Fabrication, Installation and Testing Procedure

FPSO CYRUS

PIPING FABRICATION, INSTALLATION, INSPECTION & TESTING SPECIFICATION

B0

22/07/2015

Approved for Design

TDK

SRK

ACS

SDM

A0

30/03/2015

Issued for Review

TDK

SRK

ACS

SVS

Rev.

Date

Description

Prepared

Checked

Engineer

Approved

OWNER:

Owner Document No. Job No.

ENGINEERING AND PROJECT MANAGEMENT:

Engg and Project Management Document No. P1501-TOS-70000-PP-SP-0004 Job No.

CONVERSION YARD:

Conversion Conversi on Yard Document No. Yiu Lian Dockyards (Shekou) Limited

Job No. VENDOR: -

Vendor Document No. Job No.

FACILITY NAME: FPSO CYRUS DOCUMENT TITLE: PIPING FABRICATION, INSTALLATION, INSPECTION AND TESTING SPECIFICATION

Page 1 of 44

©COPYRIGHT BY A&T OFFSHORE OR ITS AFFILIATES. THIS DOCUMENT IS THE CONFIDENTIAL PROPERTY OF A&T OFFSHORE AND SUCH DOCUMENT, OR ANY PART THEREOF, MAY NOT BE MADE KNOWN, BE COPIED OR BE MULTIPLIED OR IN ANY OTHER WAY USED WITHOUT PERMISSION OF A&T OFFSHORE.

Rev. Document No: P1501-TOS-70000-PP-SP-0004

B0 Sheet of

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Document Title: PIPING FABRICATION, INSTALLATION, Sheets INSPECTION & TESTING SPECIFICATION 2 / 44

REVISION HISTORY

Rev.

Description

A0

ISSUED FOR REVIEW

B0

APPROVED FOR DESIGN DESIGN

Nature of Changes

HOLD

Rev.

Description

Hold Details



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TABLE OF CONTENTS

1.0

INTRODUCTION .............................................................................................. 5 1.1 1.2 1.3 1.4

2.0

SCOPE ............................................................................................................. 7 2.1 2.2

3.0

PROJECT BACKGROUND ......................................................................................... ......................................................................................... 5 OBJECTIVES ............................................................. ............................................................................................................... .................................................. 5 DEFINITIONS ............................................................................................................... 5 ABBREVATIONS.........................................................................................................5

GENERAL ....................................................... .................................................................................................................... ............................................................. 7 CONFLICTING REQUIREMENT ................................................................................. 7

REFERENCES, CODES AND STANDARDS .................................................. 8 3.1 3.2 3.3

REFERENCES ........................................................... ............................................................................................................. .................................................. 8 CODES & STANDARDS................................................................... STANDARDS .............................................................................................. ........................... 8 UNITS ............................................................. ........................................................................................................................... .............................................................. 9

4.0

WELDING EQUIPMENT ................................................................................. 10

5.0

FABRICATION ............................................................................................... 11 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13

5.14 5.15 5.16

5.17 5.18 5.19 5.20 5.21

6.0

MATERIALS............................................................................................................... ............................................................................................................... 11 GENERAL REQUIREMENTS FOR LAYOUT, CUTTING AND FITTING FIT TING UP ........... 11 DIMENSIONAL ACCURACY ....................................................................... ..................................................................................... .............. 13 WELDING PROCEDURES AND TESTS ............................................................... ................................................................... .... 13 13 WELDERS COMPETENCE ....................................................................................... 14 SPECIMEN WELDS DURING PRODUCTION .......................................................... .......................................................... 15 WELD REPAIR RATES ............................................................................................. ............................................................................................. 15 WELDER IDENTIFICATION ...................................................................................... 15 WELDER QUALIFICATION RECORDS .................................................................. .................................................................... .. 15 WELDING SUPERVISION ......................................................................................... ......................................................................................... 15 WELDING PROCESSES ........................................................................................... 15 ELECTRODES AND CONSUMABLES ..................................................................... ..................................................................... 16 FABRICATION INSTRUCTIONS ............................................................................... ............................................................................... 16 5.13.1 GENERAL WELDING PRACTICES ............................................................. ............................................................. 16 5.13.2 APPEARANCE OF WELDING LAYERS ...................................................... 18 5.13.3 DEFECTS ..................................................................................................... 18 5.13.4 FABRICATED LAPS ....................................................................... ..................................................................................... .............. 18 5.13.5 WELDING OF VALVES ............................................................... ................................................................................ ................. 18 5.13.6 PROXIMITY OF W ELDS ................................................................ .............................................................................. .............. 19 BUTT WELDS ............................................................................................................ ............................................................................................................ 19 FILLET, SOCKET & SEAL WELDS, W ELDS, BRANCH PAD & SUPPORTS ....................... ....................... 20 FLANGES................................................................................................................... FLANGES................................................................... ................................................ 20 5.16.1 FLANGE TYPE ............................................................................................. ............................................................................................. 20 5.16.2 FLANGE CONNECTIONS & BOLT TIGHTENING ...................................... 21 PRE-HEATING ........................................................... ........................................................................................................... ................................................21 HEAT TREATMENT ............................................................................................... ................................................................................................... .... 22 PIPE BENDING .......................................................................................................... .......................................................................................................... 23 23 MANUFACTURER’S DATA REPORTS AND RECORDS ........................................ 23 TRACEABILITY RECORDS ...................................................................................... ...................................................................................... 24

INSPECTION, TESTING AND REPAIRS ......................... ............ .......................... .......................... ................. .... 25 6.1

INSPECTION.............................................................................................................. .............................................................................................................. 25



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6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12

7.0

EXAMINATION, ORGANISATIONS AND PERSONNEL ......................................... 26 LEVEL OF EXAMINATION ............................................................. ........................................................................................ ........................... 26 RADIOGRAPHIC EXAMINATION ............................................................................. 27 ULTRASONIC EXAMINATION .................................................................................. .................................................................................. 28 28 DIMENSIONAL TOLERANCES............................................................................. TOLERANCES................................................................................. .... 28 PRESSURE TESTING ............................................................................................... 28 MARKING............................................................................................................... MARKING.............................................. ..................................................................... .... 29 CLEANING.................................................................................................................29 PROTECTION AND PACKING....................................................... PACKING.................................................................................. ........................... 29 VENDOR’S RESPONSIBIL ITY .................................................................................. 30 PROVISION FOR F OR QUALITY QU ALITY CONTROL ................................................................... ................................................................... 30

INSTALLATION .............................................................................................. 31 7.1 7.2 7.3 7.4 7.5

8.0


GENERAL REQUIREMENTS REQUIREMEN TS FOR FITT ING UP ...................................................... 31 AS BUILT DRAWINGS .............................................................................................. .............................................................................................. 33 DATA REPORTS AND RECORDS TO BE RETAINED BY THE VENDOR ............. 33 BLASTING AND PAINTING ...................................................................................... ...................................................................................... 33 SERVICE COLOR CODE .......................................................................................... 34

SUPPLEMENTARY REQUIREMENTS FOR STAINLESS STEEL PIPING ... 35 8.1 8.2 8.3 8.4 8.5

GENERAL ....................................................... .................................................................................................................. ........................................................... 35 FABRICATION...........................................................................................................35 HEAT TREATMENT ............................................................................................... ................................................................................................... .... 36 PRESSURE TESTING ............................................................................................... 36 PICKLING AND PASSIVATION ................................................................................ ................................................................................ 36

9.0

SYSTEM COMPLETION ................................................................................ 37

10.0

APPENDICES................................................................................................. 38 APPENDIX 1: APPENDIX 2: APPENDIX 3: APPENDIX 4:

PIPING WELD EXAMINATION REQUIREMENTS ........................................ 39 PIPING FABRICATION TOLERANCES ........................................................ ........................................................ 41 41 ACCEPTANCE CRITERIA FOR WELDS WEL DS ...................................................... ...................................................... 42 FIELD INFORMATION ........................ ERROR! BOOKMARK NOT DEFINED.



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1.0

INTRODUCTION

1.1

PROJECT BACKGROUND OML 122 is located within the Gulf of Guinea, offshore Nigeria, approximately 45 kilometers from the Coast. The Field is in average water depth of 152 meters. Avantgarde is carrying out the initial development is through a Wellhead platform (WHP) and a Floating Production, Storage and Offloading (FPSO) facility. Refer Appendix 4 for Field Information.

1.2

OBJECTIVES This specification defines the minimum requirements for the design, supply, fabrication manufacturing and assembly of the Piping System in FPSO CYRUS. The requirements set forth do not relieve vendor of his responsibility to perform all services in safe manner, to meet applicable codes and standards, to comply with government regulations, to meet class requirements and to supply product/services capable of performing its intended service.

