ASME B31.12
Inspection & Test Plan

ASME B31.12 Inspection & Test Plan (ITP)

A typical stage-wise ITP / quality plan for valves supplied to ASME B31.12 — inspection activities, tests, acceptance references and verifying documents, with recommended hold, witness and review points for QC and third-party inspection.

What is the ITP for ASME B31.12 valves?

An Inspection & Test Plan (ITP) sequences every check between raw material and dispatch, and assigns each an inspection level — Review (document check), Witness (inspector may attend), or Hold (work stops until released). The plan below is a typical ITP for valves built to ASME B31.12 (Hydrogen Piping and Pipelines); the tests and documents are drawn directly from the standard's requirements. Use it to structure your QAP or coordinate third-party inspection.

Inspection level:ReviewWitnessHold

1. Documentation & design review

Review
  • Approval of drawings, datasheets and QAP against ASME B31.12
  • Material restrictions: carbon steels are limited by hydrogen embrittlement - specific grades and yield strength limits apply (e.g., max 70 ksi minimum yield for pipelines)
  • Preferred materials: austenitic stainless steel (SS 316L), nickel alloys - immune to hydrogen embrittlement at ambient temperature

2. Raw material verification

Review
  • Material Test Reports (MTRs) review per EN 10204 3.1/3.2
  • Positive Material Identification (PMI) of pressure-containing parts

3. Dimensional inspection

Witness
  • Dimensional check per ASME B31.12 / ASME B16.34 / applicable face-to-face
  • Wall thickness verification

4. NDE (as applicable)

Witness
  • Visual, and RT/UT/MPI/DPT of castings/welds per specification

5. Pressure & performance testing

Hold
  • Hydrostatic shell test: 1.5× design pressure, per ASME B16.34
  • Seat leakage test: per API 598 (Class A bubble-tight preferred for hydrogen)
  • Fugitive emission test: ISO 15848-1 Type Testing Class A (≤50 ppm methane equivalent)
  • Fire-safe type test: API 607 or API 6FA qualification
  • Low-temperature testing if cryogenic hydrogen (LH2) service

Primary hold point — witnessed shell, seat and backseat tests.

6. Fire-type test (qualification)

Hold
  • Fire test per API 607 / API 6FA with post-fire leakage acceptance

7. Marking, painting & preservation

Review
  • Nameplate & body marking verification
  • Painting/coating DFT check, end protection and preservation

8. Final documentation

Hold
  • Material test reports (EN 10204 3.1 or 3.2) with confirmation of hydrogen service suitability
  • Hardness test results for all pressure-containing parts (≤22 HRC per NACE if specified)
  • API 607 fire-safe type test certificate
  • ISO 15848-1 fugitive emission type test certificate
  • Dimensional inspection report to applicable dimensional standard (ASME B16.34, API 6D)

Final documentation review before release/dispatch.

This is a typical ITP framework populated from ASME B31.12 requirements, for reference. The actual hold/witness/review split is agreed per project between purchaser, manufacturer and the third-party inspection agency in the approved QAP. Confirm project-specific requirements before use.

Reviewed by Valve Standards Engineering, Vajra Industrial SolutionsDiscipline: Industrial Valve Standards & ComplianceLast reviewed: 20 June 2026

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