BS EN 12732:2013+A1:2014 BS EN 12732:2013 BSI Standards Publication Gas infrastructure — Welding steel pipework — Functional requirements BS EN 12732:2013+A1:2014 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 12732:2013+A1:2014 It supersedes BS EN 12732:2013 which is withdrawn The UK committee voted against this standard for several reasons, particularly because of technical differences with a long established UK gas industry standard for welding procedures, BS 4515, and on the requirements for the qualification of welding personnel Also several improvements requested by the UK gas industry stakeholders to the draft EN 12732 were not accepted A full set of UK comments may be obtained from BSI Committee Service Centre The UK will attempt again to have improvements made when this standard is revised The UK committee also acknowledges that despite voting against this standard, it can still be used by other UK industries The UK participation in its preparation was entrusted to Technical Committee GSE/33, Gas supply A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2014 Published by BSI Standards Limited 2014 ISBN 978 580 83807 ICS 25.160.40 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2013 Amendments/corrigenda issued since publication Date Text affected 30 September 2014 Implementation of CEN amendment A1:2014 EUROPEAN STANDARD EN 12732:2013+A1 NORME EUROPÉENNE EUROPÄISCHE NORM April 2014 ICS 25.160.40 Supersedes EN 12732:2013 English Version Gas infrastructure - Welding steel pipework - Functional requirements Infrastructures gazières - Soudage des tuyauteries en acier - Prescriptions fonctionnelles Gasinfrastruktur - Schweißen an Rohrleitungen aus Stahl Funktionale Anforderungen This European Standard was approved by CEN on 14 March 2013 and includes Amendment approved by CEN on February 2014 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref No EN 12732:2013+A1:2014 E BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Contents Page Foreword Scope Normative references Terms and definitions 11 4.1 4.2 4.3 4.4 4.5 4.5.1 4.5.2 4.5.3 Quality system 13 General 13 Welding contractors 14 Welders 15 Welding supervisory and coordination personnel 15 Testing companies and personnel 15 General 15 Non-destructive testing (NDT) 15 Destructive testing (DT) 15 Welding consumables 15 6.1 6.1.1 6.1.2 6.1.3 6.1.4 6.1.5 6.1.6 6.1.7 6.1.8 6.1.9 6.1.10 6.2 6.2.1 6.2.2 6.3 6.4 6.5 6.6 6.7 Production welding 16 General requirements 16 General 16 Working area 16 Layout of weld joints 17 Types of weld joints 17 Joint edge preparation 17 Weld fit-up 17 Different wall thickness 17 Pipe branches and nozzles 17 Laminations 17 Butt welds cross joints 17 Joint preparation 17 Pipe end preparation 17 Alignment of the joints 17 Preheating 18 Tacking 18 Welding 18 Actions after welding 18 Repair of weld defects 19 7.1 7.2 7.3 7.4 Special procedures 19 General 19 Attachment of structural parts 19 Attachment of cathodic protection connections 19 Hot-tapping and other welding work on in-service pipelines 20 8.1 8.2 8.3 8.4 8.5 8.6 Inspection of the weld joint 20 General 20 Scope of inspection 20 Non-destructive testing and assessment levels 22 Time of inspection 23 Acceptance criteria 23 Recording of test results 24 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) 9.1 9.2 Documentation 24 General 24 Archiving requirements 24 10 10.1 10.2 10.3 10.4 10.4.1 10.4.2 10.4.3 10.5 Specific requirements for gas infrastructure with a MOP up to and including 16 bar 24 General 24 Welders 24 Welding supervisory personnel 25 Production welding 25 General 25 Joint preparation 25 Welding 25 Requirements for records and documentation 25 11 11.1 11.2 11.3 11.4 11.4.1 11.4.2 11.4.3 11.4.4 11.4.5 11.5 11.5.1 11.5.2 11.5.3 11.5.4 11.5.5 11.6 11.7 11.8 Specific requirements for gas infrastructure with a MOP greater than 16 bar 26 General 26 Welders 26 Welding supervisory personnel 26 Qualification of welding procedures 26 General 26 Filler material requirements for welding procedure qualification 26 Impact testing 27 Transverse tensile test 27 All-weld-metal tensile test 28 Production welding 28 General 28 Joint preparation 28 Welding 28 Repairs of weld defects 29 Welding consumables 29 Destructive testing of production welds 29 Acceptance requirements 29 Requirements for records and documentation 30 12 12.1 12.2 Specific requirements for metering, regulating and compressor stations 