Fire safe double offset butterfly valve has characteristics of super unique product structure, ultra-reliable sealing performance, ultra-wide working condition, ultra-low operation torque, long service life, safe and fireproof in special working conditions. This series of high performance double eccentric butterfly valves use a variety of structural materials, including NACE compliant and abrasion resistant. It is a special valve which is used for cryogenic, steam, chlorine, oxygen, high vacuum, corrosive medium and low temperature environments.Double eccentric butterfly valve is further improved on the basis of 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 effect of double eccentricity enables the butterfly plate to quickly detach from the valve seat after the valve is opened, which greatly eliminates unnecessary excessive squeezing and scraping between the butterfly plate and the valve seat, reduces the opening resistance, reduces wear and improves Seat life. The large reduction in scratches also allows the double eccentric butterfly valve to also use metal seats, which improves the application of butterfly valves in high temperature fields.