Bsi bs en 12732 2013 + a1 2014

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It supersedes BS EN 12732:2013 which is withdrawn.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 0 580 83807 1
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 2014Implementation 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 1 approved by CEN on 3 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 ..............................................................................................................................................................6
1

Scope ......................................................................................................................................................7

2

Normative references ............................................................................................................................8

3

Terms and definitions ........................................................................................................................ 11

4
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

5

Welding consumables ........................................................................................................................ 15

6
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
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
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

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

9
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

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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 3 "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, 3 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 6 mm and 8 mm ......................................................................................................... 50
F.1

4

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

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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 1 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.

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

1

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 1 assigns the application areas to quality requirement categories as a function of the working pressure
and pipe materials used.
Table 1 — Allocation to quality requirement categories
Quality requirement
category
B

Area of activity applies to
Pressure range and base material

≤ 5 bar
Group 1.1, 1.2 and 1.4 according to
CEN ISO/TR 15608
Rt 0,5 ≤ 360 N/mm

2

Examples of use: Mains and
service pipes in gas distribution
systems, pipework in stations

C

Pressure range and base material

> 5 bar ≤ 16 bar
Group 1.1, 1.2 and 1.4 according to
CEN ISO/TR 15608
Rt 0,5 ≤ 360 N/mm

2

Examples
of
use:
Pipelines
including pipework in stations and
gas distribution systems
D

Pressure range or base material

> 16 bar

a

Group 1, 2 and 3 according to
CEN ISO/TR 15608

7

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 1
"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 2

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.

2

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.

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

EN 287-1, Qualification test of welders — Fusion welding — Part 1: Steels
EN 1418:1997, Welding personnel — Approval testing of welding operators for fusion welding and resistance
weld setters for fully mechanized and automatic welding of metallic materials
EN 1708-1, Welding - Basic welded joint details in steel - Part 1: Pressurized components

EN 10204, Metallic products - Types of inspection documents
EN ISO 636, Welding consumables — Rods, wires and deposits for tungsten inert gas welding of non-alloy
and fine-grain steels — Classification (ISO 636)
EN ISO 2560, Welding consumables — Covered electrodes for manual metal arc welding of non-alloy and
fine grain steels — Classification (ISO 2560)
EN ISO 3183, Petroleum and natural gas industries — Steel pipe for pipeline transportation systems (ISO
3183)
EN ISO 3452 (all parts), Non-destructive testing — Penetrant testing (ISO 3452)
EN ISO 3834-1, Quality requirements for fusion welding of metallic materials — Part 1: Criteria for the
selection of the appropriate level of quality requirements (ISO 3834-1)
EN ISO 3834-2, Quality requirements for fusion welding of metallic materials — Part 2: Comprehensive quality
requirements (ISO 3834-2)
EN ISO 3834-3, Quality requirements for fusion welding of metallic materials — Part 3: Standard quality
requirements (ISO 3834-3)
EN ISO 3834-4, Quality requirements for fusion welding of metallic materials — Part 4: Elementary quality
requirements (ISO 3834-4)
EN ISO 5817, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding
excluded) — Quality levels for imperfections (ISO 5817)
EN ISO 6520-1, Welding and allied processes — Classification of geometric imperfections in metallic
materials — Part 1: Fusion welding (ISO 6520-1)
EN ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
(ISO 6892-1)
EN ISO 9692-1, Welding and allied processes — Recommendations for joint preparation — Part 1: Manual
metal-arc welding, gas-shielded metal-arc welding, gas welding, TIG welding and beam welding of steels (ISO
9692-1)
EN ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel (ISO 9712)
EN ISO 10863:2011, Non-destructive testing of welds - Ultrasonic testing - Use of time-of-flight diffraction
technique (TOFD) (ISO 10863:2011)
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 14174, Welding consumables — Fluxes for submerged arc welding and electroslag welding —
Classification (ISO 14174)

