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