Products
Flange Style Double offset Butterfly Valve-Metal Seat
Actuator type: Worm Gear
End Connection: Flange
Stem position: Double Offset
Body Materials: cast steel, stainless steel
Seat Material: stainless steel
Pressure: PN 10 / PN 16/PN25/PN40
Suitable temperature：– 10 ~ 80℃
Disc type: Ductile Iron
Size Range: DN150-DN2000
Design standards: EN593
Face to Face dimension: EN 558-1, Series 14/ISO 5752, Series 14/ISO 5752, Series 13
Flange standard: EN1092/BS4504 (DIN2501) ASME B16.5 Class 150
Applicable medium: Industrial water, Sewage, Low Corrosive Liquids
Product Details
The double eccentric butterfly valve belongs to the family of the offset butterfly valves. This valve has two stems offset from the center:
The axis of the shaft is behind the centerline of the sealing point of the disc to the seat.
The axis of the shaft is eccentric to the center of the valve/pipeline.
This design creates a cam action during operation to lift the seat out of the seal and reduce the friction during the first 10 degrees of opening and final 10 degrees of closing. Thus, compared with the zero offset butterfly valve, this double offset butterfly valve offers longer life by reducing contact between valve, discs, and seats. For this reason, the double eccentric butterfly valve is ideal for operations that involve high pressures and particulate fluids.
For these applications, the flange connection and lug connection are more suitable as they offer a more firm and steady connection for high-pressure applications.
In terms of the types of the seat design, there are Metal Seated Offset Butterfly Valve and Soft Seated Offset Butterfly Valve: compared with rubber lined butterfly valve, the metal seat double offset butterfly valve withstands a higher temperature and pressure.
Specifications