EN ISO 20601:2018

Non-destructive testing of welds - Ultrasonic testing - Use of automated phased array technology for thin-walled steel components (ISO 20601:2018)

This document specifies the application of phased array technology for the semi- or fully automated ultrasonic testing of fusion-welded joints in steel parts with thickness values between 3,2 mm and 8,0 mm. This meets the typical range of tube wall thickness values in boilers, which is an important application of this testing technology. The minimum and maximum value of the wall thickness range can be exceeded, when testing level "D" of this document is applied. This document applies to full penetration welded joints of simple geometry in plates, tubes, pipes, and vessels, where both the weld and parent material are low-alloy and/or fine grained steel.
NOTE       "Semi-automated testing" encompasses a controlled movement of one or more probes on the surface of a component along a fixture (guidance strip, ruler, etc.), whereby the probe position is unambiguously measured with a position sensor. The probe is moved manually. "Fully automated testing" includes mechanized propulsion in addition.
Where material-dependent ultrasonic parameters are specified in this document, they are based on steels having a sound velocity of (5 920 ± 50) m/s for longitudinal waves, and (3 255 ± 30) m/s for transverse waves. It is necessary to take this fact into account when testing materials with a different velocity.
This document provides guidance on the specific capabilities and limitations of phased array technology for the detection, location, sizing and characterization of discontinuities in fusion-welded joints. Ultrasonic phased array technology can be used as a stand-alone technique or in combination with other non-destructive testing (NDT) methods or techniques, during manufacturing and testing of new welds/repair welds (pre-service testing).
This document specifies two testing levels:
—          level "C" for standard situations;
—          level "D" for different situations/special applications.
This document describes assessment of discontinuities for acceptance purposes based on:
—          height and length;
—          amplitude (equivalent reflector size) and length;
—          go/no-go decision.
This document does not include acceptance levels for discontinuities.

Zerstörungsfreie Prüfung von Schweißverbindungen - Ultraschallprüfung - Verwendung von automatisierter phasengesteuerter Array-Technologie für dünnwandige Bauteile aus Stahl (ISO 20601:2018)

Essais non destructifs des assemblages soudés - Contrôle par ultrasons - Utilisation de la technique multi-éléments automatisés pour les composants en acier à paroi mince (ISO 20601:2018)

Le présent document spécifie l'application de la technique multi-éléments pour le contrôle par ultrasons semi-automatisé ou entièrement automatisé des assemblages soudés par fusion de pièces en acier ayant des valeurs d'épaisseur comprises entre 3,2 mm et 8,0 mm. Cela correspond à la gamme type des valeurs d'épaisseur de paroi des tubes dans les chaudières, qui constituent une application importante de cette technique de contrôle. Les valeurs minimale et maximale de la gamme d'épaisseurs de paroi peuvent être dépassées lorsque le niveau de contrôle «D» du présent document est appliqué. Le présent document s'applique aux assemblages soudés à pleine pénétration de géométrie simple sur plaques, tubes, tuyaux et récipients dans lesquels le métal de base et le métal fondu sont tous les deux constitués d'acier faiblement allié et/ou à grains fins.
NOTE       Un «contrôle semi-automatisé» inclut un déplacement contrôlé d'un ou plusieurs traducteurs sur la surface d'un composant le long d'un montage (bande de guidage, règle, etc.), au cours duquel la position du traducteur est mesurée sans ambiguïté par un capteur de position. Le traducteur est déplacé manuellement. Un «contrôle entièrement automatisé» inclut une propulsion mécanisée en complément.
Lorsque les paramètres ultrasonores dépendant du matériau sont spécifiés dans le présent document, ils sont basés sur les aciers dans lesquels la vitesse de propagation du son est égale à (5 920 ± 50) m/s pour les ondes longitudinales et (3 255 ± 30) m/s pour les ondes transversales. Il est nécessaire de prendre en compte cette condition lors du contrôle de matériaux ayant des vitesses de propagation différentes.
Le présent document fournit des lignes directrices sur les possibilités et les limitations spécifiques de la technique multi-éléments pour la détection, la localisation, le dimensionnement et la caractérisation des discontinuités dans les assemblages soudés par fusion. La technique multi-éléments par ultrasons peut être utilisée de manière autonome ou en combinaison avec d'autres méthodes ou techniques d'essai non-destructif (END), pendant la fabrication et le contrôle de nouvelles soudures/soudures de réparation (contrôle avant service).
Le présent document spécifie deux niveaux de contrôle:
—          niveau «C» pour les situations normales;
—          niveau «D» pour des situations différentes/des applications spéciales.
Le présent document décrit l'évaluation des discontinuités à des fins d'acceptation, en se basant sur:
—          la hauteur et la longueur;
—          l'amplitude (taille équivalente du réflecteur) et la longueur;
—          une décision acceptation/rejet.
Le présent document ne comporte pas de niveaux d'acceptation pour les discontinuités.

