ISO/FDIS 18760

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ISO/FDIS 18760:2025(en)
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ISO /TC 8/SC 4/WG 11
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Date: 2025-09-02 0 pt, Section start: New page, Header distance from
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Secretariat: SAC
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Date: 2025-10-21
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Ships and marine technology — High manganese austenitic steel — .
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Longitudinally welded high manganese austenitic steel pipes for
cryogenic temperature
FDIS stage
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All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
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may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
Asian text and numbers
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
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at the address below or ISO’s member body in the country of the requester.
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ISO copyright office
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EmailE-mail: copyright@iso.org
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Website: www.iso.orgwww.iso.org
Published in Switzerland
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Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 3
4.1 Symbols . 3
4.2 Abbreviated terms . 3
5 Health, safety and quality requirements . 4
5.1 Health and safety requirements . 4
5.2 Quality requirements . 4
6 Manufacturing process . 6
6.1 Steelmaking process . 6
6.2 Rolled product . 6
7 Welding requirements . 6
7.1 General requirements . 6
7.2 Welding processes . 7
7.3 Preparation for welding . 7
7.4 Welder and welding operator performance qualification . 7
7.5 Welding consumables . 7
8 Welding procedure qualification . 8
9 Metallurgical properties . 9
9.1 Chemical composition . 9
9.2 Mechanical properties . 9
10 Dimensions, mass and tolerances . 13
10.1 Diameters, wall thickness and masses . 13
10.2 Tolerances on lengths . 14
11 Inspection . 14
11.1 Visual inspection . 14
11.2 Hydrostatic test . 15
11.3 Non-destructive testing . 15
11.4 Preparation of ends . 15
12 Marking . 16
13 Documentation . 16
Bibliography . 17

Foreword . iv
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Introduction . v
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1 Scope . 1
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2 Normative references . 1
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iii
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3 Terms and definitions . 2
4 Symbols and abbreviated terms . 3
5 Health, safety and quality requirement . 4
5.1 Health and safety requirements . 4
5.2 Quality requirements . 4
6 Manufacturing process . 5
6.1 Steelmaking process . 5
6.2 Rolled product . 6
7 Welding requirements . 6
7.1 General requirements . 6
7.2 Welding processes . 6
7.3 Preparation for welding . 7
7.4 Welder and welding operator performance qualification . 7
7.5 Welding consumables . 7
8 Welding procedure qualification . 8
9 Metallurgical properties . 9
9.1 Chemical composition . 9
9.2 Mechanical properties . 9
10 Dimensions, mass and tolerances . 12
10.1 Diameters, wall thickness and masses . 12
10.2 Tolerances on lengths . 13
11 Inspection . 13
11.1 Visual inspection . 13
11.2 Hydrostatic test . 14
11.3 Non-destructive testing . 14
11.4 Preparation of ends . 14
12 Marking . 14
13 Documentation . 15
Bibliography . 16
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iv
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee TC 8, Ships and marine technology, Subcommittee SC 4,
Outfitting and deck machinery.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.htmlwww.iso.org/members.html.

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v
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Introduction
The aim of this document is to provide a set of common requirements for metallic materials used in cryogenic
[1][ ] [2][ ]
applications, in alignment with the IGC Code 1 and IGF Code 2 adopted by the International Maritime
Organization (IMO).
The newly developed, high manganese austenitic steel is expected to possess mechanical properties including
Charpy impact energy values comparable to those materials for cryogenic service listed in both the IGC Code
and IGF Code. Consequently, high manganese steel is intended to satisfy the strength requirements of the
structure of cargo tanks, fuel tanks and piping systems.
In addition, upon agreement with a purchaser, this document can be applied to piping systemsystems for
liquefied hydrogen.
This document provides a standard specification of high manganese austenitic steel forgings for material
suppliers, ship owners, ship yards, manufacturers and shipping companies with regard to producing,
purchasing and using such materials.
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FINAL DRAFT International Standard ISO/FDIS 18760:2025(en) .
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Ships and marine technology — High manganese austenitic steel —
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Longitudinally Weldedwelded high manganese austenitic steel pipes
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for cryogenic temperature
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1 Scope
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This document specifies the delivery conditions for longitudinally welded pipes of circular cross-section, made
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of high manganese austenitic steel, intended for cryogenic temperature applications under pressure.
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This document is applicable to all pressure-retaining components and any non-pressure-retaining
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components, such as members of pipe supports, thatwhich are welded directly to a pressure-retaining
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component.
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NOTE This document is not intended to address all safety Concerns, if any, associated with its use. It is the responsibility
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of the user to establish appropriate safety and health practices and to determine the applicability of regulatory limitations
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before use.
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2 Normative references
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The following documents are referred to in the text in such a way that some or all of their content constitutes .
requirements of this document. For dated references, only the edition cited applies. For undated references,
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the latest edition of the referenced document (including any amendments) applies.
