D641X pneumatic flange type soft seal butterfly valve is composed of soft seal center line clamp butterfly valve and piston pneumatic actuator, piston cylinder has the characteristics of large torque and fast opening speed, and with solenoid valve can achieve perfect control of the valve. In addition, the double eccentric flange butterfly valve has compact structure, easy 90° rotary switch, reliable sealing and long service life, and is widely used in water plants, power plants, steel mills, papermaking, chemical industry, catering and other systems in water supply and drainage, as a regulation and cut-off use.