The Performance And Repair Method Of Solenoid Valve Broken
In the pneumatic industry, many people don’t know if the solenoid valve is about to fail or has failed. Today, it’s time to share with you. From which aspects should be used to determine whether the solenoid valve is faulty, so that you can check and repair the equipment during use. Find problems at the first time to prevent adverse effects on follow-up work.
What is the manifestation of a broken solenoid valve?
1. The tightness of the solenoid valve.
The sealing performance of a solenoid valve directly determines whether the solenoid valve will leak. The current solenoid valve seals are mainly hard seal and soft seal, and have their own suitable media. This is relatively simple to judge. You can use the sight and smell in Chinese medicine. This smell is not to smell the smell on the solenoid valve, but to listen. If the solenoid valve is in normal operation, there will be no air leakage sound. Yes, if the solenoid valve always has an exhaust sound regardless of the reversing action, it means that the solenoid valve must be leaking. The larger leak can be found through the sound, so how to find the small leak? ? So you need to use soapy water, just like repairing a tire. After you inflate the tire, apply a layer of soapy water on the tire. Bubbles will appear in the air leak. At this time, everyone should pay attention to the amount not to be too much, otherwise the soapy water Entering into the solenoid valve will cause the inner sealing ring of the solenoid valve to expand, and the solenoid valve will not operate smoothly.
2. Sensitivity and reliability of solenoid valve action
This refers to the sensitivity of the solenoid valve in response to changes in media parameters. For solenoid valves with specific functions such as throttle valves, pressure reducing valves, and regulating valves, 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 may be that the electrical signal is unstable. At this time, we need to check whether the wiring terminal is poorly connected, or the line is too long and the voltage is reduced, 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 speaking, there are no strict requirements on the opening and closing speed of the solenoid valve, but some working conditions have special requirements for the opening and closing speed. If some require rapid opening or closing to prevent accidents, some require slow closing to prevent water hammer, etc. . If it is confirmed that the electric signal transmission is normal and the solenoid valve moves slowly, and cannot keep up with the electric signal speed, then there is impurities in the valve body, which causes the valve core resistance to be too large and cannot switch synchronously with the electric signal. Disassemble the solenoid valve body, clean the inside of the valve body, and re-install and debug.
To sum up, after the process reflects that the solenoid valve is not operating, first go to the central control room to check whether the relay is powered and whether it is operating. One is close to the team, and the other is that the relay operates frequently and is prone to failure. Then go to the site, open the lid to check whether the solenoid valve is energized. If there is no power, check the junction box and cable. Whether the solenoid valve is operating, then measure the coil resistance, if it is broken, replace it; if the coil is good, the spool may be stuck. Find the fault step by step in order.
What are the maintenance methods for solenoid valves?
1. First judge whether the two wires have electricity
2. Use a screwdriver to approach the solenoid valve, which must be on top. Whether there is magnetic force, if so, please disassemble the valve body, check the valve core for small foreign matter, whether the inner spring is stuck, and clear the oil.
3. After the solenoid valve is energized, you can use the metal part of the screwdriver to test whether there is suction. If there is suction, it is still abnormal. It may be that the spool is stuck. If there is no suction, there may be a problem with the intermediate relay.
4. Measure the solenoid valve coil resistance, generally not more than 150 ohms, otherwise the solenoid valve coil will burn out. By measuring the voltage, it can be judged whether there is a problem such as the intermediate relay of the PLC cabinet. If everything is normal, the valve plug may be stuck.