Gs118 10RevWeldingOfTransm.pipeline

Copyright The British Petroleum Company p.l.c.

GS 118-10

WELDING OF TRANSMISSIONPIPELINES

Supplementary to BS 4515: 1996December 1998

(Amended February 2000)

Copyright The British Petroleum Company p.l.c.

All rights reserved. The information contained in this document is subject to the terms andconditions of the agreement or contract under which the document was supplied to therecipient's organisation. None of the information contained in this document shall bedisclosed outside the recipient's own organisation without the prior written permission ofManager, Standards, BP International Limited, unless the terms of such agreement orcontract expressly allow.

BP GROUP RECOMMENDED PRACTICES AND SPECIFICATIONS FOR ENGINEERING

Issue Date December 1998

Doc. No. GS 118-10 Latest Amendment Date February 2000

SUPPLEMENTARY TO BS 4515: 1996(Replaces BP Engineering Std 192 Part 1 and BP GS 118-10 April 1986)

APPLICABILITY

Regional Applicability: International

SCOPE AND PURPOSE

This BP Group

AMENDMENTSAmd Date Page(s) Description___________________________________________________________________

01 01 Feb 2000 19-20 Reference BS EN 1435 replacing BS 2910 23-24 Amendment to Table 8(j) 29-30 Amendment to list of referenced standards.

Approved for issue:- .December 1998 John Hammond

DOCUMENT CUSTODIAN

CUSTODIAN (See Current Status List for Contact)

WeldingIssued by:-

Engineering Practices Group, BP International Limited, Research & Engineering CentreChertsey Road, Sunbury-on-Thames, Middlesex, TW16 7LN, UNITED KINGDOM

Tel: +44 1932 76 4067 Fax: +44 1932 76 4077 Telex: 296041

DRAFTGS 118-10

WELDING OF TRANSMISSION PIPELINESPART 1 - SUPPLEMENTARY TO BS 4515

PAGE i

CONTENTS

Section Page

FOREWORD ..................................................................................................................... iii

1. GENERAL .......................................................................................................................1

1.1 Scope and General Applicability .................................................................................11.3 Definitions .................................................................................................................11.4 Information to be supplied, items to be approved and requirements to be

agreed and documented ..............................................................................................21.5 Equipment .................................................................................................................41.6 Welding Processes......................................................................................................41.7 Welding Consumables.................................................................................................51.8 General Requirements.................................................................................................6

2. TESTING, QUALIFICATION AND APPROVAL OF WELDING -PROCEDURES....................................................................................................................7

2.1 General .................................................................................................................72.3 Welding Procedure .....................................................................................................72.4 Changes Affecting Qualification and Approval (Essential Variables)............................72.5 Testing of Butt Joints for Procedure Qualification.....................................................102.6 Testing of Fillet Welds for Procedure Approval ........................................................122.7 Testing of Repair Welds for Procedure Qualification.................................................12

3. TESTING, QUALIFICATION AND APPROVAL OF WELDER..............................13

3.1 General ...............................................................................................................133.5 Changes Affecting Qualification and Approval (Essential Variables)..........................133.6 Non-destructive Testing............................................................................................133.7 Destructive Testing...................................................................................................133.8. Retests ...............................................................................................................133.9 Records ...............................................................................................................133.10. Mechanized Welding..............................................................................................13

4. PRODUCTION WELDING ..........................................................................................14

4.1. Proximity of Welds ..................................................................................................144.2 Pipe End Preparation................................................................................................144.3. Fusion Faces............................................................................................................144.4 Alignment ...............................................................................................................154.5 Line-up Clamps and Pipe Supports ...........................................................................154.6 Tack Welds ..............................................................................................................154.8 Stray Arcs ...............................................................................................................154.9 Weather Conditions ..................................................................................................164.10 Preheating and Post-weld Heat Treatment...............................................................164.11 Branches ...............................................................................................................164.12 Inter-run Cleaning...................................................................................................17

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4.13 Partially Completed Joints.......................................................................................17

5. INSPECTION AND TESTING .....................................................................................18

5.1 Inspection and Testing ..............................................................................................185.1 General ...............................................................................................................185.2 Personnel Qualification.............................................................................................185.4 Radiographic Testing................................................................................................185.5. Manual Ultrasonic Testing .......................................................................................215.6. Automatic Ultrasonic testing....................................................................................215.7 Magnetic Particle Testing .........................................................................................215.8 Destructive Testing...................................................................................................22

6. ACCEPTANCE AND RECTIFICATION OF WELDS ...............................................23

6.1 Non-Destructive Testing Acceptance Criteria ...........................................................236.2 Rectification of Welds...............................................................................................24There are no requirements additional to BS 4515:1996.......................................................

ANNEX C TO BS 4515 (INFORMATIVE). PROPOSED WELDING PROCEDURE SPECIFICATION..........................................25

ANNEX D TO BS 4515 (INFORMATIVE)EXAMPLE OF A RECORD FORM FOR WELDER QUALIFICATION TEST. .........26

ANNEX E TO BS 4515 (INFORMATIVE) .GUIDANCE FOR ESTABLISHING PREHEATING REQUIREMENTS .....................26

ANNEX F TO BS 4515 (INFORMATIVE).EXAMPLE OF A RADIOGRAPHIC SPECIFICATION................................................26

APPENDIX A.....................................................................................................................27

DEFINITIONS AND ABBREVIATIONS ........................................................................27

APPENDIX B.....................................................................................................................29

LIST OF REFERENCED DOCUMENTS ..................................................................29

APPENDIX C.....................................................................................................................32

ALTERNATIVE TECHNIQUE FOR BATCH TESTING OF WELDINGCONSUMABLES.........................................................................................................32

FIGURE C1........................................................................................................................33

PROCEDURE FOR ESTABLISHING BATCH TEST REQUIREMENT......................33

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FOREWORD

Introduction to BP Group Recommended Practices and Specifications for Engineering

The Introductory Volume contains a series of documents that provide and introduction to theBP Group Recommended Practices and Specifications for Engineering (RPSEs). In particular,the General Foreword sets out the philosophy of the RPSEs. Other documents in theIntroductory Volume provide general guidance on using the RPSEs and backgroundinformation to Engineering Standards in BP. There are also recommendations for specificdefinitions and requirements.

Value of this Guidance for Specification

This Guidance for Specification specifies all BP general requirements for welding oftransmission pipelines that are within its stated scope, and for use with a supplementaryspecification to adapt it for each specific application.

This Guidance for Specification is based upon an industry specification.

The value of this Guidance for Specification to its users will be significantly enhanced by theirregular participation in its improvement and updating. For this reason, users are urged toinform BP of their experiences in all aspects of its application.

