Butterfly Valve Manufacturers

Butterfly valve operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are popular because they cost less than other valve designs, and are lighter weight so they need less support. The disc is positioned in the center of the pipe. A rod passes through the disc to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. 

Unlike a ball valve, butterfly valve's closing mechanism is a disk that rotates.The disc is always present within the flow, therefore it induces a pressure drop, even when open.