31 General 31 Specific requirements 31 Annex A (informative) Qualification procedure for pipeline welders (Girth welds and branch connections) 32 A.1 General 32 A.2 Approval test 32 A.2.1 Execution of the approval test 32 A.2.2 Range of test pieces 32 A.2.3 Supervision of execution of approval test 33 A.3 Inspection 33 A.3.1 General 33 A.3.2 Testing girth welds 34 A.3.3 Testing weldolets 34 A.4 Approval range 34 A.4.1 General 34 A.4.2 Dimension ranges 34 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) A.4.3 Techniques 34 A.5 Certificate 35 A.5.1 General 35 A.5.2 Duration of validity 35 Annex B (informative) Testing of lamination defects 36 Annex C (informative) Time-of-flight diffraction technique (TOFD) 37 C.1 General 37 C.2 Additional and substitutional requirements to EN ISO 10863:2011 37 C.2.1 Addition to the whole document EN ISO 10863:2011 37 C.2.2 Addition to EN ISO 10863:2011, Clause "Terms and definitions" 37 C.2.3 Addition to EN ISO 10863:2011, Clause 5, "Examination Levels" 39 C.2.4 Addition to EN ISO 10863:2011, 7.2.2, "Ultrasonic probes" 39 C.2.5 Substitution of EN ISO 10863:2011, Clause 11, paragraph "Weld testing" 39 C.2.6 Substitution of EN ISO 10863:2011, 12.5.2 "Sizing" 40 rd Annex D (informative) Critical aspects for hot-tap welding or welding on in-service pipelines 45 D.1 General 45 D.2 Recommendations 45 D.2.1 Equipment 45 D.2.2 Supervision 45 D.2.3 Safety precautions 45 D.2.4 Identification 45 D.2.5 Filler materials 45 D.3 Weld preparation 46 D.4 Welding procedure specification (WPS) 46 D.4.1 Description of the WPS 46 D.4.2 Qualification of the WPS 46 D.4.3 Approval of the WPS 46 D.5 Qualification of the welder 46 D.6 Precautions 46 D.7 Execution 47 D.8 Repairs 47 D.9 WPS qualification record 47 Annex E (informative) Visual examination of joints 49 E.1 General 49 E.2 Recommendations 49 Annex F (informative) Manual ultrasonic testing of weld joints for wall thickness between approximately mm and mm 50 F.1 General 50 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) F.2 Setting 50 F.2.1 Setting of range 50 F.2.2 Sensitivity adjustment when using the Distance Gain Size method 50 Annex G (normative) Acceptance criteria - Recommendations for on-site production welds 54 G.1 General 54 G.2 Acceptance criteria according to EN ISO 5817 54 G.3 Summary of requirements for defect acceptance levels and defect limits 57 G.3.1 General 57 G.3.2 Requirements 58 G.4 Method and acceptance criteria for ultrasonic inspection assessment 65 G.4.1 Distance Gain Size method 65 G.4.2 Comparative Element method 65 G.4.3 General 65 G.4.4 Assessment of indications using automatic pulse-echo technique 67 Annex H (informative) Brazing and aluminothermic welding of leads for cathodic protection systems 68 H.1 Joining techniques 68 H.2 Procedure qualification 68 H.3 Operation qualification 70 H.4 Production joints 70 Annex I (informative) Significant technical changes between this European Standard and the previous edition 71 Bibliography 72 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Foreword This document (EN 12732:2013+A1:2014) has been prepared by Technical Committee CEN/TC 234 “Gas infrastructure”, the secretariat of which is held by DIN This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2014, and conflicting national standards shall be withdrawn at the latest by October 2014 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights This document supersedes !EN 12732:2013" This document includes Amendment approved by CEN on 2014-02-03 The start and finish of text introduced or altered by amendment is indicated in the text by tags !" This European Standard has been prepared under mandate M/017 given to CEN by the Commission of the European Communities and the European Free Trade Association Annex I provides details of significant technical changes between this European Standard and the previous edition There is a complete suite of functional standards prepared by CEN/TC 234 ”Gas infrastructure“ to cover all parts from the input of gas to the transmission system up to the inlet connection of the gas appliances, whether for domestic, commercial or industrial purposes In preparing this standard a basic understanding of gas infrastructure by the user has been assumed Gas infrastructure is complex and the importance on safety of its construction and use has led to the development of very detailed codes of practice and operating manuals