Common Fault Analysis and Daily Maintenance of Pneumatic Ball Valve
Pneumatic ball valveDuring the installation and maintenance of pneumatic ball valves, the following points should be paid attention:
1. check the air source treatment device, check whether the filter, pressure reducing valve and oil mist device are normal, and investigate whether the pressure is 3-8kg;
2. investigate whether the pneumatic actuator leaks, especially at the joint of the valve stem and the two end caps;
3. check whether the solenoid valve is operating normally and whether there is air leakage;
4. check whether the locator operation is normal and whether there is air leakage;
5. check whether the fixing screws of all connecting parts are tight;
6. try to prevent too much floating ash from covering the actuator, and keep the operating environment clean in the market.
Pneumatic ball valve common fault cause analysis:
1. pneumatic ball valve has no response signal
The signal line of the pneumatic ball valve consists of a pair of control signal lines and a pair of reaction signal lines. When the PLC gives a signal to the valve, the signal is converted in the positioner of the regulating valve, and the valve stem is controlled by the air source pressure. The stroke of the valve stem transmits the opening of the valve through the reaction signal of the regulating valve.
If the pneumatic ball valve does not respond to the signal, use a multimeter to check whether there is voltage at each contact. To check whether the line connection is correct, check whether the signal line is damaged, and check whether the signal line is loose.
2. valve cannot be closed to zero position
The valve cannot be closed to the zero position. First, the practice is closed to the zero position, but the response indication is not. This is a signal problem and can be handled by adjusting the positioner;
Second, the practice is not tight. It may be that the valve sealing gasket is damaged or the rolling joint of the valve stem is blocked. Therefore, it is necessary to remove the valve body and contact the pneumatic ball valve manufacturer to replace the sealing gasket and add lubricating oil to the rolling joint so that it can operate normally.