ASME B31.8 Inspection & Test Plan (ITP)
A typical stage-wise ITP / quality plan for valves supplied to ASME B31.8 — 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 B31.8 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 B31.8 (Gas Transmission and Distribution Piping Systems); the tests and documents are drawn directly from the standard's requirements. Use it to structure your QAP or coordinate third-party inspection.
1. Documentation & design review
Review- Approval of drawings, datasheets and QAP against ASME B31.8
- Mainline block valves required at specific intervals depending on location class (urban vs. rural) - typically 7.5-mile maximum spacing in HCA Class 3/4 areas
- Manual or automated (ESD) emergency shutoff valves (ESV) at pipeline sections, compressor stations, and high-consequence areas
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 B31.8 / 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- Valve testing per API 598 or ISO 5208 required at manufacture
- Field hydrostatic test of new pipeline: 1.25–1.5× MAOP depending on location class
- Leak survey by walking or aerial survey required after commissioning
Primary hold point — witnessed shell, seat and backseat tests.
6. Marking, painting & preservation
Review- Nameplate & body marking verification
- Painting/coating DFT check, end protection and preservation
7. Final documentation
Hold- EN 10204 3.1 MTCs for body, bonnet, stem, and pressure-containing parts
- API 598 or ISO 5208 pressure test certificate
- Certificate of conformance to API 6D or ASME B16.34
- Actuator torque certification (if motorised or pneumatic ESD valve)
Final documentation review before release/dispatch.
This is a typical ITP framework populated from ASME B31.8 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.
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Need ASME B31.8 valves with a full ITP?
We supply ASME B31.8-compliant valves with a project-specific ITP, in-house QC and third-party inspection (SGS, BV, TUV, DNV) coordination — hold and witness points accommodated. Get a 24-hour quote.