api5000Surface, Underwater Safety, and Boarding Shutdown Valves Background Products covered by API 6A include surface safety valves (SSV), underwater safety valvesWe are a API 6A flange manufacturer,API 6A Type 6B 5000 psi(34.5 MPa) Weld Neck RTJ Flange,API 6 B 3000 psi WN RTJ Flange,API 6BX 10000 PSI Weld Neck Flange,API weld neck flange