Application

This Guidance for Specification is intended to guide the purchaser in the use or creation of fit-for-purpose specification for enquiry or purchasing activity.

This document may refer to certain local, national or international regulations but theresponsibility to ensure compliance with legislation and any other statutory requirements lieswith the user. The user should adapt or supplement this document to ensure compliance forthe specific application.

Previous Changes from Previous Editions

This document completely supersedes the earlier BP Standard 192 Part 1 (April 1986) whichwas later reformatted into BP GS 118-10 (1986), both former documents being based on BS4515:1984. This document is based on BS 4515:1996 and reflects the extensive revision of thebase document.

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Feedback and Further Information

Users are invited to feed back any comments and to detail experiences in the application of BPRPSEs, to assist in the process of their continuous improvement.

For feedback and further information, please contact Standards Group, BP International or theCustodian. See Current Status List for contacts.

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1. GENERAL

1.1 Scope and General Applicability

1.1.1 This BP Group RPSE specifies general BP requirements for the weldingof transmission pipelines in accordance with BS 4515: 1996.

To apply this BP Group RPSE, supplementary specification andapproval actions by BP are required to adapt it to each specific projectapplication.

The titles and numbering of the text of this BP Group RPSE followthose of BS 4515:1996 for the convenience of the user. As a result ofthis, gaps in the numbering sequence may occur. Text either qualifies,substitutes, modifies or adds to its requirements those of BS 4515:1996. Where additional text is to be read as an extension of the text ofBS 4515:1996, the text numbering of BS 4515:1996 has been extendedaccordingly.

1.1.2 BP Group GS 118-10 is applicable where statutory regulations requirethat the pipeline is welded in accordance with BS4515:1996, as in theUK, or other areas where BS 4515:1996 may have been adopted by astatutory authority or by choice as the pipeline welding code. Itsalternative companion GS, BP Group GS 118-9 is applicable wherestatutory regulations or similar adoption of API standards require thatthe pipeline is welded in accordance with API Standard 1104.

1.3 Definitions

In this standard, the following definitions shall apply in addition to ormodifying or supplementing those of Section 1.3 of BS 4515:1996.

Any specific application of the terms and responsibilities for the partiesdefined as follows is a matter for the Conditions of Contract on aproject.

1.3.1 (a) employer: BP, acting directly or through an authorisedrepresentative.

(b) BP The British Petroleum Company p.l.c, an associate or subsidiary, or other organisation as

defined in the conditions of contract.

1.3.2 contractor: a contractor responsible BP for the welding of thepipeline

1.3.22 inspector: an employee of the contractor with overall

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responsibility for ensuring that all construction,inspection and testing are undertaken in accordancewith the requirements of this GS

1.3.23 batch: a single cast of filler wire, a single blend of flux, or, for covered electrodes , the combination of a single cast ofcore wire with a single dry blend of covering.

1.3.24 duty: pipeline service which is to be defined by BP asnormal or severe. Welds in severe duty pipelines will(may) be subject to more onerous requirements thanthose in normal duty pipelines.

1.3.25 service: to be defined by BP as either sour or non-sour (see1.3.13 of BS 4515:1996).

1.3.26 quality assurance (QA):all those planned and systematic actions necessary toensure quality and technical compliance. (i.e. to provideadequate confidence that a product will be fit for itsintended service).

1.3.27 quality manuala document setting out the general quality policies,procedures and practices of an organisation

1.3.28 quality plan (QP)a document prepared by the contractor, setting out thespecific quality practices, resources and sequence ofactivities relevant to the particular pipeline weldingcontract.

1.4 Information to be supplied, items to be approved andrequirements to be agreed and documented

1.4.1 Information to be Supplied by the Employer

Where possible, the information to be supplied is provided below underthe appropriate clause numbers. However, in addition to the itemsidentified by BS 4515: 1996, the following information will be suppliedby the employer:-

(i) Test pressure for pipeline field hydrostatic test

(ii) The pipeline duty and service.

(iii) Requirement for Charpy testing of welding consumables onsevere duty pipelines.

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(iv) Whether any change in heat input is considered significant.(See 2.4, Table 1 j5.)

(v) Whether additional hardness surveys on macro-sections arerequired.

(vi) Alternative Charpy test temperatures.

(vii) Use of fluorometallic screens.

(viii) Sensitivity levels for gamma radiography.

(ix) Welds and areas requiring ultrasonic testing

(x) Further limitations on root undercut and shrinkage groove forsour service pipelines.

1.4.2 Items to be Approved by the Employer

Where BP have specific requirements, these are stated below under theappropriate clause numbers. However, in addition to the itemsidentified by BS 4515: 1996 the following additional approvals arerequired:-

(i) Use of automatic and semi-automatic welding systems (See 1.6)

(ii) Quality plan prior to production welding. (See 1.8.3)

(iii) Acceptance of batch testing failure before re-tests are allowed.(See 1.7.1)

(iv) Acceptance of re-welding in procedure qualification tests (See3.8)

(v) Acceptance of material grouping. (See 3.5)

(vi) Acceptance of diameter and thickness group combination.(See 3.5c)

(vii) Acceptance of Charpy V-notch impact test results.(See 2.5.2.5)

(viii) Acceptance of pipe diameter or wall thickness changes.(See 3.5)

(ix) Welder re-training programme. (See 3.8).

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(x) Alternative 'pup' piece length. (See 4.1)

(xi) Angle of field bevel if different from mill bevel. (See 4.2)

(xii) Alternative method for pipe end cleaning. ( See 4.3)

(xiii) Corrective action for misalignment. (See 4.4)

(xiv) Use of fabricated fittings. (See 4.11).

(xv) Use of Iridium 192. (See 5.4.1)

(xvi) Use of gamma-radiography. (See 5.4.2)

(xvii) Use of permanent magnets or prods. (See 5.7)

(xviii) Limits on size and location of weld repair excavations.(See 6.2.4)

1.4.3 Requirements to be Agreed

Where appropriate, the requirements of BP are stated under theappropriate clause numbers. However, in addition to the itemsidentified by BS 4515: 1996 the following requirements shall be subjectto specific agreement between BP and the contractor.

(i) Use of wall thickness and pipe diameter grouping for welderqualification on severe duty pipelines. (See 3.5)

1.5 Equipment

The contractor shall supply all necessary equipment for welding, heattreatment, mechanical handling, testing and radiographic processing.

