SIST EN ISO 4761:2023

Non-destructive testing of welds - Phased array ultrasonic testing (UT-PA) for thin-walled steel components - Acceptance levels (ISO 4761:2022)

This document specifies acceptance levels for the phased array ultrasonic testing technique (UT-PA) of full-penetration welds in low-alloy and/or fine-grained steels in the wall thickness range from 3,2 mm to 8 mm which correspond to the quality levels of ISO 5817.
These acceptance levels are applicable to indications detected according to ISO 20601.

Zerstörungsfreie Prüfung von Schweißverbindungen - Phased-Array-Ultraschallprüfung (UT‑PA) dünnwandiger Stahlkomponenten - Zulässigkeitsgrenzen (ISO 4761:2022)

Essais non destructifs des assemblages soudés - Technique ultrasons multi-éléments (UT-PA) pour les composants en acier à paroi mince - Niveaux d’acceptation (ISO 4761:2022)

Neporušitveno preskušanje zvarnih spojev - Ultrazvočno preskušanje s faznim krmiljenjem (UT-PA) tankostenskih jeklenih delov - Stopnje sprejemljivosti (ISO 4761:2022)

Ta dokument določa stopnje sprejemljivosti za tehniko ultrazvočnega preskušanja s faznim krmiljenjem (UT-PA) zvarnih spojev s popolno penetracijo pri malolegiranih in/ali drobnozrnatih jeklih z debelino sten od 3,2 do 8 mm, ki ustrezajo stopnjam sprejemljivosti iz standarda ISO 5817.
Te stopnje sprejemljivosti se uporabljajo za indikacije, zaznane v skladu s standardom ISO 20601.

General Information

• Status: Published
• Public Enquiry End Date: 01-Oct-2022
• Publication Date: 09-Feb-2023
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: VAR - Welding
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 20-Jan-2023
• Due Date: 27-Mar-2023
• Completion Date: 10-Feb-2023
• Ref Project: EN ISO 4761:2022 - Non-destructive testing of welds - Phased array ultrasonic testing (UT-PA) for thin-walled steel components - Acceptance levels (ISO 4761:2022)

Relations

• Refers: SIST EN 17163:2019 - Pulp, paper and board - Determination of primary aromatic amines (PAA) in a water extract by a LC-MS method
• Effective Date: 28-Jan-2026
• Refers: SIST EN ISO 3262-8:2023 - Extenders - Specifications and methods of test - Part 8: Natural clay (ISO 3262-8:2023)
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 448:2025 - District heating pipes - Bonded single pipe systems for directly buried hot water networks - Factory made fitting assemblies of steel service pipes, polyurethane thermal insulation and a casing of polyethylene
• Effective Date: 28-Jan-2026

Overview

SIST EN ISO 4761:2023 specifies acceptance levels for the phased array ultrasonic testing (UT-PA) of full-penetration welds in thin-walled steel components. Focusing on low-alloy and/or fine-grained steels within a wall thickness range of 3.2 mm to 8 mm, this standard ensures a harmonized approach to the evaluation and acceptance of weld imperfections detected using advanced UT-PA techniques. The acceptance levels directly correspond to ISO 5817 quality requirements, establishing consistent criteria for welded joint quality in critical applications.

Key Topics

• Scope of Application: The standard is intended for non-destructive testing (NDT) of full-penetration welds in thin-walled steel structures using phased array ultrasonic testing.
• Reference and Acceptance Levels: Provides detailed definitions and criteria for reference, acceptance, and evaluation levels, including amplitude and indication length.
• Testing Guidelines: Outlines methods for setting inspection sensitivity and evaluating longitudinal and transverse indications, both for two-sided and single-sided UT-PA approaches.
• Cumulative Indications: Specifies how to calculate and evaluate the total acceptable length of individual indications along the weld.
• Alignment with ISO 5817: Each acceptance level in SIST EN ISO 4761:2023 is associated with a quality level according to the widely recognized ISO 5817 standard, ensuring international consistency.
• Reporting Requirements: Details conditions for reporting sub-acceptance-level indications and appropriate documentation practices.

Applications

SIST EN ISO 4761:2023 is essential for organizations seeking to improve the safety and quality of welded steel structures through reliable non-destructive testing. Key application areas include:

• Pressure Vessels and Piping: Supports safe operation by verifying weld quality in components subjected to internal pressure, where thin-walled steel is often used.
• Manufacturing and Fabrication: Ensures weld integrity in structural elements of steel constructions, transport equipment, and machinery.
• Automotive and Aerospace Engineering: Provides robust inspection criteria for critical welds in industries with strict safety and performance standards.
• Quality Assurance: Strengthens risk management and compliance with international quality and safety requirements for welded joints.

