9.11.7
Lifting attachments
9.11.7.1
Vertical vessels
a.
Two lifting lugs or trunnions shall be provided on vertical vessels to facilitate handling
during transport and erection at site.
b.
Typical designs of lifting lug are shown in Figure 5 and Figure 6 with dimensions in Table
5 and Table 6. These designs assume that a spreader beam is used keeping loads normal to
the plane of the lugs to a minimum.
c.
Calculations for the design of lifting lugs, trunnions, and other lifting devices shall be
submitted for review and agreement. Calculations shall include the following:
1.
Lifting lug hole diameter D shall be 1,05 x shackle pin diameter.
2.
Bearing stress area shall be 0,75 x pin diameter x (lug + bearing plate thicknesses).
d.
Lifting trunnions shall be fitted if calculations show that vessel is overstressed during lift
with lifting lugs located at top of vessel.
e.
See 7.11 for design of lifting devices.
f.
Attachment of lifting lugs shall be such that water cannot be trapped between the vessel
and lifting lug.
g.
Portion of lifting lug above tangent line shall be flat. Portion below tangent line shall fit to
curvature of vessel.
h.
Weld seams under lifting lugs shall be ground flush.
i.
Length of the lifting lug shall be such that the vessel may be fully insulated prior to the lift.
j.
Lifting lug may be attached to a lifting flange on thick-walled vessels with a formed head
and a top, centre nozzle if specified on the data sheets.
k.
1.
Calculations of the stresses in the nozzle neck and head shall be submitted for review
and agreement. See 7.8b
2.
Lifting flange shall be provided with full bolting.
3.
Lifting lug shall be inserted through the lifting flange and fillet welded on both sides
of the lifting flange.
Stress analysis shall identify the angle which results in the maximum stress at each lifting
point during the lift from horizontal to vertical.
Page 34 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure 5 - Design of light lifting lug
B
A
D
B/
2
R1.5mm (1/16 in)
C
H
LUG REMOVAL LINE
TANGENT LINE
2A
RADIUS ALL
CORNERS
J
WELD SEAM
F
G
FIELD NOTE:
FOR INSULATED
VESSELS,
CUT OFF LUG AS
SHOWN
AFTER ERECTION.
{APPROX. 25mm (1 in)
PROJECTION}
OMIT 13mm (1/2") OR
WELD TO PROVIDE DRAIN
Table 5 - Dimensions of light lifting lugs
Max vessel
erect wt.
kg (lbs)
Thickness
of Plate
mm (in)
A
4 500 (10 000)
13 (1/2)
Width
mm (in)
Length
mm (in)
Dia. of
Holes
mm (in)
B
C
D
150 (6)
400 (16)
9 000 (20 000)
16 (5/8)
190 (7 1/2)
450 (18)
13 500 (30 000)
20 (3/4)
215 (8 1/2)
500 (20)
18 000 (40 000)
25 (1)
230 (9)
500 (20)
See
9.11.7.1.c.1
Page 35 of 96
Height
of side
weld
mm (in)
Weld
leg
size
mm (in)
T.L to
top of
lug
mm (in)
T.L to
bottom
of lug
mm (in)
F
G
H
J
75 (3)
9 (3/8)
250 (10)
150 (6)
130 (5)
9 (3/8)
250 (10)
200 (8)
130 (5)
12 (1/2)
300 (12)
200 (8)
130 (5)
16 (5/8)
300 (12)
200 (8)
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure 6 - Design of heavy lifting lug
B
A
D
H
2
B/
A
R1.5mm (1/16 in)
C
K
LUG REMOVAL LINES
2
E/
TANGENT LINE
A
RADIUS ALL
CORNERS
WELD SEAM
F
J
E
G
OMIT 13mm (1/2 in) OF
WELD TO PROVIDE DRAIN
2 PLACES
Table 6 - Dimensions of heavy lifting lugs
Notch
Brace to
T.L to
Bottom
Width of height
Weld
top of bottom of of brace
notch and side leg size
lug
lug
to T.L.
weld
mm
(in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
A
B
C
D
E
F
G
H
J
K
22 750
(50 000)
25 (1)
225 (9)
460+K
(18+K)
75 (3)
125 (5)
16 (5/8)
225 (9)
225 (9)
45 000
(100 000)
40 (1 1/2)
300
(12)
585+K
(23+K)
100 (4)
125 (5)
22 (7/8)
300 (12)
275 (11)
90 000
(200 000)
50 (2)
400
(16)
760+K
(30+K)
150 (6)
200 (8)
32
(1 1/4)
400 (16)
350 (14)
136 000
(300 000)
65 (2 1/2)
500
(20)
915+K
(36+K)
175 (7)
250 (10)
38
(1 1/2)
500 (20)
400 (16)
181 500
(400 000)
75 (3)
600
(24)
1095+K
(43+K)
200 (8)
300 (12)
44
(1 3/4)
600 (24)
475 (19)
Max
vessel
erect wt.
kg (lbs)
9.11.7.2
Width
mm (in)
See 9.11.7.1.c.1
Length
Dia. of
holes
Thickness
of plate
By
Supplier
Tailing lugs
a.
A typical design of tailing lug is shown in Figure 7 with dimensions in Table 7.
b.
Calculations for the design of tailing lugs, including quantities shall be submitted for
review and agreement. Requirements specified in 9.11.7.1c.1 and 9.11.7.1c.2 shall be
incorporated.
Page 36 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
c.
Tailing lug load shall be determined assuming vessel is lifted from horizontal unless
otherwise agreed.
d.
Tailing lug material shall be the same as the vessel skirt
e.
A skirt stiffening spider shall be provided as required.
Figure 7 - Design of tailing lug
C/L VESSEL
C
B/2
TOP PLATE
B
SKIRT
A
BUTT
WELD
D
A
A
G
BASE PLATE
SECTION A-A
L
25mm (1 in) PLATE
x Ø305mm (12 in)
BOTH SIDES
PLAN
10mm (3/8 in)
BEARING PLATE
Table 7 - Tailing lug dimensions
Max. load per lug
kg (lbs)
Thickness
of plate
mm (in)
A
22 750 (50 000)
30 (1 1/8)
45 000 (100 000)
50 (1 7/8)
67 750 (150 000)
60 (2 3/8)
Length
mm (in)
Dia. of
holes
mm (in)
B
C
D
150 (6)
300 (12)
10 (3/8)
200 (8)
400 (16)
16 (5/8)
230 (9)
430 (17)
Width
mm (in)
See
9.11.7.1.c.1
Weld
leg size
mm (in)
Lug
spacing
mm (in)
G
L
16 (5/8)
90 000 (200 000)
65 (2 1/2)
300 (12)
500 (20)
117 000 (260 000)
70 (2 3/4)
340 (13 1/2)
550 (21 1/2)
16 (5/8)
135 000 (300 000)
75 (3)
355 (14)
560 (22)
16 (5/8)
9.11.7.3
16 (5/8)
By
Supplier
see
9.11.7.2.b
Horizontal vessels
a.
Horizontal vessels shall be provided with lifting lugs welded to the shell if specified on the
data sheets.
b.
Calculations for the design of lifting lugs shall be submitted for review and agreement.
Requirements specified in 9.11.7.1c.1 and 9.11.7.1c.2 shall be incorporated.
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Specification for Pressure Vessels
9.11.8
9.12
9.12.1
Earthing (grounding) bosses
a.
Vessel shall be supplied with two 40 mm (1 1/2 in) diameter x 50 mm (2 in) minimum
length earthing (grounding) bosses each complete with M12 x 30 mm (1/2 in x 1 1/8 in)
brass bolt, flat washer, and phosphor bronze lock washer. Length of earthing (grounding)
bosses may be increased to enable them to protrude fireproofing on supports.
b.
Earthing (grounding) boss material shall be of same quality of supports and attached to the
supports with 6 mm (1/4 in) continuous fillet weld.
Removable internals
a.
All portions of the vessel, including removable internals, shall be completely self-draining.
b.
Removable internals shall be designed or sectioned to pass through vessel manways.
c.
Agitator baffles shall pass through the agitator mounting flange.
d.
Weight of individual parts of components that are normally disassembled such as tray
decks, downcomers, distributor piping, baffles, minor beams, etc. shall not exceed 25 kg
(55 lbs) including attached vapour-liquid contacting devices.
e.
Flanges for internal non-pressure piping may be slip-on or fabricated from plate to the
dimensions of ASME B16.5 Class 150 unless otherwise specified on data sheets.
f.
Trays and other column internals shall conform to GIS 46-040.
g.
All fasteners shall be positively locked by nut and full size locknut or cotter pin. All
fasteners shall be threaded full length.
Mist eliminators
a.
Mist eliminators shall be of the sandwich type consisting of entrainment mesh, retained
between welded grid supports as shown in Figure 10.to Figure 12 and Table 8. Mesh,
grids, bolting, detailed in Figures are in mist eliminator supplier scope but are shown for
clarity.
b.
The screen assembly shall be attached to the support beams at a minimum of four (4)
points per panel with M12 (1/2 in) minimum diameter J-bolts with locknuts.
c.
A pressure drop of 3,5 kPa (0,5 psi) shall be used for vessel support and mist eliminator
grid design unless otherwise specified.
Figure 8 - Mist eliminator used for the full diameter of a vessel
DETAIL A
DETAIL C. (SEE DETAIL D
FOR END CONNECTION
TO SHELL)
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Specification for Pressure Vessels
Figure 9 - Mist eliminator for an enclosed internal cylinder
DETAIL A
OR DETAIL E
DETAIL C. (SEE DETAIL D
FOR END CONNECTION
TO SHELL)
CYLINDER ENCLOSED
Figure 10 - Mist eliminator for a reduced diameter
DETAIL F
DETAIL A
OR DETAIL E
Page 39 of 96
DETAIL C. (SEE DETAIL D
FOR END CONNECTION
TO SHELL)
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure 11 - Mist eliminator attachment details
19mm (3/4 in)
MFG. CLEARANCE (REF)
GRID
MESH
BLANKET
GRID
SEE DETAIL B FOR
SUPPORT RING
A
19mm (3/4 in)
T
19mm (3/4 in)
1/2 in J BOLTS WITH
HEX NUTS. TWO (2)
REQUIRED AT EACH
END OF DEMISTER
SECTION
C/L Ø16mm (5/8 in)
EQUALLY SPACED ON
140mm (5 1/2 in)
APPROX CENTRES
W
W
DETAIL A
C/L
DETAIL B
GRID
MESH
BLANKET
GRID
12mm (1/2 in)
1/2 in J BOLTS WITH
HEX NUTS. TWO (2)
REQUIRED AT EACH
END OF DEMISTER
SECTION
19mm (3/4 in)
19mm (3/4 in)
32mm (1 1/4 in)
45mm (1 3/4 in)
C/L Ø16mm (5/8 in)
EQUALLY SPACED ON
140mm (5 1/2 in)
APPROX CENTRES
DETAIL C
TRIM FLANGE
TOP & BOTTOM
AS REQUIRED
C/L TWO (2) Ø14mm
(9/16 in) HOLES IN CLIP
AND 14mm x 19mm
(9/16 in x 3/4 in)
SLOTTED HOLES IN BEAM
FOR 1/2 in BOLTS.
(TYP EACH END)
DETAIL D
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Specification for Pressure Vessels
Figure 12 - Mist eliminator support details
SEE VESSEL DRAWING
FOR THICKNESS
SECTIONAL DEMISTER.USE
25mm x 6mm (1 in x 1/4 in)
WITH TWO (2) CLIPS PER RING SECTION.
CLIPS TO BE WELDED TO RING.
RING TO BE PROVIDED WITH
Ø16mm (5/8)) HOLES ON
140mm (5 1/2 in) APPROX. CENTRES.
CLIP ANGLE:
38mm x 38mm x 6mm x 38mm LONG.
(1 1/2 in x 1 1/2 in x 1/4 in x 1 1/2 in LONG)
ONE PIECE DEMISTER.
USE FOUR (4) CLIPS ONLY
WITH Ø16mm (5/8 in)
HOLE IN CLIP.
Ø16mm (5/8 in) HOLES
FOR 1/2 in BOLTS
DETAIL E
A
13mm
(1/2 in)
T
SEE VESSEL DRAWING
FOR THICKNESS
C/L
Ø16mm (5/8 in) HOLES EQUALLY
SPACED ON 150mm (6 in) APPROX.
CENTRES FOR 1/2 in BOLTS
W
W
DETAIL F
Table 8 - Mist eliminator dimensions
Demister Nominal
Diameter
Ring
Beams
A
No.
Required
Carbon
Steel
Flange
Web
Up to 450 mm
(18 in)
2
0
_______
_______
_______
451 mm to 1800 mm
(>18 in to 72 in)
2
0
_______
_______
_______
1801 mm to 3600 mm
(>72 in to 144 in)
2
1
IPE 200
(WF 6 X 12)
100 mm x 6 mm
(4 in x 1/4 in)
150 mm x 6 mm
(6 in x 1/4 in)
3601 mm to 5400 mm
(>144 in to 216 in)
3
2
IPE 200
(WF 6 X 12)
100 mm x 10
mm
(4 in x 3/8 in)
150 mm x 10
mm
(6 in x 3/8 in)
Over 5400 mm (216 in)
3
Stainless Steel
Special Design. See Vessel Drawing
Notes:
1. T = 3 mm (I/8 in) plus twice corrosion allowance with 6 mm (1/4 in) minimum thickness.
2. W = T/2 plus corrosion allowance with 5 mm (3/16 in) minimum fillet weld.
9.13
External jackets
Design of half-pipe or pipe section jackets shall conform to one of the following:
a.
ASME BPVC VIII-1 Appendix EE.
b.
ASME BPVC VIII-2 Paragraph 4.11.6.
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Specification for Pressure Vessels
c.
9.14
Half-pipe and pipe section jacket attachment welds to shells and (or) heads shall be full
penetration, full strength welds and 100% PT examined.
Nameplates
a.
Unless otherwise specified on data sheets, nameplates shall be type 316L stainless steel
with the data stamped or engraved with minimum height 4 mm (3/16 in) lettering.
b.
Nameplate shall show at least the following information:
1.
Purchase Order number.
2.
Item number.
3.
Date of manufacture.
4.
Order placed by.
5.
Supplier name.
6.
Supplier serial number.
7.
Design code and its date.
8.
Maximum pressure rating and at coincident temperature.
9.
Minimum design temperature and coincident pressure.
10. Extent of volumetric weld NDE, inspection category or equivalent descriptor.
11. PWHT.
12. Test pressure new.
13. Test pressure corroded.
14. Total weight empty.
15. Required code or statutory markings.
16. Company equipment tag number or a Works Identification Number (of nine digits).
10
11
11.1
Spares
a.
Spares shall be provided as specified on the data sheets.
b.
Minimum spares shall be provided as follows:
1.
Two sets of spare service gaskets shall be furnished for vessel girth, manway, and
blinded flanges.
2.
An additional 10% (minimum quantity 2) for each size of bolting, and nuts shall be
provided.
Fabrication requirements
General
a.
Machining shall be performed after welding or heat treatment if such operations change
machined surface characteristics or geometry such as flange face flatness.
b.
Stainless steel, high nickel alloy, titanium, or zirconium surfaces shall be mechanically
cleaned with stainless steel brushes, stainless steel grit, glass beads, or other high quality
abrasive provided their use does not contaminate the material surfaces.
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Specification for Pressure Vessels
c.
Welder’s and welding operator’s symbols and reference lines may be stamped on the
material, in conformance to the design code, provided that a round-nose stamp is employed
and the symbol is located a minimum of 25 mm (1 in) from the edge of the weld.
d.
The following materials shall not be used to mark on or coat vessels:
1.
Marking inks that contain halogens.
