Butterfly Valve
A butterfly valve is used to regular flow through a pipe. The closing mechanism is a metal disk attached through its central axis to a vertical shaft. The rotation of the shaft moves the disk through the disk's vertical axis thereby opening or closing the pipe.
Butterfly valves are not recommended for reticulation mains <=DN 600 because they make swabbing operations difficult.
These valves come in standard, double eccentric and triple eccentric butterfly valve configurations.