A ball valve is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball to control flow through it. Therefore, it is a shut-off valve that controls the flow of a liquid or gas by a rotary ball having a bore. It is open when the ball’s hole is aligned with the flow and closed when it is pivoted 90-degrees by the valve handle.  Therefore, the handle lies flat in alignment with the flow when open and it is perpendicular when closed. Ball valves are exceptionally durable and perform well after many cycles. Consequently, these qualities make them a superior choice for shutoff and control applications, where they are often preferred to gates and globe valves.

 A ball valve is a valve with a spherical disc, the part of the valve which controls the flow through it. The sphere has a port through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. Ball valves are durable and usually work to achieve shutoff even after years of disuse. They are therefore an excellent choice for shutoff applications. They do not offer the fine control that may be necessary in throttling applications but are sometimes used for this purpose.