Common Faults and Solutions of Kiln Electromagnetic Valve

Common faults of solenoid valves include
1. Coil short circuit or open circuit
Detection method: First, use a multimeter to measure its ON/OFF value. If the resistance value approaches zero or infinity, it indicates a short circuit or open circuit in the coil. If the resistance value measured is normal (about tens of ohms), it does not necessarily indicate that the coil is good (I once measured a solenoid valve coil resistance of about 50 ohms, but the solenoid valve failed to operate, and everything is normal after replacing the coil), please perform the following final test.
Find a small screwdriver and place it near the metal rod that runs through the solenoid valve coil, and then energize the solenoid valve. If magnetism is felt, the solenoid valve coil is good, otherwise it is bad.
Treatment: Replace the solenoid valve coil.
2. There is a problem with the plug/socket
Fault phenomenon: If the solenoid valve has a plug/socket, there may be problems with the metal reed of the socket (which I have encountered), problems with the wiring on the plug (such as connecting the power cord to the ground wire), and other reasons that prevent the power supply from being sent to the coil.
It is best to form a habit: After inserting the plug into the socket, screw in the fixing screw, and screw in the fixing nut behind the valve core rod on the coil.
If the plug of the solenoid valve coil is equipped with a LED power indicator light, it is necessary to connect it correctly when using DC power to drive the solenoid valve, otherwise the indicator light will not light up.
In addition, do not switch power plugs with LED power indicators at different voltage levels, as this may cause the LED to burn out/the power supply (switch to a low voltage level plug) to have a short circuit or the LED to emit very weak light (switch to a high voltage level plug).
If the solenoid valve coil is not equipped with a power indicator light, it is not necessary to distinguish the polarity of the solenoid valve coil (unlike transistor time relays with a coil voltage of DC and intermediate relays with a diode/resistor leakage circuit connected in parallel to the coil, which have a coil voltage of DC. This type of intermediate relay is mostly manufactured in Japan, and polarity needs to be distinguished).
Solution: Correct wiring errors, repair or replace plugs and sockets.
3. Valve core problem
Fault phenomenon 1: When the pressure of the medium passed through the solenoid valve is normal, press the red manual button of the solenoid valve, and the solenoid valve does not respond at all (the pressure medium does not change on or off), indicating that the valve core must be damaged.
Treatment method: Check whether there are any problems with the medium, such as whether there is a lot of water in the compressed air (sometimes the oil water separator does not play a significant role, especially when the pipeline design is poor, there will be a lot of water in the compressed air flowing to the solenoid valve), and whether there are many impurities in the liquid medium passed through.
Then remove the accumulated water or impurities in the solenoid valve and pipeline. If it doesn't work, please repair it (if you have the time, patience, and need it) or replace the valve element, or simply replace the entire solenoid valve.
Fault phenomenon 2: After inspection, the coil is the original coil and its magnetism is normal when the coil is powered on, but the solenoid valve still does not operate (at this time, the function of the manual button of the solenoid valve may be normal), indicating that the valve core is damaged.
Treatment: Please repair or replace the valve core, or simply replace the entire solenoid valve.
As for the maintenance of the solenoid valve body, because there are too many types of maintenance methods, I can't describe many, so I won't go into details here.
Common Faults and Solutions of Kiln Electromagnetic Valve
Solenoid Valve Troubleshooting
1、 The solenoid valve does not work when energized
Check whether the power supply wiring is poor → Reconnect the wiring and connector connections
Check whether the power supply voltage is within the ± operating range - → adjust to the normal position range
Whether the coil is desoldered → re welded
Short circuit in coil → Replace coil
Whether the working pressure difference is inappropriate → Adjust the pressure difference → or replace the appropriate solenoid valve
Fluid temperature too high → Replace the appropriate solenoid valve
There are impurities that cause the main valve core and moving iron core of the solenoid valve to jam → Clean them, and if there is any seal damage, replace the seal and install the filter
The liquid viscosity is too high, the frequency is too high, and the service life has expired → Replace the product
2、 The solenoid valve cannot be closed
The seal of the main valve core or the iron moving core has been damaged → Replace the seal
Is the fluid temperature and viscosity too high? Replace the corresponding solenoid valve
There are impurities entering the solenoid valve producing valve core or moving iron core → cleaning
Spring service life expired or deformed → Replace
Restriction hole balance hole clogged → timely cleaning
Working frequency is too high or service life has expired → Select a new product or update it
3、 Other situations
Internal leakage → Check whether the seal is damaged and whether the spring is poorly assembled
External leakage → Loose connections or damaged seals → Tighten screws or replace seals
There is noise during power on → the fasteners on the head are loose and tightened. If the voltage fluctuation is not within the allowable range, adjust the voltage properly. The iron core suction surface is contaminated or uneven, and it should be cleaned or replaced in a timely manner.
Common Faults and Solutions of Kiln Electromagnetic Valve
Method for quickly judging the quality of solenoid valves on site
1、 First, check whether the solenoid valve solenoid coil is faulty?
On the DCS, send an ON or OFF signal to the two position valve, and then check whether the solenoid valve is powered on or off. Generally, it is sufficient to listen to the sound on site. If you cannot hear it, there must be a problem with the coil. As for the solenoid valve itself, is there a problem? (Explained below)
If there is a problem with the solenoid coil, first check the wiring to see if there is a virtual connection or a short circuit. If there is no problem with the wiring, the solenoid valve coil may be burned out. You can remove the wiring of the solenoid valve and measure it with a multimeter. If there is an open circuit, the solenoid valve coil may be burned out.
The reason is that the coil is affected by moisture, resulting in poor insulation and magnetic leakage, resulting in excessive current in the coil and burning. Therefore, it is necessary to prevent rainwater from entering the solenoid valve. In addition, too hard a spring, too large a reaction force, too few coil turns, and insufficient suction can also cause the coil to burn out.
2、 If the coil is good, it is the problem with the solenoid valve itself.
Generally, you can adjust the valve from 1 to 0 at the manual adjustment position using a single character to open it. If it can be opened, it indicates that there is indeed a problem with the coil, and it can be replaced. If it cannot be opened, remove the solenoid valve to see if the valve core is stuck or there is debris blockage. If it is cleaned correctly, use CCL4.
However, considering that there are no on-site conditions, gasoline can be used, even if there is no water available. After cleaning, it can be dried using on-site instrument air. When disassembling, it is important to remember the sequence of various components. If you do not pay attention, it is easy to make mistakes during installation. Even if you clean the solenoid valve properly, even if the solenoid valve is turned on, it still cannot be opened!