Xiamen Kemus Valve Co.,Ltd
Add: 5 floor, Zhimingxing Technology Building No 18, Honglian West Road, Siming District Xiamen China
Concentric butterfly valves – this type of valve has a resilient rubber seat with a metal disc.
Doubly-eccentric butterfly valves (high-performance butterfly valves or double-offset butterfly valves) – different type of materials is used for seat and disc.
Triply-eccentric butterfly valves (triple-offset butterfly valves) – the seats are either laminated or solid metal seat design.
Wafer-style butterfly valve
The wafer style butterfly valve is designed to maintain a seal against bi-directional pressure differential to prevent any backflow in systems designed for unidirectional flow. It accomplishes this with a tightly fitting seal; i.e., gasket, o-ring, precision machined, and a flat valve face on the upstream and downstream sides of the valve.
Lug-style butterfly valve
Lug-style valves have threaded inserts at both sides of the valve body. This allows them to be installed into a system using two sets of bolts and no nuts. The valve is installed between two flanges using a separate set of bolts for each flange. This setup permits either side of the piping system to be disconnected without disturbing the other side.
A lug-style butterfly valve used in dead end service generally has a reduced pressure rating. For example, a lug-style butterfly valve mounted between two flanges has a 1,000 kPa (150 psi) pressure rating. The same valve mounted with one flange, in dead end service, has a 520 kPa (75 psi) rating. Lugged valves are extremely resistant to chemicals and solvents and can handle temperatures up to 200 °C, which makes it a versatile solution.
Rotary valves constitute a derivation of the general butterfly valves and are used mainly in powder processing industries. Instead of being flat, the butterfly is equipped with pockets. When closed, it acts exactly like a butterfly valve and is tight. But when it is in rotation, the pockets allow to drop a defined amount of solids, which makes the valve suitable for dosing bulk product by gravity. Such valves are usually of small size (less than 300 mm), pneumatically activated and rotate 180 degrees back and forth.