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ISO 148--1, Metallic materials — Charpy pendulum impact test — Part 1: Test method .
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ISO 1127, Stainless steel tubes -- Dimensions, tolerances and conventional masses per unit length
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ISO 2566-1, Steel — Conversion of elongation values — Part 1: Carbon and low-alloy steels
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ISO 2566-2, Steel — Conversion of elongation values — Part 2: Austenitic steels
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ISO 3834--2, Quality requirements for fusion welding of metallic materials — Part 2: Comprehensive quality
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requirements
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ISO 4136, Destructive tests on welds in metallic materials — Transverse tensile teststest Formatted
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ISO 5173, Destructive tests on welds in metallic materials — Bend tests
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ISO 6892--1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
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ISO 9304, Seamless 10893-2, Non-destructive testing of steel tubes — Part 2: Automated eddy current testing of
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seamless and welded (except submerged arc-welded) steel tubes for pressure purposes — Eddy current testing
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for the detection of imperfections
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ISO 9606 (all parts), Qualification testing of welders — Fusion welding — Part 1: Steels
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ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
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ISO/DIS 18735FDIS 18760:2025(en)
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ISO 9765, Submerged arc-welded 10893-11, Non-destructive testing of steel tubes for pressure purposes —
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Ultrasonic— Part 11: Automated ultrasonic testing of the weld seam of welded steel tubes for the detection of
longitudinal and/or transverse imperfections
ISO 10474, Steel and steel products — Inspection documents
ISO 12096, Submerged arc-welded steel tubes for pressure purposes — Radiographic testing of the weld seam for
the detection of imperfections
ISO 14175, Welding consumables — Gases and gas mixtures for fusion welding and allied processes
ISO 14344, Welding consumables — Procurement of filler materials and fluxes
ISO 14731, Welding coordination — Tasks and responsibilities
ISO 14732, Welding personnel — Qualification testing of welding operators and weld setters for mechanized
and automatic welding of metallic materials
ISO 15609--1, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 1: Arc welding
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
ASME B31.3, Process Piping
ASME Boiler and Pressure Vessel Code, Section IX, Welding, Brazing, and Fusing Qualifications
ASNT SNT-TC-1A, Personnel Qualification and Certification in Non-destructive Testing
ASNT CP-189, ASNT Standard for Qualification and Certification of Non-destructive Testing Personnel
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
3.1 3.1
cryogenic service
service environments with a minimum design temperature lower than –104 °C
3.2 3.2
manufacturer
erector
organization responsible for the fabrication, welding, examination and testing of piping systems including any
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externally provided products or services
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3.3 3.3
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heat input
energy introduced into the weld region during welding per unit run length
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3.4 3.4
leak testing
hydrostatic leak test
pneumatic leak test
application of a pressure load, greater than the design load, to demonstrate the integrity of a pressure system
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Note 1 to entry: ASME B31.3 uses the terms hydrostatic leak test, pneumatic leak test, or a combination of both methods, and numbers
such as a hydro-pneumatic test.
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3.5 3.5
lot
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pipespipe of the same steel grade, the same cast, the same manufacturing process (using the same type of filler
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wires), the same nominal dimensions and, if applicable, subjectedsubject to the same finishing treatment in a
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continuous furnace or heat treated in the same furnace charge
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3.6 3.6
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owner
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person, partnership, organization or business ultimately responsible for design, construction, operation, and
maintenance of a facility
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4 Symbols and abbreviated terms
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4.1 Symbols
and numbers
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D nominal pipe diameter, expressed in millimetres
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W nominal wall thickness, expressed in millimetres
and numbers
L length, expressed in millimetres
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r nominal outside radius of the pipe, expressed in millimetres Formatted: Table body (+), Adjust space between
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t nominal material thickness at the weld, expressed in millimetres
and numbers
U Geometric unsharpness
g
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4.2 Abbreviated terms
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ACCP ASNT Central Certification Program
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ASNT American Society for Non-destructive Testing
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AUT Automatic Ultrasonic Testing
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AWS American Welding Society
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CSWIP certification scheme for weldment inspection personnel
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CWEng certified welding engineer
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GTAW gas tungsten arc welding
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IIW International Institute of Welding
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ITP inspection and test plan
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NDT non-destructive testing
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PT liquid penetrant testing (for use on non-magnetic materials)
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PWHT post weld heat treatment Formatted: Font: 11 pt
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ISO/DIS 18735FDIS 18760:2025(en)
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QMS quality management system
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SAW submerged arc welding
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SMAW shielded metal arc welding
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WPS welding procedure specification
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5 Health, safety and quality requirements
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5.1 Health and safety requirements
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5.1.1 5.1.1 The manufacturer shall provide at least provide the following safety equipment and systems:
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a) a) ventilation and extraction facilities for welding-related activities or work in a confined space;
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b) b) personal protective equipment including eye, breathing and hearing protection;
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c) c) access/scaffolding/working platforms and fall-arrest protective equipment for working at
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d) d) access and secure temporary formwork for working below-grade;
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e) e) protective systems to prevent electric shock, build-up or discharge of static electricity, and
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earthing of welding current through susceptible components in the piping assembly;
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f) f) ‘whip checks’ on test hoses for flushing, cleaning, leak testing/tightness testing. Formatted
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5.1.2 5.1.2 All work undertaken in a confined space shall be managed using a permit-to-work system, i.e.,.