1.3

DEFINITIONS The following words and expressions shall have the meanings hereby assigned to them except where the context otherwise requires.

OWNER”

Avantgarde Shipping

CONVERSION YARD”

Yiu Lian Dockyards (Shekou) Limited

ENGINEERING AND

A&T Offshore

PROJECT MANAGEMENT

SERVICES”

1.4

PROJECT”

FPSO CYRUS

VENDOR/SUPPLIER”

Successful bidder on whom an order for a specific scope of work was placed

ABBREVATIONS BOP

Bottom of Pipe

CA

Corrosion Allowance

CS

Carbon Steel



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CV

Control Valve

DBB

Double Block & Bleed Valve

DSS

Duplex Stainless Steel

DNV GRE

Det Norske Veritas Glass reinforced Epoxy

HSE

Health, Safety and Environment

NACE

National Association of Corrosion Engineers

NB

Nominal Bore

NPT (F)

National Pipe Thread (Female)

NPSH

Net Positive Suction Head

PE

Polyethylene

P & ID

Process and Instrumentation Diagram

RP

Recommended Practice

RTJ

Ring Type Joint

SS

Stainless Steel

TOS

Top of Steel

MTO

Material Take Off



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2.0

SCOPE

2.1

GENERAL


This specification defines the technical requirements for the fabrication, welding, heat treatment, erection, inspection, testing and documentation to ASME B31.3 of the pipe work on FPSO CYRUS. It contains additional requirements, supplementary or specifies requirements where codes and standards allow alternatives. This specification shall be applied to all piping fabrication and erection, including pipe work fabricated and delivered for erection by others (skid package vendors and piping fabricators), pipework fabricated and erected in all modules or other sub-assemblies and hook-up.

2.2

CONFLICTING REQUIREMENT The following is the order of precedence: 

Offshore Petroleum and Greenhouse Gas Storage [Safety] Regulations 2009



Classification Society i.e. CCS/DNV



Datasheets



This Specification



Project Specifications (referred to in this specification)



Referenced Project Drawings



Referenced Codes and Standards

In case of any inconsistencies or conflicting requirements between this specification and any other document forming part of the subject Purchase Order, the VENDOR shall indicate such

to PURCHASER and shall obtain PURCHASER‟s written directive .



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3.0

REFERENCES, CODES AND STANDARDS

3.1

REFERENCES The following project specifications are applicable and shall be considered in the piping design. Piping Material Specification

P1501-TOS-70000-PP-SP- 0002

Piping Standard Details

P1501-TOS-70000-PP-SP- 0003

Piping Design Basis

P1501-TOS-70000-PP-RP-0001

Pipe Stress Analysis Design Basis

P1501-TOS-70000-PP-RP-0002

Pipe Support Standard Details

P1501-TOS-70000-PP-SP- 0001

Manual Valve Specification

P1501-TOS-70000-PP-SP- 0006

General Specification - Painting & Protective Coating

P1501-TOS-70000-ME-SP-1010

General Specification – Insulation for Equipment and Piping

P1501-TOS-70000-ME-SP-1011

This specification covers the fabrication of metallic pipes only. All non-metallic pipes shall be

fabricated on strict accordance with manufacturer‟s recommendation and specifications as applicable.

3.2

CODES & STANDARDS The piping design shall fulfill the requirements of local and national regulations and codes applicable at the facility location. Furthermore, the latest codes and standards listed below shall apply. Wherever conflicts or omissions between codes, specifications and contract occur, the most onerous shall apply. The Contractor is responsible for reviewing the list below and informing the purchaser of any omissions. ASME B16.5

Pipe Flanges and Flanged Fittings

ASME B16.25

Butt Welded Ends for Pipes, Valves, Flanges and Fittings

ASME B31.3

Process Piping

ASME B31.8

Gas Transmission & Distribution Piping System

ASME B1.20.1

Pipe Threads (except Dry seal)

ASME B16.47

Large Diameter Steel Flanges, NPS 26 through NPS 60

API

American Petroleum Institute

API RP 14E

Recommended practice for design and installation of offshore production platform piping systems

API RP 578

Material Verification Program for New and Existing Alloy Piping Systems



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ASTM

American Society for Testing & Materials

AWWA

American Water Works Association

AWS

American Welding Society

EN 10204

Metallic Products – Types of Inspection Documents

ASME

Boiler & Pressure Vessel Code Section II Ferrous and Non-ferrous Material Specifications Section V Non-destructive Examination Section IX Welding and Brazing Qualifications

3.3

NACE MR0175/ ISO 15156

National Association of Corrosion Engineers Petroleum and Natural Gas Industries – Materials for Use In H2S-Containing Environments In Oil and Gas Production

NACE RP-01-78

Fabrication Details, Surface Finish Requirements and Proper Design Considerations for Tanks and Vessels to be Lined for Immersion Service.

NACE RP-057595

Internal Cathodic Protection Systems in Oil Treating Vessels

WRC-107

Welding Research Council, Bulletin 107 for Local Stresses in Spherical and Cylindrical Shells Due to External Loadings

AWS D.1.1

Structural Welding Code

UNITS The International System of Units (SI) shall be used for all unit measurement except for piping nominal diameters and where otherwise advised



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4.0


WELDING EQUIPMENT Welding machines shall have adequate controls for making the current adjustments necessary for all welding requirements. Sufficient meters, portable or permanent, shall be provided to calibrate machines and to regulate voltage and amperage as needed. All welding machines shall be calibrated prior to commencement of fabrication and calibration certificates shall be made available for audit by Contractor and /or Third Party 



All equipment to be In good working order and suitable for the associated welding process Measuring devices to be available to monitor/ confirm welding parameters & surface temperatures.



Welding machines using gauges to determine welding parameters shall be in good working order and had calibration verified within the last 6 months.



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5.0


FABRICATION Supply of material and fabrication shall be performed in accordance with ASME B31.3 together with the other nominated codes, standards and specifications listed above. The following requirements, including the appendices, are in addition to those specified in the above documents and in case of any conflict the document precedence shall apply.

5.1

MATERIALS All materials supplied by Vendor shall be new and shall comply with the Project Piping Material Specification (Doc.no. P1501-TOS-70000-PP-SP-0002). No deviation shall be permitted without a written approval from the Purchaser. Materials shall be properly handled, preserved and stored to prevent corrosion or damaged during storage and fabrication. Flange ends, welds preparations etc. shall be protected by means of plastic caps or similar. Contractor shall submit to the Purchaser for approval, a written procedure covering material receipt, inspection and storage. The procedure should cover but not limited to; 

Defective materials



Storage and segregation



Material allocation



Transfer of marking for traceability

All electrodes and filler wires shall comply with Codes and Standard listed above. The particular brand of welding consumable shall be specified on the Welding Procedure Specification. The storage and control of welding consumables shall be in accordance with the manufacturer's instructions and accepted industry practices. All piping on skids and modules shall be colour coded at locations according to the painting specification, giving the flow direction and the product medium. Before painting, coating or lining all edges shall be rounded to a radius of 2 mm or greater, inclusive of bolts holes. All surface defects and contamination, e.g. skin laminations, weld spatter etc., shall be removed.

5.2

GENERAL REQUIREMENTS FOR LAYOUT, CUTTING AND FITTING UP A template shall be used when laying out headers, laterals and other irregular details to ensure accurate cutting and a proper fit up. Other manufacturing techniques using CNC tools are acceptable. Weld bevel preparations shall be done in accordance with ASME B16.25.



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Machine cut bevels in accordance with ASME B16.25 & ASME B31.3 to form the welding groove are preferred, but smooth, clean, slag-free flame cut bevels are acceptable if produced by travograph or by turning pipe on rolls past a fixed torch for carbon steel piping. Hand-held torch cuts shall not be used except when following a template for tees, laterals, or in instances where it is not possible to make the cut in any other manner. The following conditions apply to bevels prepared by other means than machine cuts: 

For carbon steel, machine flame cutting and beveling is acceptable only if the cut is reasonably smooth and all oxides have been removed from the surface by grinding to bright metal.



Weld bevels shall be visually inspected by the Vendor prior to fit up.



Where it is considered necessary by either the Vendor‟s or Inspector‟s inspection or welding personnel, this visual inspection may be supplemented by either magnetic particle or dye penetrant examination.



Unless approved by the Purchaser, end bevels and holes for branches shall be prepared by machining or machine flame cutting except for holes for branches less

than NB 1” which shall be drilled. Flame cut edges shall be dressed to remove all oxide and dross 

For stainless steel, flame cutting is not allowed but plasma cutting may be applied.



