Liquid Penetrant Testing (PT) Requirements Under IACS UR Z17
Consumables are batch-controlled: certificates for each batch, contamination checks, and the sulphur and halogen limits where the material demands it. IACS UR Z17, enforced by International Association of Classification Societies (IACS); applied and enforced by each IACS.: Employer-based, with a third-party overlay. Under 5.2.
An auditor examining PT asks for penetrant, developer, cleaner and emulsifier batch records, plus the light meters for the inspection environment. UR Z17 sets the minimum requirements every IACS member society applies before it will accept a service supplier's results. The firm — not the individual technician — is approved. It must submit a company outline, personnel and equipment records, work procedures, training programmes, report formats and a quality manual; pass a document review; pass an on-site audit; and pass a practical demonstration of the actual service. Approval is granted per service category and per station: where a company owns several servicing stations, each is assessed and approved separately. Subcontractors performing the approved service must themselves meet Section 5. Every report issued must include a copy of the Certificate of Approval.
Source: IACS UR Z17 Rev.21, January 2025 — full 41-page text (Sections 1–9 plus Annex 1) read clause by clause from the ClassNK-hosted copy of the IACS requirement. The revision history in that text records Rev.19 and Rev.20 for uniform implementation by IACS Societies from 1 January 2026 and Rev.21 from 1 July 2026. Verified August 2026.
| Item | What applies | Why it matters |
|---|---|---|
| Regime | IACS Unified Requirement Z17 — Procedural Requirements for Service Suppliers | Enforced by International Association of Classification Societies (IACS); applied and enforced by each IACS Member class society |
| Method | Liquid Penetrant Testing (PT) | Needs its own procedure and its own qualified personnel |
| Procedure approval | The employer's Level III, qualified in this method | The signature an auditor traces |
| Other methods in scope | UT (ultrasonic thickness measurement), UT (ultrasonic tightness and leak testing), VT (close-up and remote visual), AE (acoustic emission), IRT (infrared/thermographic testing), MT | Each needs separate qualification |
| Renewal | Renewal or endorsement of the Certificate of Approval at intervals not exceeding five years by verification audit (6.2), or on expiry of the supplier's manufacturer approval where that applies, whichever comes first. For firms engaged in thickness measurements the interval must not exceed three years. Individual societies may impose shorter intervals and intermediate audits; failure to undergo a required intermediate audit is listed as grounds for cancellation under 8.2.4. | Applies to the personnel certification behind this method |
Does IACS UR Z17 require a separate procedure for PT?
Yes. Every method in scope needs its own written procedure, approved by someone qualified in that method, describing technique, equipment, calibration, scanning or coverage, acceptance criteria and reporting. A single combined "NDT procedure" covering several methods is a finding under every regime that names procedures individually.
Who can approve a PT procedure under IACS UR Z17?
A Level III qualified in PT. Because IACS UR Z17 accepts employer-based certification, that Level III may be contracted rather than employed — but their own qualification must cover PT, and an auditor will check that before accepting the signature.
What PT records does a IACS UR Z17 audit sample?
The approved procedure, the technician's PT certification on the date of work, and the equipment evidence — penetrant, developer, cleaner and emulsifier batch records, plus the light meters for the inspection environment. The auditor works backwards from a finished job, so every item has to reconcile with the report and its stated acceptance criteria.
What is the most common PT finding at audit?
Batch certificates missing for consumables used, or dwell time not recorded. It is a records failure rather than a technique failure — the examination was performed correctly and the evidence supporting it cannot be produced, which under IACS UR Z17 is recorded the same way as not having done the work.
Can a technician certified elsewhere perform PT under IACS UR Z17?
Not automatically. Employer-based certification ends when the holder leaves, so the new employer must certify them under its own written practice. Prior training and documented experience transfer as evidence; the certificate itself does not.
What equipment evidence does PT need under IACS UR Z17?
Calibration status traceable to the day of use, covering the instrument and its accessories — probes, cables, blocks and reference standards for ultrasonics; sources and densitometers for radiography. An in-calibration instrument with an out-of-calibration reference block fails the same way as an uncalibrated one.
How do PT requirements differ from the other methods in IACS UR Z17?
Scope, qualification and evidence are method-specific, so the differences are real rather than administrative. IACS UR Z17 also covers UT (ultrasonic thickness measurement), UT (ultrasonic tightness and leak testing), VT (close-up and remote visual), AE (acoustic emission), IRT (infrared/thermographic testing), and each carries its own procedure, its own personnel qualification and its own equipment evidence.
Personnel certification for PT
Employer-based, with a third-party overlay. Under 5.2.2 the supplier itself qualifies and trains its personnel to a recognised national, international or industry standard; operators need at least one year of tutored on-the-job training and supervisors at least two years' experience as an operator. For thickness measurement, Annex 1 gives EN 473 or ISO 9712 Level II for the supervisor and Level I for operators as examples of an acceptable standard. Annex 1 Section 15 names ASNT SNT-TC-1A explicitly alongside ISO 9712, but requires SNT-TC-1A holders to evidence that training was administered by an independent training body centrally certified to ASNT. An outsourced Level III can author and approve procedures and act as technical authority, but cannot replace the operator and supervisor certificates the audit inspects.
Related: the IACS UR Z17 overview, outsourced ASNT Level III cover, written practice development, NDT procedure development, a programme gap assessment, interim Level III cover.