1.6 Welding Processes

The contractor shall specify in his tender the welding process, orprocesses or combination of processes proposed for the pipelay weldingoperation. Manual processes, semi-automatic or automatic weldingsystems may be offered. Where a process or system is proposed ofwhich BP has no previous experience BP will specify welding and NDTtrials which are to be undertaken by the contractor and completedsuccessfully before the proposed technique can be approved forqualification testing. Separate qualification of a manual metal arcprocedure may also be required, for possible use in the event of failureof semi-automatic or automatic equipment in production welding.

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1.7 Welding Consumables

The contractor shall supply all necessary welding electrodes, fillerwires, fluxes, shielding and backing gases and all other consumableitems required for the work.

1.7.1 General

Where the duty of the pipeline is specified by BP as severe, each batchof welding consumables shall pass the Charpy V-notch impact testrequired for welding procedure qualification. This requirement will bewaived if further tests from the qualification weld still meet thespecified values when tested 20C below the specified test temperature.All batch testing shall be completed prior to the start of field welding.No re-tests are permitted unless a satisfactory explanation for the failurecan be given and is accepted by BP.

1.7.2 Storage and handling.

1.7.2.1 General

Each coil of filler wire, bag of flux and tin or packet of electrodes shallbe clearly marked with its batch number (and shall be stored completelyseparated). The storage and handling of welding consumables shall begenerally in accordance with BP Group GS 118-4. The contractor'sdetailed proposals shall form part of the quality plan.

1.7.2.1 Shielding Gases - General

Where appropriate, gases or gas mixtures complying with BS EN 439shall be used:-

(a) argon,(b) carbon dioxide(c) gas mixtures that have been proved to be satisfactory as a result

of procedure approval tests.

When a gas mixture is used which has specified additions e.g. 2% O2,5% CO2, the variation of such addition shall not exceed 10% of thatstated.

1.7.2.2 Shielding Gases - Storage and Handling

Shielding gases shall be stored away from extremes of temperature. Inthe field, only gases specified in 1.7.2.1, as supplied by themanufacturers, in specially marked containers, shall be used. Gases thatare of questionable purity and those in containers which show signs ofdamage shall not be used.

1.7.3 Welding Consumables for Fillet Welds

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Basic coated low hydrogen electrodes or other approved low hydrogenprocess shall be used for any fillet welding directly on to the pipeline,but rutile coated electrodes may be used for fillet welds between non-pressure bearing parts such as structural supports.

1.8 General Requirements

1.8.1 Supervision of the Work

The contractor shall employ competent supervisors to ensure that boththe standard of workmanship, and the quality of materials used, complywith the requirements of this BP Group RPSE.

1.8.2 Field Hydrostatic Test

The completed pipeline shall be hydrostatically tested for a minimumperiod of 24 hours. The test pressure, which will be defined by BP,shall not normally exceed that required to produce a hoop stress equalto 95% of the specified minimum yield strength in a pipe with thespecified minimum wall thickness.

The completed pipeline shall be proved free from internal obstructionsby the passing of a pig fitted with a gauging plate, of dimension 96% ofnominal bore.

1.8.3 Quality Assurance

1.8.3.1 Responsibility for quality assurance shall rest with the contractor. Thecontractor shall devise and implement a quality plan for the systematiccontrol of the construction, inspection and testing required by theparticular contract. This quality plan, which shall be based on ISO9002/9003 shall be submitted to BP for approval prior to productionwelding, and shall include evidence that the inspector and his team areindependent of production management.

1.8.3.2 The inspector shall ensure that all documentation required by thisStandard is gathered, collated, indexed, stored and subsequentlypresented to BP. He shall compile a log identifying by number eachpipe and fitting, and indicating the weld numbers joining them to otheritems. Each circumferential weld (whether a field joint or a shop-madeweld) shall be allocated a unique number, which shall be used forreference to the weld in all reports, radiographs and NDT documents.

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2. TESTING, QUALIFICATION AND APPROVAL OF WELDING -PROCEDURES

2.1 General

(a) All welding procedure qualification tests shall be conducted inthe presence of a BP representative.

(c) A test shall be allowed to cool for a minimum of 24 hours insimulated site conditions. After this 24 hour period, theprocedure qualification test welds shall be fully radiographed,ultrasonic tested and magnetic particle tested prior toconducting destructive tests.

(h) For pipelines designated as severe duty, BP will require weldingprocedures to be specifically qualified on the actual material forconstruction. Previous weld qualification test results will not beacceptable for such applications.

2.3 Welding Procedure

Procedure approval tests shall be carried out on pipe, made from thesame material, from the same source and in the same supply conditionthat is to be used for pipeline construction.

2.4 Changes Affecting Qualification and Approval (EssentialVariables)

Table 1. Welding Procedure Specification Details andChanges Affecting Approval.

The following additional restrictions or changes apply to all weldingprocedure specifications:-

Item Relevant Change or Restriction

(a) Welding process The gas tungsten arc process (GTAW)shall be used for welding on all pipediameters less than 60 mm.

(b) Material Specification Pipe, valves, flanges and fittings fromdifferent sources, or made frommaterial from different sources, or indifferent supply conditions shall betreated separately and shall requireseparate procedure qualification,unless some form of material groupingis approved by BP.

(c/d) Diameter /Thickness Different wall thicknesses and

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diameters shall be qualified separately,unless approved otherwise approvedby BP.

(e5) Joint configuration The use of permanent backing rings isnot permitted.

(f) Filler metal Basic coated low hydrogen electrodesor approved low hydrogen processshall be used for all fillet welds to thepipeline

(g) Number of runs The number and position of weld beadsshall be selected to give the finishedweld a substantially uniform cross-section.No two weld beads shall startat the same point, unless the area isdressed clean and sound before thesecond bead is started. Single passwelds are not permitted

(i) Electrical For Manual Shielded Metal ArcWelding characteristics of pipediameters above 300 mm welded d.c.electrode positive (d.c.e.p) polarityshall be used.An increasing tendency towards useof d.c electrode negative (d.c.e.n) forpolarity for root runs of pipe of alldiameters is noted. Where acontractor proposes use of d.c.e.n thewelding procedure qualification testshall include this feature. Arbitrarychange from d.c.e.p to d.c.e.n. or viceversa is not permissable.

(j5) Heat input Any change in heat input outwith thelimiting values calculated from valuesof arc voltage (j2), wire feed speed (j3)and travel speed (j4) or consideredsignificant by BP.

(l) Direction of welding For all tie-ins (closing welds), all weldswhere external line-up clamps areused, and for all repair welds, vertical-up welding shall be used for the rootruns. For pipe diameters less than 150mm and for all welds to valves, flangesor fittings including fillet welds, the

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complete weld shall be vertical-up.