Materials, other than Zirconium and Titanium, shall be cut to size and bevelled by plasma arc cutting, cold cutting, machining or an appropriate grinding technique



Where plasma arc cutting is used, all surfaces adjacent to the cut shall be cleaned prior to cutting by light grinding or wire brushing to bright metal. Immediately prior to cutting, the prepared surfaces are to be further cleaned by a suitable degreasant. Subsequent to plasma arc cutting all surfaces shall be ground smooth and returned to a bright metal finish.

Beveling is not required when an extra length is provided for field fitting. Piping in racks shall have end preparations at module boundaries ready for direct weld-up on site. Pipes for socket weld joints shall be cut square. Fit up and minimum dimensions shall be in accordance with ASME B31.3, Fig 328.5.2 C. The Vendor shall propose a method to ensure that the required clearance between the end of the pipe and the base of the socket is achieved on a repeatable basis. The proposed method will be subjected to the approval of the Purchaser. In fitting up preparatory to welding, spacers shall be used while tack welding so that a proper gap is made for the weld. Spacers shall be removed after tack welding. The spacer material shall be compatible with the piping material specification. Structural quality material shall not be used. Qualified welders shall carry out tack welding.



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Pipe line-up clamps shall be used. Tack welding of steel shapes to the pipe for line up purposes shall not be permitted. Backing rings and consumable inserts shall not be used. Provision shall be made in each pipe run which ties into an existing system for a closing field weld to accommodate minor dimensional variations in the field. The Vendor shall verify dimensions in the field for connection to existing piping or equipment. The Vendor shall ensure coupons (large unwanted pieces of metal) and slag resulting from cutting branch holes in pipe are removed or prevented from entering the pipe in the cutting process. Reinforcing pads, if any, shall be added only after external and internal visual

inspection of the attachment. Reinforcing pads shall be provided with ¼” tapp ed weep hole, which shall be plugged. Weep holes should be plugged after pressure testing of line and pad testing is completed. Threaded connections shall be gauge checked after welding or heat treatment. Galvanized piping shall not be bent or welded. Piping requiring bending, welding or threading shall be galvanized after fabrication.

5.3

DIMENSIONAL ACCURACY Dimensional tolerances during fabrication shall generally be in accordance with Appendix 2. Tolerance shall be considered separately; accumulative of tolerance will not be permitted. The maximum accumulative tolerance for main headers shall not exceed 3 mm.

5.4

WELDING PROCEDURES AND TESTS Welding and testing of all piping shall be performed in accordance with ASME B31.3 and ASME Section IX. Weld consumables shall be selected to produce weld metal compatible with the parent metal, having yield and ultimate tensile strength of at least equal to the parent metal and providing equal ductility. Any procedure qualification welding which fails to meet the requirements shall be discarded and a separate procedure qualification welding shall be conducted / retested. The Vendor shall be responsible for obtaining any necessary Statutory Authority and Class approvals. Written Weld Procedure Specifications (WPS) together with the Procedure Qualification Test Records (PQR) and supporting test data from a Purchaser approved registered organization, shall be prepared by the Vendor for all welds and shall be submitted to the Purchaser for acceptance before any welds are applied. WPS and PQRs shall meet the minimum requirements of ASME Section IX and include the following:



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


Where any limitation on weldment hardness is specified, macro graphic examination and hardness measurements shall also form part of the welding procedure qualification.



In addition to mechanical testing, welding procedure test samples shall be subjected to radiographic examination. Magnetic particle/dye penetrant and ultrasonic examination shall be applied to the test samples when radiographic examination is not feasible (e.g.: fillet welds) or when specified. All non-destructive examination shall be completed prior to the machining of test pieces.

The Purchaser reserves the right to require re-qualifications, by fully tested test coupon as per ASME B31.3 and ASME Boiler and Pressure Vessel Code, Section IX, for any lines rated at CL600 or greater. Project materials shall be used for the test, including forged material representing fittings as required. Procedures for the transfer of material identification marks shall be agreed with the Purchaser and Class prior to the commencement of fabrication. A new welding procedure qualification is required for impact-tested procedures if there is a change of consumable brand name, unless agreed otherwise by the Purchaser. The welding procedure specification shall require re-qualification if any of the following changes are made: 

A change out with the welding parameter tolerance ranges specified in the qualified welding procedure specification.



Any increase of more than 1 gauge number in the electrode size from that used in the qualified welding procedure.



A change in the type of current, i.e. ac to dc or, in dc welding, a change in electrode polarity, except where these changes are within the electrode manufacturer's recommendations.



For impact tested procedures, an increase in either the maximum electrode diameter or weave width, or if the maximum interposes temperature is raised above 250ºC.

5.5

WELDERS COMPETENCE Each welder shall satisfactorily perform the relevant welder qualification tests. Only persons who are currently qualified by test in accordance with ASME B31.3 & ASME Section IX shall perform welding. The test weld shall also comply with all requirements on weld run appearance stated in this specification. Any welder unable to follow the W PS or who is responsible for a re pair rate of 10% or great er of his last 40 welds shall be disqualified. He shall not continue production welds until after further training and re-qualification and to the satisfaction of The Purchaser.



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All test welding for procedure qualification shall be witnessed by the Purchaser‟s inspector or rd

approved 3 party. Ideally, welder performance tests for all positional welding should be carried out in the 6G position.

5.6

SPECIMEN WELDS DURING PRODUCTION In addition to test welds specified above, The Purchaser may call for specimen production welds at his discretion to check maintenance of weld quality.

5.7

WELD REPAIR RATES The Vendor shall maintain a record of the weld repair rate for each welder. This shall be reported to The Purchaser weekly.

5.8

WELDER IDENTIFICATION An identity card system shall be established for qualified welders and welding operators. All welders and welding operators shall carry their identification cards with photo ID when welding on the work. All welders shall have their identification number visibly displayed on their clothing and helmet. Cards shall be color coded for welding process.

5.9

WELDER QUALIFICATION RECORDS Records shall be maintained by the Vendor of all welders employed, with their identification Number, mark, dates and the results of all procedure and performance tests, including examination and test results. This register shall include the range of pipe sizes and grades qualified.

5.10

WELDING SUPERVISION The Vendor shall provide continuous and competent supervision of all work carried out under the contract. The welding supervisor shall have, as a minimum, qualification complying with AWS/CSWIP or equal.

5.11

WELDING PROCESSES Root runs shall be deposited using the following processes:

• Gas Tungsten-Arc Welding (GTAW) • Shield Metal-Arc Welding (SMAW) ©COPYRIGHT BY A&T OFFSHORE OR ITS AFFILIATES. THIS DOCUMENT IS THE CONFIDENTIAL PROPERTY OF A&T OFFSHORE AND SUCH DOCUMENT, OR ANY PART THEREOF, MAY NOT BE MADE KNOWN, BE COPIED OR BE MULTIPLIED OR IN ANY OTHER WAY USED WITHOUT PERMISSION OF A&T OFFSHORE.


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GTAW shall be used for root runs on 316 stainless steel piping. Subsequent Welding shall be carried out by one or a combination of the following processes:

• Shielded Metal-Arc Welding (SMAW) • Gas Tungsten-Arc Welding (GTAW) - noted also as TIG in the text • Submerged-Arc Welding (SAW) - for fabrication in shop only. GMAW and Flux cored welding processes are permitted only in the 1G position and only for shop welding.

5.12

ELECTRODES AND CONSUMABLES Electrodes to be used for general welding of steel pipes shall be as follows:

• For Ferrite Steels (all thicknesses) pipe and fittings where covered electrodes are employed, use basic low hydrogen electrodes to ASME Section II, Part C for root, fill and capping.

• For Austenitic Stainless Steel, the electrodes shall conform to the requirements of relevant ASME Section II, part C. All welding consumables shall be stored and treated in accordance with the manufacturer's recommendation. Baking and storage ovens for low hydrogen electrodes shall be provided. A work instruction should detail all responsibilities, equipment and activities to ensure

compliance with manufacturer‟s instructions. Certificates shall be provided for all batches of welding consumable including certification of low hydrogen electrodes, showing compliance with a hydrogen limit of 10ml / 100 gm weld metal. Each consumable batch shall have a batch certificate complying with EN10204 type 3.1 from the manufacturer. Certificate shall state consumable origin and confirm compliance to relevant consumable manufacturing standard and annual test. Certificates shall be endorsed

as compliant prior to use by the Vendor‟s Welding Supervisor. 5.13

FABRICATION INSTRUCTIONS

5.13.1

GENERAL WELDING PRACTICES The fusion faces and adjacent areas of a weldment shall be smooth and free from defects and shall be thoroughly cleaned of oil, grease, paint, marking crayons and inks, processing chemicals, machine lubricants and temperature indicating sticks, pellets, or lacquers and shall be free from all rust, scale, water for a distance of 50 mm from the edge of the bevel.