2.
Lubricants.
3.
Crayons.
4.
Adhesives.
5.
Tapes (e.g. duct tape).
6.
Coatings to prevent adhesion of weld spatter.
7.
Paints containing sulphur.
8.
Chlorine compounds that decompose to hydrogen chloride.
9.
Carbon.
10. Harmful metal or metal salts (e.g., zinc, lead, or copper).
e.
11.2
All tools used for machining shall be dedicated for use on specific CRA material. Carbon
steel tools or other steel tools dedicated to different materials shall not be used.
Tolerances
a.
Tolerances shall be in conformance to drawing number PIP VEFV1102M sheets 1 and 2.
b.
Tolerances shall be specified on the fabrication drawings in either the main dimensions or
as an additional tolerance drawing.
c.
Allowable flatness tolerances of gasket contact surfaces of flanged shell girth joints, after
PWHT if required, shall be as shown in Table 9 for the designated service condition.
Table 9 - Flatness tolerances of gasket contact surface
Vessel diameter mm (in)
< 380 (15)
> 380 (15) to 760 (30)
> 760 (30) to 1 140 (45)
> 1 140 (45)
Allowable tolerance mm (in) (1)
Normal service
Special service (2)
0,8 (0,03)
0,8 (0,03)
0,8 (0,03)
0,8 (0,03)
0,08 (0,003)
0,150 (0,006)
0,225 (0,009)
0,300 (0,012)
Notes:
1. Total tolerance on peripheral gasket contact surface shall not occur on less than a
0,35 radian (20 degree) arc.
2. Design temperatures greater than 454°C (850°F), or a flange rating greater than
ISO PN 110 (ASME Class 600).
11.3
Joints
11.3.1
General
a.
Location of all longitudinal and circumferential joints shall be shown on the fabrication
drawings.
b.
If two sections of unequal thickness are butt welded together, the inside (process face)
shall be flush.
c.
Weld joints shall be prepared by machining, grinding, or thermal cutting.
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Specification for Pressure Vessels
11.3.3
If thermal cutting is performed, the joint surfaces shall be ground to sound metal prior
to welding.
2.
Preheat requirements for thermal cutting shall be the same as specified in the WPS.
d.
Except as permitted in 11.3.1e, longitudinal joints shall be located to clear nozzle
openings, nozzle attachment welds, and reinforcing pad attachment welds by at least
50 mm (2 in), measured weld toe to weld toe.
e.
The following shall apply if a nozzle opening, nozzle attachment weld, reinforcing plate,
or reinforcement plate weld is located on a longitudinal or circumferential weld.
f.
11.3.2
1.
1.
It shall be demonstrated to Company that plates cannot be re-orientated or relocated
in instances where the required weld toe clearance is not achieved.
2.
Alignment of the butted plates under the reinforcement plate shall be flush.
3.
Longitudinal or circumferential weld shall be ground flush and given 100%
volumetric and surface examination for a length equal to three times the diameter of
the opening before attachment of pad.
4.
Location of the nozzle and weld seam shall be agreed by Company.
Welds subject to severe forming, where ratio of thickness to local radius is greater than
5%, shall have full volumetric examination before forming and full surface examination
after forming.
Longitudinal joints
a.
Longitudinal seams shall not fall within the tray-downcomer area of trays or behind other
large obstruction that prevents inspection of the welds.
b.
Longitudinal joints shall be offset between courses by at least five times the plate
thickness, or 150 mm (6 in), whichever is greater.
c.
Longitudinal joints shall be located to maximise access for internal visual inspection,
consistent with the presence of the internals.
d.
Longitudinal joints in horizontal vessels shall not be located:
1.
Under the saddle or saddle wear plate.
2.
Within 50 mm (2 in) of the saddle or saddle wear plate attachment welds.
3.
Within 15 degrees of the horn of the saddle or saddle wear plate.
Circumferential joints
a.
Circumferential joints shall be located at least 50 mm (2 in) above or below the tray ring
attachment welds.
b.
Circumferential joints shall be located at least 50 mm (2 in) away from horizontal vessel
saddle or saddle wear plate attachment welds.
11.4
Welding
11.4.1
General
a.
Butt joints shall be full penetrations.
b.
For butt joints inaccessible from the inside, a method for obtaining a full penetration and
full fusion weld from one side shall be submitted for Company review and agreement.
c.
Butt joints shall not use permanent backing strips.
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Specification for Pressure Vessels
d.
All welds, including internals, non-pressure parts and attachments, temporary attachments
and shipping attachments, shall be made by welders, welding operators, and welding
procedures qualified under the provisions of the pressure vessel code and agreed by
Company.
e.
The following documents shall be provided to Company for review and agreement before
the start of fabrication:
Welding procedure specification.
2.
Procedure qualification record.
3.
Welder performance qualification.
4.
Detailed weld map.
5.
Welding procedures.
6.
Fabrication drawings.
f.
The detailed weld map shall include, as a minimum, a sketch of all weld joints, welding
symbols used in conformance to AWS A2.4, and associated weld procedure numbers.
g.
Arc strikes shall be conditioned to eliminate surface stress concentrations.
h.
Defects found from arc strikes shall be removed and the surface shall be repaired and
re-examined.
i.
Significant weld repairs shall be subject to agreement by Company.
j.
Removable start-up and run-off tabs may be used for longitudinal welds. The tab materials
shall be of the same material specification and grade as the base metal.
k.
Unless specifically agreed by Company, use of weld materials with strengths higher than
that of low-hydrogen weld materials for any welding processes shall not be permitted.
l.
Welding consumables shall:
m.
11.4.2
1.
1.
Be the same nominal composition as the parent metal.
2.
Not contain addition of alloys via the flux, other than that required to make up for
losses (e.g., in the arc).
3.
Filler wire shall conform to GIS 18-012.
4.
Have material properties such as, tensile strength or yield strength, equal to or greater
than the minimum requirements for the base metal at ambient and design temperature.
A local DHT shall be performed for butt-welds and corner joint welds (i.e., ASME weld
category A, B, and C) that are 50 mm (2 in) and greater in thickness (See Annex E).
Welding processes
a.
The following welding processes shall not be used:
1.
Self-shielded flux-cored arc (FCAW).
2.
Welding process agreed by Company for a different Purchase Order, but not
submitted or agreed for the subject Purchase Order and item.
b.
Manual shielded metal arc with covered electrode (SMAW) of carbon and low alloy steels
shall be made using low hydrogen electrodes.
c.
Semi-automatically submerged arc (SAW) may be used.
d.
Gas metal arc using solid wire (GMAW) may be used.
1.
The type of metal transfer (short-circuiting arc, globular or spray transfer) shall be
specified on the WPS under electrical characteristics.
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Specification for Pressure Vessels
11.4.4
The process is applicable to carbon steel and weld overlay if a satisfactory level of
dilution is demonstrated.
3.
GMAW using a short-circuiting arc shall only be used for depositing metal that is
subsequently removed.
4.
Field welding is subject to Company agreement.
e.
Gas tungsten arc, manual or automatic (GTAW) may be used.
f.
Gas shielded flux-cored arc (FCAW) may be used.
g.
11.4.3
2.
1.
The type of metal transfer shall be specified on the WPS. Globular or spray is
permitted but using a short-circuiting arc is prohibited.
2.
Rutile wire may be used for welding carbon and low alloy steels and stainless steel.
FCAW shall not be used for other alloys.
3.
Basic cored wires may only be used for the deposition of fill passes in butt welds in
the 1G and 1GR position.
4.
For welds subject to PWHT and requiring impact testing, the FCAW brand name for
rutile wires shall be an essential variable.
5.
Fillet welding procedures in 1F and 2F positions shall be separately qualified for leg
length greater than 6 mm (1/4 in).
The use of metal cored wires is subject to specific agreement by Company.
Weld procedure and welder qualification
a.
Changes to the agreed WPS or PQR shall also be submitted for review and agreement by
Company.
b.
The WPQ shall be made available for review upon request.
c.
Repair procedures shall be submitted for review and agreement if the repairs could be
detrimental to the material (either in terms of mechanical performance of corrosion
performance in service) or delivery of the vessel.
d.
Unless otherwise agreed, the position of the impact test specimens for tests of weld metal
and HAZ shall be:
1.
Weld metal centreline.
2.
Fusion line.
3.
Fusion line plus 2 mm (1/16 in).
4.
Fusion line plus 5 mm (1/4 in).
Dissimilar welds between austenitic stainless steels and ferritic steels
a.
Welds joining austenitic stainless steels to ferritic steels shall be made with filler metal as
follows:
1.
2.
For services not exceeding 340°C (650°F), one of the following shall be used:
a)
ASME SFA-5.4 classification E309L.
b)
SFA-5.9 classification ER309L.
c)
The filler metals given in 11.4.4a.2 below.
For services exceeding 340°C (650°F), one of the following shall be used:
a)
ASME SFA-5.14 classification ER NiCr-3.
b)
ASME SFA-5.11 classification E NiCrFe-3 or E NiCrFe-2.
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Specification for Pressure Vessels
11.5
12
12.1
c)
Another filler metal as specified on the data sheets.
d)
Company agreement is required for dissimilar welds in services exceeding
340°C (650°F).
b.
Preheat shall be based on the ferritic material.
c.
The first layer of weld overlay deposits shall be made using the preheat required for the
base plate.
d.
Subsequent weld layers may use the preheat required for the alloy deposits.
e.
Proposals for dissimilar welds that require a PWHT shall be submitted to Company for
review and approval
Temporary welded attachments
a.
Attachment point of spiders, braces, or other temporary attachments shall be of the same
material alloy as the point on the vessel to which it is attached.
b.
Temporary welds shall conform to 11.4.1d.
c.
Temporary clips, brackets and other fabrication aids shall be removed flush with vessel
without damage to base metals.
1.
Gouges from cutting tools shall be welded with an agreed procedure and ground flush
to a finish in conformance to the pressure vessel welding code.
2.
Areas where attachments have been removed shall be subjected to examination by
PT/MT, in addition to visual examination, to ensure no cracks have been generated.
3.
Temporary attachment removal and repairs shall be performed prior to PWHT and
hydrotest.
4.
Peening shall not be used.
Examination requirements
General
a.
The extent of examination and special documentation, in addition to the minimum
requirements of the design code, shall be as specified in the Purchase Order documents.
b.
All specified NDE shall be performed in conformance to the design code.
c.
For specific welded pressure joint examination requirements, see the data sheets.
d.
The minimum degree of examination of welded butt joints shall be spot radiography.
e.
Accessible surfaces of completed corner joint welds shall be examined by MT, PT, UT, or
other non-destructive methods in conformance to Company’s Purchase Order documents.
f.
Welded joints that are inaccessible after assembly shall be examined by PT or MT in
conformance to the following instructions, and repaired as required before painting,
assembly, and testing:
g.
1.
After back-chipping to sound metal, the root pass and its opposite side shall be
examined.
2.
After any required machining or grinding, the finished surfaces of the weld shall be
examined, and all indications on the finished weld surfaces shall be repaired by
grinding or welding before pressure testing.
Imperfections shown to be unacceptable during examination shall be repaired and then, as
a minimum, the repair shall be examined by the same method, to the same extent, and by
the same acceptance criteria that revealed the condition.
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Specification for Pressure Vessels
h.
The following items shall be examined by MT or PT:
1.
2.
3.
The following surfaces of butt-type joints greater than 50 mm (2 in) thick:
a)
The surface of sound metal after back-chipping or gouging root pass to metal
surface.
b)
All accessible surfaces of completed weld.
The following surfaces of non-butt type joints, including surfaces in nozzles and
manways, if the vessel section or head is designed using a joint efficiency of 1.00:
a)
The surface of sound metal after back-chipping or gouging root pass to metal
surface.
b)
All accessible surfaces of completed weld.
The cut edge of openings in vessel walls greater than 13 mm (1/2 in) thick into which
nozzles and manways are attached with a full penetration weld through the nozzle or
manway wall.
a)
4.
i.
12.2
12.3
Examination shall be performed before nozzle attachment, and a re-examination
performed after attachment if accessible.
All accessible surfaces of completed welds for the following:
a)
Internal and external welds if the thickness of the pressure part is greater than
50 mm (2 in).
b)
Welds attaching vertical vessel supports.
c)
Welds attaching vessel lifting lugs.
d)
Welds attaching manway davits.
Fracture mechanics assessment of weld flaws shall not be used to justify weld defects not
permitted by the design code.
Preparation
a.
The NDE schedule and NDE procedures shall be submitted to Company for review and
agreement.
b.
Personnel concerned with inspection, interpretation, and NDE shall be qualified to at least
PCN Level 2 or ASNT Level 2 if the qualification has been obtained through examination
by an independent organisation. Evidence of the qualification shall be available to
Company for verification.
c.
Company reserves the right to test and monitor the performance of any NDE operator and
to exclude any that are deemed unsatisfactory.
d.
Calibration certificates for NDE equipment shall be available for inspection at all times.
e.
Before fabrication, materials shall be visually inspected for defects on accessible surfaces.
f.
Heads and shell sections that are annealed or normalised shall be free of mill scale prior to
inspection.
g.
Materials for marking, painting, or inspection on stainless or nickel based alloys shall not
contain chlorine, bromine, or other halogens, sulphur, zinc, or low melting point metals.
Examination of materials
a.
Plates of thickness 50 mm (2 in) and above shall be subject to UT check for laminations.
b.
Forgings of thickness 50 mm (2 in) and above shall be subject to a 100% UT check for
subsurface defects.
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Specification for Pressure Vessels
12.4
Surface examination of welds
a.
Extent of surface examinations, location selection, acceptance criteria, repair method, and
re-examination required in this Specification shall be performed in conformance to the
specified design code.
b.
Welds shall be free from surface breaking defects.
c.
Pressure welds in ferritic materials, not subject to RT or UT, shall be examined by MT at
back-chipped surface and at finished weld surface.
d.
Skirt attachment welds of ferritic materials shall be examined by MT.
e.
On ferritic vessels subject to PWHT, the shell to nozzle welds on nozzles greater than
DN 200 (NPS 8) shall be subject to MT after PWHT.
f.
Magnetic particle inspection techniques liable to damage the vessel by arcing shall not be
permitted.
g.
After hydrotest, the following surface examinations shall be made:
1.
MT on external welds and the location of temporary welds.
2.
Internal welded surfaces and HAZs, including pressure boundary welds, internal
attachment welds, and the location of temporary welds may be inspected by WFMT
after PWHT and hydrostatic test if specified on the data sheets. Indications revealed
by WFMT shall be removed.
3.
Areas requiring repairs shall be given PWHT after welding, equipment shall be
hydrostatically re-tested and repaired area shall be re-inspected by WFMT.
4.
Surface preparation for WFMT inspection shall be accomplished by:
5.
12.5
a)
Blasting to SSPC SP 5/NACE No. 1 (white metal) with fresh aluminium oxide
or coal slag grit.
b)
If agreed, power wire brushing or grinding to a clean metal surface for limited
areas not accessible for sand-blasting.
For small pressure vessels if internal inspection after hydrostatic testing is
impractical, the following shall apply:
a)
Welds identified for WFMT shall be inspected by WFMT prior to making final
closure seam.
b)
Inaccessible welds shall be inspected by UT from outside surface after
hydrostatic testing.
Volumetric examination of welds
a.
Extent of volumetric examinations, location selection, acceptance criteria, repair method,
and re-examination required in this Specification shall be performed in conformance to the
specified design code.
b.
Volumetric examination of welds shall use the following recordable NDT methods.
c.
1.
X-ray source.
2.
Radio isotope gamma ray source (with restrictions listed in 12.5c).
3.
Digital RT.
4.
TOFD UT equipped with creeping wave probe(s).
5.