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

EN ISO 14175, Welding consumables — Gases and gas mixtures for fusion welding and allied processes
(ISO 14175)
EN ISO 14341, Welding consumables — Wire electrodes and weld deposits for gas shielded metal arc
welding of non alloy and fine grain steels - Classification (ISO 14341)
EN ISO 14731, Welding coordination — Tasks and responsibilities (ISO 14731)
EN ISO 15607:2003, Specification and qualification of welding procedures for metallic materials - General
rules (ISO 15607:2003)
CEN ISO/TR 15608, Welding — Guidelines for a metallic materials grouping system (ISO/TR 15608)
EN ISO 15609-1, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 1: Arc welding (ISO 15609-1)
EN ISO 15609-2, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 2: Gas welding (ISO 15609-2)
EN ISO 15610, Specification and qualification of welding procedures for metallic materials — Qualification
based on tested welding consumables (ISO 15610)
EN ISO 15611, Specification and qualification of welding procedures for metallic materials — Qualification
based on previous welding experience (ISO 15611)
EN ISO 15612, Specification and qualification of welding procedures for metallic materials — Qualification by
adoption of a standard welding procedure (ISO 15612)
EN ISO 15613, Specification and qualification of welding procedures for metallic materials — Qualification
based on pre-production welding test (ISO 15613)
EN ISO 15614-1, Specification and qualification of welding procedures for metallic materials — Welding

procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys (ISO 156141)
EN ISO/IEC 17020, Conformity assessment — Requirements for the operation of various types of bodies
performing inspection (ISO/IEC 17020)
EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC
17025)
EN ISO 17636-1, Non-destructive testing of welds — Radiographic testing — Part 1: X- and gamma-ray
techniques with film (ISO 17636-1)
EN ISO 17636-2, Non-destructive testing of welds — Radiographic testing — Part 2: X- and gamma-ray
techniques with digital detectors (ISO 17636-2)
EN ISO 17632, Welding consumables — Tubular cored electrodes for gas shielded and non-gas shielded
metal arc welding of non-alloy and fine grain steels — Classification (ISO 17632)
EN ISO 17637, Non-destructive testing of welds — Visual testing of fusion-welded joints (ISO 17637)
EN ISO 17638, Non-destructive testing of welds — Magnetic particle testing (ISO 17638)
EN ISO 17640, Non-destructive testing of welds — Ultrasonic testing — Techniques, testing levels, and
assessment (ISO 17640)

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

EN ISO 18275, Welding consumables — Covered electrodes for manual metal arc welding of high-strength
steels — Classification (ISO 18275)
IIW-IAB -252-07, Personnel with responsibility for welding coordination

3

Terms and definitions

For the purposes of this document, the following terms and definitions apply. Symbols used in formulae are
defined where they occur.
3.1
design temperature
DT
temperature on which the design calculations are based
3.2
gas
gaseous fuel which is in a gaseous state at a temperature of 15 °C under atmospheric pressure (1,013 25 bar
absolute)
3.3
gas infrastructure
all pipelines, stations and installations 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
3.4
gas distribution system
pipeline system including piping above and below ground and all other equipment necessary to deliver the gas
to the consumer
3.5
gas transmission
activity intended to convey gas from one place to another through pipelines in order to deliver gas to
distribution systems or to industrial consumers
3.6
installation
equipment and facilities for the extraction, production, chemical treatment, measurement, control, storage or
off-take of the transported gas
3.7
maximum operating pressure
MOP
maximum pressure at which a system can be operated continuously under normal conditions

Note 1 to entry:

normal conditions are: no fault in any device or stream

3.8
national requirements
requirements following from national legislation or more detailed or stringent national standards
3.9
onshore pipeline
buried and/or above ground pipeline including those sections laid in or across inland lakes or water courses

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

3.10
pipeline
system of pipework with all associated equipment and stations up to the point of delivery. This pipework is
mainly below ground but also includes above ground parts
3.11
pipeline components
elements from which a pipeline is constructed. The following are distinct pipeline elements:
—

pipe including cold-formed bends;

—

fittings

EXAMPLE 1

—

fabrications, manufactured from elements referred above;

EXAMPLE 2

—

Manifolds, slug catchers, pig launching/receiving stations, metering and control runs

equipment

EXAMPLE 3

—

Reducers, tees, factory-made elbows and bends, flanges, caps, welding stubs, mechanical joints

