What are the symptoms if the solenoid valve is broken? What are the maintenance methods?

In the pneumatic industry, many people do not know that the solenoid valve is about to fail or has already failed. Today, it is time to share with you what aspects should be used to determine whether the solenoid valve is faulty, so that everyone can troubleshoot the equipment during use. Identify problems as soon as possible to prevent adverse effects on subsequent work. What are the symptoms if the solenoid valve is broken?



1. The sealing performance of the solenoid valve.

The sealing quality of a solenoid valve directly determines whether the solenoid valve will leak. The current solenoid valve seals are mainly hard seals and soft seals, each with their own suitable media. This judgment is relatively simple. Just use sight and smell in traditional Chinese medicine. This smell is not about lying on the solenoid valve to smell, but listening. When the solenoid valve is working normally, there will be no air leakage sound if there is no ventilation action. Yes, if the solenoid valve always makes an exhaust sound regardless of the direction of the solenoid valve, it means that the solenoid valve must be leaking. For larger leaks, the leak point can be found through the sound. So how to look for small leaks? ? This requires the use of soapy water, just like repairing a tire. After inflating the tire, brush a layer of soapy water on the tire. Bubbles will appear in the leaky areas. At this time, everyone should be careful not to use too much soapy water, otherwise the soapy water will Entering the inside of the solenoid valve will cause the internal sealing ring of the solenoid valve to expand, causing the solenoid valve to not operate smoothly.

2. Solenoid valve action sensitivity and reliability

This refers to the sensitivity of the solenoid valve to respond accordingly to changes in media parameters. For solenoid valves such as throttle valves, pressure reducing valves, and regulating valves used to adjust medium parameters, as well as solenoid valves with specific functions such as safety valves and pigging valves, their functional sensitivity and reliability are very important technical performance indicators. . If the sensitivity of the solenoid valve is abnormal, it is possible that the electrical signal is unstable. At this time, we need to check whether the terminal wiring is poor, or the line is too long, causing a voltage drop, and the solenoid valve cannot receive the electrical signal normally.

3. It is the opening and closing speed of the switch.

The opening and closing speed is expressed by the time required for the solenoid valve to complete an opening or closing action. Generally, there are no strict requirements for the opening and closing speed of solenoid valves, but some working conditions have special requirements for the opening and closing speed. For example, some require rapid opening or closing to prevent accidents, and some require slow closing to prevent water hammer, etc. . If it is confirmed that the electrical signal transmission is normal but the solenoid valve moves slowly and cannot keep up with the speed of the electrical signal, then there are impurities in the valve body, causing the valve core resistance to be too large and unable to switch synchronously with the electrical signal. At this time, do we need to Disassemble the solenoid valve body, clean the inside of the valve body, and then reinstall and debug.

To sum up, after the process reflects that the solenoid valve does not operate, first go to the central control room to check whether the relay has power and whether it operates. First, it is close to the team, and second, the relay operates frequently and is prone to failure. Then go to the site, open the cover and check whether the solenoid valve is powered. If there is no power, check the junction box and cables. If there is power, connect and disconnect the wires. Listen for any sound from the solenoid valve. If there is no sound, press the manual pin to check. Check whether the solenoid valve operates, and then measure the coil resistance. If it is bad, replace it;if the coil is good, the valve core may be stuck. Find faults step by step and in order



What are the maintenance methods of solenoid valve?

1. First determine whether there is power on the two lines
2. Use a screwdriver to get close to the top of the solenoid valve, which must be the top. Is there any magnetic force? If so, please disassemble the valve body, check whether there are any small foreign objects in the valve core, whether the inner spring is stuck, clean it and add oil.
3. After the solenoid valve is powered on, you can use the metal part of the screwdriver to test whether there is suction. If there is suction but it is still abnormal, the valve core may be stuck. If there is no suction, there may be a problem with the intermediate relay.
4. Measure the solenoid valve coil resistance, which generally does not exceed 150 ohms, otherwise the solenoid valve coil will burn out. Measuring the voltage can determine whether there is a problem with the intermediate relay of the PLC cabinet. If everything is normal, the valve plug may be stuck.