Phased array UT.
Gamma ray shall be subject to the following restrictions. Isotopes not listed below shall not
be used.
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Specification for Pressure Vessels
12.7
Iridium-192 shall only be used for thicknesses of 5 mm (3/16 in) up to and including
38 mm (1,5 in).
2.
Cobalt-60 shall only be used for thicknesses greater than 38 mm (1 1/2 in) up to and
including 50 mm (2 in).
3.
Selenium-75 shall only be used for thickness of 5 mm (3/16 in) up to and including
30 mm (1,125 in). The source design shall be thermally stable and non-activating.
4.
Elemental selenium shall not be used.
5.
The RT film density shall be between 2,5 and 3,5 inclusive.
6.
The RT film shall be high definition film.
7.
A radiation survey meter in good working condition and calibrated for the types and
energies of gamma radiation being used shall be available at the work location.
d.
For thickness greater than 50 mm (2 in), recordable UT methods such as TOFD UT
equipped with creeping wave probe(s) or phase array UT shall be used.
e.
If PWHT is performed, all volumetric examinations for record shall be done after any
PWHT.
f.
For vessels constructed to ASME Section VIII:
g.
12.6
1.
1.
Ferritic plates below 50 mm (2 in) thick shall be UT inspected, if required or
specified, in conformance to ASME SA-578/SA-578M, including Supplementary
Requirements S1, S2, S3, and S4. Acceptance Level C shall be used.
2.
Ferritic plates of thickness 50 mm (2 in) and above shall be UT inspected, if required
or specified, in conformance to ASME SA-435/SA-435M.
3.
Ferritic forgings shall be UT inspected, if required or specified, in conformance to
ASME SA-541/SA-541M including Supplementary Requirement S2.
For vessels constructed to BSI PD 5500:
1.
UT inspection of plate shall be in conformance to EN 10160. The required quality
classes shall be S1 for the through thickness check (on 100 mm grid) and E1 for the
edge check, unless otherwise specified by Company.
2.
Forgings shall be MT tested to EN 10228-1 and the required quality class shall be
class 3 unless otherwise specified by Company.
3.
Forgings and pipe shall be UT tested per EN 10228-3. The required quality class shall
be class 3 unless otherwise specified by Company.
Hardness testing
a.
Hardness testing shall conform to GIS 36-102.
b.
The hardness of weld metal and the heat affected zones for carbon-steel, C-Mn and low
alloy steels as measured on the vessel shall not exceed 200 HBW, unless otherwise
specified on data sheets.
c.
The maximum requirements for other materials (other than carbon-steel, C-Mn and low
alloy steel) shall conform to Table 2-8 of ASME section II part A.
d.
The upstream hardness requirements shall conform to NACE MR0175/ISO 15156-2 and 3.
e.
The downstream hardness requirements shall conform to NACE MR0103 and
NACE SP0472.
Repair of welding defects
a.
Repairs of weld defects shall be considered major if one of the following exists:
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12.8
12.9
1.
The defect size exceeds 9 mm (3/8 in) in depth.
2.
The defect size exceeds one-half the wall thickness of the component.
3.
The defect resulted in leakage during a pressure test.
b.
Weld repairs shall receive surface examination.
c.
Major weld repairs shall receive full volumetric examination.
Positive materials identification (PMI)
a.
PMI shall conform to GIS 36-103.
b.
PMI shall be performed to the extent specified on the data sheets and other documents in
Purchase Order.
c.
The PMI procedure shall be submitted for review and agreement.
Production control test plates
Production control test plates shall be supplied if specified on data sheets or required by the
design code.
13
14
Inspection requirements
a.
Company’s inspection requirements, including, review, witness, inspection, hold points,
and inspection documentation are furnished on the Purchase Order quality requirements or
other quality related documents included in the Purchase Order.
b.
Company’s inspector shall be notified and given the option of inspecting major
components or services at their point of manufacture.
c.
Company’s quality surveillance and notification requirements shall be included in all
suborders.
d.
Certified drawings shall be available for use by Company’s inspector at the point of
manufacture.
e.
Inspections shall be performed for conformance to Company’s Purchase Order documents.
f.
The performance of quality surveillance by Company’s inspector shall not relieve the
Supplier or manufacturer of responsibility for conforming to the requirements of the
Purchase Order documents.
Post weld heat treatment
a.
Unless otherwise agreed by Company, alternative PWHT requirements of
ASME BPVC VIII-1 Table UCS 56.1 or ASME BPVC VIII-2 Table 6.16 shall not be
used.
b.
Unless otherwise specified on the data sheets, PWHT of test specimens shall include one
extra PWHT cycle for potential future field repair.
c.
PWHT shall be performed after all welding, weld repairs, and non-destructive examination
is completed before and after pressure testing.
d.
Furnaces used for PWHT shall be constructed to prevent flame impingement on the vessel.
e.
A PWHT procedure shall be submitted to Company for approval and shall include as a
minimum:
1.
Furnace description.
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15
15.1
2.
Loading pattern.
3.
Details and locations of supports and bracing.
4.
Thermocouple locations.
5.
Heating and cooling rates.
6.
Soak time and temperatures.
f.
All PWHT shall be recorded and documented by temperature and time charts.
g.
Except as specified in Annex C clause C.1b, pressure parts made of austenitic stainless
steel, if hot formed, shall be solution annealed between 1 010°C (1 850°F) and 1 120°C
(2 050°F) followed by rapid cooling through the sensitization range.
h.
Vessels shall not come into contact with galvanised components during PWHT.
i.
On ferritic vessels subject to PWHT, the shell to nozzle welds on nozzles greater than
DN 200 (NPS 8) shall be subject to MT after PWHT.
j.
Local PWHT procedures shall be submitted to Company for review and approval.
k.
Vessels shall be PWHT in one section unless prior agreement has been reached with
Company.
Pressure test
General
a.
Unless otherwise specified on data sheets, the test pressure shall be based on the MAP
(new and cold).
b.
Prior to the pressure test, the inside and outside of the vessel shall be thoroughly cleaned,
free from slag, scale, dirt, grit, weld splatter, pieces of metal, paint and oil. Welds shall be
free of slag, oil, grease, paint, and other foreign substances that might prevent
interpretation of the required tests.
c.
Vessels shall not be painted or controlled shot peened before the pressure test, with the
following exceptions:
1.
Surfaces that are to be painted, but are inaccessible after assembly, such as mating
surfaces of lap-joint stub ends, flanges and nozzle necks, flange bolt holes, welded
joints, shall be painted before assembly and pressure testing.
2.
Welded joints that are inaccessible after assembly, such as joints covered by lap-type
flanges, shall be examined by PT or MT and repaired before painting, assembly and
pressure testing. See 12.1f for specific examination requirements.
d.
The test pressure shall be measured at the high point of the vessel in the test position.
e.
Welds shall be cleaned and free of scale or paint before pressure testing to permit
examination for defects.
f.
Reinforcing pad attachment welds and accessible surfaces of inside nozzle to vessel wall
welds shall be tested for leaks with a gauge pressure of 100 kPa (15 psig) dry air or
nitrogen and bubble forming solution. Test shall be performed before the final hydrostatic
or pneumatic test.
g.
All facilities and materials, including blinds, bolting, and gaskets, required for testing shall
be provided.
h.
The service bolts shall be used for the pressure test.
i.
The temperature of the pressure-retaining components during the pressure test, regardless
of test media, shall be:
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j.
15.2
1.
At least 15ºC (60°F), but not higher than 50ºC (120ºF) and
2.
At least 17ºC (30ºF) higher than the vessel minimum design metal temperature.
Gaskets shall be used for test purposes in conformance to the following:
1.
The specified service gasket shall be used. If a flanged joint is not being disassembled
after testing, service gaskets used for testing shall be left installed for shipment for all
blind flanged connections.
2.
Flanged joint assemblies fitted with service gaskets, such as main body flange joints,
manways, blind flange nozzles, and disassembled following tests shall be
reassembled using new service gaskets. If the joints are shipped unassembled, new
service gaskets for field installation shall be packaged, marked, and shipped with the
vessel. See 17.1c.
3.
Joints being disassembled after testing, employing nonstandard flanges and service
gasket is not specified, the test gasket description shall be submitted to Company for
agreement.
k.
Joint sealing compound or gasket lubricant shall not be used.
l.
Bolting and washers used for testing shall be lubricated for assembly before the initial
hydrostatic test.
m.
Leakage shall not be permitted at the time of the required inspection except for leakage
that can occur at temporary closures for openings intended for welded connections.
n.
Leakage from temporary seals shall be directed away from vessel to avoid masking leaks
from other joints.
o.
Sensitive leak tests, if specified, shall be performed before hydrostatic testing.
p.
Welding, burning, or grinding, including cosmetic grinding of pressure retaining welds,
shall not be performed on vessels that have been pressure tested unless agreed by
Company. This includes but shall not be limited to welds for shipping attachments,
refractory or insulation clips, stiffeners, spiders, or grinding for surface preparation.
q.
If field assembly and erection is specified in the Purchase Order documents, the final
pressure test shall be performed at the installation site. A detailed test procedure shall be
provided to Company for review before testing.
r.
If hydrostatic testing at the installation site is specified in the Purchase Order documents,
Company shall furnish a fill line and a drain line for the test water at a location adjacent to
the test site.
s.
A detailed test procedure shall be submitted to Company for review and agreement.
Hydrostatic test
a.
Liquids other than water may be used for hydrostatic testing in conformance to the design
code, if specified on the data sheets.
b.
Horizontal vessels designed to support a full weight load of water shall be tested resting on
its support saddles, without additional supports or cribbing.
c.
Vertical vessels being tested in the erected position, whether shop or field, shall have
design consideration given to the additional pressure and weight from the fluid head.
d.
Vessels shall be supported during the pressure test to prevent damage.
e.
Testing of vessels shall be performed with test water that is clean and free of debris.
f.
Water shall not contain more than 10 ppm suspended solids.
g.
Brackish or untreated water shall not be used.
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15.3
h.
Except as permitted in 15.2i, testing of vessels or components made of austenitic stainless
steel materials shall be performed with water containing a maximum of 30 ppm chloride.
i.
If the duration of the test procedure is 72 hours or less and the procedure includes rinsing
with water containing less than 30 ppm chloride, testing of vessels or components made of
austenitic stainless steel materials may be performed with water containing greater than
30 ppm chloride but less than 250 ppm chloride.
j.
Test water shall not be in contact with austenitic stainless steel for greater than 72 hours
unless treated with a biocide.
k.
Before application of the test pressure, the test water and the vessel material shall be
permitted to equalise to approximately the same temperature.
l.
The test pressure shall be held for a minimum of one hour, or as specified on data sheets.
m.
After completion of the hydrostatic test:
16.1
The vessel shall be immediately drained.
2.
Standing water (including on internals) shall be wiped dry and shall not be allowed to
evaporate to dryness.
3.
Vessel shall be closed as quickly as practicable.
Pneumatic test
a.
Detailed, written procedures for pneumatic testing shall be submitted for review and
agreement by Company.
b.
If acoustic emission monitoring of the pneumatic test is specified on the data sheets,
procedures for the monitoring shall be submitted to Company for review and agreement.
c.
The pneumatic test medium shall be one of the following:
d.
16
1.
1.
Inert gas.
2.
Clean, dry, oil-free air in conformance to ISO 8573-1 Class 1, 2, or 3 air, with a dew
point ranging from -20°C to -70°C (+4°F to -94°F).
Pneumatic testing shall not be permitted unless:
1.
Hydrostatic testing is not practical as determined by Company.
2.
Butt-welds have received full volumetric examination.
3.
Attachment welds, including weld attaching non-pressure parts to pressure parts have
received full surface examination.
4.
Non-essential personnel have evacuated the testing area for a safe distance specified
in ASME PCC-2 Article 5.1.
5.
Supplier demonstrates that all materials used ensure fracture toughness during the test
at the test temperature.
Cleaning, surface preparation, painting, and marking
Cleaning
a.
The vessel shall be thoroughly cleaned inside and outside.
b.
Grit, scale, oil, grease, weld rod stub ends, sand, water, free moisture, and all other foreign
material shall be removed from the vessel.
c.
High alloy vessels shall be blown dry with ambient temperature air, only after all standing
water has been removed.
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d.
16.2
The following vessel cleaning procedure shall be performed before shipping, if specified
on the data sheets:
1.
Perform solvent or detergent wash.
2.
Rinse.
3.
Perform wet-dry test in conformance to ASTM A380.
4.
If rust stains appear in wet-dry test, acid clean with passivation solution.
5.
Repeat wet-dry test.
6.
If rusting reappears, consider pickling solution.
7.
Rinse.
8.
Dry.
Surface preparation painting and non-metallic lining
a.
Surface preparation, external painting and non-metallic internal lining shall conform to
GIS 06-602.
b.
Internal and external surface preparation, priming, painting and lining shall only proceed
after completion of pressure tests.
c.
Austenitic alloy steel and nickel-iron-chromium alloy material parts with design metal
temperatures above 400°C (750°F) shall not be painted.
d.
External coating and internal lining shall be as specified on the data sheets.
e.
Removable lifting flanges, removable tailing lugs shall be painted yellow.
f.
Lifting devices that are intended to be cut off after erection shall receive full surface
preparation, priming, and painting as the component it is attached to, except the final
colour shall be yellow for the areas that are to be cut off.
g.
The Company inspector shall have absolute and immediate authority to reject any stage of
surface preparation, priming, painting or lining.
h.
Rejected surface preparation, priming, painting or lining shall be remediated as instructed
by the Company inspector to include possibly re-surface preparation on the entire vessel.
i.
Vessels coated with non-metallic linings shall conform to the following additional
requirements:
1.
All butt and fillet welds shall be ground smooth.
2.
Grinding shall be kept to a minimum to achieve a minimum radius of 6 mm (1/4 in)
for a smooth surface for the lining.
3.
Nozzles and manways shall be flush on the lining side with all corners rounded to a
radius of 6 mm (1/4 in).
4.
All outside corners and edges shall be ground to a minimum radius of 6 mm (1/4 in).
See Figure 13 for typical details. Fillet welds that are to be ground shall be oversized,
so that the grinding the radius does not reduce the fillet weld throat dimension below
the minimum Code thickness.
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Figure 13 - Surface Contours
5.
Partitions, braces, supports or other attachments on the lined side of the vessel shall
be fitted flat against the vessel surface and continuously welded around the entire
perimeter. See Figure 14 for typical details.
Figure 14 - Internal attachments
16.3
6.
Pockets or crevices that cannot drain or be abrasive-blast cleaned shall not be
permitted.
7.
Lined bolt holes shall be drilled oversized for the lining. All edges shall be rounded to
a radius of 6 mm (1/4 in) by grinding.
Marking
a.
Markings shall be in the English language.
b.
Markings shall also be in an additional language if specified on the data sheets or
Purchaser Order documents.
c.
Markings shall be at least 150 mm (6 in) high letters in contrasting paint.
d.
PWHT vessels shall have the following notice painted on two sides of the shell and
insulation covering, if present, in three-inch high letters visible in the shipping position
from grade (See 11.1d):
POSTWELD HEAT TREATED - DO NOT BURN OR WELD
e.
Vessels with non-metallic linings shall have the following notice painted on two sides of
the shell and insulation covering, if present, in three-inch high letters visible in the
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Specification for Pressure Vessels
shipping position from grade (See 11.1d):
LINED VESSEL - DO NOT BURN OR WELD
f.
The marking on vertical vessels shall be located on two opposite sides near the bottom
tangent line and repeated at approximately each 3 m (10 ft) of height, but rotated
π/2 radians (90 degrees).
g.
The markings on horizontal vessels shall be located on both sides near the horizontal
centreline.
h.