(o) Time lapse When vertical-down welding isemployed between runs the second run(hot pass) shall be depositedimmediately after completion of theroot run (stringer bead), and the timelapse shall not be greater than thatused in the welding procedurequalification test.

(p) Partially completed joint Welds shall not be cooled belowpreheat temperature before:-

For pipe to pipe welds onshore4 runs minimum completed.

For welds offshore. All runscompleted.

For welds on fittings, tie-in welds andrepair welds. All runs completed.

(q) Type of line-up clamp if used For pipe over 150 mm diameter anclamp, internal line-up clamp shall beused.Where the use of an internal clamp isimpracticable, an external line-upclamp shall be used.

(r) Lowering-off or barge move-up asapplicable

The pipe shall not be lowered-offuntil both the root pass and thesecond pass are complete, unless thecontractor can demonstrate to thesatisfaction of BP that the root runalone is adequate to resist deformationand cracking. For offshore pipelay,barge move-up shall not occur until thehot pass is complete

(t6) Interpass temperature Interpass temperature in constructionshall not exceed the maximum valueachieved in the welding procedurequalification test, which in any caseshall not exceed 250C.

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(t7) Ambient temperature Minimum ambient temperature belowwhich preheating is to be applied.

(u) Post weld heat-treatment The temperature range of any PWHTshall be selected, taking into accountthe steel composition andmanufacturing route. The PWHTtemperature, time and method ofapplication used in pipelineconstruction shall fall within the rangeused in the welding procedurequalification test.

2.5 Testing of Butt Joints for Procedure Qualification.

2.5.1 Non-destructive Testing

All test joints shall be examined visually followed by:-

(i) Radiography in accordance with clause 5.4.

(ii) Ultrasonic examination in accordance with clause 5.5.

(iii) A magnetic particle test in accordance with clause 5.7 atexternal and internal weld surfaces.

The acceptance criteria for non-destructive testing shall be inaccordance with clause 6.1.

2.5.2 Destructive Testing

The following additional tests are required:-

2.5.2.1 Test Specimens

For pipe outside diameters up to and including 114.3 mm, twotransverse weld tensile test specimens shall be taken.

For pipe outside diameters up to and including 114.3 mm, two sets ofthree Charpy impact specimens shall be taken at the 9 o'clock position.

For pipe outside diameters over 114.3 mm, two additional sets of threespecimens shall be taken at the 6 o'clock position.

When specified (separately) for severe duty pipelines, two sets of threeCTOD specimens shall be taken. An all weld tensile test to BS 709 :

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1983 is also required on each weld from which CTOD tests are taken,on material from a location as close as possible to the CTOD tests.

2.5.2.2 Transverse Tensile Test

2.5.2.2.1 Requirements

If any specimen breaks outside the weld at a tensile strength below thespecified minimum tensile strength, the material shall be consideredsuspect and its physical properties shall be investigated before anyadditional tests are made.

2.5.2.2.2 Method

The test specimens shall not be flattened before testing.

2.5.2.4 Hardness Survey


In addition to the requirements of Table 4, where the pipeline service isdefined as sour, no individual hardness value shall exceed 248 HV10(see BP Group RPSE GS 136-1).

2.5.2.4.2 Method

BP may require additional hardness surveys on macro-sections takenfrom different locations.

A macro-photograph shall be supplied to show the location of allhardness indents.

2.5.2.5 Charpy V-Notch Impact Test


Unless otherwise specified by BP, the impact test temperature shall bethe minimum design temperature and energy requirements for the weldshall be 40 J minimum average of three specimens and 30 J minimumindividual value.

2.5.2.5.2 Method

For pipe diameters up to and including 114.3 mm, one set of Charpy V-notch test specimens shall be notched in the weld metal and the other inthe heat affected zone.

For pipe diameters over 114.3 mm, the additional sets of Charpy testsat the 6 o'clock position shall be notched and tested as the othersamples.

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For pipe wall thickness over 20 mm, both sets of test specimens at the 3o'clock position shall be positioned at the weld root. One set of testspecimens shall be notched in the weld metal and the others in the heat-affected zone. For weld metals, the percentage of shear area of eachfracture surface shall be estimated and reported. If the results areinconsistent with the measured energy, BP may require furtherinvestigation before approving the test results.

2.5.2.6 Crack Tip Opening Displacement (CTOD) Testing

Detailed CTOD testing was removed from BS 4515 when the 1996edition was prepared, leaving only a minor note (3) to clause 2.5.2.5.1.

Exact CTOD requirements are not specified in this GS as these will bedependent on each individual application. Where an EngineeringCriticality Assessment (ECA) approach is required as part of pipelinedesign for installation or operation, it is the responsibility of eachproject to define the ECA philosophy and specify the methodology forCTOD testing and acceptance values according to its own needs.

It is suggested that use should be made of BS PD 6493 for any ECA philosophy. Theselection of material and sampling of each respective zone for CTOD testing shalltake into account the importance of identifying the zone of potentially lowestfracture toughness. All CTOD tests shall be conducted in accordance with BS7448: Part 2: 1998 at the minimum design temperature.

Where possible the specimens shall be full wall thickness, preferred geometry andthe pipe curvature shall not be machined from the sample. The exact notchpositions and geometry in the CTOD test samples should be subject to agreementbut should include the weld metal and the heat affected zone.

2.6 Testing of Fillet Welds for Procedure Approval

2.6.2.4 Hardness Survey


In addition to the requirements of Table 4, where the pipeline service isdefined as sour, no individual hardness value shall exceed 248 HV10(see BP Group GS 136-1).

2.6.2.4.2 A macro-photograph (or sketch) shall be supplied which shows thelocations of all hardness indents.

2.7 Testing of Repair Welds for Procedure Qualification

Section 2.7 of the new 1996 edition of BS 4515 deals with the testing of repair weldsfor procedure qualification and is deemed to meet BPs general requirementswithout a supplement.

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3. TESTING, QUALIFICATION AND APPROVAL OF WELDER

3.1 General

Welders qualification tests shall be witnessed by a BP representative.

3.5 Changes Affecting Qualification and Approval (EssentialVariables)

If the following additional item is changed, the welder using the newprocedure shall require re-approval:-

(f) For manual metal-arc welding a change in electrode trade name.

3.6 Non-destructive Testing

For manual metal-arc, tungsten inert gas (TIG) and submerged-arcwelding the test weld shall be assessed by X-radiography as specified inclause 5.4. For metal inert gas (MIG)/metal active gas (MAG), CO2and non-shielded welding, the weld shall be assessed by X-radiographyto clause 5.4 and ultrasonic examination as specified in clause 5.5.