Valves, expansion joints, insulating joints, pressure regulators, pumps, compressors

pressure vessels

3.12
pipeline operator
private or public organisation authorised to design, construct, and/or operate and maintain the gas
infrastructure, i.e. gas transmission operators (TSO) and gas distribution operators (DSO)

3.13
pipework
assembly of pipes and fittings
3.14
pressure
gauge pressure of the fluid inside the system, measured in static conditions
3.15
station
plant or facility for the operation and/or processing of gas infrastructure
3.16
test pressure
TP
pressure to which a part of the gas infrastructure is subjected to, to ensure safe operation
Note 1 to entry:

The test pressure can be different for the different parts of the infrastructure to be tested.

3.17
weld repair
process of repairing a defect that is discovered after the weld has been completed, by additional welding and
submitted for inspection
Note 1 to entry:
The repair can involve complete removal of a cylinder of pipe or removal of a localised area by
grinding or other means followed by additional welding.

12


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

3.18
welder
person who holds and manipulates the electrode holder, welding torch or blow pipe by hand
3.19
welding procedure specification (WPS)
a document that has been qualified by one of the methods described in EN ISO 15607:2003, Clause 6, and
provides the required variables of the welding procedure to ensure repeatability during production welding
3.20
temper bead method
a weld sequence whereby the heat-affected zone of the base material is softened as much as possible
3.21
Hydrogen Dissolved in Metal
HDM
the amount of diffusible hydrogen in 100 mg of weld metal

4

Quality system

4.1 General
If required by the pipeline operator, a quality system shall be applied to pipeline welding. A set of
recommended quality requirements according to EN ISO 3834 is provided in Table 2, which specifies the
requirements of EN ISO 3834 for the different categories as defined in Table 1.

13


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Table 2 — Recommended quality requirements
Requirement relating to:

Quality
requirement
category in accordance with
Table 1
B

C

D

Quality system according to:
—

EN ISO 3834-1 and EN ISO 3834-2 (complete)

+

●

●

—

EN ISO 3834-1 and EN ISO 3834-3 (standard)

+

●

●

—

EN ISO 3834-1 and EN ISO 3834-4 (elementary)

●

-

-

— welding engineer

+

+

●

— welding technologist

+

●

-

a

— welding specialist

●

●

-

a

—

Welding practitioner as defined in IIW-IAB-252-07

●

-

-

—

Testing personnel according to EN ISO 9712

●

●

●

Welding coordination personnel:
—

Personnel according to EN ISO 14731:

Welding procedure specification (WPS):
—

According to EN ISO 15609-1

●

●

●

—

According to EN ISO 15609-2 (up to 100 mbar)

●

-

-

Approval of welding procedures according to one of the following

standards:
—

EN ISO 15614-1 (welding procedure test)

+

●

●

—

EN ISO 15610 (using approved welding consumables)

●

-

-

—

EN ISO 15611 (previous experience)

-

-

-

—

EN ISO 15612 (standard welding procedures)

+

●

●

—

EN ISO 15613 (pre-production welding test)

●

●

●

a

Key
● recommended
+ optional
- not recommended
a

This may also be applicable in Category D for small projects or for materials with Rt 0,5 ≤ 360 N/mm².

4.2 Welding contractors
If required by the pipeline operator, contractors shall demonstrate their ability to perform the work. Reference
can be made to EN ISO 3834.

14


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

4.3 Welders
All welders shall be qualified for the work they are required to undertake.
The qualification should be carried out in accordance with Clauses 10, 11 and 12.

4.4 Welding supervisory and coordination personnel
If a quality system is required by the pipeline operator, the supervisory and the coordination personnel should
be qualified according to EN ISO 14731 as indicated in Table 2.
Welding tasks and responsibilities for welding shall be clearly assigned to personnel with the appropriate
experience and technical knowledge.

