The working principle of pneumatic control valve, pneumatic control valve structure principle
Working principle of pneumatic control valve, pneumatic control valve structure principle of pneumatic control valve is refers to by air as power and cylinder as actuator, 4 ~ 20 ma signals as the drive, and by means of electric valve gate locator, converters, solenoid valve, the position to drive the valve gate valve, such as accessories, valve door linear or equal percentage flow characteristics make regulating action, so as to achieve to the pipeline medium flow, pressure, temperature and other process parameters of the switch quantity or proportion type adjustment. Pneumatic valves to control with simple, quick response, and the advantages of intrinsically safe, and use in flammable and explosive occasions, don't need another explosion protection measures. Pneumatic control valve usually are connected by a pneumatic actuators and regulating valve installation and debugging, pneumatic actuators can be divided into single acting and double acting type two kinds, single-acting actuator with reset spring, and double-acting actuators is no return spring. Including single-acting actuator, loss of origin or sudden failure, automatic homing to the initial set of valve gate open or closed. Pneumatic control valve according to the form of action points gas open type and close type two kinds, namely the so-called normally open and normally closed, pneumatic control valve of gas or air close, usually by positive and negative effects of the actuator and the valve structure of different assembly. Working principle of the pneumatic control valve, Figure) Pneumatic control valve action: open type gas ( Normally closed type) Is when the film head air pressure increases, the valve door to increase the opening direction of the movement, when to input pressure limit, the valve door in the fully open position. Reduced, in turn, when the air pressure, the valve to close the door direction of movement, when no input air valve full close the door. Despite we usually call gas regulating valve type of fault type valve door. Type gas clearance ( Normally open type) Movement direction is just the reverse of gas drive type. When the air pressure increases, the valve to close the door direction action; Air pressure decrease or not, the valve door open direction or fully open. Despite we usually said gas regulating valve closed type to open type valve gate.