The North and East orientations shall be centre-punched on the outside of each vertical
vessel approximately 150 mm (6 in) above the bottom tangent line and 150 mm (6 in)
below the top tangent line. The punch marks shall be circled with white paint.
i.
The Purchase Order number and the vessel identification number shall also be painted with
contrasting paint on non-pressure attachments such as saddles, skirt, or support brackets.
j.
Temporary support components required for maintaining vessel roundness or shipping
shall be painted yellow and marked:
SHIPPING/FABRICATION DEVICE. REMOVE BEFORE UNIT STARTUP.
k.
17
17.1
The centre of gravity of the vessel shall be marked in contrasting paint.
Preparation for shipment
General
a.
Each vessel and vessel internals shall be packaged, supported and protected from damage
or loss during handling and shipment.
b.
Certified weight shall be obtained for the vessel prior to shipment preparations if specified
on the data sheets.
c.
A packing list shall be included in each shipment.
d.
Spares shall be packaged, marked, and shipped with the vessel.
e.
Bolting and other loose parts shall be packaged and identified with the Purchase Order
number and vessel tag number.
f.
Uncoated bolts and nuts shall be coated with a thread lubricant to prevent corrosion during
transportation and storage. The lubricant shall be easily removable with mineral spirits or a
solvent.
g.
Internals which cannot be safely shipped in place shall be identified, tagged, and shipped
separately.
h.
A minimum of one of each type of internals which have specified clearances or tolerances,
such as tray type or distributor type, shall be trial assembled into the vessel to ensure fit-up
before shipment.
i.
Design and construction details for shipping saddles shall be submitted to Company for
review and agreement.
j.
Austenitic stainless steel vessels shall be protected from exposure to salt water, salt spray,
and chlorides during ocean or over the road shipment.
k.
Vessels that undergo ocean shipment shall have a preparation and shipping plan submitted
for agreement.
1.
Vessels shall not be transported to the jobsite as above-deck cargo without prior
written agreement of Company.
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2.
l.
17.2
Packaging and protection shall be designed for outdoor storage for a minimum period of
6 months, unless otherwise specified in Purchaser Order.
Preparations for the vessel
a.
17.3
Vessels containing nitrogen shall be clearly marked identifying that nitrogen is
present. The method and location of such marking shall be agreed upon between
Supplier and Company.
Flanged openings shall be protected with one of the following:
1.
Plastic flange protectors.
2.
Metal flange protectors with rubber gaskets.
b.
Covers for flanged opening shall be secured with at least 25% complement of total flange
bolting (minimum of 4 bolts).
c.
Welding stub ends shall be protected with plastic caps.
d.
Threaded couplings shall be protected with bull plugs and sealed with joint compound.
e.
Socket weld fittings shall be protected with plastic caps.
f.
Weld bevels shall be closed with plastic caps.
g.
Nozzles, including attached piping, within or passing through vessel support skirts shall be
supported for shipping and handling.
h.
Machined surfaces (except weld bevels), flange faces, threaded surfaces, and other finished
or delicate parts shall be well-greased and protected against rusting and damage during
shipment.
i.
Weld bevels shall be free of dirt, oil, grease, scale, rust, and other foreign materials.
j.
Weld bevels of carbon steel and ferritic alloy steel materials shall be coated, after cleaning,
on the inside and outside for a distance of approximately 75 mm (3 in) from the end of the
weld bevel with a weldable rust preventive agreed by Company.
k.
Holes in reinforcing pads and saddle wear plates shall be plugged with RTV silicone sealer
or rust preventative grease that shall not damage the base material.
l.
Blind flanged connections, including manways, shall have the blinds attached with a full
complement of new service bolts and service gasket.
m.
Joints shall be assembled in conformance to ASME PCC-1.
n.
Saddle extensions constructed of timber or other materials shall be secured to permanent
saddles of horizontal vessels if the saddles are used for support during shipment.
o.
Saddle extensions shall provide the required ground clearance for boot or nozzle
projections that extend below the permanent saddle base plate.
Preparations for spares and crated parts
a.
Items shipped not attached to the vessel shall be packaged and crated for secure shipment.
b.
Parts with nozzles, flanges, or connections, such as piping spools, shall be protected as
listed in 17.2.
c.
Crates shall be durably marked with:
1.
The receiving address.
2.
The vessel item number.
3.
The Purchase Order number.
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17.4
17.5
d.
Markings shall be in a minimum of two locations and a minimum lettering size of 25 mm
(1 in).
e.
Markings shall be in the English language.
f.
Markings shall also be in an additional language if specified on the data sheets, or
Purchaser Order documents.
Securing and padding
a.
Ropes, chains, and straps may be used to secure the vessel and associated equipment to the
transporter deck.
b.
Padding shall be placed between cables or chains and stainless steel or high alloy
equipment to prevent discoloration of the vessel shell or contamination of the metal.
c.
Nozzles and manways shall not be used as tie-down points.
d.
External attachments other than lifting lugs and tailing lugs shall not be used as tie down
points unless specifically designed to.
e.
Carbon steel shipping saddles that are used for stainless steel or high alloy vessels shall be
padded.
Material safety data sheets
a.
18
Vessels or materials that contain or are coated with any of the following shall be
prominently tagged at openings to indicate nature of contents and precautions for shipping,
storage, and handling:
1.
Insulating oils.
2.
Corrosion inhibitors.
3.
Antifreeze solutions.
4.
Desiccants.
5.
Chemical substances.
6.
Hydrocarbon substances.
b.
Regulated substances shall have a MSDS.
c.
MSDS shall fully conform to regulations for MSDS preparation specified by entity that has
jurisdiction and shall include a statement that the substance is considered hazardous by
regulation.
d.
If any products are exempt from regulation, a statement to that effect shall be included.
e.
MSDSs shall be forwarded to the receiving facility before shipment.
f.
MSDSs shall be placed in a protective envelope(s) and shall be affixed to the outside of the
shipment.
Documentation
The following documentation shall be required.
18.1
Proposal documentation
a.
The Supplier shall supply all specified information required for appraisal of the mechanical
design by Company, which includes but is not limited to the following:
1.
Confirming conformance to code of construction and all documents within the
enquiry or provide requests for clarification or deviations.
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A typical quality control plan.
3.
The proposed manufacturing plan.
4.
Listing of proposed Suppliers and sub-Suppliers, including names and addresses.
5.
Definition of the welding processes and techniques to be used, including that for
overlay applications.
6.
List of any requested exceptions or deviations to the Purchase Order documents
including this Specification.
7.
Details of previous fabrication experience on vessels of similar size and of the same
materials and construction.
b.
The base proposal for construction of vessel shall be provided in conformance to the
request for proposal.
c.
An alternative design proposal may be submitted if considered less costly or an
improvement in the delivery schedule. The improvements in cost and schedule shall be
realised without any of the following:
d.
18.2
2.
1.
Loss of capability.
2.
Shortening the anticipated life of the vessel.
3.
Increase in the total lifecycle cost of the vessel.
Alternative design proposals shall conform to the following and:
1.
Shall be accompanied by the base proposal and be clearly identified as an alternate
proposal.
2.
Shall clearly state the intended use of ASME Code Cases.
3.
Shall be fully and clearly described and substantiated by sketches or drawings.
4.
Shall include a list of specific exceptions to Company’s request for proposal, the data
sheets, and the Purchase Order documents including this Specification.
During design and fabrication
a.
Work shall not begin unless the plans and procedures applicable to that work have been
agreed by Company.
b.
The following shall be submitted for review and agreement by Company:
1.
Quality plan.
2.
Inspection and test plan.
3.
Fabrication plan.
4.
Names and addresses of all Suppliers and sub-Suppliers.
5.
Full set of fabrication drawings.
6.
Complete calculations.
7.
WPS.
8.
PQR.
9.
Weld map.
10. Heat treatment procedures.
11. Pressure test procedure.
12. PWHT procedure.
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13. NDE procedures.
14. Drawings of trays, packing, and internals, if applicable.
15. Centre of gravity and foundation loading diagram.
16. Draft ASME forms.
17. Draft final pressure vessel record book (see 18.3b).
c.
The fabrication drawings shall include, but shall not be limited to, the following:
1.
Applicable information on the pressure vessel data sheets.
2.
Dimensions of vessel components.
3.
General vessel details including nozzle details.
4.
Gasket and flange details including flange face finishes.
5.
Internal construction details including shell attachments and location.
6.
Full scale drawing of the vessel nameplate.
7.
Support and other appurtenance details including an anchor bolt template.
8.
Weld joint details in cross-section, weld map, and applicable welding procedures.
9.
Clad and weld overlay details.
10. Heat treatment requirements.
11. Weld hardness requirements.
12. Non-destructive testing requirements.
13. Identification of pressure limiting components.
14. Tolerances to which the vessel shall be built.
d.
Fabrication drawings shall use the system of units specified in the Purchaser Order.
e.
Revisions of drawings, plans, procedures, and other previously submitted documents shall
be submitted for further agreement by Company.
f.
No modifications shall be made to the agreed drawings, plans, procedures, and other
agreed documents without the agreement of Company.
g.
Documents shall reference both the Purchase Order number and the vessel item number.
h.
As a minimum, the following documents shall be available for review during manufacture:
i.
18.3
1.
Purchase orders and specifications for plates and forgings, CMTRs, chemical
analysis, and mechanical properties of pressure containing materials including weld
filler materials, except weld filler materials in carbon steel vessels.
2.
Copies of actual heat treatment charts indicating complete temperature cycles,
holding times, cooling and heating rates.
3.
Radiographs.
4.
WPSs, PQRs, and welder qualification records.
5.
NDE examination reports.
Calculations shall be provided for design of components that fall beyond the scope of the
code and shall be submitted to Company for review and agreement.
Final documentation
a.
Pressure vessel record books shall be assembled and delivered to Company on completion
of construction of each vessel.
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b.
The pressure vessel record book shall contain, as a minimum, the following information:
1.
Manufacturer’s Data Report (ASME forms).
2.
Photocopy or photograph (not a rubbing) of the vessel nameplate.
3.
Mechanical design calculations required to demonstrate conformance to code, or to
justify and prove the integrity of the design for components and aspects that fall
beyond the scope of the code.
4.
The latest revision of the data sheets marked up to reflect the as-built conditions.
5.
Quality control plan including fabrication sequence, all heat treatment requirements,
forming and rolling procedure, an inspection and test plan with schedule identifying
all inspection points required by Company and signed inspection reports.
6.
As-built fabrication drawings.
7.
Welding procedure specifications (WPS), procedure qualification records (PQR),
weld map, and welder or welding operator qualification test results.
8.
Personnel qualification certificates for all non-destructive examinations.
9.
Reports required by the code of construction stating the results of non-destructive
inspection and testing including RT, UT, MT, PT, and hardness tests.
10. Pyrometer charts or other detailed records for all heat treatment performed, such as
PWHT, normalising, and heating for forming.
11. Exceptions, deviations, and non-conformance reports (including resolution) and a
detailed description of any repairs including a sketch, photo, or drawing indicating the
location and size of the repaired area.
12. Charts or other records of required pressure tests.
13. Certified material test reports or certificates of conformance which fully identify the
specific materials they represent.
14. The PMI report for all materials subject to PMI examination.
15. A completed inspection checklist in conformance to the inspection test plan.
16. Results of all impact testing.
17. Operations and maintenance requirements procedures as applicable.
c.
Three (3) copies of the pressure vessel record book shall be delivered to Company unless a
different number of copies is specified in the Purchase Order documents.
d.
The pressure vessel record book shall also be provided on a CD or DVD securely attached
within each furnished hardcopy of the book containing the following:
1.
A PDF version of the pressure vessel record book.
2.
The computer files of the pressure vessel calculations (i.e., COMPRESS, PVElite,
Finglow, FE/Pipe, NozzlePro files).
3.
FEA model files with solution (i.e., ANSYS or Abacus files).
e.
The pressure vessel record book shall include all correspondence relating to the approval
of “state special” designs as required by the applicable jurisdictions.
f.
The pressure vessel record book shall be retained by the vessel manufacturer and shall be
furnished to Company upon their request for a minimum of five (5) years.
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Specification for Pressure Vessels
19
Quality management
The quality management system shall conform to ISO 9001, API Specification Q1, or other agreed
internationally recognised standard to ensure that the products and services provided conform to the
requirements for supplier quality identified in the Purchase Order.
20
20.1
20.2
20.3
Inspection, test and certification
Inspection and test plan
a.
Prior to the start of manufacture, an ITP shall be submitted for approval by Company
responsible engineer.
b.
The ITP shall include inspection and testing activities to be performed, including those at
sub-suppliers’ works and shall make reference to all testing procedures, control documents,
and resulting records and reports.
c.
The ITP shall be approved by Company prior to start of manufacture.
Inspection access
a.
Company and the Company appointed representative shall at all times have access to the
workshops and testing facilities, including workshops of sub-suppliers engaged in
supplying material or in fabricating the equipment for the purpose of inspecting the
purchased equipment.
b.
Company and the Company appointed representative shall be granted permission to
photograph the equipment in the scope of the Purchase Order during manufacturing,
assembly and test.
Quality assurance
a.
A quality control system shall be operated to ensure technical requirements of the specified
pressure vessel code are achieved.
b.
A fabrication plan, an inspection and test plan, and a quality plan shall be submitted for
agreement by Company prior to the start of fabrication.
c.
The inspection and test plan shall contain the following elements as a minimum:
d.
1.
Activities and associated control procedure and specification reference governing the
activity.
2.
Acceptance criteria.
3.
Responsible party for activity execution.
4.
Objective evidence of activity execution or verifying document.
5.
Quality documents including inspection and test records to be compiled into the
pressure vessel record book.
6.
Supplier participation at the inspection and test stages.
7.
Company participation at the inspection and test stages.
8.
Regulatory agency or third party authorised inspector participation at the inspection
and test stages.
Quality plan shall state all quality related activities, reference standards, acceptance
criteria, and names of the responsible persons in the Supplier’s organization. Spaces for
signatures and dates for each inspection activity shall be provided.
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Specification for Pressure Vessels
e.
21
Technical and quality assurance requirements specified in the purchase order shall apply to
all materials, equipment and services provided by sub-Supplier.
Packing, preservation, marking and shipping
Preparation of equipment for transportation shall conform to the packing, marking, and shipping
instructions or other documents identified in the Purchase Order.
22
Supplier deliverables
Technical data, registers, documents, and drawings that together define the scope of the Purchase
Order shall conform to the requirements for supplier information identified in the Purchase Order.
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Specification for Pressure Vessels
Annex A
(Normative)
Supplementary requirements for special services
A.1
General
If data sheets indicate any of the following special services are present, the requirements
contained within that clause below shall apply.
A.2
A.3
A.4
A.5
A.6
Anhydrous ammonia service
a.
Longitudinal and circumferential butt welds shall receive full volumetric NDE, after any
PWHT.
b.
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
c.
Carbon steel vessels shall receive PWHT.
Butane storage
a.
The specified minimum tensile strength of C-Mn steels shall not exceed 550 MPa (80 ksi).
b.
Weldment hardness shall not exceed Hv10 248 (Brinell 237 HBW).
Amine service
a.
Carbon steel vessels shall receive PWHT.
b.
Longitudinal and circumferential butt welds shall receive full volumetric NDE, after any
PWHT.
c.
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
d.
In amine service, welds and HAZ shall be blasted and examined by WFMT. This
examination shall be performed after any PWHT.
e.
Full penetration welds shall be provided on pressure boundary parts to internal attachments
such as downcomer bolting bars and segments, bed support beam seats, or any
load-carrying attachments that have the long axis parallel to the longitudinal axis of the
vessel. This requirement for full penetration welds does not extend to tray support rings, or
other circumferentially oriented attachments.
