Butterfly Valves

Butterfly valves in wafer and lug bodies, lever or worm gear operated, with a choice of cast iron or stainless steel disc. A wafer body is clamped between two flanges and is the usual way to isolate a larger line; a lug body is tapped, so the pipework downstream can be removed while the valve still holds pressure on the upstream side. From around six inches a worm gear is worth having instead of a lever, both for effort and for the control it gives on closing. Specify size, disc material, the liner elastomer to suit the medium, flange standard and operation: lever, gear or actuator.