Ball valve

Ball valve is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball (called a "oating  ball") to control ow through it. It is open when the ball's hole is in line with the ow and closed when it is pivoted 90- degrees by the valve handle. The handle lies

at in alignment with the ow when open, and is perpendicular to it when closed, making for easy visual conrmation  of the valve's status.Ball valves are durable, performing well after many cycles, and reliable, closing securely even after long periods of disuse. These qualities make them an excellent choice for shutoff applications,

where they are often preferred to gates and globe valves, but they lack their ne control in throttling applications.