초록 ▼

A subsurface well safety valve having a flow tube telescopically movable in a housing for controlling the movement of a valve closure member. A piston and cylinder assembly actuates the flow tube and is in communication with hydraulic control fluid from the well surface on one side and a gas biasing

A subsurface well safety valve having a flow tube telescopically movable in a housing for controlling the movement of a valve closure member. A piston and cylinder assembly actuates the flow tube and is in communication with hydraulic control fluid from the well surface on one side and a gas biasing chamber on the second side and includes a spring acting on the flow tube to close the valve. An equalizing system equalizes fluid pressure on opposite sides of the piston and cylinder assembly in the event of a failure in the seal between the piston and cylinder thereby allowing the spring to close the valve.

대표청구항 ▼

A subsurface well safety valve for controlling the fluid flow through a well conduit comprising, a housing having a bore, a valve closure member moving between open and closed positions for controlling the fluid flow through the bore, a flow tube telescopically moving in the housing for controlling

A subsurface well safety valve for controlling the fluid flow through a well conduit comprising, a housing having a bore, a valve closure member moving between open and closed positions for controlling the fluid flow through the bore, a flow tube telescopically moving in the housing for controlling the movement of the valve closure member, a piston and cylinder assembly positioned in the housing and one of the piston and cylinder engages the flow tube, a first side of the assembly adapted to be in communication with a fluid control passageway to the well surface, a gas chamnber in the housing in communication with the second side of the assembly acting on the assembly in a direction to close said valve, spring means between the housing and the flow tube acting on the flow tube in a direction to close said valve, seal means between the piston and cylinder, and openable and closable equalizing means for equalizing fluid pressure on opposite sides of the piston and cylinder assembly in the event of a failure in the seal means thereby allowing the spring means to close the valve.