API 624

Applies to: Rising-stem valves (gate, globe, stop-check) with flexible graphite packing in hydrocarbon and VOC service where fugitive emissions compliance is required; ISO 15848-1 Class A/B equivalent certification; valves purchased under LDAR regulatory requirements (EPA 40 CFR Part 60/63).

Does NOT cover: Quarter-turn or rotary valves (use API 641); production acceptance testing of individual valves (type test only); valves with non-graphite packing without separate qualification.

• 610-cycle mechanical endurance test at ambient temperature
• Thermal cycling: −29 °C to 200 °C (−20 °F to 392 °F) for standard range
• Test medium: methane at 1 bar(g) ± 0.1 bar
• Emission class limits: Class A ≤ 50 ppm(v), Class B ≤ 100 ppm(v), Class C ≤ 500 ppm(v)
• Static body joint leakage test
• Testing by accredited third-party laboratory

API 624 is the primary US type-test standard for rising-stem valve fugitive emissions, reflecting LDAR regulatory requirements under EPA 40 CFR Part 60 and 63 and equivalent state VOC rules. Refinery and chemical plant purchase specifications routinely require API 624 Class A certification for all process valves in hydrocarbon service.

Engineering note: Type certification is granted for a specific valve design and packing combination. Any change in packing material, stem diameter, packing box depth, or valve trim requires re-testing. Engineers reviewing MSDS/SDS of replacement packing materials should verify that the packing system is within the scope of the existing type test certificate before approving packing box re-packing.