Sealing Ring Gasket (wellhead equipment): Standard:API 6A,ISO9001 Application:Wellhead component Type:Octagonal,Oval and ... in petroleum, wellhead products,gate valve,flange,etc. StandardApplicationshapeAPI 6A,ISO 90012000,ISO9001 2008,ANSI etccasing head,flange, gate valve, oil ... valve, chock valve, etc)3) Fitting(union, manifold,elbows),bops. Standard Sealing Ring Gasket (wellhead equipment)