Double Eccentric Butterfly Valve

Double Eccentric Butterfly Valve - Liwei

Compared with the centerline butterfly valve, the double eccentric butterfly valve is more resistant to high pressure, has a longer life and good stability. Compared with other valves, the larger the caliber, the lighter the material, and the lower the cost. But because there is a butterfly plate in the middle, the flow resistance is large, so a butterfly valve smaller than DN200 is meaningless.

The double eccentric butterfly valve is further improved on the basis of the single eccentric butterfly valve. Its structural feature is that the axis of the valve stem deviates from the center of the butterfly plate and the center of the body. The double eccentric effect enables the butterfly plate to be released from the valve seat immediately after the valve is opened, which greatly eliminates unnecessary excessive extrusion and scratching between the butterfly plate and the valve seat, reduces the opening resistance, reduces wear and improves The life of the valve seat is improved. The scraping is greatly reduced, and at the same time, the double eccentric butterfly valve can also use a metal seat, which improves the application of the butterfly valve in the high temperature field.

Scenarios for double eccentric butterfly valves?

Double eccentric butterfly valves are most commonly used in underground water supply applications as an alternative to gate valves. When installed underground, butterfly valves require a lower depth of embedment and they are often more cost effective than gate valves, especially in larger sizes. They can certainly be used above ground as well.

What is the difference between double eccentric butterfly valve and triple eccentric butterfly valve, zero eccentric butterfly valve?

Double eccentric butterfly valves can be used at higher pressures than zero eccentric butterfly valves. Double offset is available in carbon steel, stainless steel, Hastelloy, and other valve body materials to ANSI Class 600 ratings, with a variety of Teflon seats and fire resistant designs with metal support seats.   

Triple eccentric valves are used in industries similar to double eccentric butterfly valves, but for more demanding applications. If you have any additional questions, please feel free to contact us! Our valve team has years of experience and would be happy to help you!