Description

A butterfly valve is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they are lower in cost to other valve designs as well as being lighter in weight, meaning less support is required.

• A butterfly valve is from a family of valves called quarter-turn valves.

• In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod.

• When the valve is closed, the disc is turned so that it completely blocks off the passageway.

• When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid.