National Oilwell Varco, L.p.

James Landrith

Frank Benjamin Springett

James William Weir

Travis James Miller

Richard W Cowan

A valve for use in a hydraulic circuit to drive a piston is fluidly connected to a first actuating chamber of the hydraulic piston. The valve is piloted to close when the first chamber is pressurized. The valve vents the fluid in the first actuating chamber when the first chamber is not pressurized. The valve permits several fluid supplies connected to the chamber via check valves to be used to drive the piston. The hydraulic piston and hydraulic circuit may be implemented in a blowout preventer operating in a subsea environment to ensure safe drilling of deepwater wells.

Pilot close vent valve

Hydraulic circuits for controlling a movable component use one or more of a plurality of fluid supplies. Pressurized fluid flowing from one supply is routed toward the component and is not inadvertently vented into another fluid supply, or into an exit port. A backflow path is provided for fluid returning from the hydraulic component when the component is actuated in a reversed direction. The hydraulic circuits can be used, for example, on blowout preventers in a subsea environment.

Growing community of inventors

Humble, TX, United States of America

James Landrith