4.5 Testing companies and personnel
4.5.1

General

Destructive testing and non-destructive testing personnel shall be employed either by the pipeline contractor
or by the pipeline operator or by an independent testing company. All companies providing such personnel
!shall at least" be certified in accordance with the paragraphs below.
4.5.2

Non-destructive testing (NDT)

!The NDT company shall at least be certified according to EN ISO/IEC 17020 or EN ISO/IEC 17025. The
personnel shall be certified according to EN ISO 9712."
4.5.3

Destructive testing (DT)

The DT company shall !at least be certified" according to EN ISO/IEC 17025.

5

Welding consumables

Welding consumables shall be in accordance with:
—

EN ISO 2560 and EN ISO 18275 for shielded metal arc welding (process no. 111);

—

EN ISO 14341 and EN ISO 636 for gas metal arc welding (process nos. 135, 141);

—

EN ISO 17632 for flux-cored arc welding (process nos. 114, 136);

—

EN ISO 14175 for shielding gases;

—

EN ISO 14171 for submerged arc welding (process no. 12);

—

EN ISO 14174 for fluxes for submerged arc welding (process no. 12).

The numbering of the processes given in brackets is in accordance with EN ISO 4063.
All filler materials shall be certified as conforming to the above listed European Standards.
Batch testing of the filler materials can be required by the pipeline operator. In this case the certificates shall
be in accordance with EN 10204, type 3.1. The chemical composition of the deposited weld metal shall be
compatible with the parent metal, taking into account any specific property requirements.

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Unless otherwise agreed, matching weld metal for girth welds shall be required. For the selection of
consumables, the use of Table 3 is recommended.
After filler material has been removed from its original package, it shall be protected or stored in accordance
with the manufacturer's requirements, so that its characteristics or welding properties are not affected.
Table 3 — Matching filler material requirements
Steel specification to EN ISO 3183

a

Filler material requirements
Rt 0,5
or

Designatio
n

Rt 0,5
N/mm

Rp 0,2

Rm
2

N/mm

2

Rm

N/mm

2

KV
N/mm

2

L 210

210

335 – 475

355

440 – 570

L 245

245 – 440

415

355

440 – 570

L 290

290 – 440

415

355

440 – 570

L 360

360 – 510

460

420

500 – 640

L 415

b

415 – 565

520

460

530 – 680

L 450

b

450 – 570

535

460

530 – 680

L 485

b

485 – 605

570

500

560 – 720

L 555

b

555 – 675

625

550

610 – 780

620

690 – 890

J

47/32

Key
2

Rt 0,5 Specified minimum yield strength measured in N/mm .
Rm

2

Tensile strength according to EN ISO 3183 measured in N/mm .
2

Rp 0,2 0,2 % proof strength according to EN ISO 6892-1 measured in N/mm .
KV Impact test value (Charpy-V method) obtained for full size specimen (average/individual)
measured in joules.
a

Fitting materials are to be specified in accordance with the appropriate European
Standard.
b

For wall thicknesses > 8 mm a lower strength consumable may be used for the root and
hot pass.

6

Production welding

6.1 General requirements
6.1.1

General

All welding shall comply with the approved welding procedure specification.
6.1.2

Working area

The working space shall enable adequate access to the working area in order to provide a safe environment
and to allow satisfactory production and testing of a weld joint.

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BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

6.1.3

Layout of weld joints

Weld joints, in particular tie-ins, shall be arranged and designed in a way suited to the planned welding and
testing technique. The placement of tie-in welds is particularly important.
6.1.4

Types of weld joints

Unless otherwise agreed, pipes and pipeline fittings shall be connected using butt-welded joints.
6.1.5

Joint edge preparation

Joint edge preparations shall comply with the appropriate European Standards and the approved welding
procedure, such as EN 1708-1 and EN ISO 9692-1. The choice of joint configuration shall take into account
the welding technique, the welding position and the accessibility of the joint.
6.1.6

Weld fit-up

Weld fit-up shall be sufficient to ensure a good penetration of the joint.
6.1.7

Different wall thickness

When pipes and/or fittings of different wall thicknesses have to be joined together, special precautions shall be
taken to avoid stress concentration and weld defects.
When butt welding pipework of different wall thicknesses has to be performed, 6.2.2 and/or EN 1708-1 shall
apply.
6.1.8

Pipe branches and nozzles

Forged fittings are preferred. Weld-on branches and nozzles are allowed.
6.1.9

Laminations

Examination of the pipe ends for the presence of laminations should be performed after a significant length of
pipe has been removed, except for branches, nozzles and structural parts. Additional precautions can be
required where welding is performed in the area of laminations.
6.1.10 Butt welds cross joints
Unless otherwise agreed, butt welded cross joints shall be avoided.