in the member countries These detailed statements embrace recognised standards of gas engineering and the specific requirements imposed by the legal structures of the member countries CEN/TC 234 will continue its work updating this standard to the latest developments at regular intervals According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Scope This European Standard contains requirements for the production and testing of weld joints for the installation and modification of onshore steel pipelines and pipework used in gas infrastructure, including in-service pipelines, for all pressure ranges for the carriage of processed, non-toxic and non-corrosive natural gas according to EN ISO 13686 and for the carriage of non-conventional gases such as injected biomethane, where — the pipeline elements are made of unalloyed or low-alloyed carbon steel; — the pipeline is not located within commercial or industrial premises as integral part of the industrial process on those premises except for any pipelines and facilities delivering gas to such premises; — the pipework is not located within household installations according to EN 1775; — the design temperature of the system is between -40 °C up to and including 120 °C The onshore steel pipelines and pipework used in gas infrastructure include in-service pipelines, for all pressure ranges for the carriage of processed, non-toxic and non-corrosive natural gas according to EN ISO 13686 and for the carriage of non-conventional gases complying with EN ISO 13686, and for which a detailed technical evaluation of the functional requirements (such as injected biomethane) is performed ensuring there are no other constituents or properties of the gases that can affect the integrity of the pipeline This standard is not applicable to welds produced prior to the publication of this European Standard Table assigns the application areas to quality requirement categories as a function of the working pressure and pipe materials used Table — Allocation to quality requirement categories Quality requirement category B Area of activity applies to Pressure range and base material ≤ bar Group 1.1, 1.2 and 1.4 according to CEN ISO/TR 15608 Rt 0,5 ≤ 360 N/mm Examples of use: Mains and service pipes in gas distribution systems, pipework in stations C Pressure range and base material > bar ≤ 16 bar Group 1.1, 1.2 and 1.4 according to CEN ISO/TR 15608 Rt 0,5 ≤ 360 N/mm Examples of use: Pipelines including pipework in stations and gas distribution systems D Pressure range or base material > 16 bar a Group 1, and according to CEN ISO/TR 15608 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Quality requirement category Area of activity applies to Examples of use: Pipelines including pipework in stations and gas transmission systems Key Rt 0,5 is the specified minimum yield strength according to EN ISO 3183 NOTE "Category A" for pipework up to and including 100 mbar, as mentioned in the previous version EN 12732:2000, has been incorporated in the pressure range of "Category B" and has been deleted from this table NOTE Gas infrastructure with a MOP up to and including 16 bar is generally dedicated to gas distribution a Pipelines having hoop stresses at design pressure up to 30 % of specified minimum yield strength (Rt 0,5) and operated at a pressure up to 24 bar may be allocated to quality requirement Category C by the pipeline operator Additional requirements may be specified when, for example: — the strain on pipelines and systems, — the materials, — the line routing, — the design or the welding technique are considered critical This European Standard specifies common basic principles for gas infrastructure Users of this European Standard should be aware that there can exist more detailed national standards and/or codes of practice in the CEN member countries This European Standard is intended to be applied in association with these national standards and/or codes of practice setting out the above-mentioned basic principles In the event of conflicts in terms of more restrictive requirements in national legislation/regulation with the requirements of this standard, the national legislation/regulation takes precedence as illustrated in CEN/TR 13737 (all parts) NOTE CEN/TR 13737 (all parts) contains: — clarification of relevant legislation/regulations applicable in a country; — if appropriate, more restrictive national requirements; — national