EN ISO 15626:2018

Non-destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptance levels (ISO 15626:2018)

This document specifies acceptance levels for the time‑of‑flight diffraction technique (TOFD) of full penetration welds in ferritic steels from 6 mm up to 300 mm thickness which correspond to the quality levels of ISO 5817.
These acceptance levels are applicable to indications classified in accordance with ISO 10863.

Zerstörungsfreie Prüfung von Schweißverbindungen - Beugungslaufzeittechnik (TOFD) - Zulässigkeitsgrenzen (ISO 15626:2018)

Dieses Dokument legt die Zulässigkeitsgrenzen fest für die Prüfung von durchgeschweißten Verbindungen von ferritischen Stählen mit einer Dicke von 6 mm bis 300 mm mittels Beugungslaufzeittechnik (TOFD), die den Qualitätsanforderungen in ISO 5817 entsprechen.
Diese Zulässigkeitsgrenzen sind anwendbar auf Anzeigen, die nach ISO 10863 eingestuft wurden.

Essais non destructifs des assemblages soudés - Technique de diffraction des temps de vol (méthode TOFD) - Niveaux d'acceptation (ISO 15626:2018)

Le présent document spécifie les niveaux d'acceptation pour la technique de diffraction des temps de vol (méthode TOFD) utilisée sur des joints soudés à pleine pénétration pratiqués sur des aciers ferritiques d'épaisseur comprise entre 6 mm et 300 mm, correspondant aux niveaux de qualité énoncés dans l'ISO 5817.
Ces niveaux d'acceptation sont applicables à des indications classifiées conformément à l'ISO 10863.

Neporušitveno preskušanje zvarnih spojev - Tehnika TOFD - Stopnje sprejemljivosti (ISO 15626:2018)

Ta dokument določa stopnje sprejemljivosti za tehniko TOFD, namenjeno za zvarne spoje s popolno prevaritvijo pri feritnih jeklih debeline od 6 mm do 300 mm, ki ustrezajo stopnjam sprejemljivosti iz standarda ISO 5817.
Te stopnje sprejemljivosti se uporabljajo za indikacije, razvrščene v skladu s standardom ISO 10863.

General Information

• Status: Published
• Publication Date: 21-Aug-2018
• Withdrawal Date: 27-Feb-2019
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: CEN/TC 121 - Welding
• Drafting Committee: CEN/TC 121/WG 21 - Testing of welds
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 22-Aug-2018
• Completion Date: 22-Aug-2018
• Ref Project: SIST EN ISO 15626:2018 - Non-destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptance levels (ISO 15626:2018)

Relations

• Replaces: EN ISO 15626:2013 - Non-destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptance levels (ISO 15626:2011)
• Effective Date: 04-Oct-2017

Overview

EN ISO 15626:2018 - “Non‑destructive testing of welds - Time‑of‑flight diffraction technique (TOFD) - Acceptance levels” - specifies acceptance criteria for TOFD inspection of full‑penetration welds in ferritic steels with nominal thicknesses from 6 mm to 300 mm. The acceptance levels are aligned with the weld quality levels of ISO 5817 and apply to indications classified in accordance with ISO 10863. This EN version is the CEN adoption of ISO 15626:2018.

Key topics and technical requirements

• Scope and applicability
  • TOFD acceptance levels for full‑penetration welds in ferritic steels, t = 6–300 mm.
  • Acceptance criteria mapped to ISO 5817 quality levels.
• Relation to other standards
  • Acceptance levels are defined relative to ISO 5817 (quality levels B, C, D) and use examination/indication classification from ISO 10863; vocabulary reference ISO 5577 is cited.
• Size definitions
  • Length (l) and height (h) of indications are defined by coordinate differences (x- and z-coordinates).
• Length determination
  • Techniques for elongated straight and elongated curved indications: fitting hyperbolic (arc‑shaped) cursors and defined cursor-placement procedures to measure indication length.
• Height determination
  • Height must be measured from A‑scans with consistent cursor placement; recommended methods include:
    • Method 1: transit time between leading edges
    • Method 2: transit time between first peaks
    • Method 3: transit time between maximum amplitudes
    • Method 4: transit time between first zero crossings
• Acceptance levels
  • Three acceptance levels are specified and mapped to ISO 5817 quality levels:
    • Acceptance level 1 - corresponds to ISO 5817 level B (stringent)
    • Acceptance level 2 - corresponds to ISO 5817 level C (intermediate)
    • Acceptance level 3 - corresponds to ISO 5817 level D (moderate)
• Additional topics
  • Rules for total length, grouping of indications and treatment of point‑like indications.