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a formal written procedure that authorizes and controls hazardous activities.
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[3][ ]
NOTE 1 ISO 45001 3 specifies requirements for an occupational health and safety management system, and gives
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guidance for its use, to enable organizations to provide safe and healthy workplaces by preventing work-related injury .
and ill health, as well as by proactively improving its occupational health and safety performance.
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NOTE 2 ANSI Z49.1 4 and ISO/TR/ 18786 5 give specific requirements and guidance on safety in Weldingwelding .
fabrication activities.
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5.2 Quality requirements
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5.2.1 5.2.1 The manufacturer shall have a quality management system in place to ensure consistent
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product quality and compliance with this document.
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5.2.2 5.2.2 The manufacturer shall meet the following requirements related to the The defined
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responsibilities for the manufacturer, and the welding, inspection and testing personnel: are as follows.
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a) a) theThe manufacturer shall meet the comprehensive welding quality requirements of ISO 3834-
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2;.
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b) b) weldingWelding coordination personnel shall demonstrate that they meet the requirements of
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ISO 14731 by either a comprehensive level of competency or a specific level of competency as appropriate
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for the relevant essential welding-related tasks described in ISO 3834-2;.
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NOTE 1 For the purposes of this provision, personnel with AWS CWEng certification in conformance to
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[6][ ]
AWS B5.16 6 can be considered equivalent to personnel holding EWF European welding engineer (EWE) or IIW
[7][ ]
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International Welding Engineer (IWE) certification as explained in EWF Publication EWF-663-–19 7 and IIW
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[8] [ ]
Publication IAB-362-–19 ,, 8 respectively.
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c) c) weldingWelding inspection personnel shall hold certification in accordance with onebe
competent and shall meet the requirements of the followingISO 14731 or ISO 9712, as applicable to the
inspection activities performed.
NOTE 2 Examples of schemes:
— that can provide evidence of meeting these requirements include IIW international welding inspector
– standard or IIW international welding inspector– comprehensive;
— International Welding Inspector (Standard or Comprehensive), AWS QC1 certified welding inspector
or AWS QC1 senior certified welding inspector;
— Certified Welding Inspector/Senior Certified Welding Inspector, and CSWIP 3.1 welding inspector or
CSWIP 3.2 senior welding inspector;
— other equivalent certificate holders, as agreed between the manufacturer and the purchaser.
NOTE 2 Welding inspection personnel schemes. Personnel with lower levels of certificationqualification can only
be employedperform inspection activities under the direct supervision of competent personnel havingmeeting the
required certificationabove requirements.
d) NDT personnel, including personnel forthose performing techniques covered by the ASME Boiler and
[9] [ ]
Pressure Vessel Code, Section V, Article 1, Mandatory Appendix II ,, 2023 9 and UT operators
responsible for examining welds materials, shall hold certification in accordance with one of the following
schemes:
— an industry-recognized central personal certification scheme meetingbe competent and shall meet the
requirements of ISO 9712;
d) — an employer-based certification scheme meeting the requirements of ASNT SNT-TC-1A or
ASNT CP-189, wherein Level III personnel for the relevant technique(s) shall hold certification from an
industry-recognized central personal certification scheme meeting the requirements of ISO 9712.
— the use of When automated ultrasonic testing (AUT) is used, personnel shall requirereceive
appropriate training in operating the specific equipment, and a documented procedure shall be established to
demonstrate the operator’s ability of the operator to detect the relevant defects.
[10] [11]
NOTE 3 For the purposes of this provision, ASNT ACCP-CP-1 and ASNT CP-106 schemes can be considered to meet
the requirements of ISO 9712.
e) PersonnelNOTE 3 Examples of qualification or certification schemes that can provide evidence of meeting
[ ] [ ]
these requirements include ASNT SNT-TC-1A, ASNT CP-189, ASNT ACCP-CP-1 10 , and ASNT CP-106. 11
e) personnel responsible for undertaking PMI, hardness, flushing/cleaning and subsequent leak
testing/tightness testing activities shall demonstrate appropriate competency using industry-recognized
or employer-based assurance schemes.
5.2.3 5.2.3 The QMS of the manufacturer shall address the following activities:
a) a) traceability, storage and handling of pipes, welding consumables, NDT and testing to avoid
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damage or degradation;
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b) b) traceability and verification of each pressure retaining weld and direct attachment weld to th
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