How does a pneumatic control valve work?

Pneumatic control valve is one of the most commonly used control valves, which uses compressed air to manufacture power. It is convenient and simple to use, so it is widely loved by the public. Below, the editor will take a look at its working reasons and classification.





The operation of any machine requires power, some of which is external fuel power, while others use energy conversion to achieve the effect of obtaining power. The valve of the machine is one of the tools that uses energy conversion to make the machine operate. Among them, pneumatic valve is a device that uses compressed air to drive machines, with a sophisticated principle.





Working principle of pneumatic control valve:





Pneumatic control valve refers to a type of valve that uses a gas source as power source, a cylinder as an actuator, a 4-20mA signal as a driving signal, and accessories such as electrical valve positioners, converters, solenoid valves, and holding valves to drive the valve. The valve is adjusted to achieve linear or equal percentage flow characteristics, thereby achieving on/off or proportional control of various process parameters such as flow rate, pressure, and temperature of the pipeline medium.





Pneumatic control valves have the advantages of simple control, fast response, and intrinsic safety, and do not require additional explosion-proof measures when used in flammable and explosive environments.





Pneumatic control valves are usually composed of pneumatic actuators and control valves connected, installed, and debugged. Pneumatic actuators can be divided into single acting and double acting types. Single acting actuators have a reset spring inside, while double acting actuators do not have a reset spring inside. The single acting actuator can automatically return to the initially set open or closed state of the valve in the event of loss of origin or sudden failure.





Pneumatic control valves are divided into two types based on their action form: normally open and normally closed. The pneumatic opening or closing of pneumatic control valves is usually achieved through the positive and negative action of the actuator and different assembly methods of the valve state structure.