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All welding shall be fully fused and shall penetrate the full wall thickness of the pipe. In multiple beads welding, the slag shall be cleaned from each layer and any defects chipped out before the next layer is applied. The maximum allowable over-penetration (internal weld reinforcement) shall be 1.5mm. Tack welds shall be restricted to the minimum necessary to hold the assembly together. Only sufficient tack welds shall be made for alignment of the joint to be retained without danger of breaking the tacks, but they must be sufficiently substantial to ensure that the root opening does not close during the welding process. Tack welding shall be done by qualified welders. Cracked tack welds shall be ground out and the ground area magnetic particle or dyepenetrant tested prior to further welding. Tack welds which are to become an integral part of the root weld shall be ground to a feather edge while those not intended to become part of the final weld shall be removed as welding proceeds.

The starting point for overlapping weld runs shall be staggered 50 mm for pipes NB3” nominal size and above or no less than 1/3rd of the circumference for pipes NB2” nomin al size and smaller. However, no downhill welding shall be undertaken. Root runs shall be cleaned of all dyepenetrant (if used). For SMAW butt and fillet welding root run, electrodes exceeding 3.2 mm shall not be used. Each run of weld metal shall be thoroughly cleaned and all slag and foreign matter removed before the next run is deposited. On restarting, care shall be taken to ensure proper fusion with the weld metal previously deposited. Peening of weld runs and hammering of finishing welds is not permitted. Contact with the electrode or other non-insulated part of the electrode holders with the pipe or fitting shall be avoided. The arc shall be struck in the groove. Any arc strike on a pipe or fitting outside the face of the weld preparation may necessitate repairs or replacement, to the satisfaction of the Purchaser. The welding on orifice runs shall be carried out to ensure smooth bore of the pipe. The root penetration shall be ground flush to achieve this. Purging dams shall be of soluble type, where the dam cannot be removed after completion of the weld.

SAW and, where permitted, FCAW and GMAW shall not be used for pipes smaller than NB6” unless otherwise agreed by The Purchaser. All GTAW equipment shall use either a high frequency starting unit or an alternative programmed touch starting unit. A current decay device should also be fitted, together with a gas lens to improve gas shielding of the weld pool. GTAW shall only be used under enclosed shop conditions unless adequate weather protection is provided at each outdoor location where the technique is to be used.



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All welds should be completed without intermediate cooling. However, where this is impractical, intermediate cooling under an insulating blanket is permitted, but only after completion of 30% of the final weld depth. In the case of P No. 3, 4, 5, 6 & 7 materials, the heat treatment cycle detailed in ASME B31.3 shall be applied. Before welding is permitted to re-start, the weld surface shall be subject to magnetic particle examination and any preheat re-established. Pipes shall not be moved or lifted until at least 50% of the final weld depth has been deposited. Vertical down welding is not permitted. Whenever practicable, fillet welded joints for pressure containment should have a minimum of three weld passes, two of which should be showing for visual inspection. All branch connections shall be joined to the header with full penetration welds. Orifice flange butt welds shall be internally ground smooth and flushed.

5.13.2

APPEARANCE OF WELDING LAYERS The manner of depositing the weld metal shall be such that the layers of weld as deposited shall have a good even appearance. The final pass shall fully tie into the base metal on both sides, indicating complete fusion and shall not be dressed other than to de-slag. Weld reinforcement on capping run shall be of single bead and not to exceed 3 mm. The finishing weld shall be visibly clean, free from slag and weld spatter, uniform in contour and in accordance with ASME B31.3.

5.13.3

DEFECTS Any cracks or blow ho les that appear on the surface of any welding bead shall be removed by chipping or grinding and Magnetic particle / Dye Penetrant tested prior to depositing the next successive bead.

5.13.4

FABRICATED LAPS Fabricated laps shall not be used without the agreement of The Purchaser.

5.13.5

WELDING OF VALVES Valves with soft seats shall not be welded while the soft seat material is in place. Unless otherwise stated in the manufacturers installation instructions, all welding adjacent to in-line valves shall be performed with the valve in the fully opened position. Soft seated valves (e.g. butt welded or socket welded ball valves) should not be welded inline unless a weld procedure has been qualified to demonstrate that the soft seats are undamaged or unless the soft seat has been removed in accordance with the valve

manufacturer‟s instructions, prior to welding.



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5.13.6


PROXIMITY OF WELDS The toes of adjacent circumferential butt welds shall be no closer than minimum of two times the wall thickness of the line pipe with applicable NDT-MPI/PT on welded joints for NB12” and below, but shall have a minimum separation of 50 mm. For pipe sizes greater than

NB12” the minimum acceptable separation shall be 100 mm. Branch and non-pressure part attachment welds shall not cross longitudinal seams or circumferential butt welds and shall be subject to the toe to toe separation distance specified for circumferential butt welds. In the cases where such intersections are unavoidable, the Vendor shall seek the approval of The Purchaser. Joints involving the intersection of more than two welds shall be avoided.

5.14

BUTT WELDS All butt welds shall be of full penetration type. The term `butt welds' refers to circumferential butt joints only. Special requirements may be imposed where longitudinal welds are to be made and these welds shall not be carried out before the Purchaser has approved the method to be used. Weld preparations shall be in accordance with ASME B16.25. If any of the equipment nozzles require different bevel ends, the matching pipe bevel shall be re-machined to suit the equipment nozzle details. Such instances shall be brought to the attention of the Purchaser for approval prior to fabrication. Care shall be taken to ensure that the use of such preparations does not alter the length of fittings or reduce the wall thickness below the minimum allowable per Pipe Specification. During weld joint fit-up, if the misalignment in the inside diameters of the components at the ends to be joined exceeds the specified value per WPS, the Vendor shall taper bore as per ASME B31.3. Pipes with a wall thickness of 6mm and greater shall not have hi-lo greater than 1.0 mm. Lesser thicknesses shall not be misaligned by more than 15%. Note that tapering is allowed to the extent that wall thickness is not reduced below the minimum thickness required. If welded pipe is used, adjacent sections of welded pipe that are joined by butt welding shall have the longitudinal weld seams positioned so that they are at least 15 deg apart. Branch connections shall be located such that they are clear of the longitudinal weld seams. Integration and interconnecting spools which require welding on-board or offshore shall have a 300 mm over length per joint (150mm on each side), unless otherwise noted in the fabrication isometrics. Minimum distance between fusion lines on the surface of two butt welds in carbon steel process piping shall be 30mm.



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All the above does not apply for welding standard fitting such as elbows, reducers, etc. directly to the other standard fittings or when the distance is made up by the standard fitting itself.

5.15

FILLET, SOCKET & SEAL WELDS, BRANCH PAD & SUPPORTS These welds shall be in accordance with ASME B31.3. All fillet welds attached to pressure containing components shall be ground to a smooth configuration to avoid notches and stress concentration points. Limitations on imperfections shall conform to ASME B31.3 Table 341.3.2 and Appendix 3 of this specification. When screwed joints are to be seal welded, no thread compound or lubricant shall be used and the joints shall be hand tight only. Seal welding at hydrostatic test vent and drain connections shall be a minimum of 2 passes. For socket weld connections, the pipe shall be spaced approximately 1.6mm from the end to avoid bottoming which can result in excessive stress. Minimum distance between fusion lines on the surface of two welds in carbon steel shall be 15 mm. Non-pressure welded attachments shall be installed prior to heat treatment, galvanizing or lining. Where non pressurized attachments are welded to low temperature carbon steel (LTCS) piping, impact test properties for the attachments materials shall be equivalent to those of the piping material. Pipe insulation shoes, which are attached to a pipe, shall be centered over pipe supports in the installed position.

5.16

FLANGES

5.16.1

FLANGE TYPE Flange types shall be as per the project Piping Material Specification. Attachment of flanges shall be in accordance with ASME B31.3. Slip-on flanges are not allowed for sour service. In other services, the front fillet weld of a slipon flange shall not project above the joint face, refer ASME B31.3 Fig 328.5.2B. Flange bolts holes are to be oriented as follows, unless otherwise indicated on the piping layout: 

Flange face vertical – bolt holes to straddle vertical centre line.



Flange face horizontal – bolt holes to be straddle FPSO port-starboard centre line.

