Wafer butterfly and check valves have no flanges of their own and are centered by the bolts or locating holes. They are light and cheap, but if one side of the line is unbolted the valve is no longer held. Lug-style bodies solve that by giving each bolt its own threaded hole, so the valve can hold pressure with the downstream pipe removed.
Don't use a wafer there, when we pull the strainer that valve has to hold the header, get a lug body.
Also heard as
- wafer body
- wafer style
Related terms
Butterfly valve
A quarter-turn valve with a disc on a shaft that rotates in the bore to open, close or throttle flow.
BFV
Butterfly valve: the clipped form used on valve tags, takeoff sheets and HVAC and fire protection drawings.
Knife gate valve
A gate valve with a thin, sharp-edged blade that cuts through slurry, pulp or solids as it closes.
Raised face
A flange facing where the gasket surface stands slightly proud of the bolt circle area, concentrating gasket load.