The main structure of the solenoid valve is two parts. One is the coil and the other is the valve body. Therefore, the failure of the general solenoid valve also occurs in these two places, the coil or the valve body. The solenoid valve coil specifications are DC24V, AC24V, AC110V, AC220V, etc. When replacing the coil, be sure to pay attention to the type and specification of the coil to match the old one.
To preliminarily determine the quality of a solenoid valve, first manually press or rotate the switch button. It depends on whether it moves. If it does, it means that the entire valve body is fine. That is the problem with the coil, and the coil needs to be replaced. If there is no action, the coil and valve body should be inspected, repaired and replaced.
The following is maintenance experience.
First, energize the solenoid valve and unplug the coil. You can insert a small screwdriver or a small iron rod into the center of the coil, feel whether there is electromagnetic attraction, and judge whether the coil is good or bad based on whether there is electromagnetic attraction. This method is used when there is no detection tool on hand, and is generally not recommended. The normal process is to use a multimeter to detect in the event of a power failure.
Second, common coil problems. Generally judging whether the coil is good or bad is to use a multimeter to set the resistance to detect the on-off state of the coil. If the resistance is infinite or zero, it means that the coil is open or short-circuited.
The commonly used DC24V coil is about 180Q. Once it was detected that the coil resistance was less than 100Q, and it was not broken or short-circuited, it just didn’t work. Finally, it returned to normal after replacing it with a new coil.
So sometimes using a multimeter to detect the short circuit or open circuit of the coil can not judge the quality of the coil. Another common fault occurs in the plug and socket. This happens but the chance of it happening is less than that. Such a situation is caused by poor contact between the plug and the socket of the coil. Therefore, after the coil is replaced normally, the coil and the plug must be tightened with a tightening screw, and the packaged coil does not have this problem.
The third is the problem of valve body and valve core. When the pressure of the medium through the solenoid valve is normal, if the switch button is manually actuated and the solenoid valve does not respond, there must be a problem with the solenoid valve body. Need to be disassembled and repaired. Generally, this kind of failure is that the spool is stuck due to the moisture or impurities in the passing medium. When disassembling and repairing, be sure to pay attention to the installation direction and position of each component. The general spool is rarely unusable due to hardware failure. Just clean the valve core and valve body, and apply a layer of petroleum jelly or grease on the valve core.
There is no problem if the movement between the spool and the valve body is smooth.
After the assembly is completed according to the steps, the solenoid valve body is maintained.