Preheat temperature calculations shall take into account the carbon equivalent of the flange material. ©COPYRIGHT BY A&T OFFSHORE OR ITS AFFILIATES. THIS DOCUMENT IS THE CONFIDENTIAL PROPERTY OF A&T OFFSHORE AND SUCH DOCUMENT, OR ANY PART THEREOF, MAY NOT BE MADE KNOWN, BE COPIED OR BE MULTIPLIED OR IN ANY OTHER WAY USED WITHOUT PERMISSION OF A&T OFFSHORE.


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5.16.2


FLANGE CONNECTIONS & BOLT TIGHTENING Vendor shall prepare a written procedure and implement them during installation to ensure correct tightening of bolted connections. This procedure shall require Purchaser approval prior to commencement of the work and shall include as a minimum: 

Details of bolted connections (material and sizes for flanges, bolts and gaskets as applicable



Min/Max pre-stress values for each type of connections



Tools to be used incl. type of lubrication



Max allowable forces introduced due to flange misalignments, including means for controlling such forces



Documentation including operator qualification and reports

Vendor to use torque wrenches or tension tools to ensure correct tension of bolted connections unless otherwise approved by Purchaser. Unless specifically designed otherwise, flange connections shall generally be pre-tensioned to 50% of the minimum specified yield strength of the bolts. Bolts in dynamically loaded connections and in connections exposed to large external moments shall be pre-tensioned using hydraulic tension tools, unless otherwise approved by Purchaser. Such connections shall have lock nuts or similar provisions installed to prevent nuts from coming loose. Sheet type and similar type soft gasket without compression stop shall not be used in connections exposed to large external moments. Bolts that have been tensioned in a controlled matter can be re-used. All other bolts, including bolts used for hydro test shall not be used for permanent installation.

5.17

PRE-HEATING Preheating for welding may be required in accordance with the Codes and Standards listed above. Details must be included in the welding procedures submitted as per the requirements of this specification. Where weather conditions give rise to condensation, pipes and fitting shall be dried by heating prior to welding. Oxy-fuel gas welding or cutting torches may only be used for pre-heating when fitted with proprietary preheating nozzles. If the carbon content of a P1 material is > 0.25%, a minimum preheat temperature of 80ºC shall be required irrespective of thickness or minimum tensile strength. The pre-heat zone shall extend 75 mm or a distance equal to four times the material thickness, whichever is the greater, beyond each edge of the bevel. The maximum interpass temperature shall not exceed 250ºC.



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Thermocouples may not be directly attached to pressure parts without the agreement of the Purchaser.

5.18

HEAT TREATMENT Heat treatment where required shall be carried out in accordance with the Codes and Standards listed above and/or when specified in the Piping Material Specification, Line List or fabrication drawings. Heat treatment to be used in production and erection welding shall be stated in the Welding Procedure Specification and used in the Procedure Qualification Record. The approval of the heat treatment procedures shall not limit the Vendor's responsibility, to correct any distortion caused by the heat treatment. Where required, all welds, including attachment welds, shall be given a stress relief post weld heat treatment as per Codes and Standards listed above, to comply with the hardness requirement in NACE MR-0175/ISO 15156. The complete post-weld heat treatment cycle shall be recorded with details such as heating and cooling rates and holding time. For local Post Weld Heat Treatment (PWHT), the minimum heated band width shall be 5 x

√(R x t) and the minimum insulation width shall be 10 x √(R x t) where "R" is the inside diameter of the pipe in mm and "t" is the wall thickness in mm. Heat treatment shall be done on carbon steel piping systems where the heat affected zones of the adjacent welds overlap. PWHT of welded in-line valves is NOT permitted. Low melting point metals such as aluminum, lead, tin, copper, zinc, cadmium and mercury, and their alloys, shall not be permitted to contact any steel surfaces which will undergo hot forming, welding or post-weld heat treatment. When a furnace heat treatment is applied, the furnace temperature shall not exceed 400ºC when the pipework is loaded or removed. The maximum heating or cooling rate above 400ºC shall not exceed 200°C per hour, and for wall thickness, ‟t‟ mm, greater than 30 mm shall not exceed 6000/t°C per hour. Procedures for the attachment of thermocouples by capacitor discharge welding shall be approved by the Purchaser, and the use of this technique carefully monitored. If a weldment in material of P No. 3, 4, 5, 6 or 7 is to be allowed to cool to ambient temperature prior to final post weld heat treatment, intermediate post weld heating shall be applied, as required by the following:-



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


On completion of welding joints of thickness in excess of 10 mm deposited by processes other that GMAW or GTAW shall be immediately raised to 300°C, for a period of 1 hour per 25 mm of thickness, with a minimum of 30 minutes.



Subsequently, the joint shall be cooled slowly under dry insulation.

Heat treatment shall not be carried out without the approval of the Purchaser or Class. Any site attachment weld carried out on PWHT lines (e.g.: pipe supports) shall be heat treated after welding.

5.19

PIPE BENDING Bending of pipes shall only be done where indicated on the isometric drawings. Procedures shall meet the requirements of ASME B31.3, Section 332. The bending procedure, with percentage ovality and thinning shall be submitted by the contractor for approval before manufacture. Suitable allowance for pipe wall thinning due to bending process shall be applied to obtain the specified wall thickness after bending.

Fabricated mitre bends are not acceptable unless approved by the Purchaser. The „cut and shut‟ design shall not be used. 5.20

MANUFACTURER’S DATA REPORTS AND RECORDS The following (when applicable) shall be kept available by the Vendor for examination by the Purchaser: 

Welding procedure specifications, welding procedure qualification records and certificate of test.



Weld map, weld number, W PS and Welder‟s ID.



Associated NDE Report [s] for each welded joint.



NDE Operator's identification and welding qualification test results.



Location of each weld, by each NDE operator.



Welder Repair Rate Records



All reports on U.T, R.T. etc.



Results of penetrant tests.



Charts and other records of hydrostatic pressure tests, including calibration records.



Records of heat treatment after welding.



Records of heat treatment after bending or forming.



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


Records of weld repairs necessitated by failure to comply with acceptance requirements.

5.21



Hardness survey records, where specified.



Ferrite count of stainless steel Welds.

TRACEABILITY RECORDS It is required that the Vendor has an acceptable piping fabrication management system in place to include traceability procedures for materials, welding and NDE details. Weld consumables are to be purchased as bulk buys under common batch serial numbers, and traceability is to be controlled by means of recorded manufacture date against consumable issue dates. Full traceability is required for materials received by the Vendor, or site (end user). Each item received must be positively identified with the correct heat number/test certificate. Heat numbers shall be prominently marked on pipes by the Vendor and heat numbers shall be transferred to off-cuts. All stainless steel materials shall be kept segregated from other carbon steels. As a minimum, the following traceability records/data shall be kept: 

Material heat number, and relation to a material certificate



Fitting or valve heat number, and relation to a material certificate



Weld procedure and Welder identification weld location



NDE reference (results and the unique weld number)



Consumable batch number



Weld repairs



Traceability of the welder/s to each piping isometric.



Heat Treatment records, where required.



Hardness testing records, where specified or required.



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6.0

INSPECTION, TESTING AND REPAIRS

6.1

INSPECTION For all materials, final examination shall be performed after completion of any heat treatment. All welds shall be visually e xamined over 100% of weld length externally and internally where accessible, for defects, e.g. incomplete penetration, lack of fusion, undercut misalignment, and concave reinforcement on butt welds. Weld surfaces shall be uniform and shall merge smoothly into the pipe surface. All fabricated pipes shall be inspected for dimensional and material conformity with the Drawings, Piping Material Specification and this Specification. Inspection shall be in accordance with the Codes and Standards listed above and the following requirements: 

All visual and radiographic inspection and flaw detection of welds shall be carried out after completion of the specified heat treatment (if any).



To limit repairs after heat treatment the Vendor may carry out visual and NDT inspection prior to heat treatment. The costs of this extra quality control testing will be

at the Vendor‟s expense. 

Any judgment made by the Purchaser on the quality of the welding prior to the heat treatment will not be binding on the Purchaser in making his inspection after heat treatment.