Applications and users

EN ISO 15626:2018 is intended for professionals performing or specifying TOFD weld inspections and for organizations that need harmonized acceptance criteria for weld quality. Typical users include:

• NDT engineers and technicians (TOFD specialists)
• Welding inspectors and QA/QC personnel in fabrication, pressure vessel, pipeline and structural steel industries
• Engineering firms, inspection bodies and construction contractors specifying weld acceptance criteria

Related standards

• ISO 15626:2018 (original international standard)
• ISO 5817 (weld quality levels)
• ISO 10863 (examination/indication classification for TOFD)
• ISO 5577 (NDT ultrasonic vocabulary)

Keywords: EN ISO 15626:2018, TOFD, time‑of‑flight diffraction, NDT of welds, acceptance levels, ISO 5817, ISO 10863, weld inspection, ferritic steels.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2018
1DGRPHãþD
SIST EN ISO 15626:2013
Neporušitveno preskušanje zvarnih spojev - Tehnika TOFD - Stopnje
sprejemljivosti (ISO 15626:2018)
Non-destructive testing of welds - Time-of-flight diffraction technique (TOFD) -
Acceptance levels (ISO 15626:2018)
Zerstörungsfreie Prüfung von Schweißverbindungen - Beugungslaufzeittechnik (TOFD) -
Zulässigkeitsgrenzen (ISO 15626:2018)
Essais non destructifs des assemblages soudés - Technique de diffraction des temps de
vol (méthode TOFD) - Niveaux d'acceptation (ISO 15626:2018)
Ta slovenski standard je istoveten z: EN ISO 15626:2018
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 15626
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2018
EUROPÄISCHE NORM
ICS 25.160.40 Supersedes EN ISO 15626:2013
English Version
Non-destructive testing of welds - Time-of-flight
diffraction technique (TOFD) - Acceptance levels (ISO
15626:2018)
Essais non destructifs des assemblages soudés - Zerstörungsfreie Prüfung von Schweißverbindungen -
Technique de diffraction des temps de vol (méthode Beugungslaufzeittechnik (TOFD) -
TOFD) - Niveaux d'acceptation (ISO 15626:2018) Zulässigkeitsgrenzen (ISO 15626:2018)
This European Standard was approved by CEN on 14 July 2018.

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, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15626:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 15626:2018) has been prepared by Technical Committee ISO/TC 44 "Welding
and allied processes" in collaboration with Technical Committee CEN/TC 121 “Welding and allied
processes” 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 February 2019, and conflicting national standards
shall be withdrawn at the latest by February 2019.
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.
This document supersedes EN ISO 15626:2013.
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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 15626:2018 has been approved by CEN as EN ISO 15626:2018 without any modification.

INTERNATIONAL ISO
STANDARD 15626
Second edition
2018-07
Non-destructive testing of welds —
Time-of-flight diffraction technique
(TOFD) — Acceptance levels
Essais non destructifs des assemblages soudés — Technique
de diffraction des temps de vol (méthode TOFD) — Niveaux
d'acceptation
Reference number
ISO 15626:2018(E)
©
ISO 2018
ISO 15626:2018(E)
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ii © ISO 2018 – All rights reserved

ISO 15626:2018(E)
Contents Page
.Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 1
5 Relation between quality levels and acceptance levels . 1
6 Definition and determination of length and height . 2
6.1 General . 2
6.2 Determination of length . 2
6.2.1 General. 2
6.2.2 Length sizing of elongated straight indications . 2
6.2.3 Length sizing of elongated curved indications . 3
6.3 Determination of height . 4
6.3.1 General. 4
6.3.2 Surface-breaking discontinuities . 5
6.3.3 Embedded discontinuities . 6
7 Acceptance levels . 6
7.1 General . 6
7.2 Indications from single discontinuities . 7
7.2.1 General. 7
7.2.2 Acceptance level 1 . 7
7.2.3 Acceptance level 2 . 8
7.2.4 Acceptance level 3 . 8
7.3 Total length of indications . 8
7.4 Grouping of indications . 9
7.5 Point-like indications . . 9
Bibliography .11
ISO 15626:2018(E)
Foreword
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