High performance butterfly valve is also called double offset butterfly valve, which is mainly used in water plant, power plant, steel plant smelting, chemical industry, water source engineering, environmental facility construction and other systems for drainage, especially for the use of oil pipeline and road as regulating and intercepting equipment. Compared with the concentric butterfly valve, the double eccentric butterfly valve is more resistant to high pressure, longer life and good stability. The larger the diameter, the lighter the material, the lower the cost compared to other valves. However, due to the butterfly plate in the middle and high flow resistance, the butterfly valve smaller than 8 inches is of little significance. Double offset butterfly valves are further improved on the basis of single eccentric butterfly valves.The structure is characterized by deviation from center of butterfly plate and center of body at stem axis.The double eccentricity effect makes the disc rapidly disengage from the seat after the valve is opened, greatly eliminating unnecessary over-extrusion and scraping of disc and seat, reducing the opening resistance, reducing wear and improving the seat life.The sharp reduction of scraping also enables the double eccentric butterfly valve to use metal seat, which improves the application of butterfly valve in the field of high temperature.