Butterfly valves are simple yet versatile valves. They are quarter turn operated valves which are commonly used in multiple industries for varied applications. Quarter turn operation ensures quick operating of the valve. In the open condition there is minimum obstruction to the fluid flow through the valve as the flow passes around the disc aerodynamically. This results in very low pressure drop through the valve. Due to its unique mode of operation, the valve can be actuated easily without requiring high torques and wear and tear.
Butterfly valves work similarly to ball valves, rotating the handle, either manually or with an actuator, turns the disc perpendicular or parallel to the flow of the fluid. Butterfly valves can also be used for regulating flow by adjusting the lever and keeping a close eye on the desired output flow. Due to lack of friction, use of bulky actuators can be avoided.
Another advantage offered by butterfly valve is their compact size. The valve is quite compact, resembling a metal disc. This makes their installation very easy. They can be used to handle slurries and fluids with suspended solids as there are no cavities for deposition of solid particles inside the valve body. Butterfly valves are less expensive and generally lighter weight than other types of valves. A butterfly valve for a large diameter pipe is much smaller than its ball valve equivalent. Butterfly valves, like ball valves, operate with a 1/4 turn. They are generally used for handling large flows of gases or liquids, including slurries, but should not be used for throttling for extended periods of time. They are used as throttling valves to control flow. Butterfly valves offer a rotary stem movement of 90 degrees or less in a compact design. Unlike ball valves, butterfly valves do not have pockets in which fluids and gas may become trapped when the valve is closed.