3.7 Destructive Testing

In addition to NDT, destructive testing shall be used for examination ofwelds made by any process other than manual metal arc, TIG andsubmerged arc.

3.8. Retests

If, in the opinion of BP, An individual welder is responsible for a highlevel of repairs in production, he/she shall be removed from the workand shall undergo a re-training programme approved by BP beforebeing retested.

3.9 Records

The details of each welders approval test and test results shall berecorded by the contractor and be available for inspection by BP. Thecontractor shall submit all documentation relating to welder approvaltests to BP for approval prior to the welder commencing productionwork. BP will specify the period for which records shall be maintained.(The content and requirement for this may vary from project to projectand will be individually specified).

3.10. Mechanized Welding

Welders for mechanised welding shall be approved for all parts of theoperation. The inspection, testing and re-testing of welds for approvalpurposes and records shall be in accordance with the following:-

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(i) Visual examination to clause 3.6.

(ii) X-radiography to clause 5.4.

(iii) Ultrasonic examination to clause 5.5

(iv) Destructive testing to clause 3.7.

(v) Retests to clause 3.8.

(vi) Records to clause 3.9.

The acceptance criteria for NDT shall be in accordance with 6.1.2.

4. PRODUCTION WELDING

4.1. Proximity of Welds

Branches, fittings and attachments shall be sited away from other welds(including longitudinal and circumferential welds) on the pipeline. Theminimum separation between any two welds shall be the largest of thediameter of the branch or fitting, six times the wall thickness of thethicker component, or 150 mm.

No two circumferential welds shall be closer than the diameter of thepipe, but if a pup piece is used to replace a defective section, its lengthshall not be less than twice its diameter, unless otherwise approved.

4.2 Pipe End Preparation

The pipe end bevel may be specified by the contractor and shall besuitable for the welding process to be used. In general, the API 5Lstandard bevel will be considered suitable for manual weldingprocesses, but for thick-wall pipe or for certain types of GMAWmechanised welding, an alternative compound bevel may be proposed.The bevel design shall be subject to agreement by BP.

Manual cutting shall not be used for bevelling.

If the blending of burns, small score marks, indentations or other minorimperfections within the joint area is agreed, then it shall be confirmedby ultrasonic measurement that the remaining wall thickness is abovethe allowable minimum.

Weld repairs to pipe ends shall not be permitted.

4.3. Fusion Faces

Before welding, the pipe shall be cleaned inside and out using powerdriven wire brushes, grinding or other method approved by BP, for aminimum distance of 40 mm from the edge of the weld bevel.

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4.4 Alignment

Where misalignment exceeds 1.5 mm, corrective action shall be subjectto the approval of the BP representative in each case. Hammering of thepipe to obtain correct alignment should be kept to a minimum and shallbe carried out using only a bronze headed hammer. The mass of thebronze headed hammer shall not exceed 5 kg. Any surfacecontamination of the pipe surface from the hammering shall beremoved. Heat shall not be used for corrective purposes.

4.5 Line-up Clamps and Pipe Supports

4.5.1 Power operated internal clamps shall be used for pipe of over 150 mmdiameter, and they shall be demonstrated as capable of reducing themaximum permitted out-of-roundness of the as-manufactured pipesufficiently to meet the alignment requirements of clause 4.4. Externalclamps shall be used only when the root run is deposited by the vertical-up technique.

4.5.2 For on-land pipelines, at least the root run and the second run shall becompleted before the pipe is lowered on to skids or, in the case offittings, the support is removed, unless the contractor is able todemonstrate to the satisfaction of BP that the root run alone is adequateto resist deformation and cracking.

4.6 Tack Welds

Tack welds are allowed for vertical up welding only. All tack weldsshall be deposited by approved welders and in accordance with thewelding procedure specification. Where pre-heat is required for theroot run, this shall be applied prior to tack welding and maintained untilthe joint is completed.

4.8 Stray Arcs

Repair of stray arcs in sour service pipelines may be restricted by BP.When repair is allowed this shall be bt grinding only. Repairs bywelding are not allowed.

If grinding to remove the effects of stray arcs reduces the wall thicknessbelow the minimum specified in the data sheet, the defective pipesection shall be cut out and the pipe re-bevelled and re-welded. If apup piece has to be used to replace the defective section, its lengthshall not be less than twice its diameter. Note that stray arcs are alsopossible between the pipe and the return cable and shall be avoided bygood electrical connections.

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4.9 Weather Conditions

When necessary, the end of the pipe shall be covered to prevent waterbeing channelled into the weld root. Windshields shall be used whennecessary.

4.10 Preheating and Post-weld Heat Treatment

4.10.2 Preheating

Except as permitted under clause 4.13, preheating shall be maintainedthroughout the entire welding of the joint.

4.10.3 Post-weld Heat Treatment Temperatures

Thermocouples shall be used for recording post-weld heat treatmenttemperature. As a minimum, thermocouples shall be placed at the 6 and12 o'clock positions. For pipe sizes above 600 mm outside diameter,thermocouples shall also be placed at the 3 and 9 o'clock positions. Thepipe shall be heated for a minimum distance of 2.5 Rt (where R is theexternal radius and t is the wall thickness) on either side of the joint.The temperature at the edge of this heated band shall not be less thanhalf the peak temperature at the centre (in C).

4.10.4 Thermocouple Attachment and Junctions

Thermocouples shall be attached by the capacitance discharge method.After use, thermocouples shall be removed by grinding and the areashall be examined by magnetic particle inspection as for a stray arc.

4.11 Branches

Unless otherwise approved by BP, forged fittings shall be used forbranches and other pressure containing attachments. To simplify thewelding of some large fittings such as tees or elbows into the line, a'pup' piece may be welded to the fitting and the length of such puppieces should be sufficient to accommodate the line-up clamp to beused. Other large fittings may be girth welded directly into the pipelineprovide that wall thickness of the fitting and pipe are reasonablymatched and that suitable clamping can be accommodated.

Items such as weld-o-lets may be welded directly on to the pipeline,using the appropriate qualified procedures. Large weld-o-lets and heavyfittings may require special support, particularly when welded on to thinsection pipelines.

Where accessible, all welds to valves, flanges and fittings shall beground back smooth internally prior to radiography.

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4.12 Inter-run Cleaning

Each run shall be thoroughly cleaned by power tools.

4.13 Partially Completed Joints

(i) Land Pipelines

The welding of fittings, tie-ins and repairs shall be completed inone cycle. When production conditions are such that pipe-to-pipe joints have to be left partially completed, at least four weldruns shall be completed prior to cooling unless a procedurequalification test involving fewer runs has been carried out.

