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 complete the regulation of various process parameters such as flow, pressure, and temperature of pipeline media. The characteristics of pneumatic control valves are simple control, fast response, and inherent safety, and no additional explosion-proof measures are required.
2. The pneumatic control valve has two types of action: air-open type and air-close type. The air-open type (Air to Open) is when the air pressure on the membrane head increases, the valve moves in the direction of increasing the opening, and when the input air pressure upper limit is reached, the valve is in a fully open state. Conversely, when the air pressure decreases, the valve moves in the closing direction, and 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.
