🔩 Automated testing of welds with phased array probes (PAUT) — PN-EN ISO 13588

Materials and NDT PN-EN ISO 13588

Overview

WHAT THIS TEST IS (clause 1 of ISO 13588:2019). Application of the phased array technique to the semi- or fully automated ultrasonic testing of fusion-welded joints in metallic materials with a thickness of at least 6 mm. It applies to full-penetration joints of simple geometry in plates, pipes and vessels, where the weld and the parent material are low-alloy and/or fine-grained steel; for other steels the standard gives guidance, and for coarse-grained and austenitic steels ISO 22825 is applied in addition. The technique can be used on its own or combined with other methods — during manufacture, before service and in service. The standard specifies four testing levels and allows discontinuities to be evaluated on the basis of amplitude (equivalent reflector size) and length or of height and length, but it does NOT give acceptance levels. It does not apply to the automated testing of welds during the production of steel products covered by ISO 10893-8, ISO 10893-11 and ISO 3183.

TESTING LEVELS (clause 4). From level A to C the probability of detection increases — through greater coverage (the number of beam incidence directions, the combination of techniques). Level D is agreed for special applications with a written procedure — among others metals other than ferritic steel, partial-penetration welds, object temperatures outside the range. When ISO 17635 is invoked, the assignment from Table 1 applies: testing level A ↔ quality levels C and D according to ISO 5817, B ↔ B, C — by agreement, D — special application. MINIMUM REQUIREMENTS (Table 2 and text): the setup is always checked on a reference block; when scanning from one surface (except TOFD) the half and the full skip are used and recorded, from two surfaces the half skip is sufficient; for level C at least two different setups from Table 2 are combined, at least one of which is an S-scan or TOFD; with E-scans from two sides with two angles, the difference between the angles is at least 10°; when the evaluation is based on amplitude only, the deviation of the beam direction from the normal to the weld groove must not exceed 6°. Transverse discontinuities — an additional setup with a skewed beam direction, if the specification requires it.

INFORMATION AND PROCEDURE (clause 5). Before the procedure is drawn up, the following must be known, among others: the purpose and extent of the testing, the testing level, the acceptance criteria, the reference blocks, the manufacturing or service stage, the weld details and the width of the heat-affected zone, access, surface condition and temperature. A written procedure is required at EVERY testing level and contains a documented scan strategy or scan plan: the position and movement of the probe, the coverage, the beam angles and directions relative to the weld axis, and the examination volume of each weld.

PERSONNEL AND EQUIPMENT (clause 6). Personnel qualified according to ISO 9712 (a separate entry in this database) or equivalently in the given sector, with practical experience in the phased array technique; training and an examination on representative specimens are recommended. Equipment according to ISO 18563-1, -2 and -3; A-scan sampling at least six times the nominal probe frequency is recommended. Longitudinal and transverse waves may be used; adaptation of the probes to curved surfaces according to ISO 17640. In the active aperture at most 1 dead element in 16, dead elements must not be adjacent; with an aperture of fewer than 16 elements, no dead elements are permitted unless adequate performance is demonstrated. Guiding mechanisms and scan position encoders are mandatory.

PREPARATION (clause 7). For testing at the manufacturing stage, the examination volume comprises the weld and the parent material at least 10 mm on each side (5 mm for laser and electron beam welds) or the width of the heat-affected zone — whichever is greater. The effectiveness of the setup is checked on reference blocks (9.3). The scan increment along the weld depends on the thickness: up to 10 mm — not more than 1 mm.

WHAT THE 2019 EDITION CHANGED (foreword): clauses 2 and 3 were updated, a method for measuring the length and height of discontinuities and a new Annex B (examples of signals) were added, and editorial changes were made.

EDITIONS (state on 25.09.2026). PKN: PN-EN ISO 13588:2019-04 — English version, publication 19-04-2019, 38 pages, KT 165 Welding and Allied Processes, introduces EN ISO 13588:2019 and ISO 13588:2019 [IDT]; it replaced PN-EN ISO 13588:2013-04 (English version, withdrawn 19-04-2019). ISO: ISO 13588:2019, edition 2 of February 2019, 24 pages, ISO/TC 44/SC 5 — the ISO website gives stage 90.92 ("to be revised") and the draft ISO/CD 13588 that is to replace it, and at the same time the information that the review in 2024 confirmed the present edition as current.

