Which type of valve is used to control flow by allowing or stopping it?

The ball valve is utilized for controlling flow effectively by allowing or stopping it with the turn of a handle. Its design features a spherical disc (the "ball") that rotates within the valve body. When the valve is in the open position, the hole through the ball aligns with the flow direction, enabling the fluid to pass through. Conversely, when the valve is closed, the solid part of the ball blocks the flow completely. This straightforward mechanism provides reliable sealing and quick shut-off capabilities, making ball valves particularly efficient in applications where on/off control is essential.

While other types of valves, such as globe valves and butterfly valves, also serve flow control purposes, they function differently and may not provide the same quick shut-off and ease of operation as a ball valve.