Pneumatic cut-off valve, also known as pneumatic cut-off valve, which is a kind of actuator in automation system, is composed of multi-spring pneumatic thin film actuator or floating piston actuator and regulating valve. It receives the signal from regulating instrument and controls the fluid in process pipe Cut, switch on or switch. Has a simple structure, responsive, reliable and so on. Pneumatic cut-off valve can be widely used in petroleum, chemical, metallurgical and other industrial sectors. The pneumatic source of the shut-off valve requires filtered compressed air and the medium flowing through the valve body should be free of contaminants and particle-free liquids and gases. According to the allowable pressure difference, medium characteristics and process pipe requirements, single seat, sleeve and tee can be used. According to the pressure conditions, the shut-off valves with nominal pressure PNl.6Mpa, PN4.0Mpa and PN6.4Mpa can be selected; According to the media anti-corrosion requirements and pressure levels, the choice of cast iron, cast steel, cast stainless steel, cast steel and other materials cut off valve; According to the medium temperature and special requirements, the choice of standard, high temperature (heat) Set of insulation-type shut-off valve; According to media leakage and safety considerations, the choice of hard seal, soft seal, bellows seal off valve; According to process control requirements, can be equipped with the following accessories: hand wheel mechanism, air filter pressure reducer , Rapid exhaust valve, solenoid valve, travel switch.