Abstract: 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.

Abstract: Valves having seats and counterseats with various contours are provided. In one embodiment, a valve includes a body and a flow control assembly inside the body. The flow control assembly includes a ball, a seat installed on the ball, and a counterseat. The ball is rotatable between open and closed positions to control flow through the body and the seat and counterseat include mating surfaces that engage when the ball is in the closed position such that the seat seals against the counterseat along the mating surfaces.

Abstract: Valves having seats and counterseats with various contours are provided. In one embodiment, a valve includes a body and a flow control assembly inside the body. The flow control assembly includes a ball, a seat installed on the ball, and a counterseat. The ball is rotatable between open and closed positions to control flow through the body and the seat and counterseat include mating surfaces that engage when the ball is in the closed position such that the seat seals against the counterseat along the mating surfaces. Further, the mating surface of the counterseat can be a concave surface, the mating surface of the seat can be a convex surface, and at least one of the mating surfaces can have a toroidal contour.

Abstract: Valves having seats and counterseats with various contours are provided. In one embodiment, a valve includes a body and a flow control assembly inside the body. The flow control assembly includes a ball, a seat installed on the ball, and a counterseat. The ball is rotatable between open and closed positions to control flow through the body and the seat and counterseat include mating surfaces that engage when the ball is in the closed position such that the seat seals against the counterseat along the mating surfaces. Further, the mating surface of the counterseat can be a concave surface, the mating surface of the seat can be a convex surface, and at least one of the mating surfaces can have a toroidal contour.