By offering precise acceptance criteria for UT-PA detected indications, this standard helps improve defect detection, reduce repair costs, and increase confidence in welded component integrity.

Related Standards

For comprehensive non-destructive testing of welds and for the effective application of SIST EN ISO 4761:2023, consider integrating the following related standards:

• ISO 20601: Non-destructive testing of welds - Ultrasonic testing - Use of automated phased array technology for thin-walled steel components
• ISO 5817: Welding - Fusion-welded joints in steel, nickel, titanium and their alloys - Quality levels for imperfections
• ISO 5577: Non-destructive testing - Ultrasonic testing - Vocabulary
• ISO 23243: Non-destructive testing - Ultrasonic testing with arrays - Vocabulary
• ISO 9712: Non-destructive testing - Qualification and certification of NDT personnel
• ISO 11666: Non-destructive testing of welds - Ultrasonic testing - Acceptance levels
• ISO 13588: Non-destructive testing of welds - Ultrasonic testing - Use of automated phased array technology
• ISO 17635: Non-destructive testing of welds - General rules for metallic materials
• ISO 17640: Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment

Practical Value

Implementing SIST EN ISO 4761:2023 ensures standardized, effective phased array ultrasonic testing of welds in thin-walled steel, promoting safety, reliability, and compliance across multiple industries. This standard is indispensable for manufacturers, inspectors, and quality assurance professionals intent on maintaining high-quality welded structures and meeting international best practices in non-destructive testing.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2023
Neporušitveno preskušanje zvarnih spojev - Ultrazvočno preskušanje s faznim
krmiljenjem (UT-PA) tankostenskih jeklenih delov - Stopnje sprejemljivosti (ISO
4761:2022)
Non-destructive testing of welds - Phased array ultrasonic testing (UT-PA) for thin-walled
steel components - Acceptance levels (ISO 4761:2022)
Zerstörungsfreie Prüfung von Schweißverbindungen - Phased-Array-Ultraschallprüfung
(UT‑PA) dünnwandiger Stahlkomponenten - Zulässigkeitsgrenzen (ISO 4761:2022)
Essais non destructifs des assemblages soudés - Technique ultrasons multi-éléments
(UT-PA) pour les composants en acier à paroi mince - Niveaux d’acceptation (ISO
4761:2022)
Ta slovenski standard je istoveten z: EN ISO 4761:2022
ICS:
25.160.40 Varjeni spoji in vari Welded joints and welds
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 4761
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 25.160.40
English Version
Non-destructive testing of welds - Phased array ultrasonic
testing (UT-PA) for thin-walled steel components -
Acceptance levels (ISO 4761:2022)
Essais non destructifs des assemblages soudés - Zerstörungsfreie Prüfung von Schweißverbindungen -
Technique ultrasons multi-éléments (UT-PA) pour les Phased-Array-Ultraschallprüfung (UT-PA)
composants en acier à paroi mince - Niveaux dünnwandiger Stahlkomponenten -
d'acceptation (ISO 4761:2022) Zulässigkeitsgrenzen (ISO 4761:2022)
This European Standard was approved by CEN on 20 December 2022.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4761:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 4761:2022 has been prepared by Technical Committee ISO/TC 44 "Welding and allied
processes” of the International Organization for Standardization (ISO) and has been taken over as
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 June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 4761:2022 has been approved by CEN as EN ISO 4761:2022 without any modification.

INTERNATIONAL ISO
STANDARD 4761
First edition
2022-01
Non-destructive testing of welds —
Phased array ultrasonic testing (UT-
PA) for thin-walled steel components
— Acceptance levels
Essais non destructifs des assemblages soudés — Technique ultrasons
multi-éléments (UT-PA) pour les composants en acier à paroi mince
— Niveaux d’acceptation
Reference number
ISO 4761:2022(E)
ISO 4761:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 4761:2022(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 1
5 Sensitivity setting and levels .2
6 Acceptance levels.2
7 Evaluation of indications . 2
8 Acceptance criteria for two-sided testing . 3
8.1 General . 3
8.2 Longitudinal indications . 3
8.3 Transverse indications . 5
8.4 Cumulative length of indications . 5
9 Acceptance criteria for single-sided testing . 6
9.1 General . 6
9.2 Longitudinal indications . 6
9.3 Transverse indications . 7
9.4 Cumulative length of indications . 7
Bibliography . 8
iii
ISO 4761:2022(E)
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
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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 documents 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).
Attention is drawn to the possibility that some of the
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