~Bolt cover,structure of flip-chip balanceable pressure and light on/off operation.An oil grove is set between valve body and seal surface,which may infuse the seal grease to increase the seal capability.
Standards compliance Design and Manufacture: API 599,API 6D Face to face(end to end): API B 16.10 Flanged connection: ANSI B16.5 Butt welded end: ANSI B16.25 Test and inspection: API 598,API 6D