OS&Y, Rising stem, Flexible wedge
Pressure seal bonnet, Threaded or welded seat ring
ASTM A216 WCB, A217 WC6, A351 CF8, A351 CF8M, A351 CF3, A351 CF3M, A351 CN7M

Standards compliance 
Design and Manufacture: ANSI B16.34, API 600, API 6D, BS1414
Face to face(end to end): ANSI B16.10, API 6D
Flanged connection: ANSI B16.5
Butt welded end: ANSI B16.25
Test and inspection: API 598, API 6D
A. Back up ring: Absors thrust applied by internal pressure
B. Thrust ring: Protects the soft metallic gasket from deformation
C. Gasket: Unique angular design provides superior sealing