The lug type butterfly valve in ductile iron, Carbon steel or stainless is available with various seal options from Buna, EPDM, Teflon or Metal Faced. Handle or wheel options are available. Additional mounting of actuator limit switches Andy gear boxes are optional. A wafer butterfly valve’s function is to retain a seal to protect against dual-directional pressure differential in the flow of fluid. In other words, the wafer version of butterfly valves was designed to hold a tight seal, safeguarding against bi-directional pressure differential in order to avoid any backflow in systems that have been manufactured for uni-directional flow. This is accomplished by using a tightly fitted seal, such as an O-ring, gasket, precision machined, along with a flat valve face on the downstream and upstream sections of the valve.

Wafer Soft Seal Butterfly Valve uses the flexibility of rubber seat, could easily achieve zero leakage, Wafer type is the common style of butterfly valve and is less expensive than the lug type. The wafer butterfly valve is installed between two flanges. The valve is kept in place by using bolts or studs and nuts from flange to flange. This type of installation, of course, makes it impossible to disconnect just one side of the piping system from the valve.