contact point for the latest information Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Table G.4 — Summary of defect acceptance levels (Tier 1) and defect limits (Tier and Tier3) Type of defect Tier Tier Tier Acceptance criteria Limit criteria Limit criteria External profile Excess weld metal should be uniform and not more than mm in height It should merge smoothly with the parent metal and not extend beyond the original joint preparation by more than mm each side No area should have the weld face lower than the adjacent pipe surface Internal profile The root bead or any concavity should merge smoothly into the adjacent surface but at no point should the weld be thinner than the pipe thickness Root concavity Undercut (cap) Undercut (root) - Length 25 % of weld circumference - Depth 1,5 mm or 0,1 x T (if less) 50 mm 7xT - Total 50 mm in 300 mm or 15 % of circumference (if less) x T in any 300 mm - Depth mm or 0,1 x T (if less) - Length 7xT - Total 25 mm in 300 mm or % of circumference (if less) x T in any 300 mm - Depth mm or 0,1 x T (if less) Inade- Length quate root penetration - Total Incomplete - Length (lack of) root fusion - Total Incomplete - Length (lack of) cap fusion - Total 60 Assumed to be < mm 25 mm - Length Figure G.1 Figure G.1 Assumed to be < mm 25 mm 7xT 25 mm in 300 mm or % of circumference (if less) x T in any 300 mm 25 mm 7xT 25 mm in 300 mm or % of circumference (if less) x T in any 300 mm 25 mm 7xT 25 mm in 300 mm or % of circumference (if less) x T in any 300 mm Figure G.1 Figure G.1 Figure G.1 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Type of defect Incomplete - Length fusion due to cold lap - Total Lack of - Length sidewall fusion - Total Lack of - Length inter-run fusion- Total Tier Tier Tier Acceptance criteria Limit criteria Limit criteria 50 mm 7xT 50 mm in 300 mm or 15 % of circumference (if less) x T in any 300 mm 50 mm 7xT 50 mm in 300 mm or 15 % of circumference (if less) x T in any 300 mm 50 mm 7xT 50 mm in 300 mm or 15 % x T in any 300 mm of circumference (if less) Figure G.1 Figure G.1 Figure G.1 61 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Type of defect Tier Tier Tier Acceptance criteria Limit criteria Limit criteria Cracks Not allowed Crater cracks Burnthrough mm - Individual mm - Total Porosity, T < 10 mm - Individual - Total Porosity, T ≥ 10 mm - Individual - Total Hollow bead, T > 10 mm - Length - Total Slag, T ≥ 10 mm mm or 0,25 x T (if less) as for T < 10 mm % of projected area on radiograph Figure G.1 50 mm 50 mm in 300 mm or 15 % of circumference (if less) mm or 0,25 x T (if less) as for T < 10 mm % of projected area on radiograph Figure G.1 50 mm 50 mm in 300 mm or 15 % of circumference (if less) - Length 40 % of circumference - Total - Width 62 When projected radially through the weld, not to exceed a total area of % of the projected weld area in the radiograph, calculated by multiplying the length of the weld affected by porosity, with a minimum of 150 mm, by the maximum width of the weld - Length - Total Slag, T < 10 mm mm or 0,25 x T (if less) - Individual - Total Hollow bead, T < 10 mm per 300 mm Figure G.1 as for T < 10 mm mm BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Type of defect Inclusions, T < 10 mm - Total Tier Tier Tier Acceptance criteria Limit criteria Limit criteria 12 mm in 300 mm and in 300 mm mm or 0,5 x T (if less) - Width Inclusions, T ≥ 10 mm - Total - Width Defect accumulation, T < 10 mm Figure G.1 40 % of circumference as for T < 10 mm 100 mm in 300 mm or 15 % of pipe circumference (if less), excluding porosity Figure G.1 mm Figure G.1 (Root concavity is not included in accumulation calculations, unless it causes the weld thickness to be less than that of the pipe.) 63 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Type of defect Defect T < 10 mm Tier Tier Tier Acceptance criteria Limit criteria Limit criteria interaction, Inherent in defect accumulation criteria Defect accumulation, 100 mm in 300 mm or T > 10 mm 15 % of pipe circumference (if less), excluding porosity If a planar, slag or porosity defect is separated from a planar defect by a distance smaller than the length of the shorter of the two defects, then re-categorize as a single planar defect of length equal to the two individual lengths + separation Figure G.1 gives limits for interacting planar defects The larger of x T in any 300 mm or 100 mm in any 300 mm, excluding