The frequency of malfunction of solenoid valves in production sites is not high, and the main faults are mostly caused by poor quality of the control medium or control gas source of the solenoid valve. Generally, the following situations inside the solenoid valve are the reasons that hinder its normal operation and shorten its service life: (1) changes in the medium during use; (2) Rust inside the takeover; (3) The oil oxidation of the air compressor produces impurities such as carbon particles and tar, which mix into the pipeline, or there are impurities such as dust particles and dirt in the pipeline, causing blockage of the solenoid valve pilot valve pneumatic control or jamming of the valve core; (4) The solenoid valve coil has been charged for a long time and burned out.
Therefore, regular maintenance 1-2 times a year is the best method for the reliable operation and longevity of solenoid valves. Taking advantage of equipment downtime, the following inspection and maintenance work should be carried out on solenoid valves: (1) The solenoid valve coil components should not be disassembled. The inspection method for coils is mainly to measure the coil resistance value and establish an original ledger. Coils with coil resistance values that deviate significantly from the same type of solenoid valve standards should be replaced to avoid misoperation; (2) For the solenoid valves of the ash removal system and turbine oil system, due to operating environment or oil quality issues, the valve core is prone to jamming. Regular disassembly of the solenoid valve as a whole should be carried out and cleaned with solutions such as kerosene and trichloroethylene. However, attention should be paid to the possibility of rubber parts swelling, so they should be replaced.
It should be noted that solenoid valves are generally equipped with manual screws. When the solenoid valve needs to be tested or malfunctions, it can be used to force the moving iron core of the solenoid valve to change its working state. When the solenoid coil is not charged, the air path of the solenoid valve can be switched by operating the manual screw of the solenoid valve to open or close the controlled object. But if manual switching is performed, the manual screw of the solenoid valve must be switched to the "off" position, otherwise when the control device is switched to electric control, the solenoid valve will not be able to operate. This principle is like a dual electric control solenoid valve. If the direction coil is energized, the manual screw of the solenoid valve cannot be manually operated to open and close it, just like the solenoid valve manufacturer.
