A Ball Valve is like the butterfly valve, one of a family of valves called quarter turn valves that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or 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. The handle position lets you "see" the valve's position.
Ball Valves are durable and usually work to achieve perfect shutoff even after years of disuse. They are therefore an excellent choice for shutoff applications (and are often preferred to globe valves and gate valves for this purpose). They do not offer the fine control that may be necessary in throttling applications but are sometimes used for this purpose.
The body of Ball Valves may be made of metal, plastic or metal with a ceramic center. The Ball Valves is often chrome plated to make it more durable. The body of Ball Valves may be made of metal, ceramic, or plastic. The Ball Valves may be chrome plated to make it more durable.