Wafer Type Butterfly Valve and Lug Type Butterfly Valve
Wafer Type Butterfly Valve
Wafer type butterfly valve is the most economical version and it is sandwiched between two pipe flanges and the flange bolts surround the valve body. The pipe flanges are connected through long bolts that cross the entire valve body. The sealing between the valve and pipe flanges 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. This type of connection is designed for sealing against bi-directional differential pressures and to prevent backward flow in systems designed for universal flow.
Lug Type Butterfly Valve
Lug type butterfly valve has threaded lugs outside the valve body. Two sets of bolts connect pipe flanges to each side of the bolt inserts without nuts. This design enables the disconnection of one side without affecting the other for dead-end service. Lug type butterfly valves used in dead end service generally have a lower pressure rating. The lug type butterfly valves, unlike the wafer-style, carry the weight of the piping through the valve body.
Wafer and Lug butterfly valves have own advantages and disadvantages
- Wafer type butterfly valve is less expensive than a lug type butterfly valve.
- Wafer type butterfly valve do not transfer the weight of the piping system directly through the valve body. The lug-style butterfly valves, unlike the wafer-style, carry the weight of the piping through the valve body.
- Lug type butterfly valve allows dead-end service or removal of downstream piping. Lug type design is preferred if a valve may be required to remain in place in closed position on removal of the pipe on one side for a temporary operation, it must be flanged for bolting to a pipe flange on the other side.
Wafer and Lug butterfly valves supplier and manufacturer
China VALTECCN valve is a professional manufacturer of industrial butterfly valves, which can provide various wafer and lug butterfly valve catalogs, pictures, prices, dimensions, drawings.