Neporušitveno preskušanje zvarnih spojev - Ultrazvočno preskušanje - Uporaba avtomatske tehnike s faznim krmiljenjem za tankostenske sestavne dele iz jekla (ISO 20601:2018)

Ta dokument določa uporabo avtomatske tehnike s faznim krmiljenjem za polavtomatsko ali avtomatsko ultrazvočno preskušanje talilno zvarjenih zvarov v kovinskih delih z debelino od 3,2 mm do 8,0 mm. To ustreza običajnemu razponu vrednosti debeline sten cevi v kotlih, kar je pomembna uporaba te preskusne tehnologije. Najmanjšo in največjo vrednost razpona debeline stene je mogoče preseči, kadar se uporablja preskusna raven »D« tega dokumenta. Ta dokument se uporablja za zvarne spoje s popolno penetracijo pri preprostih geometrijskih oblikah v ploščah, ceveh in posodah, pri čemer sta zvarjeni in osnovni material malolegirana in/ali drobnozrnata jekla.
OPOMBA: »polavtomatsko preskušanje« zajema nadzorovano gibanje ene ali več preskuševalnih glav na površini komponente vzdolž veznega elementa (vodilni trak, ravnilo itd.), pri čemer je položaj preskuševalne glave nedvoumno izmerjen s senzorjem položaja. Preskuševalna glava se premika ročno. »Avtomatsko preskušanje« dodatno zajema mehanski pogon.
Kadar so v tem dokumentu določeni od materiala odvisni ultrazvočni parametri, temeljijo na jeklih s hitrostjo (5920 ± 50) m/s za longitudinalne valove in (3255 ± 30) m/s za transverzalne valove. To je treba upoštevati pri preskušanju materialov z različno hitrostjo.
Ta dokument podaja smernice o specifičnih zmogljivostih in omejitvah tehnike s faznim krmiljenjem za zaznavanje, ugotavljanje lokacije in velikosti ter karakterizacijo prekinjenosti talilno zvarjenih zvarov. Tehnologijo ultrazvočne tehnike s faznim krmiljenjem je mogoče uporabiti kot samostojno tehniko ali v kombinaciji z drugimi metodami ali tehnikami neporušitvenega preskušanja med proizvodnjo in preskušanjem novih zvarov/popravljenih zvarov (preskušanje pred uporabo).
Ta dokument določa dve ravni preskušanja:
– raven »C« za standardne situacije;
– raven »D« za različne situacije/posebne uporabe.
Ta dokument opisuje oceno nehomogenosti za namene sprejemanja na osnovi naslednjega:
– višina in dolžina;
– amplituda (ekvivalentna reflektorska velikost) in dolžina;
– odločitev o ustreznosti/neustreznosti.
Ta dokument ne vključuje ravni sprejemljivosti za nehomogenosti.

General Information

• Status: Published
• Publication Date: 18-Dec-2018
• Withdrawal Date: 29-Jun-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: 19-Dec-2018
• Completion Date: 19-Dec-2018
• Ref Project: SIST EN ISO 20601:2019 - Non-destructive testing of welds - Ultrasonic testing - Use of automated phased array technology for thin-walled steel components (ISO 20601:2018)

Overview - EN ISO 20601:2018 (Ultrasonic phased array for thin-walled steel welds)

EN ISO 20601:2018 specifies the application of automated phased array ultrasonic testing (PAUT) for semi‑ or fully‑automated inspection of fusion-welded joints in thin‑walled steel components. The standard targets wall thicknesses between 3.2 mm and 8.0 mm (typical boiler/tube ranges) and applies to full‑penetration welds of simple geometry in plates, tubes, pipes and vessels where both weld and parent material are low‑alloy and/or fine‑grained steel. It supports pre‑service testing of new and repair welds and permits phased array UT to be used alone or combined with other NDT methods.

