What are the common faults of solenoid valves?

The solenoid valve is composed of a solenoid coil and a magnetic core, and is a valve body containing one or several holes. When the coil is energized or de-energized, the operation of the magnetic core will cause the fluid to pass through the valve body or be cut off to achieve the purpose of changing the direction of the fluid. The electromagnetic part of the solenoid valve is composed of fixed iron core, moving iron core, coil and other parts; the valve body part is composed of spool valve core, spool valve sleeve, spring base, etc. The solenoid coil is directly installed on the valve body, and the valve body is enclosed in a sealed tube, forming a simple and compact combination. The solenoid valves commonly used in our production include two-position three-way, two-position four-way, two-position five-way, etc. Let me first talk about the meaning of the two positions: for the solenoid valve, it is charged and lost, and for the controlled valve, it is open and closed.

The fault of the solenoid valve will directly affect the action of the switching valve and the regulating valve. The common fault is that the solenoid valve does not operate, which should be investigated from the following aspects:
1. The solenoid valve terminal is loose or the thread is off. The solenoid valve must not be energized and the thread can be tightened.
2. The solenoid valve coil is burned out. You can remove the solenoid valve's wiring and measure with a multimeter. If it is open, the solenoid valve coil will burn out. The reason is that the coil is damp, causing poor insulation and magnetic leakage, causing excessive current in the coil and burning. Therefore, it is necessary to prevent rainwater from entering the solenoid valve. In addition, if the spring is too hard, the reaction force is too large, the number of turns of the coil is too few, and the suction force is not enough, the coil can be burnt. For emergency treatment, you can turn the manual button on the coil from the "0" position to the "1" position during normal operation to open the valve.
3. Solenoid valve jam: the matching gap between the solenoid valve slide valve sleeve and the valve core is very small (less than 0.008mm), generally a single-piece assembly, when mechanical impurities are brought in or there is too little lubricating oil, it is easy to jam . The treatment method can be made by inserting a steel wire through a small hole in the head to make it rebound. The fundamental solution is to remove the solenoid valve, take out the valve core and valve core sleeve, and clean it with CCI4 to make the valve core move flexibly in the valve sleeve. When disassembling, pay attention to the assembly sequence of the components and the position of the external wiring, so that the reassembly and wiring are correct, and check whether the oil spray hole of the lubricator is blocked and whether the lubricating oil is sufficient.
4. Air leakage: Air leakage will cause insufficient air pressure, which makes it difficult to open and close the forced valve. The reason is that the sealing gasket is damaged or the slide valve is worn, which causes blow-by in several cavities. When dealing with the fault of the solenoid valve of the switching system, the appropriate time should be selected and the solenoid valve should be dealt with when the solenoid valve is de-energized. If the processing cannot be completed within a switching gap, the switching system can be suspended and handled calmly.