6.2 Joint preparation
6.2.1

Pipe end preparation

To ensure that the required weld quality is achieved; all necessary details concerning the joint preparation
shall be laid down in the welding procedure specification.
6.2.2

Alignment of the joints

Alignment clamps shall be used where possible; the details and how they are to be used shall be included in
the welding procedure specification.
Root misalignment is acceptable as far as it is not affecting the integrity of the joint. For recommendations see
Table G.1.

17


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Misalignment of pipes and pipelines made of steel grades with a minimum specified yield strength Rt 0,5 less
2
than or equal to 360 N/mm which is outside the tolerance range of the tables given in Annex G can be
compensated for by deformation, if agreed by the pipeline operator, by the use of special equipment or by
transition pieces. The heat-treatment condition of the material shall be taken into account.
NOTE
In some cases, the strength of thermo-mechanically treated as well as quenched and tempered steels is
permanently reduced by heating to temperatures above 580 °C .

Root misalignment of pipes and pipelines of different wall thicknesses and made of steel grades with a
2
specified minimum yield strength Rt 0,5 greater than 360 N/mm , which is outside the tolerance range of the
tables given in Annex G, shall be compensated for by using transition pieces.
During correction of excessive root misalignment, measures shall be taken to avoid defects. Examples of
permissible weld configurations are given in EN 1708-1.

6.3 Preheating
Preheating shall be applied in accordance with the welding procedure specification.

6.4 Tacking
Whenever tack welds are used, they shall be made using the welding procedure designed for the root pass
and they shall be performed by a qualified welder. They shall be distributed equally around the circumference.
The tacks shall be free from cracks. Cracked tacks shall not be welded over, and shall be ground out and rewelded. When blocks are used to line up, the material shall be of an appropriate steel grade.

6.5 Welding
Each weld on a pipe with a diameter larger than or equal to DN 400 shall be welded simultaneously by at least
two welders, (one on each side of the girth weld).
Precautions shall be taken to:
—

minimise hydrogen pick-up in the work, in particular for steels which are sensitive to cold cracking;

—

avoid condensation;

—

avoid air movements in the pipe;

—

avoid uncontrolled electrical current;

—

minimise magnetic effects;

—

avoid cold cracking;

—

avoid arc strikes.

6.6 Actions after welding
After the weld is completed, weld spatter shall be removed. The weld surface shall be cleaned of slag. The
cooling process shall not be accelerated beyond the rate specified in the welding procedure specification.

Where air temperatures are below 5 °C and/or poor climatic conditions like wind or rain prevail, or if the
pipeline operator requires it, the weld joint shall be protected against excessive rapid cooling.

18


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Stress-relief heat treatment can be necessary.

6.7 Repair of weld defects
Weld joints which do not meet the specified requirements shall be repaired or cut out. On each weld joint
which requires repair, the faulty area shall be clearly marked. The marking shall not be removed until the
defect has been repaired and the repair work has been inspected. If a defect, which requires repair, exceeds
more than 20 % of the total weld length, or if several defective weld sections amount to 20 % of the total weld
length, the weld joint in question shall be cut out and re-welded unless otherwise agreed by the pipeline
operator.
Weld joints with cracks shall be completely cut out. However, in special cases, and where approved by the
pipeline operator, cracks may be repaired, provided the cause of the crack has been established beyond
doubt and provided it is confirmed that the fault has been correctly identified.
Repairs shall be retested non-destructively using suitable techniques. If non-destructive testing of a repair
reveals that the repaired area still has unacceptable indications, the weld shall be cut out and re-welded
unless otherwise agreed by the pipeline operator.

