Working Principle Of Pneumatic Valve
The working principle of Ball Valve is as follows:
1. The pneumatic control valve uses compressed air as the power source, the cylinder as the actuator, and uses accessories such as electrical valve positioners, converters, solenoid valves, and position-holding valves to drive the valve to achieve switch quantity or proportional regulation, and receive control signals from industrial automation control systems to adjust the flow, pressure, temperature and other process parameters of the pipeline medium. The characteristics of pneumatic control valves are simple control, fast response, and inherent safety, without the need to take additional explosion-proof measures.
2. The action of pneumatic control valves is divided into air-open type and air-close type. Air-open type (Air to Open)
When the air pressure on the membrane head increases, the valve moves in the direction of increasing the opening. When the upper limit of the input air pressure is reached, the valve is in a fully open state. Conversely, when the air pressure decreases, the valve moves in the closing direction. When there is no input air, the valve is fully closed.
3. Therefore, sometimes the air-open valve is also called the fault-closed type (Fail to Close FC). The action direction of the air-closed type (Air to Close) is exactly opposite to that of the air-open type. When the air pressure increases, the valve moves in the closing direction; when the air pressure decreases or disappears, the valve moves in the opening direction or fully opens. Therefore, it is sometimes called Fail to Open FO. The air opening or air closing of the pneumatic control valve is usually achieved through the positive and negative effects of the actuator and different assembly methods of the valve state structure.