Caustic service
a.
Longitudinal and circumferential butt welds shall receive full volumetric NDE after any
PWHT.
b.
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
Cyanides service
a.
Longitudinal and circumferential butt welds shall receive full volumetric NDE after any
PWHT.
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Specification for Pressure Vessels
b.
A.7
A.8
A.9
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
Cyclic service
a.
Fillet welds shall be contoured.
b.
Fillet welds shall receive toe grinding.
c.
Butt weld joints shall receive full volumetric examination.
d.
All welds shall receive surface examination by PT or MT.
e.
For vessels with a shell thickness of 50mm or more, all nozzles shall be swept-type
forgings that allow full volumetric examination.
Hydrofluoric acid
a.
Longitudinal and circumferential butt welds shall receive full volumetric NDE, after any
PWHT.
b.
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
c.
Material shall be to licensor and Company requirements, with restrictions on composition.
Unless otherwise agreed, it shall be ASME SA-516/SA-516M Gr. 60 normalised with:
1.
Carbon equivalent less than or equal to 0,40%.
2.
Combination of Ni + Cu + Cr less than or equal to 0,15%.
3.
S less than 0,002%.
4.
Oxygen content less than 0,002%.
5.
P less than 0,008%.
6.
Nb (Cb) less than 0,005%.
d.
The steel shall not be calcium treated for shape control.
e.
Full penetration welds shall be provided on pressure boundary parts to internal attachments
such as downcomer bolting bars and segments, bed support beam seats, or any
load-carrying attachments that have the long axis parallel to the longitudinal axis of the
vessel. This requirement for full penetration welds does not extend to tray support rings, or
other circumferentially oriented attachments.
Hydrogen service
a.
Longitudinal and circumferential butt welds shall receive full volumetric NDE after any
PWHT.
b.
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
c.
Materials shall be subject to UT to ASME SA-578/SA-578M, including supplementary
requirements S1, S2, S3, and S4. Acceptance standard shall be Level A.
d.
Internal and external attachments welds should be full penetration welds. The enclosed
space shall be vented if a full penetration weld is achievable.
e.
Longitudinal and circumferential butt welds shall receive full volumetric NDE after any
PWHT.
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Specification for Pressure Vessels
f.
A.10
Cryogenic service
a.
b.
A.11
A.12
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
NDE inspections shall include the following if the lowest operating temperature is below
0°C (32°F):
1.
All butt welds shall receive full volumetric NDE after any PWHT.
2.
All welds, including external and internal non-pressure retaining welds, shall receive
100% surface inspection by MT or PT after any PWHT.
All pressure containing welds shall be subject to full volumetric examination after any
PWHT if the lowest operating temperature is below -20°C (-4°F).
Propane storage
a.
The specified minimum tensile strength of C-Mn steels shall not exceed 550 MPa (80 ksi).
b.
Weldment hardness shall not exceed Hv10 248 (Brinell 237 HBW).
Sour water, wet H2S, or wet sour service
a.
Materials shall meet the requirements of NACE MR0175/ISO 15156 parts 1 and 2 and
API 5L/ISO 3183 Annex H and K.
b.
Longitudinal and circumferential butt welds shall receive full volumetric NDE after any
PWHT.
c.
All welds, including external and internal non-pressure containing welds, shall be subject
to 100% surface inspection by MT or PT after any PWHT.
d.
Materials specified shall be purchased and fabricated in order to be resistant to
environmental cracking in sour service and conform to the hardness and other
requirements of GIS 36-025 and ISO 15156 for upstream applications and for downstream
(refinery) applications to NACE MR0103 and sour service requirements defined in
GP 36-26.
e.
Material shall be in the normalised condition unless agreement is given for the steel to be
supplied quenched and tempered (Q+T) or made by TMCP as specified in data sheets and
the following:
1.
Normalised plate shall conform to EN 10028-3 or ASTM A516/A516M.
2.
Quenched and tempered plates shall conform to EN 10028-6.
3.
TMCP plates shall conform to EN 10028-5 or ASTM A841/A841M.
f.
The vessel shall be PWHT.
g.
Z quality and HIC plate shall be used for carbon steel. Z-quality steel plate shall be
designated as one of the following:
h.
1.
EN 10028-3 Grade P275NH + EN 10164, Z35.
2.
ASME SA-516/SA-516M Grade 70 (or equivalent) + ASTM A770/A770M with S3 at
35%.
The plate shall meet EN 10028-3 or equivalent steel grades together with the following
supplementary requirements.
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Specification for Pressure Vessels
1.
Steels shall be made by a low sulphur and low phosphorus refining process, for
example, in an electric furnace with double de-slagging or in the basic oxygen
furnace. The steel shall be vacuum degassed while molten.
2.
The following limits by check analysis (product analysis) shall apply:
a)
Carbon
0,200% max.
b)
Sulphur
0,008% max.
c)
Phosphorus
0,025% max.
d)
Carbon equivalent (CE)
0,430 max.
The carbon equivalent value shall be calculated by the following formula:
CE  C 
Mn (Cr  Mo  V ) ( Ni  Cu )


6
5
15
i.
Plate shall be ultrasonically examined and meet EN 10160 quality classes S1/E1 or
equivalent.
j.
Through-thickness tensile test
1.
Each plate shall conform to acceptance class Z35 of EN 10164 or equivalent.
2.
Company may agree to a retest after consideration of information supplied. The
through-thickness test shall be made after the completion of all heat treatments.
3.
In addition to the above, the tests required by the material specification shall be
carried out.
k.
Plate shall not be weld repaired without agreement and shall be subject to an agreed repair
procedure before repair.
l.
The following additional requirements shall apply if data sheets specify that HIC resistant
plate shall be used.
1.
Plates shall meet one of the following:
a)
EN 10028-3/ASME SA-516/SA-516M (normalised).
b)
EN 10028-6 (Q+T).
c)
ASME SA-841/SA-841M (TMCP)/EN 10028-5.
2.
For low temperature applications (down to -46°C) the impact tested carbon steel
plates meeting ASTM A516/A516M Grades 60, 65, 70 or EN 10028-3 grades P275
(NL2) and P355 (NL2) shall be used.
3.
Steels shall be made by a low sulphur and low phosphorus refining process, for
example in an electric furnace with double de-slagging or in the basic oxygen
furnace. The steel shall be vacuum degassed while molten.
4.
Plates shall be in the normalised, Q+T, or TMCP condition as specified in data sheets.
5.
The following limits by check analysis (product analysis) shall apply:
a)
Carbon
0,200% max.
b)
Sulphur
0,002% max.
c)
Phosphorus
0,008% max.
d)
Oxygen
0,003% max.
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Specification for Pressure Vessels
e)
Carbon equivalent (CE)
0,430 max.
The carbon equivalent value shall be calculated by the following formula:
CE  C 
Mn (Cr  Mo  V ) ( Ni  Cu )


6
5
15
6.
Plate shall be ultrasonically examined and meet EN 10160 quality classes S1/E1 or
equivalent.
7.
Plate shall not be weld repaired.
8.
HIC/SWC test
9.
a)
Tests shall be made in conformance to NACE TM0284, in the NACE TM0284
Test Solution A (i.e., 5 wt.% NaCl + 0,5 wt.% glacial acetic acid).
b)
One set of 3 specimens shall be tested from each thickness of plate from each
heat.
c)
Following exposure, the test coupons shall be ultrasonically tested for evidence
of hydrogen-induced cracking and stepwise cracking before sectioning.
Additional sections for microscopic examination shall be prepared through any
suspect locations, agreed by Company.
d)
The acceptance criteria shall be all of the following:
1)
Less than 5,0% CLR (crack length ratio).
2)
Less than 1,5% CTR (crack thickness ratio).
3)
Less than 0,5% CSR (crack sensitivity ratio).
A NACE Standard Tensile Test shall be carried out to NACE TM0177 using
Method A and Test Solution A if a SOHIC or SZC test is specified in addition to the
HIC test. The material test samples which pass this test shall be evaluated for
acceptance by one of two methods:
a)
At least two metallographic sections shall be taken parallel to the sample axis.
There shall be no ladder-like cracks > 0,5 mm in length in the through-thickness
direction.
b)
The remaining tensile strength (after hydrogen degassing at 150°C (302°F)) shall
be ≥ 80% of the original actual tensile strength of the material.
m.
Hardness of carbon steel HAZ for downstream applications, as measured in the weld
procedure test, shall not exceed 248 Hv10 (Brinell 237 HBW) as given in NACE SP0472.
Hardness values for other materials shall be as given in NACE MR0103. Hardness checks
on the weld deposit of the completed vessel shall conform to NACE SP0472, which
specifies a maximum hardness of Brinell 200 HBW in the weld metal.
n.
Hardness in the weldment on cracking resistant carbon and low alloy steels for upstream
applications, measured in the weld procedure test, shall conform to ISO 15156-2, which
specifies a maximum hardness of 250 Hv10 for the weld root area and a minimum
temperature for PWHT of 620°C (1 150°F).
o.
After PWHT, weldments shall be subject to blasting of surface to SSPC SP 5/NACE No. 1
and tested by WFMT.
p.
Vessels clad with a corrosion resistant lining or fabricated from solid corrosion resistant
alloys for Upstream environments shall conform to ISO 15156-3. The conditions of
acceptability for each of the material classes given in Annex A in ISO 15156-3 shall be
met. For Downstream environments, the material requirements given in NACE MR0103
shall be met.
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Specification for Pressure Vessels
q.
Full penetration welds shall be provided on pressure boundary parts to internal attachments
such as downcomer bolting bars and segments, bed support beam seats, or any
load-carrying attachments that have the long axis parallel to the longitudinal axis of the
vessel. This requirement for full penetration welds does not extend to tray support rings or
other circumferentially oriented attachments.
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Specification for Pressure Vessels
Annex B
(Normative)
Supplementary requirements for chrome-moly vessels
B.1
General
a.
The plate edge preparation for welding shall be by flame cutting and grinding or by
machining. Nozzle openings shall be made by machining.
b.
Material for starting and run-off plates for longitudinal automatic welding shall be of the
same chemical composition as the base material.
c.
The hardness of weld crown and root surfaces, and HAZs shall not exceed:
1.
Cr-Mo steels
225 HBW (HRB 97,6)
2.
Cr-Mo-V steels (Vanadium modified)
235 HBW (HRB 99)
d.
A fabrication sequence with IPWHT, DHT, and final PWHT, including temperature and
holding times shall be submitted with the proposal.
e.
NDE inspections shall be referenced on the fabrication sequence.
f.
Procedure qualification tests shall be made on plates or forgings of the same material
specification, grade, class, and thickness as the vessel using filler metal, flux, and (or) inert
gases of the same type, brand, nominal chemistry, and size to be used on the actual work.
g.
Two production test specimens shall be produced to test the weld metal and HAZs. One
test specimen shall simulate the weldment between two shell courses, and one test
specimen shall simulate the weldment between nozzle forging and shell.
h.
The qualification test coupons shall be in the same heat treated condition as the base
material prior to welding. Test coupons shall undergo the heat treatments (IWHT or
PWHT) anticipated for the completed vessel before testing. The 0,2 per cent proof strength
shall be determined.
i.
The temperature and maximum amount of PWHT time is applicable to base material and
welding procedure qualification testing.
j.
1.
The maximum amount of time available for IWHT and PWHT shall be established.
2.
Probable times for IWHT and final PWHT to fabricate the vessel shall be reported.
3.
These times shall be subject to agreement prior to the start of work.
Temporary shop attachments such as aids for handling and fitting shall be as follows:
1.
Attachments shall be preheated (as specified for the material) with the base metal
local to the attachment.
2.
If temporary attachments are of a material different from the base metal, welds shall
be alloyed to match the base metal, not the attachment. After welding, the material
shall be allowed to air cool to ambient temperature.
3.
Attachment welds shall be cut above the weld during removal of the attachment.
4.
The remaining stub shall be ground flush with the base material surface.
5.
The surface shall be MT inspected to confirm that it is free from defects.
k.
Material for starting and run-off plates for longitudinal automatic welding shall be of the
same chemical composition as the base material.
l.
One subsize production weld for chemistry and mechanical properties verification shall be
made for each heat of electrode and flux combination.
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Specification for Pressure Vessels
B.2
B.3
B.4
B.5
Fabrication
a.
A local DHT shall be performed for all butt-welds and corner joint welds (i.e., ASME weld
category A, B, and C) that are 50 mm (2 in) and greater in thickness (See Annex E).
b.
An IPWHT shall be performed for all nozzle attachment welds (i.e., ASME weld
category D) that are 50 mm (2 in) and greater in thickness (See Annex E).
Examination requirements
a.
UT checks for laminations shall be made on all plate.
b.
Forgings shall be subject to a 100% UT scan.
c.
Plate edges after bevelling, but prior to welding root passes in shell, heads, and nozzles,
weld build-ups on shell and heads, background surfaces, skirt to head or shell attachment
welds, fillet welds, attachment welds and temporary welds after removal of attachments,
shall be subject to MT.
d.
Welds, including external and internal non-pressure containing welds, shall be subject to
100% surface inspection (by MT or PT) after hydrotesting.
e.
Pressure containing welds and skirt attachment or support welds shall be subject to RT or
UT after hydrotesting. Radiographs shall be taken within 48 hours after weld completion.
f.
Full penetration welds shall be subject to MT on the back-chipped surface and on finished
weld surfaces prior to overlay.
1,25Cr-0,5Mo vessels (including Vanadium enhanced)
a.
The measured tensile strength, as recorded on the material test certificate or report, shall be
limited to 585 MPa (84,8 ksi) for plate and 655 MPa (95 ksi) for forgings.
b.
The requirements included and guidance given in API RP 934-C and API RP 934-E shall
apply.
c.
Head or shell plate welds shall not be subjected to an austenitising heat treatment without
specific agreement.
d.
Minimum preheat temperature throughout thickness shall be 150°C (300°F). The actual
interpass temperature for WPS qualification tests shall be determined and defined on PQR
documents. Welding preheats shall be maintained until IPWHT has been performed.
e.
Minimum PWHT temperatures shall be based on API RP 934-C or API RP 934-E as
applicable. API RP 934-E applies for vessels with operating temperatures above 440°C
(825°F).
2.25Cr-1Mo vessels (including Vanadium enhanced)
a.
Vessel shall be made by the electric furnace or basic oxygen process.
b.
Guidance and requirements included in API RP 934-A shall apply.
c.
A minimum and maximum PWHT shall be established. Two sets of weld procedure
specimens shall be heat treated, one for each time. The strength of the vessel shall be such
that at least two PWHT cycles remain available for Company in service, except that if the
closing seam of the vessel requires an additional PWHT, only at least one remaining
PWHT cycle shall be available for Company.
d.
Materials for reactor vessels shall be vacuum degassed.
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Specification for Pressure Vessels
e.
For plate and forgings:
1.
The measured tensile strength for conventional shall not exceed 690 MPa (100 ksi).
2.
Hot tensile tests at design temperature per API RP 934-A Paragraph 5.5.2.2 shall be
required.
3.
Test specimens shall be taken from the transverse ¼ t locations.
f.
Plates shall be fine grain with a grain size of five (5) or higher in conformance to
ASTM E112.
g.
Step cooling tests of all materials, plates, forgings, and weld metals, shall be performed in
conformance to paragraph 6.2.3 of API RP 934-A. Acceptance criteria shall conform to
API RP 934-A paragraph 6.2.3.3.
h.
Welding wire heats and electrode and flux lots shall be selected and tested to confirm that
tensile, impact, and step cooling requirements specified in B.6.3 are met in both the
PWHTmin and PWHTmax conditions.
i.
