First, the core test requirements of API 600 standard
1.Shell Test
Test Purpose: To verify the structural integrity of the valve body, bonnet and other pressure-bearing components.
Test Method:
Inject water into the inner cavity of the valve and pressurize it to 1.5 times the nominal pressure (e.g. 45MPa for Class 300 valve test).
Hold pressure time ≥ 10 minutes, check the valve body without permanent deformation, leakage or cracks.
Qualification standards: in line with ASME B16.34 pressure vessel code.
2.Sealing performance test
Low Pressure Seat Test:
Medium: air or nitrogen (pressure ≤ 0.6MPa).
Check the leakage between the valve seat and the gate, allow the leakage rate of ≤ 0.01 × DN mm ³ / s (such as DN100 valve leakage ≤ 1.0mm ³ / s).
High pressure sealing test (High Pressure Seat Test):
Medium: water or oil, pressurized to 1.1 times the nominal pressure.
Hold pressure for 2 minutes, requiring zero visible leakage.
3.Fire Safe Test
Test Standard: API 607/API 6FA.
Test Procedure:
Valve passes sealing test at room temperature.
Exposed to 650℃~1000℃ flame for 30 minutes.
Immediately cooled by water shock and pressurized again to test the sealing.
Passing standard: can still keep sealing after burning, leakage ≤ 10 times of the allowed value.
Special environmental testing (optional)
| Test Type |
Applicable Scenarios |
Test Standard |
| Low temperature impact test |
LNG, liquid nitrogen and other cryogenic media |
ASTM A352/A350 |
| Resistant to sulfur stress corrosion |
H₂S-containing oil and gas environment |
NACE TM0177 |
| Particle wear test |
Highly abrasive conditions with sand and slurries |
ISO 17292 |
Second, API 600 valve certification process
1.Factory audit and qualification
API Monogram License:
Authorized by the API third-party agencies (such as DNV, SGS) to audit the plant, including design capabilities, production processes, quality management system (ISO 9001).
After passing the audit, valves can be labeled with the API Monogram, demonstrating compliance with the API 600 standard.
NACE MR0175 certification: for sulfur-containing conditions, to verify the material resistance to hydrogen sulfide corrosion.
2.Product sampling test
Batch sampling test: 5%~10% of each batch of valves are randomly selected for full testing (strength, sealing, etc.).
Type testing (Type Testing): Before the first mass production of new products, they need to pass the full parameter limit test and keep records.
3.Third-party authoritative certification
International organizations:
DNV-GL (Offshore Engineering), TÜV (EU Pressurized Equipment), ABS (American Bureau of Shipping).
The scope of certification covers special performance such as fireproof, low temperature, anti-explosion and so on.
Reports and Certificates: Provide bilingual test reports in Chinese and English to support global project bidding.
API 600 Valve vs. normal valve test comparison
| Test Item |
API 600 Valves |
General industrial valves |
| Test Pressure |
1.5 times the nominal pressure, hold pressure for 10 minutes |
1.1 times the nominal pressure, hold pressure for 3 minutes |
| leakage rate |
Zero visible leakage (high pressure test) |
Tiny leaks allowed |
| Fire Test |
Mandatory requirements (API 607/6FA) |
No or selective testing |
| Material Certification |
100% batch material chemical composition and mechanical properties testing |
Sampling or supplier self-inspection |
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