Patent attributes
Valves having seats and counterseats that can be moved by fluid within the valve. In one embodiment, a valve includes a flow control assembly inside a body. The flow control assembly includes a ball rotatable between an open position and a closed position to control flow, a seat installed on the ball, and a counterseat installed in the body. The seat and the counterseat can move radially with respect to the ball and have mating surfaces that engage and seal against one another when the ball is in the closed position. The flow control assembly allows pressurized fluid in the body to cause net forces on the seat and the counterseat that push the seat and the counterseat toward each other when the ball is in the closed position. Additional valve systems, devices, and methods are also disclosed.