We know that pneumatic control valves are composed of pneumatic actuators and regulating valves, so the selection of pneumatic control valve types generally includes actuators and valves.The driving mode of the actuator generally has pneumatic, electric and hydraulic these three, the three driving methods also bring different characteristics to the actuator, the choice of pneumatic control valve actuator is naturally pneumatic actuator, this actuator is compressed gas as energy, can be divided into single-acting and double-acting two types, with simple structure, safe and reliable characteristics.The choice of pneumatic control valve types is straight-through single-seat, straight-through double-seat, angular, diaphragm, small flow, tee, eccentric rotation, butterfly, sleeve, spherical, etc. When making a specific choice, the following considerations can be made: 　　 　　

1. Valve core shape structureIt is mainly considered according to factors such as the selected flow characteristics and unbalance force.

2. Abrasion resistanceWhen the fluid medium is a suspension containing a high concentration of abrasive particles, the internal material of the valve should be hard.

3. Corrosion resistanceDue to the corrosive nature of the medium, try to choose valves with simple structures.

4. Temperature and pressure of the mediumWhen the temperature and pressure of the medium are high and the change is large, the material of the valve core and valve seat should be selected to change the valve with little temperature and pressure, and a radiator should be added when the temperature ≥ 250 °C.

5. Prevent flash and cavitationFlash and cavitation are only produced in liquid media. In the actual production process, flash and cavitation will form vibration and noise, shortening the service life of the valve, so flash and cavitation of the valve should be prevented when selecting the valve.Pneumatic control valve is a kind of control valve, in the field of industrial automation control plays a very important role, the main role is to adjust the pressure, flow, temperature and other parameters of the medium, is an indispensable control element in the process loop.