Abstract: A high pressure ball valve including a valve body with inlet and outlet ports, a ball having a passageway therethrough disposed between the ports, and seats between the ball and the ports guidably supporting the ball. Each seat includes a core of polyethersulphone having a ball engaging face with the same radius as the ball, a metal reinforcing ring, and elastomeric seals bonded to the ball engaging face and the face that seats in the valve body.

Abstract: A valve for controlling the flow of fluids of a flammable nature and under high pressure, which includes a hollow body having a plug rotatably mounted within the body between the floating seats at inlet and outlet ports with a packing plate in the bonnet capable of maintaining a seal against loss of fluids when the valve has been subjected to high temperature caused by fire.

Abstract: An expanding gate valve having seats (74) which are mechanically secured in place. The valve body has seat pockets which include undercut grooves (78) intersected by a cylindrical body cavity (24) to form a pair of openings (80) to each groove. Each valve seat has a pair of lugs (90) which may be fitted through the openings and into the undercut groove. Subsequent rotation of the seat locks the lugs in the groove to secure the seat in place in its seat pocket. Each seat is able to pivot about an axis extending between the lugs in order to compensate for irregularities in the contact surfaces of the gate or seat.

Abstract: A gate valve which is mounted on a wellhead assembly and which may be closed to shear off workover lines, macaroni tubing and other suspension members so as to quickly shut in a well under emergency conditions. The gate has a flow port which aligns with the flow passage of the valve when the gate is open. A cutting edge of the port cooperates with a corner area of the downstream valve seat to shear the suspension member when the gate is forcefully closed by a hydraulic actuator mechanism. An undercut open space is presented immediately below the cutting edge to accommodate the sheared suspension member without jamming the gate or otherwise hampering its closure function.