The pneumatic regulating butterfly valve has the advantages of simple and compact structure, convenient processing, easy to manufacture large diameter, self-cleaning action, small drag coefficient and large circulation capacity. It is additionally equipped with a valve positioner, which can be controlled by input control signals (4-20mADC) and a gas source of 0.4-0.7MPa. Pneumatically regulated butterfly valves are suitable for the regulation of fluids in suspended particles and in concentrated, turbid slurry fluids. Clean media can be replaced with a valve plate with a soft seal (rubber ring, PTFE ring) to reduce leakage (up to zero leakage). The high-temperature and high-pressure working conditions can be selected by a three-eccentric hard sealing valve body. Pneumatically regulated butterfly valves are the best means of regulating flow and shutting off fluids in automated control systems. Therefore, the pneumatic regulating butterfly valve is widely applied to the pipeline of corrosive medium such as metallurgy, electric power, petroleum, chemical, air, gas, combustible gas and water supply and drainage with medium temperature â?¤550°C.