7

Special procedures

7.1 General

Before special procedures, as given below, are carried out, the type and scope of testing of the weld joint shall
be specified. The scope of the testing shall be in accordance with 8.2. The testing technique used will depend
on the type and dimension of the weld.

7.2 Attachment of structural parts
Structural parts shall be attached using a continuous weld. Intermittent welds shall not be used.
When welding structural parts onto components made of steel grades with specified minimum yield strength
2
greater than 360 N/mm , special measures shall be employed which take account of the material
characteristics.
EXAMPLE

Buttering with low-yield/low-hydrogen electrodes.

These precautions shall be specified in the welding procedure specification.

7.3 Attachment of cathodic protection connections
Electrical bonds to the pipe surface shall be made with a welding or brazing method which does not alter the
integrity of the metal. It shall be demonstrated by a performance test that the metallurgical structure is not
adversely affected.
To qualify for making cathodic protection connections, the operator's skill shall be tested under site conditions
before work begins.
When cable connections are made to the pipeline, the adhesion of the weld shall be verified.
Comprehensive information is given in Annex H.

19


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

7.4 Hot-tapping and other welding work on in-service pipelines
All hot-tap welding procedures shall include the following additional requirements.
Hot-tap welding shall only be carried out after sufficient research and development to ensure the safety of the
operation and the correct mechanical properties of the weld.
Prior to the execution of welding work on in-service pipelines, the pipeline operator shall decide whether the
design, the material and the construction condition of the pipeline allow welding under operating pressure.
Critical aspects for hot-tap welding shall be included in the welding procedure specification and shall be
subject to approval by the pipeline operator. Detailed information on critical aspects is given in Annex D.
Welding sleeves and split-tees greater than DN 50 for use on pipelines made of steel grades with specified
2
minimum yield strength greater than 360 N/mm shall be of the split full-encirclement type or shall incorporate
additional local reinforcement.
The longitudinal seam weld of a split attachment shall not be allowed to impinge on the pipe wall of the inservice pipe.
2

Where the attachments are of steel grades with specified minimum yield strength greater than 360 N/mm or
are designed so that longitudinal contraction stresses can cause deformation, the first circumferential fillet
weld shall be completed before the second is started. The cooling rate shall not be increased.
Where tacks for installation purposes are necessary in the area of the second circumferential weld these shall
be ground out completely.

8

Inspection of the weld joint

8.1 General
Weld quality shall be ensured by inspection of the welds using destructive tests and/or non-destructive testing.
The results of these tests shall be documented.

8.2 Scope of inspection
The inspection shall comprise inspection during welding, final visual inspection, non-destructive testing and
destructive testing.
The minimum extent of non-destructive testing in respect of the quality requirement category and the
type/position of the weld joint is given in Table 4.
The pipeline operator shall select which welds are to be tested.
Where less than 100 % non-destructive testing is performed and the quality of the weld joint does not meet
the requirements, further welds shall be examined to determine the extent of the problem. The cause of the
fault shall be eliminated. Except when otherwise agreed, two further welds shall be inspected for each
rejected weld.

20


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Table 4 — Minimum extent of non-destructive testing
Radiography

Quality

Visual

or

examination

US impulse echo

by welding

or

supervisor

US TOFD

Circumferential welds

b

b

--

Branches, nozzles and fillet welds

b

--

b

100 %

10 %

--

Unconcealed
pipe
spans;
pipelines on bridges, pipeline
sections crossing railways, major
roads and motorways, navigable
waterways
or
landing
strips/runways

100 %

c

--

Circumferential welds

20 %

10 %

--

Branches, nozzles, fillet welds

100 %

--

10 %

Longitudinal seams

100 %

100 %

--

Weld joints not included in the
pressure test

100 %

100 %

--

Unconcealed
pipe
spans;
pipelines on bridges, pipeline
sections crossing railways, major
roads and motorways, navigable
waterways
or
landing
strips/runways