Preheat temperatures for welding, manual weld overlay and thermal cutting operations
shall conform to API RP 934-A. The following minimum preheat temperatures shall be
maintained during machining and welding.
1.
200°C (392°F) for all welding.
2.
120°C (250°F) for machining.
3.
150°C (300°F) for manual weld overlay.
4.
150°C (300°F) for thermal cutting operations.
j.
The actual maximum interpass temperature for WPS qualification tests shall be determined
and defined on PQR documents, but shall not exceed 300°C (570°F).
k.
During fabrication, IPWHT shall be at temperatures lower than the final PWHT
temperature. The latter shall not exceed the tempering temperature performed at the mill
for any of the materials used.
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Specification for Pressure Vessels
Annex C
(Normative)
Supplementary requirements for stainless steel vessels
C.1
C.2
C.3
Fabrication
a.
Forming rolls used to form any austenitic stainless or nonferrous materials shall covered to
prevent carbon pickup or contamination of the formed material.
b.
Formed heads shall be solution annealed after forming.
c.
An allowance shall be made for the removal of not less than 3 mm (1/8 in) of metal by
machining or grinding to the finished dimension for stainless steels cut by any thermal
process, such as plasma arc or air arc.
d.
Grinding and cleaning of stainless steels shall be done with tools that do not leave
detrimental deposits.
e.
Only stainless steel brushes and clean, iron-free sand, ceramic, or stainless steel grit shall
be used for cleaning stainless steel and non-ferrous surfaces.
f.
Cleaning tools or materials shall not have been previously used on carbon steel.
Welding
a.
The ferrite content of ASS weld metal, with the exception of type 904L (which is fully
austenitic), shall be in the range 3% to 10% in the as-welded and post-weld heated
condition.
b.
Ferrite checks shall be made on at least 5% of the welds, unless a higher percentage is
specified on the data sheets.
c.
Comparable low carbon austenitic filler materials shall be used if welding low carbon
grade austenitic base materials.
d.
Additional requirements for type 904L and 6Mo are as follows:
1.
The high nickel alloy welding consumables of Ni-Cr-Mo (alloy 624 or ERNiCrMo-3)
filler metals shall be used for welding of 904L and 6Mo steels.
2.
Autogenous welding techniques shall not be used.
3.
Shielding gas shall conform to ASME B31.3 paragraph 328.3.4.
Examination requirements
a.
Welds shall be free from cracks and fissures. The extent of PT on welds shall be as
specified on the data sheets.
b.
The pressure test fluid for ASS vessels shall not contain more than 30 ppm chlorides. See
clause 15.2h
c.
ASS vessels shall be dried within 48 hours of draining, using swabs or a flow of air at
ambient temperature. Heat shall not be applied.
d.
Unless directed otherwise, ASS vessels that operate in the range of 50°C to 150°C (120°F
to 300°F) shall be painted externally to the specification listed on the data sheets.
e.
Insulated ASS vessels operating below 50°C (120°F) shall be painted externally to the
specification listed on the data sheets.
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Specification for Pressure Vessels
C.4
f.
Equipment shall be protected such that chloride contamination cannot occur during
shipment.
g.
For vessel constructed to BSI PD 5500:
1.
Inspection of forgings by PT shall be to EN 10228-2 and the required quality class
shall be class 3 unless otherwise specified on the data sheets.
2.
Inspection of forgings by UT shall be to EN 10228-4 and the required quality class
shall be class 3 unless otherwise specified on the data sheets.
Cleaning and surface preparation
Water used during cleaning shall not contain more than 30 ppm chlorides.
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Specification for Pressure Vessels
Annex D
(Normative)
Supplementary requirements for clad plate or weld-overlay construction
D.1
Design
a.
Linings, made by strips fillet welded to the base material, shall not be used.
b.
Corrosion resistant alloy cladding or weld overlay shall not be considered in calculating
required pressure boundary thickness.
c.
All cladding materials, other than titanium, for nozzles shall be made either by weld
overlay or from roll clad plate as shown in Figure D.1.
d.
Solid alloy nozzles DN 100 (NPS 4) and less may be used instead of clad nozzles
provided:
1.
The design temperature is less than 300°C (570°F).
2.
The vessel is not in any of the special services listed in Annex A of this Specification.
3.
An analysis of the thermal and mechanical stresses at the interface is performed.
e.
Raised faced clad flanges shall be fabricated as shown in Figure D.4.
f.
Ring type joint clad flanges:
1.
Shall be fabricated as shown in Figure D.5.
2.
A minimum of 3 mm (1/8 in) of cladding material shall remain under the ring groove.
3.
Flange thickness, Tf, shall conform to ASME B16.5 and ASME B16.47 and shall not
be reduced.
Figure D.1 - Typical clad nozzle attachment to shell
Figure D.2 - Attachment of lightly loaded attachment to a clad vessel
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Specification for Pressure Vessels
Figure D.3 - Attachment of a moderately loaded attachment to a clad vessel
Figure D.4 - Method for cladding a raised face flange
Figure D.5 - Method for cladding a ring type joint flange
3 mm (1/8 in)
STANDARD RING
TYPE GROOVE
Tf
3 mm (1/8 in) MINIMUM
CLADDING THICKNESS
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Specification for Pressure Vessels
D.2
D.3
Clad plate material
a.
Clad plate shall conform to GIS 18-013.
b.
Integrally clad plate shall be ordered per ASME SA-263, SA-264, or SA-265 with Quality
Level 1 with supplementary requirement S12.
c.
Integrally clad plate shall be ordered with examination in conformance to
ASME SA-578/SA-578M with Acceptance Level B and supplementary requirements S1,
S3, and S4.
d.
Integrally clad plate shall be ordered with shear strength tests performed in conformance to
the applicable material specification.
e.
The heat treatment of integrally clad plate in conformance to ASME SA-263,
ASME SA-264, and ASME SA-265 shall be performed by the plate manufacturer.
f.
Integrally clad plate, including explosion clad plate, in conformance to ASME SA-263,
ASME SA-264, and ASME SA-265 shall be cold flattened, if required, after final heat
treatment and descaling.
g.
Following forming and any associated heat treatment, the knuckle region of heads pressed
or spun from clad plate shall be subject to UT and PT, and weld overlay seams shall be
inspected by UT for lack of bond at the weld to clad interface along the entire seam length.
h.
Clad plate on PWHT vessels shall have indications that show a 50% or greater loss of back
reflection marked and recorded prior to heat treatment.
i.
Subsequent to PWHT, integrally clad material shall be re-examined ultrasonically in
locations of previously recorded discontinuities and other indications that resulted in 50%
or greater loss of back reflection.
Cladding re-instatement
a.
The typical detail applied in cladding re-instatement local to a seam is shown in Figure
D.6.
b.
Chipped, gouged, or ground surface shall be cleaned of all residual alloy material.
c.
The removed of the residual alloy material shall be verified with a CuSO4 etch.
d.
Depth of base material removed during clad removal shall not exceed 0,8 mm (1/32 in).
e.
If chip back or gouge is done from inside, as shown in Figure D.6b, 5 mm (3/16 in)
minimum shall be left between edge of chipped or gouged surface and cladding.
f.
Final base material weld deposit from inside shall not contact cladding and shall be ground
flush before depositing alloy weld material.
g.
Weld seams that require volumetric examination shall be tested before cladding
re-instatement.
h.
Each main seam of 11-13% chrome (405, 410S) clad vessels shall be spot radiographed
before and after cladding re-instatement.
i.
The weld overlay requirements of Clause D.4 shall also apply to cladding re-instatement
welding.
Page 78 of 96
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Specification for Pressure Vessels
Figure D.6 - Cladding re-instatement at a vessel seam
0.8mm MAX.
(1/32 in)
12mm MIN.
(1/2 in)
0.8mm MAX.
(1/32 in)
CHIPPED OR
GOUGED SURFACE
(a) MACHINING
5mm MIN.
(3/16 in)
AFTER GOUGING
(b) ROOT PASS
CHIPPED OR
GOUGED SURFACE
COMPLETED WELD
IN BASE MATERIAL.
GRIND FLUSH BEFORE
DEPOSITING ALLOY
12mm MIN.
(1/2 in)
(c) MAIN FILL &
BACK GOUGE
D.4
2 ND PASS
ELECTRODE
1 ST PASS
ELECTRODE
(d) BACK FILL &
CLADDING
Weld overlay
a.
Weld overlay shall conform to GIS 18-013.
b.
Weld overlay shall provide a minimum, guaranteed undiluted chemistry to a depth of
3 mm (1/8 in) from the surface unless otherwise specified on the data sheets.
c.
The weld overlay shall be applied in such a manner that the weld beads run
circumferentially around the vessel.
1.
The surface contour shall be relatively smooth. Adjacent weld beads shall fuse and
blend to create a flat surface without any interbead grooving.
2.
Waviness is permissible but without notches and undercuts that might act as stress
raisers.
3.
The beads may run longitudinally for nozzles with an inside diameter of 300 mm
(12 in) and smaller and for pipe elbows if followed by blend grinding.
d.
With ASS, the chemical composition of the final surface on both weld overlay and
cladding re-instatement shall conform to the corresponding AWS welding consumable
classification.
e.
Welding consumables used for ASS weld overlays that are subject to PWHT shall be “L”
grade, or stabilised with additions of Ti or Nb (Cb) to minimise sigma phase formation
during the heat treatment.
f.
The ferrite content of ASS overlays, with the exception of type 904L (which is fully
austenitic), shall be in the range 3 - 10% in the as-welded and post-weld heated condition,
see data sheets. Welding consumables for 904L clad restoration shall be Ni-Cr-Mo type
such as ERNiCrMo3
g.
Vessels with Alloy 400 weld overlay designated for HF acid service shall have the
following:
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Specification for Pressure Vessels
D.5
1.
Overlay shall contain a maximum of 5% iron (Fe) in the top 1,6 mm (1/16 in) of the
final deposit.
2.
Overlays, deposited by manual processes, shall have a minimum of three layers.
3.
ERNi-1 filler metal shall be used for the first pass if welding with the GTAW or
GMAW process.
h.
The maximum diameter of SMAW electrodes shall be 3 mm (1/8 in).
i.
Carbon content of low-carbon (L, LC, or ELC) grades of ASS, shall not exceed 0,03 %.
j.
The columbium to carbon ratio of the deposited metal for columbium (niobium) bearing
grades of ASS (e.g., 347 and 309 Cb) shall not exceed 16:1.
k.
If a single layer overlay is offered, metallurgical and analytical evidence shall be produced
to demonstrate its acceptability.
l.
The welding process shall not transfer alloying elements via the flux to achieve the
specified weld metal composition.
m.
Flux shall not be re-used.
n.
Each batch of welding consumables, including each batch of submerged arc or electroslag
flux, for ASS overlays shall be tested in conformance to the agreed weld overlay procedure
to ensure that the resultant overlay conforms to the specified microstructure and chemical
analysis.
Welding procedures
a.
Welding procedures shall be qualified in conformance to the design code.
b.
Qualified welding procedures for weld overlay and cladding re-instatement shall be
submitted for agreement.
c.
The base material for the test pieces of the welding procedure shall be of the same material
specification and grade as the vessel.
1.
The same heat treatment batch of welding wire or electrode as that to be used in
production welding shall be used and the same type and brand of flux.
2.
The temperature range used on the overlay qualification test plates for PWHT shall be
the same as that used in production.
3.
The PWHT time at temperature for the qualification test plates shall be greater than
that used in production in order to leave at least one heat treatment available for
Company.
d.
The test welds shall be subject to chemical analysis throughout its depth to confirm that the
required purity of Clause D.7.3 has been achieved.
e.
The test welds shall be subject to 100% UT per Clause D.7.1
f.
The test welds shall be subject to 100% PT per Clause D.7.2.
g.
The achievement of the required weld overlay thickness shall be demonstrated.
h.
A macro section of the overlay shall be prepared and a series of Hv10 measurements shall
be made across the interface at three separate locations.
i.
The measurement of ferrite content shall be by metallographic determination and an
instrumental technique.
j.
The chemical analysis results shall be used to calculate the ferrite content per the
Schaeffler-DeLong diagram.
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Specification for Pressure Vessels
k.
D.6
The ferrite content of ASS weld metal, with the exception of type 904L (which is fully
austenitic), shall be in the range 3% to 10% in the as-welded and post-weld heated
condition.
Internal attachments
a.
If the design temperature is greater than 300°C (570°F), full penetration welds shall be
used for internal attachments.
b.
Internal attachments shall be classified as follows:
c.
1.
Lightly loaded supports: Average shear stress across the section does not exceed
25 MPa (3 625 psi).
2.
Moderately loaded supports: Average shear stress across the section lies between
25 MPa (3 625 psi) and 50 MPa (7 250 psi).
3.
Heavily loaded supports: Average shear stress across the section exceeds 50 MPa
(7,25 ksi).
On vessels made from clad plate, lightly and moderately loaded supports (e.g., tray support
rings) may be welded directly to the cladding without stripping back to the base material
providing the following two conditions are satisfied:
1.
The weld is essentially unidirectional (such as at a tray support ring) and not
multi-directional (such as at a bracket).
2.
The area is checked with UT for lack of bond prior to welding.
d.
On vessels with weld overlay, lightly loaded supports (such as tray support rings) may be
welded to the overlay without stripping back to the base material.
e.
Heavily loaded supports shall be integral with the shell if thermal stress is present.
D.7
Examination of weld overlay and clad re-instatement
D.7.1
UT examination
a.
b.
Weld deposited overlay shall be subject to UT in conformance to ASTM A578 primarily to
establish the presence of any lack of fusion between the weld deposit and the base
material.
1.
10% of the overlay deposited during each shift shall be examined.
2.
Any area of lack of fusion or other defect that cannot be contained within a 25 mm
(1 in) diameter circle shall be cause for rejection and 100% of the overlay completed
during the shift by the equipment or operator concerned shall be examined.
3.
Defects shall be repaired by an agreed procedure and re-examined.
After DHT or IPWHT (if performed), the stainless steel overlay shall be spot checked for
bond consistency by UT on strips 75 mm (3 in) wide over the vessel length at four
equally-spaced positions around the circumference.
1.
Any lack of fusion causing a loss of back reflection accompanied by an echo
indication from the plane of the interface of the overlay and base metal and having an
area greater than that of a 25 mm (1 in) diameter circle shall be repaired. This area
may be of any shape.
2.
If any repair is needed, 100% of the surface shall be checked as above.
Page 81 of 96
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Specification for Pressure Vessels
D.7.2
D.7.3
PT examination
a.
10% of the first layer of weld deposit overlay or clad re-instatement, plus as many “T”
joints as can be examined, shall receive PT surface examination.
b.
If specified on the data sheets, the surface of weld overlay shall be subject to 100% PT in
conformance to ASTM E165 following any PWHT, but prior to pressure testing.
Chemical analysis
a.
The surface of weld overlay shall be subject to chemical analysis.
b.
A minimum of two checks shall be made in each shell course and each head with a
minimum of one check for each 5 m (16 ft) length of butt-weld joint.
c.
A minimum of one check shall also be made at each nozzle attachment weld.
d.
The test locations shall be selected by Company.
e.
Secondary standard FN blocks shall be available to confirm the calibration of the
instrument.
f.
The ferrite content of the final layer of 300 series austenitic stainless steel weld overlay
deposits shall be between 3 to 10FN, except for the stabilised austenitic stainless steel
types 321 and 347.
g.
Stabilised 300 series austenitic stainless steel types 321 and 347 shall have a ferrite content
between 5 to 8FN in the final layer.
h.
The WRC-1992 constitution diagram shall be used to predict the ferrite number.
i.
Ferrite analysis shall be done with an instrument calibrated in conformance to AWS A4.2
or ISO 8249.
j.