porosity Slag is not included in the accumulation calculation, provided pipe material strength ≤ 450 N/mm Accumulation of planar defects shall be ≤ 15 % of circumference Accumulation of planar and non-planar defects shall be ≤ 40 % of circumference Figure G.1 (Root concavity is not included in accumulation calculations, unless it causes the weld thickness to be less than that of the pipe.) Defect T ≥ 10 mm interaction, Inherent in defect If a planar, slag or porosity defect is separated accumulation criteria from a planar defect by a distance smaller than the length of the shorter of the two defects, then re-categorize as a single planar defect of length equal to the two individual lengths + separation The re-categorized Figure G.1 gives limits planar defect should for interacting planar have the same identity defects as the planar defect 64 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) All wall thicknesses are in mm Key X = minimum wall thickness or wall thickness measured Y = defect length (% pipe circumference) = total – all defects = total – all planar defects = interacting planar defects = individual planar defect Figure G.1 — Girth weld defects limits for Tier G.4 Method and acceptance criteria for ultrasonic inspection assessment G.4.1 Distance Gain Size method The Distance Gain Size method should be used for the assessment of ultrasonic indications The recording limits given in Table G.5 are applicable Indications of defect reflections which exceed the results in Table G.6 are inadmissible G.4.2 Comparative Element method When using the Comparative Element method, the test sensitivity after inclusion of the comparative line on a mm cross hole shall be increased by dB Assessment shall be in accordance with Table G.6 G.4.3 General Adjacent fault reflections at the same depth shall be separated by at least the length of the largest individual fault reflection; if not, they should be considered as a continuous fault reflection length The examination shall be performed in accordance with test rate as given in EN ISO 17640 In critical cases or to improve the assessment, the test rate should be increased or other additional test procedures (e.g radiographic examination) should be used 65 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Weld joints on materials which have a tendency to hydrogen-induced cracking shall be checked after the postwelding diffusion of hydrogen, at the earliest 24 h after the welding Table G.5 — Recording of indications Calibration standards and fault reflection lengths using the Distance Gain Size method: Calibration level Wall thickness (T) disc shape reflector mm diameter Fault reflection lengths Sensitivity setting amplitude below calibration level to be recorded above this length by dB mm mm < T ≤ 10 1,0 10 10 < T ≤ 15 1,0 10 15 < T ≤ 20 1,5 10 20 < T ≤ 40 2,0 10 T > 40 3,0 12 10 Table G.6 — Assessment of indications using the Distance Gain Size method Maximum allowable numbers and sizes of reflectors: Wall thickness T a Number of indications per m of seam mm ~ ≤ T ≤ 10 10 < T ≤ 20 20 < T ≤ 40 40 < T ≤ 60 a Maximum allowable lengths of reflectors per b echo Echo level above mm dB calibration level 10 ≤6 and 20 ≤6 10 10 ≤6 and 20 ≤6 and 10 ≤ 12 10 10 ≤6 and 25 ≤6 and 10 ≤ 12 10 10 ≤6 and 30 ≤6 and 10 ≤ 12 c c c If wall thicknesses differ, the lower wall thickness shall be decisive b For confirmed volume defects (not in the vicinity of the surface), fault lengths exceeding the calibration levels by up to dB can be allowed up to 1,5 times the allowable length Confirmation may take the form of a radiographic examination c The acceptability of single, large defects shall be confirmed on the basis of random samples, e.g by means of radiographic examination 66 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) G.4.4 Assessment of indications using automatic pulse-echo technique In addition to the evaluation level in EN ISO 17640 indications, unless otherwise agreed, greater than 20 % evaluation level shall be evaluated The indications shall be investigated to determine the location shape, extent and type of reflector and the following criteria shall be valid: a) All cracks are unacceptable, regardless of size or location in the weld b) Indications (other than cracks) interpreted to be open to the surface are unacceptable if they exceed 25 mm in total length in a continuous 300 mm length of weld or % of the weld