The marking of welds for welder identification shall be in accordance with the requirements of this Specification. The acceptance standard shall be that specified in ASME B31.3 Table 341.3.2, amplified by the requirements shown on Appendix 3, except that complete penetration is essential, no notches, undercutting, or cracks being permitted. Interpretation of NDE acceptance criteria for repaired welds shall be as per that required for 100% radiography. Where doubt exists as to the soundness of welds of any type, the welds shall be examined by Non Destructive Testing techniques at the discretion of the Purchaser. The visible surface of all welds are to be clean of slag, regular, uniform in contour, without undercuts, cracks, blowholes and free from spatter. The weld reinforcement shall not exceed the limits defined in ASME B31.3 Table 341.3.2. When the non-destructive examination reveals a defect:



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(1) Two additional welds by the same welder shall be given the same type of examination; and (2) If the welds examined as required by (a) above are acceptable, the defective weld shall be repaired or replaced and re-examined as specified, and all welds represented by this additional examination shall be accepted; but (3) If any of the welds examined as required by (a) above reveals a defect, two further welds of the same kind shall be examined for each defective weld found by that examination; and (4) If all the welds examined as required by (c) above are acceptable, the defective weld(s) shall be repaired or replaced and re-examined as specified, and all items represented by this additional examination shall be accepted; but (5) If any of the welds examined as required by (c) above reveals a defect, all welds represented by the progressive examinations shall be either: 1. Repaired or replaced and re-examined as required; or 2. Fully examined and repaired or replaced as necessary, and re-examined as necessary to meet the requirements of the specified performance code. For each welder, the first three production welds and the first two production welds of all other procedures shall be subjected to 100% radiography. For expediency, it will be acceptable to conduct simulated production welds to confirm welder acceptance. When the Purchaser is satisfied with the quality of workmanship, the level of examination shall then be in accordance ASME B31.3 and the Project Line List. When unacceptable defects are found in completed welds, they are to be removed by grinding, chipping, machining or thermal gouging to leave only sound metal.

6.2

EXAMINATION, ORGANISATIONS AND PERSONNEL NDT examination shall be carried out by a Purchaser approved organization which is registered and recognized by the relevant certifying body. The personnel shall be certified competent for the type of tests conducted. Vendor to submit the NDT personnel qualification

and NDT procedures for Purchaser‟s or Class Survey approval. 6.3

LEVEL OF EXAMINATION The Project Line List specifies the percentage of non-destructive examination to be applied for each line. The details are provided in Appendix A. Non pressure piping subject to atmospheric pressure, such as tail pipes, drains and vents, do not require any special testing, unless otherwise specified.



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Welded joints shall be NDE tested in accordance with ASME B 31.3 and ASME Section V. Field welded joints that cannot be checked by pressure testing shall be checked by 100% radiography and any other test as stipulated by the Purchaser.

6.4

RADIOGRAPHIC EXAMINATION The Vendor shall carry out radiographic examination on welds, in accordance with ASME B31.3 and ASME Section V. The Vendor shall ensure that all necessary safeguards are taken to protect personnel and equipment from harmful effects of the γ-ray and X-ray sources. This shall include the provision of barricades and signs to restrict access into areas where radiography is being carried out. The radiography shall be at such time and in such a manner that no interference is caused to the work of other Sub-vendors. The Purchaser shall have the right to designate the welds to be radiographed on a random weld and spool basis. The Vendor shall indicate on the drawings the location and number of welds that have been radiographed. The Vendor shall radiograph any other welds when so directed by the Purchaser. If the weld examined fails to pass the requirements of ASME B31.3, the cost of the examination and further examinations necessitated by the failure, any repair or replacement necessary shall

be to the Vendor‟s account. The Vendor shall radiograph the welds performed by the same welder immediately previous to and immediately following the weld which failed to satisfy all requirements of ASME B31.3.

This procedure shall be continued until satisfactory welds are found. Refer to „Inspection and Testing‟ above. X-ray techniques are preferred for all shop radiography of pipework up to 25 mm wall thickness. However, where the use of X-rays is impractical, gamma ray isotopes may be used subject to the approval of the Purchaser. In each case the technique shall be qualified using a source side image quality indicator of the wire type to ASME, BS EN 462 or DIN EN 462 Part 1. The single wall, single image technique should be used whenever possible. Lead intensifying screens and fine grain high contrast film shall be used. Film density shall be 2.0 - 3.0 through the thickest portion of the weld and the radiographic sensitivity shall be as shown in the applicable tables contained in the above Standards.



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Radiography of production welds shall use a wire type IQI with each film exposure and this shall be placed on the source side where accessible. When the complete joint circumference is radiographed in a single exposure four IQIs placed at 90 degree intervals shall be used. Spot radiography shall not be used for girth, mitre or branch welds. All joint testing shall be performed after PWHT if applicable. Visual inspection of each weld, upon completion, shall be performed in accordance with ASME B31.3 and the following additional requirements. All welds shall be free from slag, undercut, excessive spatter, craters and other surface defects. Weld reinforcement shall be of regular contour, even weld ripple, and indicative of good workmanship. All welds in high temperature service are to have a smooth surface finish, if necessary, by grinding. All welds shall have full penetration and complete fusion.

6.5

ULTRASONIC EXAMINATION On joints subject to post weld heat treatment where examination is necessary both prior to and after heat treatment a dual approach to examination may be considered. While radiography might be the most appropriate form of examination during fabrication prior to heat treatment, ultrasonic may be more relevant in some locations subsequent to heat treatment.

6.6

DIMENSIONAL TOLERANCES All fabricated pipes shall be dimensionally checked to the dimensional tolerances and recorded on Dimensional reports shown in Appendix 2 and as approved by Purchaser and the relevant certifying body.

6.7

PRESSURE TESTING Pressure Testing shall be performed in accordance with ASME B31.3. The hydrostatic test pressure shall be in accordance with the Line List, Piping Material Specification and/or the piping isometric drawings. Prior to hydrostatic testing, piping shall be either air blown or water flushed in accordance with Purchaser‟s approved procedure for Flushing, Air Blowing & Drying of Pipework. Vendor

shall submit this procedure for Purchaser‟s approval.



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6.8


MARKING Each spool piece shall be clearly marked on both ends with the line number. Marking shall not be done by stenciling the pipe. Marking shall be done by a method which shall ensure that it will withstand exposure to the hazards during shipping to the job site. When spools will be subject to post-weld heat treatment a suitable titanium oxide pigmented heat resisting paint containing less than 250 ppm of lead, zinc or copper shall be used. All applied marking shall have a life of at least one year in covered, unheated storage. The marking applied shall identify the material and the fabricator and include an item number enabling the spool to be traced to the relevant isometric drawing. At the end of each shift the

welders‟ identification reference shall also be transferred to the isometric drawings. 6.9

CLEANING The bore of all fabricated pipe work shall be cleaned to be free from all rust, sand, scale, weld spatter and debris. The pipe internals shall be physically wiped clean to a minimum distance of 100 mm from the cut after cutting/beveling to ensure all visible slag and swarf are removed. When chemical cleaning, internal dry blast cleaning, pickling and passivation of carbon steel piping are required, they shall be carried out in accordance with Purchaser approved procedure from Vendor. Vendor shall submit thi s procedure for Purchaser‟s approval. Treaded connections, flange face, valve spindles and etc. shall be protected while cleaning. Pickling of carbon steel shall be followed by passivation and conservation. All valves, doglegs etc., shall be drained to ascertain removal of all pickling liquids. Any blasting shall be followed by conservation.

6.10

PROTECTION AND PACKING Vendor shall empty, dry up or conserve the pipe spools or piping systems after each stage of fabrication, treatment, tests, etc. After hydrostatic testing and cleaning, where specified , the pipes shall be thoroughly drained, air-dried and the ends immediately sealed. The protection applied shall ensure no contamination is capable of passing into the bore of the pipe. The Vendor shall submit his proposed protection procedure for approval. Method and acceptance criteria for dryness must be approved by Purchaser. The Vendor shall pay particular attention to pipe cleanliness on this project to minimize the extent of air blowing required later on-board. All sensitive systems, e.g. fuel gas, lube oil,



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combustion air, seal oil, injection water, glycol etc., must be sealed immediately after pickling, conservation or inspection by means of flanges. The proposed capping protection procedure should be suitable for 3 types of end protection, small bore pipe ends, and medium to large bore piping ends as well as flange covers. Piping protection is to be rigorously maintained after fabrication, through the painting process, to transport to site, storage and final erection. Protection shall be sufficient for a minimum of one-year outdoor storage. Spool storage on site is to be on supports clear of the ground. Prior to site erection the Vendor shall ensure that piping spools are free of foreign materials, slag, sand, rust, scale, weld spatter and debris. Prior to lifting into position, caps shall be removed, the piping shall be upended to maximize the likelihood of dislodging foreign material inside the pipe, and the spool shall be air blown. Each spool is to be visually checked and signed off as clean by the Purchaser prior to erection. Flange faces shall have protective covers in place after fabrication and during storage.

6.11

VENDOR’S RESPONSIBILITY Any inspection by Contractor or the certifying authority shall not absolve the Vendor from his responsibility to exercise quality control procedures to ensure that the requirements of the specification are met.