(ii) Submarine Pipelines and land pipelines in construction on steepgradients.

All welds shall be completed in one cycle.

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5. INSPECTION AND TESTING

5.1 Inspection and Testing

5.1 General

The frequency of non-destructive testing shall be as specified under theseparate clauses 5.4, 5.5 and 5.7.

Prior to examination of the weld, each joint shall be thoroughly cleanedusing power driven wire brushes. All spatter, bonding media and anyinks or dyes used for crack detection, shall be removed. The completedweld shall be examined visually prior to being examined by radiography.

Ultrasonic and magnetic particle flaw detection testing equipment shallbe available to supplement radiography on any area nominated by BP.

When automatic and semi-automatic welding systems have beenapproved by BP, ultrasonic testing shall be required to supplementradiography. The extent of this testing will be specified by BP.

5.2 Personnel Qualification

All inspection personnel shall be experienced in the appropriateinspection and control and control techniques and shall hold current,valid certificates demonstrating approval to either BGAS Transco,CSWIP or PCN systems.

Note that the BGAS Transco and CSWIP examinations are run by TWI Training &Examinations Dept. The Certification body for CSWIP is TWI Certification Ltd,Granta Park, Great Abington, Cambridge, UK. PCN is administered by the BritishInstitute of Non-Destructive Testing (BINDT) at Northampton, UK).

Both Institutes are able to verify the validity of individual certificates. Certificatesare issued for specific periods only and an out-of-date certificate is invalid. Careshould be taken to ensure that the certificate and approval category coverscompetence in the required skills for the job. e.g. BGAS Transco Senior PipelineInspector covers welding inspection and radiographic interpretation, but CSWIPwelding inspector and radiographic interpreter are discrete and differentcategories.

5.4 Radiographic Testing

5.4.1 General

100% radiographic testing is required in the following cases:-

(a) All welds in severe duty pipelines.

(b) All welds between pipes of different nominal bore.

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(c) All welds to valves, flanges and fittings.

(d) All tie-ins (closing welds).

(e) All welds in river and other crossings.

On a pipe-lay barge, the weld shall not be moved past the weld repairstation until the interpretation of the radiograph is complete and theweld is judged satisfactory. Unless otherwise approved by BP, coatingand wrapping of the joint shall not begin until the weld is judgedsatisfactory.

For normal duty pipelines, the first five welds of each thickness anddiameter made by each welder shall be 100% radiographically tested. Ifany of these welds requires a repair, all subsequent welds by the samewelder shall be 100% radiographically tested until five consecutivelyproduced welds are judged to be satisfactory. Thereafter, BP will selectat least one weld from every ten welds, and radiograph this 100%. Ifany of these one-in-ten welds should require repair, BP will requiresome or all of the other nine to be radiographed 100%.

BP may specify 100% radiography for some normal duty pipelines.

Radiography shall be conducted using X-rays. Under certaincircumstances BP may approve the use of Iridium 192, but othersources of gamma rays are not permitted.

As exposure of any part of the human body to X-rays or gamma rayscan be injurious, it is essential that whenever X-ray equipment orradioactive sources are in use, adequate precautions are taken toprotect the radiographer and all other personnel in the vicinity.

Note 1. The use of X-ray machines and gamma-radiography sealed sources infactories and certain other premises and works coming within the scope of theFactories Act is controlled by the Ionising Radiations (Sealed Sources) Regulations1969 and th Radioactive Substances Act (1960).

Note 2. Attention I is drawn to the Code of Practice for Site Radiography preparedby the Oil and Chemical Plant Contractors Association and published by Kluwer-Harrap Handbooks, Brentford. Attention is also drawn to the need for audible andvisual warning arrangements and for regular monitoring of radiation levels.

The above paragraph and two notes formed section 37.2 Protection of BS 4515:1984 - but were not included in BS 4515:1996. The proposal of WEE/21/7 was thatthe warning should be covered in separate regulations, rather than in the basestandard for pipeline welding but, as it is uncertain where such warnings arecovered elsewhere, it is deliberately included in this BP GS.

5.4.2 Approved Radiographic Procedures

The following details shall be included in the radiographic procedure.

(The following items were additional to section 37.3 of BS 4515: 1984 but theformat of the whole section - now 5.4.2 of BS 4515: 1996 has changed, the list has

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been dropped and reference has been made to BS 2910. In 1997, BS 2910 wassuperseded by BS EN 1435. Amendment No 1 of this GS draws on BS EN 1435 inrespect of the following details of radiographic technique and assessment ofradiogrpahic sensitivity. .

(a) technique Radiographic techniques shall be in accordancewith BS EN 1435 Class B (Improvedtechinques). The preferred technique forradiographic examination of pipeline girth weldsis film outside with the source of radiation insidethe pipe.(BS EN 1435 Para 6.1.4 and Figure 5).Exceptionally, where the preferred technique isnot practicable, a double wall single image (BSEN 1435 Para 6.1.8 and Fig 13) may beconsidered

(b) type of film Fine grain, high contrast, direct type BS EN 584-1 Class C3 or better.

(c) intensifying Lead screens shall be used, unless fluorometallicscreens screens have been approved by BP Amoco.

(d) limit of film The limit of diagnostic film coverage length forpipes over 1 metre in diameter shall not exceedone third of the pipe circumference. (BS EN1435 Para 5.6)

(e) Image quality A wire-type image quality indicator* (IQI)indicator conforming to BS EN quality 462-1: 1994 shall

be used. (* Also termed penetrameter). The IQIshall be used in accordance with placementdirections in Para 5 of BS EN 462-1: 1994.

(f) Processing All radiographic film shall be dried thoroughlyprior to viewing and shall be processed to allowstorage of the film without deterioration for aperiod of at least five years.

5.4.3 Acceptable Radiographic Sensitivity Levels

Radiographic sensitivity is expressed as a percentage, and is defined bythe ratio of the diameter of the smallest IQI wire clearly visible on theradiograph to the material thickness. The radiographic sensitivityachieved for the single wall single image (SWSI) techniques shall be asdefined by Table B3 of BS EN 1435 and for the double wall singleimage (DWSI) technique, as defined by Table B11.

Gamma-radiography is not normally acceptable where the pipewall

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thickness is below 12 mm and its use shall be subject to approval byBP.. If approved, sensitivity levels will be specified by BP.

The radiographic procedure shall be repeated at the discretion of BPwhenever any change is made to the operating techniques, or wheneverproduction films differ appreciably from the detail, contrast, or densityof the qualifying radiographs.

