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- API 598 — Valve Inspection and Testing
- API 598 — Valve Inspection and Testing
API 598 — Valve Inspection and Testing
The test standard behind every pressure test on the line. Shell test, seat test, backseat test — and the leakage rates that decide whether a valve actually counts as tight.
API 598 defines the hydrostatic shell test, the hydrostatic and pneumatic seat tests, the backseat test and the air-low-pressure seat test, together with the allowed leakage rates for each. It is the standard referenced by API 600, API 602, API 603 and API 6D for the pressure testing they require.
The detail that matters commercially is the seat leakage acceptance. API 598 sets different rates for resilient-seated and metal-seated valves, and the difference is large. If a piping class asks for metal-seated leakage rates on a resilient-seated valve — or the reverse — the test result will not be what the buyer expected.
We test to API 598 by default and issue a test report per valve or per batch as specified. Third-party witnessed testing to API 598, API 6D Annex or a project-specific procedure is available.
Coverage
- Hydrostatic shell test
- Hydrostatic and pneumatic seat test
- Backseat test on OS&Y valves
- Air low-pressure seat test
- Leakage acceptance rates by seat type
- Per-valve or per-batch reporting
Related standards
Send the piping class, not the part number
We check the dimensions, the material and the standard before we price — which is the part that decides whether the valve actually fits. RFQ answered within one working day.