100 %

100 %

--

Circumferential welds

100 %

100 %

--

Branches, nozzles, fillet welds

100 %

f

20 %

Longitudinal seams Sweepolets

100 %

100 %

--

Weld joints not included in the
pressure test

100 %

100 %

e

--

If pipelines/units are laid
installed in built-up areas

or

100 %

100 %

--

Unconcealed
pipe
spans;
pipelines on bridges, pipeline
sections crossing railways, major
roads and motorways, navigable
waterways

or
landing
strips/runways

100 %

100 %

--

requirement
category in

Type/position of the weld joint

accordance
with Table 1
B

Longitudinal seams

C

D

a

Surface
crack
test

d

Key
UT ultrasonic testing
TOFD
a

Time-of-flight diffraction technique

The proportion of techniques shall be agreed.

21


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Radiography

Quality
requirement
category in

Type/position of the weld joint

accordance
with Table 1

Visual

or

examination

US impulse echo

by welding

or

supervisor

US TOFD

a

Surface
crack
test

b

The extent of NDT depends on the representative random sample on the basis of the total number of weld
joints made by a welder during the course of one year.

c

The pipeline operator shall specify the extent of non-destructive testing taking into account the design
conditions, for example:

— external loads in addition to internal pressure;
— supports;
— expansion due to temperature;
— earthquake risk.
d
Where welds with incomplete penetration are used, the pipeline operator can require 100 %.
e

Seams shall be tested 100 % by two different inspection techniques.

f

For branches and nozzles, consideration should be given by the pipeline operator to these methods.

8.3 Non-destructive testing and assessment levels
The method or combination of methods for visual and other non-destructive testing of the welds shall be
specified by the pipeline operator. Prior to commencement of welding, the non-destructive testing procedures
shall be submitted to the pipeline operator for acceptance. Inspection test methods may be replaced by other
methods, if agreed by the pipeline operator. Non-destructive testing procedure shall be approved by a NDT
expert Level III according to EN ISO 9712 for the appropriate examination technique.
Other forms of non-destructive testing can be required, depending on the material used, the design and/or the
welding technique.
Visual examination of welds shall be carried out in accordance with EN ISO 17637. Supplementary
information is given in Annex E.
Radiographic examination shall be carried out in accordance with EN ISO 17636-1 and EN ISO 17636-2. If
not otherwise agreed by the pipeline operator, the image quality class given in EN ISO 17636-1 and EN
ISO 17636-2 shall be:
—

Class A for categories B and C;

—

Class B for Category D.

Ultrasonic impulse echo examination shall be carried out in accordance with EN ISO 17640. For wall
thickness from 6 mm to 8 mm guidance is given in Annex F.
Ultrasonic TOFD examination according to EN ISO 10863 may be used for detection and sizing of weld
defects and defects adjacent to the weld. Supplementary specification on EN ISO 10863 is given in Annex C.
In welding process numbers 114, 135 and 136 given in EN ISO 4063, additional ultrasonic testing can be
applied.
Dye-penetrant examination shall be carried out in accordance with EN ISO 3452.
Magnetic-particle examination shall be carried out in accordance with EN ISO 17638.

22


BS EN 12732:2013+A1:2014
EN 12732:2013+A1:2014 (E)

Figure 1 indicates the documents in which the criteria for execution, extent and acceptance for various nondestructive testing methods are given.

a

Type of reference block to be agreed.

b

To be specified by operator.

Figure 1 — Standards for non-destructive testing and assessment levels

8.4 Time of inspection
All non-destructive testing shall be carried out before pressure testing, with the exception of final tie-in welds
which are not subjected to the pressure test (”golden welds”).

8.5 Acceptance criteria
The pipeline operator shall specify the acceptance criteria.
The acceptance criteria given in Table G.1 for radiographic findings and in Table G.5 for ultrasonic findings
are based on workmanship criteria. The pipeline operator can use EPRG guidelines (see G.3) or alternative
acceptance criteria based on fracture mechanics analysis and fitness-for-purpose criteria, provided they are
fully documented and based on a proven safe approach.
Weld defects detected by means of ultrasonic examination shall be evaluated in accordance with the
requirements of Table G.6.
The acceptance requirements for alternative examination methods shall be determined from case to case.

23