Common faults of solenoid valve

The solenoid valve consists of an electromagnetic coil and a magnetic core, and is a valve body with one or several holes. When the coil is energized or de-energized, the operation of the magnetic core will make the fluid pass through the valve body or be cut off, thus changing the direction of the fluid. The electromagnetic components of the solenoid valve are composed of fixed iron core, moving iron core, coil and other components; The valve body consists of a spool, a spool sleeve and a spring seat. The electromagnetic coil is directly installed on the valve body, and the valve body is encapsulated in a sealed tube, forming a simple and compact combination. The commonly used solenoid valves in our production include two-position three-way, two-position four-way, two-position five-way and so on. Let's talk about the meaning of "two" first: for solenoid valves, it means charging and power loss, and for controlled valves, it means opening and closing.

The failure of solenoid valve will directly affect the action of on-off valve and regulating valve. The common fault is that the solenoid valve does not act, and the following aspects should be investigated:

1. If the connector of the solenoid valve is loose or falls off, the solenoid valve shall not be energized, but the connector can be tightened.

2. If the solenoid valve coil is burnt out, remove the wiring of the solenoid valve and measure it with a multimeter. If the circuit is open, the solenoid coil is burnt out. The reason is that the coil is damp, resulting in poor insulation and magnetic leakage, which leads to excessive coil current and burning, so it is necessary to prevent rainwater from entering the solenoid valve. In addition, the spring is too hard, the reaction force is too large, the number of turns of the coil is too small, and the suction force is not enough, which will also lead to the coil burning. In case of emergency, the manual button on the coil can be turned from the "0" position in normal operation to the "1" position to open the valve.

3. The solenoid valve is stuck: the clearance between the spool sleeve and the spool of the solenoid valve is very small (less than 0.008mm), and it is generally assembled into a whole. When there are mechanical impurities or too little lubricating oil, it is easy to get stuck. The treatment method can be to pierce the steel wire from the 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, so that the valve core can move flexibly in the valve sleeve. During disassembly, attention should be paid to the assembly sequence and external wiring position of each component for correct assembly and wiring. Also check whether the injection hole of the oil mist injector is blocked and whether the lubricating oil is sufficient.

4. Air leakage: Air leakage will cause insufficient air pressure, making it difficult to open and close the forced valve. The reason is that the gasket is damaged or the slide valve is worn, resulting in air leakage in several cavities. When dealing with the failure of the solenoid valve in the switching system, we should choose a suitable opportunity to deal with it when the solenoid valve is powered off. If it can't be handled within the switching interval, we can suspend the switching system and handle it calmly.