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 18 entries at 17 laboratories; notations "PN-EN ISO 13588:2019-04" (12), "PN EN ISO 13588:2019-04" without a hyphen (2), "PN-EN ISO 13588" without a year (2), "EN ISO 13588:2019", "PN-EN ISO 13588: 2019-04" and once the WITHDRAWN edition "PN-EN ISO 13588:2013-04" (AB 313); one entry combines the standard with ASME Section V, Article 4. The subject of the test is most often "Złącza spawane materiałów metalowych" [Welded joints of metallic materials] (9); methodology: "Nieciągłości" [Discontinuities] (6), "Nieciągłości wewnętrzne" [Internal discontinuities] (4); thickness range — from 6 mm, once (8–300) mm. In the same entries: PN-EN ISO 17640 (8 entries — ultrasonic testing of welds, a separate entry in this database), PN-EN ISO 10863 (6 — TOFD technique), PN-EN ISO 16828 (5).

THE KEY OF THE "LABORATORIES" TAB: "PN-EN ISO 13588" — 15 laboratories and 16 entries, without foreign entries. The tab will not show 2 laboratories (AB 1425, AB 1927), which wrote the standard without a hyphen ("PN EN ISO 13588:2019-04").

WHAT WE DO NOT GIVE. We had a fragment of the text of ISO 13588:2019 made available by the publisher: the table of contents, the foreword and clauses 1–7.3 (up to the scan increment for thicknesses up to 10 mm). We do not have the further scan increments, the requirements for temperature and couplant, the setting of range and sensitivity (clause 9), the reference blocks, the qualification of the procedure, the data interpretation, sizing or Annexes A and B. We do not give these parameters.

Method principle

The welded joint is scanned with a mechanically guided phased array probe with an encoder; electronically steered beams (fixed angles, E-scan, S-scan, possibly TOFD) cover the examination volume according to a written scan plan. The recorded data (phased array images) are analysed: identification and classification of indications, position, length and height, evaluation according to criteria adopted from other documents (e.g. ISO 19285).

Applications

• Full-penetration welded joints in plates, pipes and vessels, thickness ≥ 6 mm, low-alloy and fine-grained steel
• Testing during manufacture, before service and in service — on its own or with other methods (e.g. TOFD, ISO 17640)
• Other steels — according to the guidance of the standard; coarse-grained and austenitic steel — in addition ISO 22825
• NOT: automated testing of welds during the production of products according to ISO 10893-8, ISO 10893-11 and ISO 3183

Key parameters

Standard

Standard number

PN-EN ISO 13588:2019-04 (wersja angielska; wprowadza EN ISO 13588:2019 i ISO 13588:2019 [IDT]; zastąpiła PN-EN ISO 13588:2013-04)

Title (PL)

Badania nieniszczące spoin — Badanie ultradźwiękowe — Stosowanie zautomatyzowanej techniki głowicy mozaikowej

Title (EN)

Non-destructive testing of welds — Ultrasonic testing — Use of automated phased array technology

Step-by-step procedure

1. Preliminary information

   Purpose and extent, testing level, acceptance criteria, reference blocks, stage, weld details and HAZ, access, surface, temperature, qualifications (5.1–5.2).

2. Written procedure and scan plan

   Mandatory at every level; the plan shows the position and movement of the probe, the coverage, the beam angles and directions, the examination volume.

3. Examination volume

   Weld + at least 10 mm on each side (5 mm for laser and electron beam welds) or the HAZ — whichever is greater.

4. Checking the setup

   On a reference block (7.2 and 9.3); WE DO NOT GIVE the setting of range and sensitivity (clause 9).

5. Scanning

   With an encoder, with an increment depending on the thickness (up to 10 mm — ≤ 1 mm); setups according to Table 2 for level A, B or C.

6. Data analysis and test report

   Assessment of the data quality, identification and classification of indications, position, length and height, evaluation according to the adopted criteria (clauses 14–15) — WE DO NOT GIVE the details.

Required equipment and apparatus

Health and safety (OHS)

• Scanners on objects in service (pipelines, vessels) — rules for work at height and in hazardous areas
• Testing of hot objects — temperature limits are set by the procedure (level D at temperatures outside the range)

Frequently asked questions