1. Standard positioning and applicable objects
API 607: Fire protection test standard for 1/4 turn valves (such as ball valves, butterfly valves) and non-metallic seat valves, verifying the sealing performance and structural integrity under fire environment; Applicable valve types include valves with soft seals such as rubber and PTFE. API 608: Design and manufacturing standards for metal ball valves, focusing on sealing, material strength and operating performance under normal working conditions; Applicable only to all-metal sealed ball valves with floating ball or fixed ball structures.
2. Test requirements and performance verification
| Features | API 607 | API 608 |
|---|---|---|
| Core Verification Content | Fire resistance (leakage control under 650℃~1,000℃ flame) | Sealing, strength and opening and closing life under normal temperature conditions |
| Sealing structure requirements | It is necessary to design a fireproof and anti-static structure. After a fire, the metal seal will automatically replace the failed soft seal. | Only metal hard sealing performance is required, no fireproof redundant design |
| Test Medium | Gas/liquid dual-phase medium testing in simulated fire environment | Normal temperature gas or liquid medium test |
3. Application scenarios and industry adaptation
API 607 applicable scenarios:
High-risk flammable and explosive environments such as oil and gas pipelines and chemical plants;
LNG storage and transportation, and diversion control valves for refining units that require fire protection certification.
API 608 applicable scenarios:
General industrial pipeline systems (such as ASME B31.3 process pipelines);
Medium cutoff control under low pressure and normal temperature conditions (DN≤24, Class≤800).
4. Design and selection differences
Structural design:
API 607 valves must have built-in fireproof graphite packing and anti-static springs;
API 608 valves emphasize all-metal hard seals (such as Stellite alloy) and outlet sealing structures.
Certification process:
API 607 needs to pass the flame simulation test of a third-party laboratory, and the size and pressure level covered require multi-specification prototype verification;
API 608 certification focuses on factory production system audits and routine performance sampling.