Key topics and technical requirements

• Testing scope: Semi‑automated (manually moved probes with positional encoding) and fully‑automated (mechanized propulsion) PAUT for thin walls. Level “D” permits exceeding the nominal thickness range for special cases; level “C” covers standard situations.
• Material ultrasonic parameters: Default calibration velocities are longitudinal 5920 ± 50 m/s and transverse 3255 ± 30 m/s; users must account for different material velocities.
• Procedure essentials: Information required before testing, written test procedures, personnel qualifications, equipment and probe specifications, scanning mechanisms, couplant, temperature and surface preparation.
• Calibration and verification: Reference blocks, test block requirements (especially for level D), instrument/display checks, and verification of test setup.
• Data handling: Data storage, phased array data interpretation, assessment of indication quality, location, sizing and characterization.
• Assessment methods: Indications assessed for acceptance based on height & length, amplitude (equivalent reflector size) & length, or go/no‑go decisions. Note: EN ISO 20601:2018 does not define numerical acceptance levels for discontinuities.

Practical applications

• Inspection of boiler tubes, heat‑exchanger tubing, thin‑walled pipes and vessels where welding quality is critical.
• Manufacturing quality assurance, pre‑service acceptance testing, and verification after weld repairs.
• Automated inline inspection where repeatability and positional accuracy of phased array data are required.

Who should use this standard

• NDT engineers and technicians implementing PAUT for weld inspection.
• Inspection companies and fabrication quality managers in boilers, power plants, petrochemical and pressure‑equipment industries.
• Standards writers, regulatory authorities and procurement/specification writers who require harmonized PAUT procedures for thin‑walled steel components.

Related standards

• Applicable alongside other international and national ultrasonic testing and weld inspection standards and ISO technical committee guidance for welding and allied processes (ISO/TC 44). Use EN ISO 20601:2018 in concert with organization‑specific acceptance criteria and industry codes.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2019
1HSRUXãLWYHQRSUHVNXãDQMH]YDUQLKVSRMHY8OWUD]YRþQRSUHVNXãDQMH8SRUDED
DYWRPDWVNHWHKQLNHVID]QLPNUPLOMHQMHP]DWDQNRVWHQVNHVHVWDYQHGHOHL]MHNOD
,62
Non-destructive testing of welds - Ultrasonic testing - Use of automated phased array
technology for thin-walled steel components (ISO 20601:2018)
Zerstörungsfreie Prüfung von Schweißverbindungen - Ultraschallprüfung - Verwendung
von automatisierter phasengesteuerter Array-Technologie für dünnwandige Bauteile aus
Stahl (ISO 20601:2018)
Essai non destructif des assemblages soudés - Contrôle par ultrasons - Utilisation de la
technique multi-éléments automatisés pour les composants en acier à paroi mince (ISO
20601:2018)
Ta slovenski standard je istoveten z: EN ISO 20601:2018
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 20601
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2018
EUROPÄISCHE NORM
ICS 25.160.40
English Version
Non-destructive testing of welds - Ultrasonic testing - Use
of automated phased array technology for thin-walled
steel components (ISO 20601:2018)
Essai non destructif des assemblages soudés - Contrôle Zerstörungsfreie Prüfung von Schweißverbindungen -
par ultrasons - Utilisation de la technique multi- Ultraschallprüfung - Verwendung von automatisierter
éléments automatisés pour les composants en acier à phasengesteuerter Array-Technologie für
paroi mince (ISO 20601:2018) dünnwandige Bauteile aus Stahl (ISO 20601:2018)
This European Standard was approved by CEN on 26 November 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 20601:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 20601:2018) 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 June 2019, and conflicting national standards shall be
withdrawn at the latest by June 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.
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 20601:2018 has been approved by CEN as EN ISO 20601:2018 without any modification.