Ferrite measurements shall be made adjacent to analytical checks on the as-deposited weld
metal and these measurements repeated following any PWHT.
Page 82 of 96
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Specification for Pressure Vessels
Annex E
(Normative)
Supplementary requirements for DHT and IPWHT
E.1
E.2
Dehydrogenation heat treatment
a.
Prior to commencing DHT, the weld joint shall not be allowed to cool below the minimum
preheat temperature applicable to the weld joint. The minimum preheat temperature for P4
materials shall be 150°C (300°F) minimum. Preheat temperature for P5A and P5C
materials shall be 200°C (392°F) minimum.
b.
Heating for DHT shall be provided using gas ring burners or by electrical heating
elements. Ring burners shall be constructed to provide uniform heat distribution to the
entire weld joint. The weld joint and a minimum of 25,4 mm (1 in) each side of the weld
joint shall be heated to achieve an even temperature distribution through the full wall
thickness of the weld joint.
c.
DHT temperature shall be checked using temperature-indicating crayons, contact
thermometers, calibrated thermocouples, digital pyrometers, or laser heat measuring
instrument. If accessible, temperature shall be measured at the side opposite from which
the heat source is applied to ensure through wall thickness heating.
d.
The weld joint shall be heated and held at a DHT holding temperature of 350°C to 370°C
(662°F to 700°F). Hold time at temperature shall not be less than 2 hours.
e.
After the hold time is completed, the weld joint shall be wrapped in dry thermal insulation
blankets and allowed to slow cool to ambient temperature.
f.
Non-destructive testing PT or MT shall be performed 48 hours after the weld joint has
cooled to ambient temperature.
g.
A written report shall be prepared traceable to each weld joint receiving DHT.
Intermediate post weld heat treatment
a.
IPWHT shall be carried out in a furnace and immediately after the weld joint has been
completely welded.
b.
Prior to carrying out IPWHT the weld joint shall not be allowed to cool below the
minimum preheat temperature applicable to the weld joint.
c.
The preheat temperature for the following materials shall be:
1.
For P4 materials, 150°C (300°F) minimum.
2.
For P5A and P5C materials, 200°C (392°F) minimum.
d.
Preheat temperatures shall be maintained during handling and moving weld joint to the
furnace.
e.
The furnace shall be prepared for IPWHT and heated to not less than the minimum preheat
temperature specified in the weld procedure specification applicable for the weld joint.
f.
Furnace heating the weld joint above the minimum preheat temperature and the cooling the
weld joint after the IPWHT cycle shall conform to the applicable ASME Boiler and
Pressure Vessel Code.
g.
The weld joint shall be heated and held at a temperature indicated below.
1.
For P1 materials the ISR temperature shall be between 540°C and 593°C (1 000°F
and 1 100°F).
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Specification for Pressure Vessels
2.
For P5A and P5C materials the ISR temperature shall be between 650°C and 680°C
(1 202°F and 1 256°F).
h.
Hold time at IPWHT temperature shall not be less than 2 hours.
i.
Cooling the weld joint from the IPWHT holding temperature shall be done in a closed
furnace. Below 315°C (600°F) the weld joint shall be allowed to cool to ambient
temperature inside the furnace with the furnace doors opened.
j.
IPWHT heat treatment shall be recorded and charted in a furnace heat treatment chart.
Page 84 of 96
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10 October 2013
Specification for Pressure Vessels
Annex F
(Normative)
Allowable piping loads on nozzles
a.
This annex defines maximum permissible nozzle loads applied by piping to offshore and
onshore pressure vessels which shall be designed to withstand these loads.
b.
Should there be a requirement for increased forces or moments due to field piping
restrictions in one or more directions during detailed engineering, Supplier shall evaluate
these loads and advise impact on design of pressure vessel.
c.
Nozzle reinforcement as determined by nozzle reinforcement calculations shall be used
when evaluating stresses using values listed in Table F.3.
d.
If, following evaluation, the vessel shell or head is overstressed, Supplier shall not increase
reinforcement on nozzle but shall submit the calculations for review by Company
responsible engineer.
e.
The tabulated forces and moments are applicable for vessels fabricated in carbon steel,
austenitic stainless steel and duplex stainless steel materials. The tabulated values shall be
reduced to 70% for titanium and 50% for copper-nickel piping systems.
f.
The piping loads tabulated in Table F.3 shall apply at maximum design conditions.
g.
The following provides the basis for tabulated values in Table F.3 and calculation method
for pipe sizes not listed in Table F.3:
FS
Force allowable stress
MPa (psi)
MS Moment allowable stress
MPa (psi)
Am Metal area
mm2 (ft2)
Z
Section modulus
mm3 (ft3)
P
Axial force
N (lbf)
VL Longitudinal force (for shell nozzles)
N (lbf)
VC Circumferential force (for shell nozzles)
N (lbf)
FR
N (lbf)
Resultant force (for head nozzles)
MT Torsional moment
Nm (ft lbf)
ML Longitudinal moment (for shell nozzles)
Nm (ft lbf)
MC Circumferential moment (for shell nozzles)
Nm (ft lbf)
MR Resultant moment (for head nozzles)
Nm (ft lbf)
P is the nozzle centreline and VL and VC are mutually perpendicular to P.
Values of FS and MS for each pipe size are given in Table F.2 below:
Page 85 of 96
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10 October 2013
Specification for Pressure Vessels
Table F.1 - Pipe size forces
Pipe size DN (NPS)
FS MPa (psi)
MS MPa (psi)
≤ 150 (6)
2,1 (304,6)
41,4 (6 004,6)
200 (8)
2,1 (304,6)
39,1 (5 671)
250 (10)
2,1 (304,6)
36,8 (5 337,4)
300 (12)
2,1 (304,6)
34,5 (5 003,8)
350 (14)
2,1 (304,6)
32,2 (4 670,2)
400 (16)
2,1 (304,6)
29,5 (4 278,6)
450 (18)
2,1 (304,6)
27,6 (4 003,1)
500 (20)
1,87 (271,3)
25,3 (3 669,5)
≥ 600 (24)
1,4 (203,1)
20,7 (3 002,3)
Allowable resultant force
FR = FS x Am
Allowable axial force
P = 0,5 x FR
Allowable longitudinal and circumferential force
VL or VC = 0,6124 x FR
Allowable resultant moment (SI Units)
MR = Ms x Z x 10-3
Allowable resultant moment (U.S. Customary Units)
MR = Ms x Z
Allowable torsional moment
MT = 0,7071 x MR
Allowable longitudinal and circumferential moment
ML or MC = 0,5 x MR
h.
All tabulated force and moment components may be +ve or –ve.
i.
Flange ratings are in conformance to ASME B16.5 and ASME B16.47.
j.
Allowable loads as given are valid for materials up to 200C (392F). Above 200C
(392F), a de-rating factor shall be applied as shown in Table F.2:
Table F.2 - De-rating factor
Temperature °C (°F)
De-rating factor
200 (392)
1,00
250 (482)
0,92
300 (572)
0,83
350 (662)
0,75
400 (752)
0,67
450 (842)
0,58
500 (932)
0,50
Note:
1. Interpolation between given values shall be
permitted
Page 86 of 96
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10 October 2013
Specification for Pressure Vessels
Table F.3 - Allowable piping loads on nozzles
Pipe size
DN (NPS)
ASME
Class
P
(N) (lbf)
VL, VC
(N) (lbf)
FR
(N) (lbf)
MT
(Nm) (ft lbf)
ML, MC
(Nm) (ft lbf)
MR
(Nm) (ft lbf)
40 (1 1/2)
150
725
(163)
885
(199)
1 450
(326)
200
(147,6)
140
(103,3)
280
(206,6)
300
970
(218,1)
1 185
(266,4)
1 935
(435,1)
245
(180,8)
170
(125,4)
345
(254,5)
600
970
(218,1)
1 185
(266,4)
1 935
(435,1)
245
(180,8)
170
(125,4)
345
(254,5)
900
970
(218,1)
1 185
(266,4)
1 935
(435,1)
245
(180,8)
170
(125,4)
345
(254,5)
1 500
1 280
(287,8)
1 565
(351,9)
2 545
(572,2)
290
(213,9)
200
(147,6)
405
(298,8)
2 500
1 280
(287,8)
1 565
(351,9)
2 545
(572,2)
290
(213,9)
200
(147,6)
405
(298,8)
150
1 000
(224,9)
1 225
(275,4)
2 000
(449,7)
350
(258,2)
250
(184,4)
495
(365,1)
300
1 000
(224,9)
1 225
(275,4)
2 000
(449,7)
350
(258,2)
250
(184,4)
495
(365,1)
600
1 485
(333,9)
1 820
(409,2)
2 975
(668,9)
470
(346,7)
335
(247,1)
665
(490,5)
900
1 485
(333,9)
1 820
(409,2)
2 975
(668,9)
470
(346,7)
335
(247,1)
665
(490,5)
1 500
1 800
(404,7)
2 205
(495,8)
3 600
(809,4)
530
(391)
375
(276,6)
750
(553,2)
2 500
1 800
(404,7)
2 205
(495,8)
3 600
(809,4)
530
(391)
375
(276,6)
750
(553,2)
150
1 510
(339,5)
1 850
(415,9)
3 020
(679)
825
(608,5)
585
(431,5)
1 170
(863)
300
1 510
(339,5)
1 850
(415,9)
3 020
(679)
825
(608,5)
585
(431,5)
1 170
(863)
600
2 045
(459,8)
2 500
(562,1)
4 085
(918,4)
1 070
(789,3)
755
(556,9)
1510
(1 113,8)
900
2 855
(641,9)
3 500
(786,9)
5 710
(1 283,7)
1 380
(1 017,9)
975
(719,2)
1 955
(1 442,0)
1 500
3 705
(833)
4 535
(1 019,6)
7 405
(1 664,8)
1 645
(1 213,4)
1 160
(855,6)
2 325
(1 714,9)
2 500
3 705
(833)
4 535
(1 019,6)
7 405
(1 664,8)
1 645
(1 213,4)
1 160
(855,6)
2 325
(1 714,9)
50 (2)
80 (3)
Page 87 of 96
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10 October 2013
Specification for Pressure Vessels
Pipe size
DN (NPS)
ASME
Class
P
(N) (lbf)
VL, VC
(N) (lbf)
FR
(N) (lbf)
MT
(Nm) (ft lbf)
ML, MC
(Nm) (ft lbf)
MR
(Nm) (ft lbf)
100 (4)
150
2 150
(483,4)
2 635
(592,4)
4 300
(966,7)
1 540
(1 135,9)
1 090
(804)
2 180
(1 608,0)
300
2 150
(483,4)
2 635
(592,4)
4 300
(966,7)
1 540
(1 135,9)
1 090
(804)
2 180
(1 608,0)
600
2 985
(671,1)
3 655
(821,7)
5 940
(1 335,4)
2 050
(1 512,1)
1 450
(1 069,5)
2 900
(2 139,0)
900
3 785
(851)
4 640
(1 043,2)
7 575
(1 703,0)
2 485
(1 832,9)
1 760
(1 298,2)
3 515
(2 592,6)
1 500
5 450
(1 225,3)
6 720
(1 510,8)
10 975
(2 467,3)
3 260
(2 404,5)
2 305
(1 700,2)
4 610
(3 400,3)
2 500
5 450
(1 225,3)
6 720
(1 510,8)
10 975
(2 467,3)
3 260
(2 404,5)
2 305
(1 700,2)
4 610
(3 400,3)
150
3 780
(849,8)
4 630
(1 040,9)
7 560
(1 699,6)
4 075
(3 005,7)
2 880
(2 124,3)
5 765
(4 252,2)
300
4 600
(1 034,2)
5 630
(1 265,7)
9 200
(2 068,3)
4 860
(3 584,6)
3 440
(2 537,3)
6 880
(5 074,5)
600
5 695
(1 280,3)
6 975
(1 568,1)
11 390
(2 560,6)
5 865
(4 325,9)
4 145
(3 057,3)
8 295
(6 118,2)
900
7 250
(1 629,9)
8 880
(1 996,4)
14 505
(3 260,9)
7 185
(5 299,5)
5 080
(3 746,9)
10 160
(7 493,8)
1 500
10 595
(2 381,9)
12 975
(2 917,0)
21 185
(4 762,7)
9 605
(7 084,4)
6 795
(5 011,9)
13 585
(10 020,0)
2 500
10 740
(2 414,5)
13 150
(2 956,3)
21 475
(4 827,8)
9 700
(7 154,5)
6 860
(5 059,8)
13 720
(10 119,5)
150
5 690
(1 279,2)
6 970
(1 567,0)
11 380
(2 558,4)
7 615
(5 616,7)
5 385
(3 971,9)
10 770
(7 943,7)
300
6 060
(1 362,4)
7 425
(1 669,3)
12 125
(2 725,9)
8 075
(5 955,9)
5 710
(4 211,6)
11 420
(8 423,1)
600
7 100
(1 596,2)
8 700
(1 955,9)
14 205
(3 193,5)
9 325
(6 877,9)
6 595
(4 864,3)
13 190
(9 728,6)
900
12 100
(2 720,3)
14 820
(3 331,7)
24 200
(5 440,5)
14 785
(10 905,1)
10 455
(7 711,4)
20 910
(15 422,7)
1 500
16 005
(3 598,1)
19 600
(4 406,3)
32 005
(7 195,1)
18 415
(13 582,4)
13 020
(9 603,2)
26 045
(19 210,1)
2 500
17 865
(4 016,3)
21 880
(4 918,9)
35 725
(8 031,4)
19 950
(14 714,6)
14 110
(10 407,2)
28 215
(20 810,6)
150 (6)
200 (8)
Page 88 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Pipe size
DN (NPS)
ASME
Class
P
(N) (lbf)
VL, VC
(N) (lbf)
FR
(N) (lbf)
MT
(Nm) (ft lbf)
ML, MC
(Nm) (ft lbf)
MR
(Nm) (ft lbf)
250 (10)
150
8 070
(1 814,3)
9 880
( 2 221,2)
16 135
(3 627,4)
12 755
(9 407,8)
9 020
(6 652,9)
18 040
(13 305,8)
300
10 910
(2 452,7)
13 360
(3 003,5)
21 820
(4 905,4)
16 820
(12 406,0)
11 895
(8 773,5)
23 780
(17 539,5)
600
12 840
(2 886,6)
15 730
(3 536,3)
25 680
(5 773,2)
19 460
(14 353,2)
13 760
(10 149,0)
27 520
(20 298,0)
