Working principle: use compressed air to drive the movement of multiple groups of combined pneumatic pistons in the actuator, transmit the force to the beam and the internal curve track, drive the hollow spindle to rotate, and the compressed air is delivered to each cylinder by air disk, change the air inlet and outlet position to change the rotation direction of the spindle. According to the requirements of the rotation torque required by the load (valve), the number of cylinder combinations can be adjusted to drive the load (valve) to work.
The two-position five-way solenoid valve is usually used together with the double-acting pneumatic actuator. The two-position five-way solenoid valve is controlled in two positions: on-off. The five-way solenoid valve has five channels for ventilation, one of which is connected with the air source, two of which are connected with the inlet and outlet of the external air chamber of the double-acting cylinder, and two of which are connected with the inlet and outlet of the internal air chamber. For the specific working principle, please refer to the working principle of the double-acting pneumatic actuator. As there are more and more control methods and means, there are many methods used to control pneumatic actuators in actual industrial production and industrial control, including the following.
Intelligent display：
The intelligent display instrument is used to monitor the working state of the valve and control the operation of the valve during the execution period. It monitors the working state of the valve through two position sensors, judges whether the valve is in the open or closed state, records the number of the valve switch through programming, and has two 4~20mA outputs corresponding to the valve opening and two normally open and closed output contacts. These output signals control the opening and closing action of the valve.
Control system：
PLC is more and more widely used in the control system. Because this scheme is developed on OMRON PLC, OMRON PLC is introduced.
Hardware composition: 1 computer, 1 set of PLC (including CPU, I/O module, ID212, OC224, AD003 module), 2 relays, 2 solenoid valves, 1 pneumatic valve actuator.
General requirements：
1. The specifications and types of pneumatic valves produced shall meet the requirements of the pipeline design documents.
2. The model of pneumatic valve shall be indicated with the national standard number requirements. If it is an enterprise standard, the relevant description of the model shall be indicated.
3. The working pressure of the pneumatic valve shall be ≥ the working pressure of the pipeline. The working pressure that the valve can bear shall be greater than the actual working pressure of the pipeline without affecting the price; Any side of the pneumatic valve shall be able to bear 1.1 times of the valve working pressure without leakage when it is closed; When the valve is open, the valve body shall be able to withstand twice the valve working pressure.
4. The manufacturing standard of pneumatic valve shall specify the national standard number. If it is an enterprise standard, the enterprise document shall be attached to the purchase contract.