5.5. Manual Ultrasonic Testing

5.5.1 General

BP will require ultrasonic testing of the following areas:-

(a) Following field cut back of pipe, a zone extending 100 mm backfrom the new field bevel shall be ultrasonically tested forlaminations.

(b) A zone 100 mm wide around the planned cut-outs of nozzles forlaminations.

(c) To verify minimum wall thickness.

(d) To verify defects found by radiography.

(e) Additional welds and areas as requested by BP, including weldsinvolving the use of automatic and semiautomatic weldingsystems.

5.5.4 Reporting and Evaluation - Testing of Pipe Material

The acceptance criteria for ultrasonic examination within the pipe endsand at the planned cut-outs for nozzles shall be to quality grade B4given in Table 1 of BS 5996, unless an alternative quality has beenagreed with BP.

5.6. Automatic Ultrasonic testing.

The use of automatic ultrasonic testing shall be subject to the approvalof BP in each instance.

5.7 Magnetic Particle Testing

The following welds shall be tested using the magnetic particle flawdetection method:

(a) All repair welds.

(b) All welds to fittings.

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(c) All fillet welds.

(d) In severe duty pipelines, the finished weld bevel shall bemagnetic particle flaw detected following field cut back of pipe.

Electromagnetic (a.c.) yoke and/or adjacent cable techniques arepreferred. Permanent magnets or prods shall not be used without priorBP approval.

5.8 Destructive Testing

BP will require completed welds to be removed for testing if there isany suspicion that they have not been produced strictly in accordancewith the approved procedure. The contractor may attempt to guardagainst this eventuality by qualifying welding procedures at the extremeparameters which the welders may consider using.

The above requirement which related to 36.3 of BS 4515: 1984 was not included inBS 4515: 1996 but is retained in this BP GS as the qualification of a weldingparameter range is routinely carried out.

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6. ACCEPTANCE AND RECTIFICATION OF WELDS

6.1 Non-Destructive Testing Acceptance Criteria

6.1.1 General

The acceptance criteria for non destructive testing shall be inaccordance with 6.1.2.

Acceptance criteria based on engineering critical assessment to clause6.1.3 of BS 4515:1996 do not apply to this Standard except in specificinstances, where the design of the pipeline specifies ECA in accordancewith PD 6493.

6.1.2 Acceptance Criteria Based on Quality Control

In areas of weld preparation such as pipe ends, fusion faces andbranches, planar defects are not acceptable.

TABLE 8. Acceptance Criteria for Welds

The following limits on acceptance modify those given in BS4515:1996:-

Flaw type Acceptance Criteria

(c) Root penetration Not to exceed 1.5 mm for pipediameters less than 60 mm.

(d) Root concavity At no point shall the weld be thinnerthan the calculated design thickness ofthe pipe.

(e) Root undercut BP may specify further limitations forroot undercut and shrinkage groove forpipelines in sour service.

(f) Incomplete root These defects are unacceptable in sour-penetration service pipelines.

(h) Cap undercut Undercut exceeding 0.5 mm in depth isunacceptable in severe duty and shallbe blended out by light grinding priorto radiography.If this reduces the pipewall thickness below the specifiedminimum, the entire circumferentialweld shall be cut out and bevelled andre-welded.

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(j) Porosity (other than elongatedporosity in the root run)

Not to exceed a total area, whenprojected radially through the weld of1% of any 600 mm2 of projected weldarea. An isolated pore greater than20% of the pipe thickness or 1.5 mm,whichever is the smaller, in anydirection, shall be consideredunacceptable.

(k) Tungsten inclusions Tungsten inclusions shall not exceedtwo per weld and shall be separated bya minimum of 50 mm

6.1.3 Acceptance Criteria Based on Engineering Critical Assessment

Not applicable to this BP Group GS unless the design of the pipelinespecifies ECA in accordance with BS PD 6493.

6.2 Rectification of Welds

6.2.2 Preparation for Re-welding

6.2.2.1 Partial Removal of Weld

Defects shall be removed by grinding and the repair excavation checkedby magnetic particle inspection to ensure complete removal of thedefect. Cracked welds shall be cut out and the weld re-made

6.2.3 Re-welding

Root sealing or single run repairs shall not be practised. There shall beno internal welding on sour service pipelines. For severe duty pipelinesa repair shall only be attempted once, thereafter the weld shall becompletely removed. For normal duty pipeline a second repair may bemade. If this second repair fails to meet the requirements of clause 6.1the entire circumferential weld shall be cut out and re-bevelled.

For offshore pipe-lay of submarine pipelines, the limits on size andlocation of proposed weld repair excavations beyond the final tensionershall be submitted to BP for approval, supported with calculations andappropriate diagrams.

NOTE: Stresses imposed by construction techniques existing at the time of making arepair such as at a lay-barge repair station, may be such that to remove 20% of theweld length may render this operation unsafe. In such cases, the permitted length ofa repair should be reduced to ensure that the stress applied to the weld under repairdoes not exceed 80% of the specified yield stress of the pipe.

A full record of all repairs shall be maintained by the contractor. Therecord shall be made as each defect is discovered, and shall include thefollowing:

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(i) The weld number.

(ii) The type and size of defect.

(iii) The circumferential location (defined to an approved system).

(iv) An estimate of the depth (assessed by ultrasonic test wherepossible).

(v) Name and/or number of the welder who produced the defect.

(vi) Repair welding procedure number.

(vii) Name and/or number of repair welder.

(viii) Copy of the inspection report for the repair.

(ix) Date of repair.

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ANNEX C TO BS 4515 (INFORMATIVE).PROPOSED WELDING PROCEDURE SPECIFICATION

There are no requirements additional to BS 4515:1996. The contractor may proposealternative format welding procedure specification forms to those shown in Annex C ofBS 4515:1996 but any alternative shall be subject to approval by BP.

ANNEX D TO BS 4515. (INFORMATIVE) EXAMPLE OF A RECORD FORM FOR WELDER QUALIFICATION TEST.

There are no requirements additional to BS 4515:1996. The contractor may proposealternative format welding procedure specification forms to those shown in Annex D ofBS 4515:1996 but any alternative shall be subject to approval by BP.

ANNEX E TO BS4515. (INFORMATIVE) GUIDANCE FOR ESTABLISHINGPREHEATING REQUIREMENTS

This informative annex is for guidance only. Where necessary the contractor shallundertake trials to establish an adequate level of preheat to ensure compliance with therequirements of this standard. The precise preheat level shall be as proven satisfactoryby the welding procedure qualification test. A minimum preheat of 150C shall apply tothe welding of fittings, repair welds and tie in welds.