6.12

PROVISION FOR QUALITY CONTROL Quality management and certification requirements set out elsewhere in the contract and purchase order documents also apply.



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7.0


INSTALLATION This section covers the general requirements for the installation of steel piping. Any field material, fabrication, welding, heat treatment, bending, marking, etc. required for the field installation, shall be in accordance with the requirements specified in the previous sections of this document.

7.1

GENERAL REQUIREMENTS FOR FITTING UP General requirements for fitting up shall be as specified in above sections and the following: 

A nickel based anti-seize compound shall be applied to all stud bolts.



Flange bolts, when tightened, shall expose two threads (minimum) past the nut.



All flanged joints shall be brought up flush so that entire flange face (or groove) bears uniformly on the gasket and then made up with uniform bolt tension.



A flange cover shall be kept on all flanged connections to equipment, until ready to connect the piping.



Flanges connecting to vessels and mechanical equipment, such as pumps, turbines, or compressors, shall be fitted-up in close parallel and lateral alignment prior to tightening the bolting. The alignment of the piping and equipment flanges shall be within acceptable tolerances of ± 1.0 mm.



During field welding the welder shall ensure that valves and instruments are not included in the welding current circuit, i.e. between weld point and earthing point on piping.



All piping shall be properly supported during erection to prevent any permanent buckling or bending.



Threaded connections shall be seal welded where specified in the drawings or specifications. Where seal welding is not permitted, a thread sealant of approved material shall be used



Plug materials shall be compatible to the respective pipe material specification materials.



For horizontal run piping bolt holes shall straddle center lines of all flanges unless otherwise designated on the drawings. For Vertical and inclined lines, the fittings to be orientated in accordance with the relevant isometric.



All necessary pipe hangers, supports, stanchions, and anchors shall be installed as shown on the Piping Isometric Drawings. When necessary, adequate temporary supports shall be installed during erection so as not to overstress piping, or



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equipment to which piping is connected. All such temporary supports shall be removed when erection is complete. 

The spring supports shall be checked to ensure that they are set to their cold set load and the load set pins shall not be removed until successful completion of the hydrostatic pressure test. The spring support Vendor's recommended procedures shall be followed for installation of supports and removal of load set pins after pressure test.



Unless noted otherwise on isometrics, no cold springing for fit-up is allowed.



Care shall be taken to protect flange faces and pipe threads during erection. Flange faces shall be clean and pipe shall be clean and free from foreign matter before assembly. Damaged flange faces shall be refaced by machining. Should the damage be such as to reduce the flange thickness to below the code requirements, then the flange shall be discarded.



For flanged piping, new gaskets shall be used for every assembly operation unless such assembly is intended solely for fit-up. The Vendor shall furnish sufficient gaskets to meet this fit-up requirement.



Weld spatter shall be cleaned off pipe and flanges around the welds leaving a smooth clean surface.



The Vendor shall use great care in keeping all pipe, fittings, valves and the like free of dirt and other foreign material while storing and handling in the field. The Vendor shall ensure that all pipes, fittings, valves and the like are clean and free of dirt and other foreign material prior to erection.



Guides and anchors shall not be installed unless shown in the drawings. Pipe supports shall be shimmed to ensure supports take required loads.



Drawings will indicate the position of valve stems on sizes NB1 ½” mm and above. For smaller valves, these stems shall not be installed in a position below horizontal.



Valves shall be installed such that flow direction marked on valves is aligned with flow directions as shown on the piping drawings. Single side sealing valves with a preferred pressure side shall be installed as shown on the Piping Isometrics drawings



Back-welded screwed fittings are not an acceptable substitute where the drawings or specifications require socket-welded fittings, unless approved in writing by the Purchaser before use.



Distribution lines shall take off from the top of the main distribution header unless shown otherwise on the isometric drawings.



Inline items shall not be installed until completion of all hydrostatic testing, flushing and cleaning on the pipeline. Where inline items are welded in and contain stainless steel internals, then low chloride water (30ppm maximum) shall be used.



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


Prior to hydrostatic testing, relief valves shall be removed by the Vendor. Valves shall be tested on a suitable PSV test bench and adjusted as required. Valves shall be reinstalled after pressure testing. Valve testing shall be witnessed and signed off by the Purchaser.



A record of all orifice plates on each unit shall be submitted to the Purchaser for approval prior to installation of the plates. This list shall include instrument identification numbers, and orifice bores measured to the nearest 0.02 mm.



Special care shall be taken with all types of expansion joints to prevent damage during installation, during pressure testing of piping and until the piping system is ready for operation. Expansion joint shipping bars shall not be removed except with the permission of the Purchaser.



7.2

Insulation of piping shall be done after completion of hydro testing.

AS BUILT DRAWINGS Any variation from the drawings in the erection of the pipework, for whatsoever reason, shall be brought to the attention of the Purchaser and marked on to a master set of drawings by the Vendor for acceptance by the Purchaser. All variations marked on the master drawings shall be in sufficient detail for the Purchaser to

prepare a final set of 'As Built' drawings (including P&ID‟s, PFD‟s, Layouts, General Arrangement drawings, Plot Plans).

7.3

DATA REPORTS AND RECORDS TO BE RETAINED BY THE VENDOR Site data reports and records to be retained by the Vendor shall be as specified in this specification, with the addition of Records of orifice plates installed. The tightening of all Hydraulic tensioned bolts shall be recorded on the Field Installation Check list.

7.4

BLASTING AND PAINTING All carbon steel piping shall be painted in accordance with project Painting Specification. Unless agreed otherwise, all pipe spools shall be painted prior to installation in pipe racks and/or connection to equipment. All field welds shall be manually painted after completion of welding and NDT. Welded valves shall be painted along with piping. All nameplates, spindles and any other moving parts shall be suitably masked prior to painting and masking shall be removed after application of final top coat.



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Yiu Lian Dockyards

7.5


SERVICE COLOR CODE All piping shall be color coded according to the service type/medium as per the project Painting Specification. Arrows and service description shall be located as per the project Painting Specification prior to delivery to shipyard.



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8.0

SUPPLEMENTARY REQUIREMENTS FOR STAINLESS STEEL PIPING

8.1

GENERAL Stainless steel piping storage and fabrication area shall be physically segregated or screened to prevent iron contamination from grinding or any other means from carbon steel and low alloy steel fabrication area. Only iron-free handling equipment and grinding discs shall be used for stainless steel handling and fabrication. If Chrome-Moly steel pipe are used, flame cut bevels are acceptable only where after flame cutting approximately 2mm of material has been removed from surfaces by grinding to bright metal. Pipe line up clamps shall be used in the fabrication of Chrome-Moly, Stainless Steel and Nickel Alloy Piping. Cleanliness is very important in case of fabrication of stainless steel and Nickel Alloy Piping (if applicable). Special attention shall be paid to weld area to avoid carbon pickup, hardening and hard cracking. To prevent cross contamination, files grinding wheels, wire brushes etc., shall be designated separately for carbon steel and stainless steel materials. Stainless Steel and copper tubing lines resting on galvanized steel surfaces shall be protected against galvanic corrosion using non-metallic wear pads (e.g.: rubber).

8.2

FABRICATION The austenitic stainless steel grades used include 316, 316L, 321 (Stabilized grade) and Duplex SS. The following shall apply: 

Tack welds shall be made at small intervals.



Cleanliness is very important; special attention shall be paid to the weld area to avoid carbon pick-up, hardening and hot cracking.



All weld root runs shall be made using TIG welding.



Heat input shall be low to avoid too high interpass temperature and overheating of the weld area.



For GMAW and GTAW welding, backing gas shall be applied to prevent oxidation of the weld.



Ferrite content of all 316 (inclusive of L grades) welds shall be limited to a Ferrite Number (FN) of 3 to 8 to avoid sigma phase embrittlement. FN shall be determined



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by use of a Ferrite scope. All weld procedures shall demonstrate compliance to this requirement.

8.3

HEAT TREATMENT Where a stress relief heat treatment of austenitic steels is specified by the engineering design the welds shall be heated to a temperature in the range 900- 950ºC and held for a period of one hour per 25 mm of material thickness. The minimum soaking period shall be one hour. If furnace heat treatment is applied, the furnace temperature shall not exceed 300°C when the pipework is loaded. The maximum heating rate shall not exceed 200°C per hour. Once completed, the pipework shall be removed from the furnace and rapidly cooled in atmospheric air.

