Common failure analysis and daily maintenance of pneumatic ball valve
For the daily protection of pneumatic ball valves, the following points should be paid attention to during the installation and protection of pneumatic ball valves:
1. Check the air source treatment device, check whether the filter, pressure reducing valve, and oil mist device are normal, and check whether the pressure is 3-8kg;
2. Investigate whether there is air leakage in the pneumatic actuator, especially at the joint of the valve stem and the two end covers;
3. Check whether the solenoid valve is operating normally and whether there is air leakage;
4. Check whether the fixing screws of all connecting parts are tight;
5. Try to prevent too much floating dust from covering the actuator, and keep the operating environment clean in the shopping mall.
Analysis of common failure causes of pneumatic ball valves:
1. No response signal of pneumatic ball valve
The signal line of the pneumatic ball valve is composed of a pair of control signal lines and a pair of reaction signal lines. When PLC gives a signal to the valve, the signal is converted in the positioner of the regulating valve, and the action of the valve stem is controlled by the air source pressure. The stroke of the valve stem transmits the valve opening through the response signal of the regulating valve.
If the pneumatic ball valve does not respond to the signal, use a multimeter to check whether each contact has voltage. To check whether the line connection is correct, check whether the signal line is damaged, and check whether the signal line is loose.
2. The valve cannot be closed to the zero position
The valve cannot be closed to the zero position. First, it is closed to the zero position in practice, but there is no response indication. This is a signal problem, which can be dealt with by adjusting the positioner;
The second is that the practice is indeed not tight. It may be that the valve sealing gasket is damaged, or the valve stem is stuck in rolling at the joint. This requires the valve body to be removed during maintenance and contact the pneumatic ball valve manufacturer to replace the sealing gasket and Add lubricating oil to the rolling part to make it work normally.
