Working principle of pneumatic control valve
Time: 2019-07-15 21:51:38 Source: Yonglong Valve Reading: zero second
Working principle of pneumatic control valve
The pneumatic control valve adopts the balance sleeve design, with small unbalanced force, large allowable pressure difference, and large guiding area of the valve core, which can improve the oscillation caused by vortex and impact and reduce damage, and is used to control various process fluids, gases and steam. Its design meets the requirements of EN and ASME standards. The valve body has S-streamline channel, small pressure drop loss, large flow, wide adjustable range, high flow characteristic accuracy, and conforms to IEC60534-2 standard.
Operating principle of pneumatic control valve:
1. The pneumatic control valve uses compressed air as the power source, air cylinder as the actuator, and electrical valve positioner, converter, solenoid valve, retaining valve and other accessories to drive the valve to achieve on-off or proportional regulation, and receives the control signal from the industrial automation control system to complete the regulation of various process parameters such as the flow, pressure, temperature of pipeline media. The pneumatic control valve is characterized by simple control, fast response, and intrinsically safe, so no additional explosion-proof measures are required.
2. The action of pneumatic control valve is divided into air open type and air close type. Air to Ope means that when the air pressure on the diaphragm head increases, the valve acts in the direction of increasing opening. When the upper limit of input air pressure is reached, the valve is fully open. Conversely, when the air pressure decreases, the valve acts in the closing direction. When no air is input, the valve is fully closed.
3. Therefore, sometimes air to open valves are also called fail to close FC. The action direction of the air to close type is just opposite to that of the air to open type. When the air pressure increases, the valve acts in the closing direction; When the air pressure decreases or does not exist, the valve shall be turned to the opening direction or fully opened. Therefore, it is sometimes called Failto Open FO. The air opening or air closing of the pneumatic control valve is usually realized by the positive and negative action of the actuator and the different assembly methods of the valve state structure.
[Recommended reading] / TECHNICAL ARTICLES