ANNEX F TO BS 4515. EXAMPLE OF A RADIOGRAPHIC SPECIFICATION

There are no requirements additional to BS 4515. Any specification of alternativeformat shall be subject to approval by BP.

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APPENDIX A

DEFINITIONS AND ABBREVIATIONS

Definitions

Standardised definitions may be found in the BP Group RPSEs Introductory Volume.Other definition which supersede, qualify or are an addition to Section 1.3 of BS 4515:1996are found in the corresponding section of this standard

Abbreviations

API American Petroleum Institute

BGAS Transco A qualification and certification system, formerly known as ERS, forpipeline inspection personnel, originally instituted and run by the formerBritish Gas Engineering Research Station, Killingworth, UK. Nowknown as BG Approval Scheme and managed by TWI Certification Ltdfor Transco

BS British Standard

CSWIP Certification Scheme for Welding and Inspection Personnel managed byTWI Certification Ltd Granta Park, Great Abington, Cambridge, UK

CTOD Crack Tip Opening Displacement

DIN Deutsches Institut fur Normung

GMAW Gas Metal Arc Welding

HV Vickers hardness

MAG Metal Active Gas

MDT Minimum design temperature

MIG Metal Inert Gas

NACE National Association of Corrosion Engineers

NDT Non-Destructive testing

PCN Personal Certification in Non-Destructive Testing ( a scheme for the qualification of non-destructive testing and inspection personnel

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managed by The British Institute of Non-Destructive Testing (BINDT) Northampton, UK

PWHT Post Weld Heat Treatment

SI Systeme International d'Unites

TIG Tungsten Inert Gas

TWI The Welding Institute, Granta Park, Great Abington,Cambridge CB1 6AL, UK

.UNITS This Standard employs SI metric units.

WEE/21/7 British Standards Sub-Committee responsible for BS 4515

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APPENDIX B

LIST OF REFERENCED DOCUMENTS

A reference invokes the latest published issue or amendment unless stated otherwise.

Reference standards may be replaced by equivalent standards that are internationally orotherwise recognised provided that it can be shown to the satisfaction of the purchaser'professional engineer that they meet or exceed the requirements of the referenced standards.

American Standards

API Standard 1104 Standard for welding pipelines and related facilities

British Standards

BS 709:1983 Methods of destructive testing fusion welded joints and weld metal insteel.

BS 3971:1980/(1985) Specification for image quality indicators for industrialradiography(including guidance on their use)* Partly replaced by BS EN 462-2:1994

BS 639: 1986 Covered carbon and carbon manganese steel electrodesfor manual metal-arc welding (The former standard BS 639 has beenwithdrawn and is superseded by BS EN 499:1995. However, referenceto the former BS 639 is retained here for the method of testing specifiedin Appendix C)

PD 6493:1991 Guidance on methods for accessing the acceptability of flaws in fusionwelded structures.

BS 4515: 1996 Specification for process of welding of steel pipelines on land andoffshore

BS 5996: 1993 Specification for acceptance levels for internal imperfections in steelplate, strip and wide flats, based on ultrasonic testing.

BS 7448 Part 1: 1991: Fracture mechanics toughness tests. Part 1 Method for determination of K1c, critical CTOD and critical J values of metallic materials

BS 7448 Part 2: 1998 Fracture mechanics toughness tests. Part 2 Method for determination of fracture toughness of weldments in metallic materials.

BS EN 439: 1994 Welding Consumables - Shielding Gases for Arc Welding and Cutting

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BS EN 462-1: 1994 Image quality indicators (wire type). Determination of image qualityvalue. * Partly replaces BS3971: 1980 (1985)

BS EN 462-2: 1994 Image quality indicators (step/hole type). Determination of imagequality value. * Partly replaces BS3971: 1980 (1985)

BS EN 499: 1995 Welding consumables. Covered electrodes for manual metal arc weldingof non-alloy and fine grained steels. Classification.

BS EN 584-1: 1995 Non-destructive testing - Industrial radiographic film. Part 1.Classification of film systems for industrial radiography.

BS EN 1435:1997 Non-destructive examination of welds. Radiographic examination ofwelded joints

BS EN ISO 9002: 1994 Quality systems. Model for quality assurance in production,installation and servicing.

BS EN ISO 9003: 1994 Quality systems. Model for quality assurance in final inspection andtest.

BP Group RPSE

GS 136-1 Materials for sour service to NACE Standard MR-01-75 (1990Revision) Note latest NACE MR-01-75 is 1998 Revision

GS 118-4 Storage and control of welding consumables

GS 118-9 Welding of transmission pipelines. Part 2.Supplementary to API Standard 1104

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German Standard

DIN 54 109 : Part 1 Nondestructive testing; image quality of radiographs of metallicmaterials; definitions, image quality indicators, determination of imagequality index

Note:

1. The definitions for employer and inspector replace those given in BS 4515:1996.

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APPENDIX C

Alternative Technique for Batch Testing of Welding Consumables

Batch tests of welding consumables are not intended to undertaken as a routine measure for allpipelines, but may be required by BP for certain offshore pipelay operations and land-basedpipelines designed for certain categories of critical service. When batch testing is specified byBP it shall be carried out in accordance with this Appendix by the consumable manufacturerrather than by the pipe-welding contractor. All batch test welds shall be made as all-weld-metal deposits as defined in former standard BS 639: 1986. In the following list of steps, theillustrative results (given in parenthesis) refer to this Addendum, Figure C1 :-

(i) BP will define the Charpy test requirements for the welding procedure qualificationtest (Average 50 J at -10C).

(ii) The contractor shall obtain acceptable results from the welding procedure qualificationtest at mid-wall thickness (Average 80 J at -10C).

(iii) The consumable supplier shall prepare an all-weld-metal deposit using the same batchof consumables that was used in the welding procedure qualification test. Where morethan one size of consumable is used, a separate deposit should be made for each size.Consumables used for the root run only do not require batch testing.

(iv) The consumable supplier shall test a set of three Charpy test pieces, of the same size asthose taken from the welding procedure qualification test, at the temperature of thewelding procedure qualification test (Average 160 J at -10C).

(v) The consumable supplier shall test further sets of three Charpy test pieces, decreasingtemperature by -10C per set, until the average falls below that specified for thewelding procedure qualification test:-

150 J at -20C140 J at -30C90 J at -40C40 J at -50C

(vi) By interpolation, the temperature will be found, at which the all-weld-metal depositgives the same energy as that measured in the welding procedure qualification test(-42C).

(vii) All batch tests shall be carried out at this temperature, against the same energyrequirement as that specified for the welding procedure qualification test (50 J).

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FIGURE C1

Procedure for Establishing Batch Test Requirement

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