API 526 Inspection & Test Plan (ITP)
A typical stage-wise ITP / quality plan for valves supplied to API 526 — 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 526 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 526 (Flanged Steel Pressure-Relief Valves); 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 526
- Orifice designation (D through T) determines flow capacity per API 520
- Face-to-face dimensions: standardised so any manufacturer's D through T fits the nozzle piping
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 526 / 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- Set pressure test: valve must open at ± tolerance of set pressure
- Blowdown test: valve must reseat within 7–10% of set pressure
- Seat leakage test: per API 527
- Cold-differential test pressure (CDTP) accounting for back pressure and temperature correction
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 526 data sheet with orifice designation and set pressure
- ASME Section I/VIII/PTC25 certification (for boiler and pressure vessel installations)
- National Board Certification (for ASME-code vessels)
- IBR Form III-E/III-C (for steam service in India)
Final documentation review before release/dispatch.
This is a typical ITP framework populated from API 526 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 526 valves with a full ITP?
We supply API 526-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.