Butterfly Valve

Butterfly valve is from a family of quarter-turn valves. Butterfly valve is typically used to regulate a fluid flowing through a section of pipe. A flat circular plate is positioned in the center of the pipe. The plate has a shaft through it connected to an actuator on the outside of the valve. Rotating the actuator turns the plate either parallel or perpendicular to the flow. Unlike a ball valve, the plate is always present within the flow, therefore a pressure drop is always induced in the flow regardless of valve position.

Wafer Butterfly Valve	High Performance Butterfly Valve	Pneumatic Butterfly Valve

There are different kinds of butterfly valves, each adapted for different pressures and different usage.

The resilient butterfly valve, which uses the flexibility of rubber, has the lowest pressure rating.

The high performance butterfly valve, used in slightly higher-pressure systems, features a slight offset in the way the disc is positioned, which increases the valve's sealing ability and decreases its tendency to wear.

The valve best suited for high-pressure systems is the triple eccentric butterfly valve, which makes use of a metal seat, and is therefore able to withstand a greater amount of pressure.

Butterfly valves are relatively easy to maintain. The resilient seat is held in place by mechanical means, and neither bonding nor cementing is necessary, Because the seat is replaceable, the valve seat does not require lapping, grinding, or machine work.

Butterfly valve is also a type of flow control device, used to make regulating fluid flowing through a section of pipe.