INTERNATIONAL ISO
STANDARD 20601
First edition
2018-12
Non-destructive testing of welds —
Ultrasonic testing — Use of automated
phased array technology for thin-
walled steel components
Essais non destructifs des assemblages soudés — Contrôle par
ultrasons — Utilisation de la technique multi-éléments automatisés
pour les composants en acier à paroi mince
Reference number
ISO 20601:2018(E)
©
ISO 2018
ISO 20601:2018(E)
© ISO 2018
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]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 20601:2018(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Testing levels . 2
5 Information required before testing . 4
5.1 Items to be specified before procedure development . 4
5.2 Specific information required by the operator before testing . 4
5.3 Written test procedure . 4
6 Requirements for personnel and test equipment . 5
6.1 Personnel qualifications . 5
6.2 Test equipment . 5
6.2.1 General. 5
6.2.2 Instruments and display . 5
6.2.3 Probes. 5
6.2.4 Scanning mechanisms . 6
7 Preparation for testing . 6
7.1 Volume to be tested . 6
7.2 Verification of test set-up . 6
7.3 Scan increment setting . 7
7.4 Geometry considerations . 7
7.5 Preparation of scanning surfaces . 7
7.6 Temperature . 7
7.7 Couplant . 7
8 Testing of parent material . 7
9 Range and sensitivity settings . 8
9.1 Settings . 8
9.1.1 General. 8
9.1.2 Pulse-echo time window . 8
9.1.3 Pulse-echo sensitivity settings . 8
9.2 Checking of the settings . 8
9.3 Reference blocks . 9
9.3.1 General. 9
9.3.2 Material . 9
9.3.3 Dimensions and shape . 9
9.3.4 Reference reflectors . 9
9.4 Test blocks testing level D .10
9.4.1 General.10
9.4.2 Material .10
9.4.3 Dimensions and shape .10
9.4.4 Reflectors in test blocks .10
10 Equipment checks .10
11 Verification of the test procedure .11
12 Weld testing .11
13 Data storage .11
14 Interpretation and analysis of phased array data .11
14.1 General .11
14.2 Assessing the quality of the phased array data .12
14.3 Identification of relevant indications .12
ISO 20601:2018(E)
14.4 Classification of relevant indications .12
14.5 Determination of location and length .12
14.5.1 Location .12
14.5.2 Length.12
14.6 Indication assessment .13
14.6.1 General.13
14.6.2 Assessment based on amplitude and length.13
14.6.3 Assessment based on height and length .13
14.6.4 Characterization of discontinuities .13
14.7 Evaluation against acceptance criteria .13
15 Test report .14
Annex A (informative) Typical reference blocks .16
Bibliography .18
iv © ISO 2018 – All rights reserved

ISO 20601:2018(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
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 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 elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
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 .html.
This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes,
Subcommittee SC 5, Testing and inspection of welds.
Any feedback, question or request for official interpretation related to any aspect of this document
should be directed to the Secretariat of ISO/TC 44/SC 5 via your national standards body. A complete
listing of these bodies can be found at www .iso .org/members .html. Official interpretations, where they
exist, are available from this page: https: //committee .iso .org/sites/tc44/home/interpretation .html.
INTERNATIONAL STANDARD ISO 20601:2018(E)
Non-destructive testing of welds — Ultrasonic testing —
Use of automated phased array technology for thin-walled
steel components
1 Scope
This document specifies the application of phased array technology for the semi- or fully automated
ultrasonic testing of fusion-welded joints in steel parts with thickness values between 3,2 mm and
8,0 mm. This meets the typical range of tube wall thickness values in boilers, which is an important
application of this testing technology. The minimum and maximum value of the wall thickness range
can be exceeded, when testing level “D” of this document is applied. This document applies to full
penetration welded joints of simple geometry in plates, tubes, pipes, and vessels, where both the weld
and parent material are low-alloy and/or fine grained steel.
NOTE “Semi-automated testing” encompasses a controlled movement of one or more probes on the surface of
a component along a fixture (guidance strip, ruler, etc.), whereby the probe position is unambiguously measured
with a position sensor. The probe is moved manually. “Fully automated testing” includes mechanized propulsion
in addition.
Where material-dependent ultrasonic parameters are specified in this document, they are based on
steels having a sound velocity of (5 920 ± 50) m/s for longitudinal waves, and (3 255 ± 30) m/s for
transverse waves. It is necessary to take this fact into account when testing materials with a different
velocity.
This document provides guidance on the specific capabilities and limitations of phased array
technology for the detection, location, sizing and characterization of discontinuities in fusion-welded
joints. Ultrasonic phased array technology can be used as a stand-alone technique or in combination
with other non-destructive testing (NDT) methods or techniques, during manufacturing and testing of
new welds/repair welds (pre-service testing).
This document specifies two testing levels:
— level “C” for standard situations;
— level “D” for different situations/special applications.
This document describes assessment of discontinuities for acceptance purposes based on:
— height and length;
— amplitude (equivalent reflector size) and length;
— go/no-go decision.
This document does not include acceptance levels for discontinuities.
2 Normative references
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, the latest edition of the referenced document (including any amendments) applies.
ISO 5577, Non-destructive testing — Ultrasonic testing — Vocabulary
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 20601:2018(E)
ISO 17640, Non-destructive testing of welds — Ultrasonic testing — Techniques, testing levels, and
assessment
ISO 18563-1, Non-destructive testing — Characterization and verification of ultrasonic phased array
equipment — Part 1: Instruments
ISO 18563-2, Non-destructive testing — Characterization and verification of ultrasonic phased array
equipment — Part 2: Probes
ISO 18563-3, Non-destructive testing — Characterization and verification of ultrasonic phased array
equipment — Part 3: Combined systems
EN 16018, Non-destructive testing — Terminology — Terms used in ultrasonic testing with phased arrays
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5577 and EN 16018 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
phased array image
one- or two-dimensional display, constructed from the collected information of phased array operation
3.2
indication
phased array indication
pattern or disturbance in the phased array image (3.1) which may need further evaluation
3.3
phased array set-up
probe arrangement defined by probe characteristics (e.g. frequency, probe element size, beam angle,
wave mode), probe position, and the number of probes, adaptation to the curvature of the test object
3.4
scan increment
distance between successive data collection points in the direction of scanning (mechanically or
electronically)
3.5
skewed scan
scan performed with a skewed beam angle
Note 1 to entry: The skewed beam angle can be achieved electronically or by changing the probe orientation.
4 Testing levels
Quality requirements for welded joints are mainly associated with the material, welding process and
service conditions. To accommodate all of these requirements, this document specifies two testing
levels “C” and “D”. A written procedure is mandatory for both testing levels C and D.
Testing level C applies to the standardized approach for thin-walled components (see Tables 1 and 2),
e.g. testing from two sides or testing from one side of the weld with the cap removed.
2 © ISO 2018 – All rights reserved

ISO 20601:2018(E)
Testing level D shall be agreed upon for special applications, e.g. tests on wall thickness below 3,2 mm,
varying thicknesses (counter bore) and tests at object temperatures outside the range specified in 7.6.
For testing level D, verification on test blocks is mandatory.
In general, the testing levels are related to quality levels (given in ISO 5817, for example). The appropriate
testing level can be specified by standards for weld testing (e.g. ISO 17635), product standards or other
specifications. When ISO 17635 is specified, the recommended testing levels are as given in Table 1.
Table 1 — Recommended testing levels
Testing level Quality level in ISO 5817
C B, C, D
D Special applications
Table 2 shows the minimum requirements for the individual test modes for testing levels C and D. The
set-up shall be verified with reference and/or test blocks; as described in 7.2. In cases where scanning is
performed from one scanning surface (e.g. the outer surface of a vessel), at least half and full skip shall
be used. If scanning is performed from both scanning surfaces (e.g. top and bottom surfaces), testing at
half skip could be sufficient, depending on weld and probe dimensions.
If the evaluation of the indications is based on amplitude only, the deviation of the beam axis from the
normal to the weld bevel shall not exceed 6°. In case it is not possible to stay within this 6° value, because
of the geometry of the test object (e.g. weld cap, narrow gap weld), the scan plan shall describe the
corrective measures and explain how the areas outside the 6° requirement are covered with sufficient
sensitivity.
Table 2 — Description of testing levels
Testing levels
Mode Examples
C test set-up D test set-up
E-scan at fixed probe
position to weld (line Two sides To be specified
scan)
S-scan at fixed probe Two sides or two
position to weld (line probe positions on To be specified
scan) the same side
One side, weld cap
S-scan raster To be specified
removed
a
Skewed scan Not applicable To be specified
a
If detection of transverse discontinuities is required by specification, a suitable additional test set-up shall be applied.
Skewed probe or electronically skewed beam can be used.
ISO 20601:2018(E)
5 Information required before testing
5.1 Items to be specified before procedure development
Information on the following items is required:
a) purpose and extent of testing;
b) type(s) of parent material (i.e. cast, forged, rolled), grain size;
c) testing levels;
d) acceptance criteria;
e) specification of reference blocks;
f) manufacturing or operational stage at which the testing has to be carried out;
g) weld details and information on the size of the heat-affected zone;
h) requirements for access, surface conditions and temperature;
i) personnel qualifications;
j) reporting requirements.
5.2 Specific information required by the operator before testing
Before any testing of a welded joint can begin, the operator shall have access to all the information
specified in 5.1, together with the following additional information:
a) written test procedure;
b) joint preparation and dimen
...