900
17 795
(4 000,5)
21 795
(4 899,8)
35 595
(8 002,2)
25 755
(18 996,2)
18 210
(13 431,2)
36 425
(26 866,1)
1 500
22 920
(5 152,7)
28 075
(6 311,6)
45 845
(10 306,5)
31 555
(23 274,1)
22 315
(16 459,0)
44 630
(32 917,9)
2 500
27 150
(6 103,6)
33 250
(7 475,0)
54 300
(12 207,2)
35 800
(26 405,1)
25 315
(18 671,7)
50 625
(37 339,6)
150
9 880
(2 221,2)
12 100
(2 720,3)
19 755
(4 441,2)
17 520
(12 922,3)
12 390
(9 138,6)
24 780
(18 277,1)
300
10 665
(2 397,6)
13 065
(2 937,2)
21 335
(4 796,4)
18 830
(13 888,5)
13 315
(9 820,8)
26 630
(19 641,6)
600
17 665
(3 971,3)
21 635
(4 863,8)
35 330
(7 942,6)
29 840
(22 009,2)
21 100
(15 562,8)
42 200
(31 125,6)
900
25 010
(5 622,5)
30 630
(6 886,0)
50 020
(11 245,0)
40 250
(29 687,3)
28 460
(20 991,3)
56 925
(41 986,3)
1 500
32 930
(7 403,0)
40 330
(9 066,6)
65 860
(14 806,0)
50 160
(36 996,7)
35 470
(26 161,7)
70 940
(52 323,4)
2 500
37 630
(8 459,7)
46 085
(10 360,4)
75 255
(16 918,1)
55 395
(40 857,8)
39 170
(28 890,7)
78 340
(57 781,4)
150
10 875
(2 444,9)
13 320
(2 994,5)
21 795
(4 899,8)
19 870
(14 655,6)
14 050
(10 362,9)
28 100
(20 725,8)
300
12 640
(2 841,6)
15 485
(3 481,2)
25 285
(5 684,4)
22 895
(16 886,8)
16 200
(11 948,7)
32 375
(23 878,9)
600
21 150
(4 754,8)
25 905
(5 823,8)
42 300
(9 509,5)
36 635
(27 021,0)
25 905
(19 106,9)
51 810
(38 213,7)
900
30 050
(6 755,6)
36 805
(8 274,2)
60 095
(13 510,0)
49 580
(36 568,9)
35 060
(25 859,3)
70 115
(51 714,9)
1 500
41 830
(9 403,9)
51 235
(11 518,2)
83 665
(18 808,8)
64 465
(47 547,6)
45 585
(33 622,3)
91 170
(67 244,5)
2 500
61 185
(13 755,1)
74 940
(16 847,3)
122 370
(27 510,1)
83 345
(61 473,0)
58 935
(43 468,9)
117 870
(86 937,7)
300 (12)
350 (14)
Page 89 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Pipe size
DN (NPS)
ASME
Class
P
(N) (lbf)
VL, VC
(N) (lbf)
FR
(N) (lbf)
MT
(Nm) (ft lbf)
ML, MC
(Nm) (ft lbf)
MR
(Nm) (ft lbf)
400 (16)
150
12 470
(2 803,4)
15 275
(3 434,0)
24 940
(5 606,8)
24 340
(17 952,6)
17 215
(12 697,4)
34 425
(25 391,0)
300
16 495
(3 708,3)
20 200
(4 541,2)
32 985
(7 415,4)
31 700
(23 381,1)
22 415
(16 532,7)
44 830
(33 065,4)
600
27 225
(6 120,5)
33 345
(7 496,3)
54 445
(12 239,8)
50 125
(36 970,8)
35 445
(26 143,3)
70 890
(52 286,5)
900
38 345
(8 620,4)
46 965
(10 558,3)
76 690
(17 240,7)
67 405
(49 716,1)
47 660
(35 152,7)
95 325
(70 309,1)
1 500
52 085
(11 709,3)
63 795
(14 341,8)
104 170
(23 418,5)
86 180
(63 564,0)
60 940
(44 947,7)
121 880
(89 895,3)
2 500
74 145
(16 668,6)
90 815
(20 416,2)
148 290
(33 337,1)
110 400
(81 428,0)
78 065
(57 578,6)
156 130
(115 157,2)
150
14 065
(3 162,0)
17 230
(3 873,5)
28 130
(6 324,0)
28 665
(21 142,5)
20 270
(14 950,6)
40 535
(29 897,5)
300
20 855
(4 688,5)
25 545
(5 742,8)
41 715
(9 378,0)
41 630
(30 705,2)
29 435
(21 710,5)
58 870
(43 420,9)
600
34 060
(7 657,1)
41 715
(9 378,0)
68 120
(15 314,1)
65 210
(48 097,1)
46 110
(34 009,5)
92 220
(68 018,9)
900
48 650
(10 937,1)
59 585
(13 395,4)
97 295
(21 872,9)
88 770
(65 474,3)
62 770
(46 297,4)
125 540
(92 594,8)
1 500
65 855
(14 804,9)
80 660
(18 133,2)
131 710
(29 609,8)
113 180
(83 478,4)
80 030
(59 027,9)
160 065
(118 059,5)
2 500
93 195
(20 951,2)
114 140
(25 659,9)
186 385
(41 901,3)
144 465
(106 553,4)
102 155
(75 346,7)
204 310
(150 693,4)
150
15 050
(3 383,4)
18 435
(4 144,4)
30 105
(6 768,0)
35 175
(25 944,1)
24 875
(18 347,2)
49 745
(36 690,6)
300
21 810
(4 903,2)
26 715
(6 005,9)
43 620
(9 806,3)
50 020
(36 893,4)
35 370
(26 088,0)
70 745
(52 179,6)
600
37 005
(8 319,1)
45 320
(10 188,4)
74 005
(16 637,1)
81 250
(59 927,8)
57 455
(42 377,2)
114 910
(84 754,4)
900
52 505
(11 803,7)
64 305
(14 456,5)
105 010
(23 607,4)
110 055
(81 173,5)
77 820
(57 397,9)
155 645
(114 799,4)
1 500
67 175
(15 101,7)
82 275
(18 496,3)
134 345
(30 202,2)
134 465
(99 177,7)
95 085
(70 132,1)
190 165
(140 260,4)
2 500
99 125
(22 284,3)
121 405
(27 293,1)
198 250
(44 568,6)
178 055
(131 328,4)
125 905
(92 864,0)
251 810
(185 728,0)
450 (18)
500 (20)
Page 90 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Pipe size
DN (NPS)
ASME
Class
P
(N) (lbf)
VL, VC
(N) (lbf)
FR
(N) (lbf)
MT
(Nm) (ft lbf)
ML, MC
(Nm) (ft lbf)
MR
(Nm) (ft lbf)
550 (22)
150
15 630
(3 513,8)
19 140
(4 302,9)
31 260
(7 027,6)
41 790
(30 823,2)
29 ,550
(21 795,3)
59 105
(43 594,2)
300
22 110
(4 970,6)
27 080
(6 087,9)
44 215
(9 940,0)
58 120
(42 867,7)
41 100
(30 314,3)
82 200
(60 628,5)
600
38 865
(8 737,3)
47 600
(10 701,0)
77 730
(17 474,5)
97 650
(72 023,9)
69 ,050
(50 929,4)
138 100
(101 858,7)
900
54 795
(12 318,5)
67 110
(15 087,1)
109 585
(24 635,9)
131 ,605
(97 068,2)
93 ,060
(68 638,5)
186 120
(137 276,9)
1 500
74 895
(16 837,2)
91 840
(20 646,6)
149 970
(33 714,8)
169 ,585
(125 081,2)
119 915
(88 446,0)
239 830
(176 891,9)
2 500
107 155
(24 089,6)
131 245
(29 505,2)
214 310
(48 179,1)
218 390
(161 078,4)
154 425
(113 899,6)
308 855
(227 802,8)
150
16 670
(3 747,6)
20 420
(4 590,7)
33 340
(7 495,2)
50 955
(37 583,0)
36 030
(26 574,8)
72 065
(53 153,2)
300
22 755
(5 115,6)
27 870
(6 265,5)
45 510
(10 231,2)
68 475
(50 505,3)
48 420
(35 713,3)
96 840
(71 426,5)
600
39 400
(8 857,6)
48 255
(10 848,3)
78 800
(17 715,1)
113 445
(83 673,9)
80 220
(59 168,1)
160 440
(118 336,1)
900
57 040
(12 823,2)
69 865
(15 706,4)
114 085
(25 647,5)
156 400
(115 356,3)
110 590
(81 568,1)
221 180
(163 136,2)
1 500
76 260
(17 144,1)
92 405
(20 773,6)
152 520
(34 288,1)
197 660
(145 788,5)
139 770
(103 090,5)
279 535
(206 177,2)
2 500
108 905
(24 483,0)
133 390
(29 987,5)
217 810
(48 965,9)
254 550
(187 749,0)
179 995
(132 759,3)
359 990
(265 518,6)
150
18 091
(4 067,1)
22 158
(4 981,4)
36 183
(8 134,4)
60 101
(44 328,9)
42 498
(31 345,4)
84 996
(62 690,7)
300
25 432
(5 717,4)
31 149
(7 002,7)
50 864
(11 434,8)
83 141
(61 322,5)
58 790
(43 361,9)
117 581
(86 724,5)
600
44 227
(9 942,7)
54 169
(12 177,8)
88 454
(19 885,4)
138 603
(102 229,7)
98 808
(72 878,1)
196 016
(144 575,9)
900
62 160
(13 974,2)
76 133
(17 115,5)
124 320
(27 948,4)
186 779
(137 763,0)
132 074
(97 414,1)
264 148
(194 828,2)
1 500
95 439
(21 455,7)
116 894
(26 279,0)
190 879
(42 911,6)
263 915
(194 656,3)
186 618
(137 644,2)
373 236
(275 288,4)
2 500
143 549
(32 271,3)
175 818
(39 525,7)
287 098
(64 542,6)
347 240
(256 114,5)
245 538
(181 102,0)
491 077
(362 204,7)
600 (24)
660 (26)
Page 91 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Pipe size
DN (NPS)
ASME
Class
P
(N) (lbf)
VL, VC
(N) (lbf)
FR
(N) (lbf)
MT
(Nm) (ft lbf)
ML, MC
(Nm) (ft lbf)
MR
(Nm) (ft lbf)
750 (30)
150
20 929
(4 705,1)
25 634
(5 762,8)
41 859
(9 410,4)
80 637
(59 475,6)
57 020
(42 056,4)
114 040
(84 112,8)
300
32 639
(7 337,6)
39 976
(8 987,1)
65 278
(14 675,2)
123 367
(90 992,1)
87 234
(64 341,4)
174 469
(128 683,5)
600
57 483
(12 922,8)
70 405
(15 827,8)
114 967
(25 845,8)
208 363
(153 682,7)
147 336
(108 670,9)
294 673
(217 342,6)
900
82 646
(18 579,7)
101 225
(22 756,4)
165 293
(37 159,6)
286 600
(211 388,2)
202 659
(149 475,6)
405 318
(298 951,2)
1 500
126 564
(28 452,9)
155 016
(34 849,2)
253 128
(56 905,8)
404 222
(298 142,8)
285 830
(210 820,2)
571 661
(421 641,1)
2 500
190 461
(42 817,6)
233 277
(52 443,1)
380 922
(85 635,1)
532 377
(392 666,4)
376 451
(277 659,7)
752 902
(555 319,4)
Page 92 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Annex G
(Normative)
Ladders and platforms
G.1.
G.2.
G.3
General
a.
This annex applies to the design of ladders and platforms supported off pressure vessels.
b.
Refer to structural steel materials, design and fabrication requirements included in
Purchase Order.
Layout
a.
Arrangement of ladders and platforms on vertical vessels shall be as detailed in Figure G.1
specifying elevation of service platforms relative to manways, maximum ladder run and
minimum distance between platforms.
b.
The standout of circular platforms and ladders from the vessel shall be in conformance to
PIP STF05535.
c.
Platform arrangements shall be amended to allow access around vertical piping passing
through the platform, see PIP STF05530 pages 6 and 7, but for columns over 40 m
(130 ft), platforms and ladders shall be orientated around the circumference of vessel to
avoid vertical piping.
Platforms
a.
The minimum recommended clearance between the face of a manway cover and
equipment, such as control valves or handrails, shall be 0,9 m (3 ft). Minimum clearances
between manways, valves, ladders, and handrails shall be as shown in Figure G.2 and
Table G.1.
b.
Clearances for platforms at the top head of pressure vessel shall be as shown in Figure G.3.
c.
Typical details of vessel platforms are shown in PIP STE05535 and PIP STF05535.
d.
Unless otherwise specified in Purchase Order, floor gratings shall be fitted. Gratings shall
be laid with grating bearing bars spanning across the long span, see PIP STF05530 and
PIP STF05535 pages 5 and 6.
Page 93 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure G.1 - Typical column platform and ladder elevations
TOP HEAD PLATFORM
VENT ACCESS
MAINTENANCE &
BLIND ACCESS
LADDER RUN
2440mm (96 in)
9140mm
(360 in) MAX.
MINIMUM
ACCESS PER
PURCHASERS SPECIFICATION
915mm TO 1525mm
(36 in TO 60 in)
MAINTENANCE &
VALVE ACCESS
C/L MAINTENANCE
ACCESS
450mm TO 2060mm
(18 in TO 81 in)
PLATFORM
[TYPICAL]
INTERMEDIATE
PLATFORM TO
SUIT MAXIMUM
LADDER RUN
ALTERNATIVE VALVE
ACCESS WITH OR
WITHOUT EXTENSION
STEM
305mm (12 in) MINIMUM
T.L.
LEVEL GAUGE ACCESS
BY LADDER OR
PLATFORM
CONTROL INSTRUMENT &
MAINTENANCE ACCESS
LADDER
[TYPICAL]
GRADE
Page 94 of 96
DRAIN VALVE ACCESS
FROM GRADE
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure G.2 - Minimum clearances in platform design
N
MI
m IN)
7m M
45 8 i n
(1
N
MI )
m
IN
7m n M
5
i
4 8
(1
DAVIT
POINT
LADDER
CAGE
VESSEL
A
LADDER
CAGE
B
DAVIT
POINT
PROVIDE
PARTIAL
CAGE
LADDER
CAGE
LADDER TO PLATFORM ABOVE
INTERMEDIATE LANDING SHALL BE
DIMENSION 'B' WHERE
'B'= FLANGE O.D.+ 152mm (6 in) MIN.
VESSEL
A IS SHOWN IN TABLE Z.1
TYPE 1
PLATFORM AT MANHOLE
61
0
( 24 mm
in MIN
MI
N)
LADDER
CAGE
TYPE 2
INTERMEDIATE LANDING AT MANHOLE
VESSEL
WITH OR WITHOUT
VALVE
N
MI
m IN)
7m M
4 5 8 in
(1
IN
M )
m IN
7m n M
45 8 i
(1
LADDER
CAGE
LADDER
CAGE
PROVIDE
PARTIAL
CAGE
EXTRA BARS
VESSEL
TYPE 4
PLATFORM AT NOZZLE
TYPE 3
INTERMEDIATE LANDING
Table G.1 - Minimum platform clearances
Column diameter
Dimension A
1,2 m (4 ft) or less
1,2 m (4 ft) - 2,4 m (8 ft)
2,4 m (8 ft) - 3,6 m (12 ft)
3,6 m (12 ft) or more
0,6 m (2 ft)
0,75 m (2 ft 6 in)
0,9 m (3 ft)
1,1 m (3 ft 6 in)
Page 95 of 96
GPO-EN-SPE-46010
10 October 2013
Specification for Pressure Vessels
Figure G.3 - Typical platform at the top of a vessel
FLANGE OR MANWAY
DIMENSION TO PERMIT
REMOVAL OF FLANGE
BOLTS
PLATFORM
13mm (1/2 in) MAX. CLEARANCE
FROM PLATFORM EDGE TO
OD OF NOZZLE METAL OR
INSULATION. AS APPLICABLE.
100mm (4 in) MINIMUM
CLEARANCE FROM BOTTOM
OF PLATFORM SUPPORT
MEMBER TO OD OF
VESSEL HEAD METAL
ORINSULATION.
AS APPLICABLE.
G.4.
G.5.
Ladders, ladder cages, and safety gates
a.
Ladders complete with cages and safety gates, shall provide access to vessel platforms in
conformance to standard drawings PIP STE05501 and PIP STF05501.
b.
Width of ladder rung, measured between stringers, will be specified by Company.
c.
Ladder rungs shall be equally spaced at a spacing to be specified by Company.
Handrailing
a.
Handrailing shall conform to standard drawings PIP STF05520 and PIP STF05521
b.
Pipe handrailing shall be seal-welded to prevent internal corrosion.
c.
Coating of carbon steel handrailing shall conform to GIS 06-602.
Page 96 of 96
GPO-EN-SPE-46010
10 October 2013