length c) Indications interpreted buried (embedded) within the weld are unacceptable if they exceed 50 mm in total length in a continuous 300 mm of weld or 15 % of the weld 67 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Annex H (informative) Brazing and aluminothermic welding of leads for cathodic protection systems H.1 Joining techniques Full details of the joining technique and associated equipment should be submitted to the pipeline operator for approval prior to use and should be in line with the manufacturer‘s recommendations H.2 Procedure qualification Prior to starting, the contractor should submit a preliminary welding/brazing procedure specification to the pipeline operator for approval The procedure should be qualified by making three consecutive test joints on material to be used in production in the presence of the pipeline operator The test material should be selected by the pipeline operator to represent the upper quartile of the carbon equivalent range The electrical resistance of each joint should be measured and should not exceed 0,1 Ω The mechanical strength of the joint should be tested by means of a sharp blow from a kg hammer All three test joints should be sectioned and prepared for metallographic examination The following tests should be performed on the sections a) Copper penetration measurement The depth of copper penetration below the surface of the pipe material should be measured metallographically The fusion line of the weld or braze should not be more than 1mm below the pipe surface Intergranular copper penetration of the pipe material should not exceed 0,5 mm beyond the fusion line when a micro-section is examined at a magnification not exceeding x 50 b) Hardness survey Each section should be tested using a 10 kg load A traverse should be made across the weld zone as shown in Figure H.1 and H.2 and should consist of at least six impressions; two in the heat-affected zone each side of the weld/braze and one in the parent metal each side of the weld/braze The hardness values should not exceed 325 HV10, or they should be as specified by the pipeline operator 68 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) All dimensions are in millimetres Key Weld heat-affected zone (visible after etching) A = braze metal B = parent metal surface C = traverses to = hardness impressions Hardness impressions 2, 3, and should be entirely within the heat-affected zone and located as close as possible to the fusion boundary Figure H.1 — Recommended locations for hardness traverses and impressions for aluminothermic welding All dimensions are in millimetres Key Weld heat-affected zone, might be visible after etching A = braze metal B = parent metal surface C = traverses to = hardness impressions Figure H.2 — Recommended locations for hardness traverses and impressions for pin brazing 69 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) H.3 Operation qualification Prior to carrying out production work, each operator should complete three test joints which should pass the tests for electrical conductivity and mechanical strength (hammer test) required in H.2 All welding and tests should be witnessed by the pipeline operator H.4 Production joints The attachments should be located at least 150 mm from any seam or circumferential weld The weld area should be clean, dry and free from oil, grease, mill scale or other foreign matter Preheating should be applied as specified in the approved procedure All attachments should be tested for mechanical resistance strength (e.g hammer test, pull-up test) followed by an electrical continuity test, both as recommended in H.2 Should any attachment prove to be defective, it should be carefully removed, ensuring that the parent material thickness is not reduced below the specified tolerances Rejoining should be carried out at a new location on the pipe 70 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Annex I (informative) Significant technical changes between this European Standard and the previous edition Clause Title/Paragraph/Table/Figure Change Scope a paragraph which expresses that the EN 12732 is also applicable to pipelines for carriage of non-conventional gases such as biomethane Normative references Are updated to the valid standards on the date of compilation of this document 4.5 testing companies and personal The companies for non-destructive testing and destructive testing are