Ball Valve

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 hole or port,through the middle so that when the port is in line with both ends of the valve, flow willoccur. When the valve is closed the hole is perpendicular to the ends of the valve, and flow is blocked. The handle will be inline with the port position letting you “see” the valve 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. They do not offer the fine control that may be necessary in throttling application