8.4

PRESSURE TESTING Potable water having a chloride content of less than 30 ppm shall be used for hydrostatic testing on all austenitic stainless steels piping fabricated. If this is not possible, water having chloride content below 100 ppm may be used but subject to Purchaser‟s approval and the lines shall be flushed with water having a chloride content of less than 30 ppm within a short period after testing. After pressure testing, all stainless steel piping shall be cleaned by air blowing in accordance

with Vendor‟s approved procedure for Flushing, Air Blowing & Drying of Pipework. 8.5

PICKLING AND PASSIVATION All welding of stainless steel and duplex stainless steel pipe shall include for pickling and passivation of the external pipe surfaces using pickling paste.



B0 Sheet of

Yiu Lian Dockyards

9.0


SYSTEM COMPLETION In order to demonstrate system completion ready for pre-commissioning, the Contractor shall

carry out a „line by line walk‟ to check the system if its components have been installed in accordance with latest revision of the P&IDs. The installed system shall also be checked against isometrics and pipe support design drawing for compliance and punch list shall be provided for any outstanding items for rectification.



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10.0

APPENDICES

APPENDIX 1

PIPING WELD EXAMINATION REQUIREMENTS

APPENDIX 2

PIPING FABRICATION TOLERANCES

APPENDIX 3

ACCEPTANCE CRITERIA FOR WELDS

APPENDIX 4

FIELD INFORMATION



B0 Sheet of

Yiu Lian Dockyards

APPENDIX 1:


PIPING WELD EXAMINATION REQUIREMENTS

SCOPE This minimum requirement is applicable for metallic piping welding inspection and testing of all Piping Systems to ASME B31.3 and ASME Section IX. The requirements herein are supplementary to those of chapters V and VI of ASME B31.3.

LEVEL OF PIPING WELDING EXAMINATION All welds shall be visually inspected over 100% of the weld lengths. Branch welds are the welds between the pipe header and outlet fittings. Seal welds of threaded joints shall be examined as socket welds. Visual examination shall consist of: 

Preparation, alignment and fit-up prior to welding.



Verification of correct WPS, PQR, Welder certification, consumables and other main variables



Physical appearance of external surface of the root passes

Welds selected for examination shall include each welding process, welder and type of welding equipment. The entire length of the selected welds shall be examined. If defective welding is found, progressive sampling for examination shall be conducted in accordance with Paragraph 341.3.4 of ASME B31.3. All welding, heat treatment and inspection shall be in accordance with the requirements covered in this document and ASME B 31.3. In addition: 





All weld examinations, which are to be submitted for acceptance, are to be carried out after any required post weld heat treatment. External weld reinforcement, where applicable, shall conform to paragraph UW-35 (c) of ASME Section VIII, Division 1. External weld reinforcement, where applicable, shall not exceed 1.6mm.

Fluid Service categories shall be as defined in ASME B31.3.Utility line services refer to category D fluid of Fluid Service definitions. The Magnetic Particle Inspection (MPI) shall be done in accordance with Paragraph 344.3 of ASME B 31.3. The entire accessible area of the finished weld surface shall be examined. Branch welds shall be examined before and after any addition of a reinforcing pad. MPI shall be applied to magnetic materials. DPI shall be applied to non-magnetic materials. Purchaser or its representative or its client has the right to select, if necessary, the welds for RT or UT, where the percentage of test less than 100%. For detailed requirements, refer to NDE Summary Table below.



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NDE Summary Table

ASME Rating 150# to 300# Service

Hydrocarbon

Utility

Weld type

Visual %

RT %

Butt

100 (all)

Branch, socket fillet

ASME Rating 600# and above

MPI %

DPI%

Visual %

RT %

MPI %

DPI%

10 (all)

-

-

100 (all)

100 (all)

-

-

100 (all)

-

100 (all)

100 (all)

100 (all)

-

100 (all)

100 (all)

Pipe to pipe support

100 (all)

-

10 (all)

10 (all)

100 (all)

-

100 (all)

100 (all)

Butt

100 (all)

10 (all)

-

-

100 (all)

100 (all)

-

-

Branch, socket fillet

100 (all)

-

100 (all)

100 (all)

100 (all)

-

100 (all)

100 (all)

Pipe to pipe support

100 (all)

-

10 (all)

10 (all)

100 (all)

-

100 (all)

100 (all)

Notes: 1). 10% RT and 10% MPI/DPI acceptable for atmospheric drains in hydrocarbon & utility systems. 2). (CS) = Carbon steel, (SS) = Stainless steel, (all) = All steel material 3). NDE requirements are also subject to the pipe system class c ategory (I, II or III) according to class guidelines. The more stringent one applies.



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Yiu Lian Dockyards

APPENDIX 2:

PIPING FABRICATION TOLERANCES

Item Dimension/Angle

Allowable Tolerances

A

+ 3 mm max

B

+ 1 degree max angle

C

+ 3 mm max

D

+ 1.5 mm max rotation of flange bolt hole

E

0.75 mm max out of alignment

Note: For item D, + 1.0 mm for equipment connections. Flange bolt holes shall straddle the established horizontal and vertical centerlines of the pipe except where connection to equipment dictates otherwise.



Document Title: PIPING FABRICATION, INSTALLATION, Sheet of Sheets INSPECTION & TESTING 42 / 44 SPECIFICATION

Yiu Lian Dockyards

APPENDIX 3:

B0

ACCEPTANCE CRITERIA FOR WELDS

The acceptance criteria for welds and examination methods for evaluating weld imperfections shall comply with the requirement of Table 341.3.2 of ASME B31.3. In addition to that, the following requirement shall apply:

#

Type of Imperfection

Acceptance Criteria

1

Lack of fusion

'A' for all welds.

2

Incomplete penetration *

'A' shall apply to all welds in severe cyclic or normal fluid service.

3

Internal porosity

'D' shall apply to all welds in severe cyclic or normal fluid service. 'E' shall be applicable to category D fluid service

4

Slag inclusion, tungsten

'F' shall apply to all welds irrespective of service condition

inclusion, or elongated indication * 5

Undercutting

'H' shall apply to girth and, where approved, mitre groove welds in category D fluid service.

6

Concave root surface (suck

„A‟ in severe cyclic and normal fluid service unless a

back) *

specific limit is set by the engineering design. A maximum of 1.6 mm shall apply to welds in category D fluid service

7

Weld reinforcement or

For all welds irrespective of service conditions external

internal protrusion

weld reinforcement shall be uniform, 1.6 mm to 3 mm in height and shall merge smoothly into the pipe surface. Positive root penetration shall not exceed 1.6 mm for

NB2” and smaller, or 3 mm for larger pipe. * When these defects are permitted, the total cumulative length of lack of root penetration, slag inclusions or concave root shall not exceed 10% of the weld joint circumference.



B0

Document Title: PIPING FABRICATION, INSTALLATION, Sheet of Sheets INSPECTION & TESTING 43 / 44 SPECIFICATION

Yiu Lian Dockyards

11.0 ANNEXURES 11.1

Annexure 1 – Field Information

The FPSO shall be spread moored in close vicinity of the WHP ~ 100 meters. There will be 3 flexibles (12

“ production header, 6 “ test header and 8 “ water injection header) and 1 Power umbilical with Fibre optic cable (11 KV, 3 phase, 60 Hz) between the WHP and the FPSO, in a free hanging catenary between raiser balconies at either ends. The Power umbilical will export 2.5 MW of power from FPSO to feed the

ESP‟s for artificial lift of the production wells on the WHP. The FPSO shall be capable of handling 45,000 blpd of production fluids, 35,000 bopd of oil production, 38,000 bwpd of produced water treatment and over boarding, 15000 bwpd of water injection, Flare capacity of 35 mmscfd max and test separator of 8000 bopd. The FPSO will be equipped with tri fuel (Gas/ Crude oil/ HFO) fired steam boilers and turbo-generators to meet captive and export power requirements and for process heating. The FPSO shall have an accommodation designed for 76 POB and helideck. The minimum storage shall be 600,000 bbls and the offtake pumps shall be capable of offloading 500,000 bbls in 24 hrs. The offloading facility shall be capable of handling upto 320,000 DWT tankers.

OML 122 – Phase OML 122 – Phase 1 Initial development

OML 122 – Phase 2 (future)

Figure 1 – Field location ©COPYRIGHT BY A&T OFFSHORE OR ITS AFFILIATES. THIS DOCUMENT IS THE CONFIDENTIAL PROPERTY OF A&T OFFSHORE AND SUCH DOCUMENT, OR ANY PART THEREOF, MAY NOT BE MADE KNOWN, BE COPIED OR BE MULTIPLIED OR IN ANY OTHER WAY USED WITHOUT PERMISSION OF A&T OFFSHORE.

Fabrication, Installation and Testing Procedure

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