The ball valve uses a metal ball with a hole in the center that is sandwiched between the two seats to control the flow. With the rotation of the ball, the ball valve is capable of throttling gas and steam, especially for low flow conditions.
The ball valve does not use the handwheel, but uses a wrench to control the flow. The valve can be opened or closed by turning the wrench 90°. This operation produces the lowest pressure drop when the valve is in the fully open position.
