Double Eccentric Butterfly Valves sourcingAbout Double Eccentric Butterfly Valves
High-performance double eccentric butterfly valves in wafer and lug patterns, DN50 to DN1200, ASME Class 150 and 300, with RTFE, PTFE or fire-safe seats.
A double eccentric (double offset) butterfly valve, widely called a high-performance butterfly valve, mounts its shaft behind the disc sealing plane and offset from the pipe centreline. The two offsets create a cam action that lifts the disc off the seat almost immediately on opening, so the seat is not rubbed through the stroke as it is in a concentric valve. This allows harder seat materials, higher pressures and temperatures, and long cycle life. Indian manufacturers commonly supply wafer and lug bodies in WCB carbon steel, CF8, CF8M and duplex, ASME Class 150 and 300 or PN 16 to PN 40, with RTFE, PTFE, metal or fire-safe seats certified to API 607. Typical duties are steam, thermal fluids, hydrocarbons, chemicals and gas, replacing gate and globe valves where weight and space matter. Design and testing follow API 609 Category B, EN 593, ASME B16.34 and API 598, with face-to-face to ISO 5752. An enquiry should state size, class, body pattern, body and disc material, seat type, service medium, temperature, differential pressure, operator or actuation, fire-safe requirement and quantity.
