US Patent 9915359 Double piston effect lip seal seating assemblies

A valve including a double piston effect seat assembly with unidirectional lip seals is provided. In one embodiment, a valve includes a ball disposed in a cavity of a hollow valve body. The ball includes a flow port and is rotatable to control flow through the valve. The valve also includes a seat assembly having a seat in contact with the ball, a ring positioned on an opposite side of the seat from the ball, and unidirectional lip seals. The seat assembly is a double piston seat assembly, with the double piston effect provided by the arrangement of the seat, the ring, and the unidirectional lip seals. Additional valve systems, devices, and methods are also disclosed.