Ball valves consist of several parts including an outer shell (body), a ball with a hole in it, seat ring and bonnet. Ball valves are used for fast-acting application. Generally ball valves are only required to turn 90° (quarter turn) to open or shut the valves. Ball valves can be shut by turning the handle or the actuator.
Ball valves are known for bubble-tight and quick response sealing. In gas and liquid application ball valves are widely used where tight shutoff is required. Ball valves are not suitable for throttling application because the exposed seat will erode due to high flow velocity and pressure. This will eventually cause the valve to leak.
In general, there are two types of ball valves: Floating Ball Valves and Trunnion Mounted Ball Valves. Each design has its benefits and function.