required to meet certification criteria Welding consumables Table 3, the designation of the consumables has been removed 6.5 A strong recommendation included on welding with two welders on one girth weld for DN 400 and over 8.2 Table 4, ToFD included as technique 8.3 Table Requirement category A has been withdrawn, and falls under the new scope of category B 10.2 Welders are to be certified by an accredited certification body 11.2 Welders are to be certified by an accredited certification body 11.4 When qualifying automated and/ or mechanised welding procedures of material with a yield strength of and over, calibrated electronic Rt0,5 360 N/mm automated registration devices shall be used 11.6 Destructive testing of production welds; more detail is given on actions to be performed when a production weld test fails Annex C Wall thickness compensation has been withdrawn reference is made to EN 1708-1 in 6.2 The current Annex C gives guidance on the use of ToFD for girth welds Annex D Text clarified on types of joints, direction given on type of tests required if other filler materials are to be used Annex G Annex is changed from informative to normative respecting CEN/CENELEC rules NOTE The technical changes referred include the significant changes from the EN revised but is not an exhaustive list of all modifications from the previous version 71 BS EN 12732:2013+A1:2014 EN 12732:2013+A1:2014 (E) Bibliography EN 444, Non-destructive testing — General principles for radiographic examination of metallic materials by Xand gamma-rays EN 462-1, Non-destructive testing — Image quality of radiographs — Part 1: Image quality indicators (wire type) — Determination of image quality value EN 462-2, Non-destructive testing — Image quality of radiographs — Part 2: Image quality indicators (step/hole type) — Determination of image quality value EN 1775, Gas supply - Gas pipework for buildings - Maximum operating pressure less than or equal to bar Functional recommendations EN 10025-1, Hot rolled products of structural steels - Part 1: General technical delivery conditions EN 12517-1, Non-destructive testing of welds — Part 1: Evaluation of welded joints in steel, nickel, titanium and their alloys by radiography — Acceptance levels EN ISO 4063, Welding and allied processes — Nomenclature of processes and reference numbers (ISO 4063) EN ISO 6947, Welding and allied processes — Welding positions (ISO 6947) EN ISO 7963, Non-destructive testing — Ultrasonic testing — Specification for calibration block No (ISO 7963) EN ISO 10893-8, Non-destructive testing of steel tubes — Part 8: Automated ultrasonic testing of seamless and welded steel tubes for the detection of laminar imperfections (ISO 10893-8) EN ISO 11666, Non-destructive testing of welds — Ultrasonic testing — Acceptance levels (ISO 11666) EN ISO 13686, Natural gas — Quality designation (ISO 13686) EN ISO 14171, Welding consumables — Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels — Classification (ISO 14171) EN ISO 17635, Non-destructive testing of welds — General rules for metallic materials (ISO 17635) EN ISO 23277, Non-destructive testing of welds — Penetrant testing of welds — Acceptance levels (ISO 23277) EN ISO 23278, Non-destructive testing of welds — Magnetic particle testing of welds — Acceptance levels (ISO 23278) Gerhard Knauf and Phil Hopkins: The EPRG guidelines on the assessment of defects in transmission pipeline girth welds, 3R international, 35 (1996), Journal number 10/11, October/November, 1996, pp 620-624 NOTE EPRG (EUROPEAN PIPELINE RESEARCH GROUP) is a cooperation of European gas transmission and pipe manufacturing companies, Contact address: Mannesmannröhren-Werke AG, Mannesmann Forschungsinstitut, Ehinger Straße 200, D-47259 Duisburg, Postfach 25 11 60, D-47251 Duisburg 72 This page deliberately left blank NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards Institution (BSI) BSI is the national body responsible for preparing British Standards and other standards-related publications, information and services BSI is incorporated by Royal Charter British Standards and other standardization products are published by BSI Standards Limited About us Revisions We bring together business, industry, government, consumers, innovators and others to shape their combined experience and expertise into standards -based solutions Our British 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