API 641 Inspection & Test Plan (ITP)
A typical stage-wise ITP / quality plan for valves supplied to API 641 — 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 API 641 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 API 641 (Qualification Testing of Quarter-Turn Valves for Fugitive Emissions); 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 API 641
- 310 mechanical cycles at ambient temperature (open-close-open = 1 cycle)
- 3 thermal cycles between −29°C and +200°C (or applicable service temperature range)
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 API 641 / 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- 310 mechanical operating cycles at ambient temperature per API 641 procedure
- Thermal cycling from −29°C to +200°C (3 cycles minimum)
- Stem and body-bonnet leak measurement per EPA Method 21 at every stage
- Leak rate result reported as ppm methane-equivalent
- Final test pressure: 10% of rated pressure for leak measurement
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- API 641 type test report from accredited third-party test laboratory
- Test report must include valve design drawings, packing material specification, and leak rate data at each test stage
- Statement of qualified valve sizes and pressure classes covered by the test
- Live-loaded packing specification if specified for qualification
Final documentation review before release/dispatch.
This is a typical ITP framework populated from API 641 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.
Connected Engineering
Need API 641 valves with a full ITP?
We supply API 641-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.