How to judge the quality of solenoid valve quickly?
The quality of the solenoid valve depends on two aspects: one is the coil, The second is valve body. So the test is mainly to test these two aspects. If you find a 24V power supply, connect it to the coil. If you can hear the sound, it means that the coil and valve core of the solenoid valve are normal, and can be sucked normally. Then check whether the air leaks. If there is air source, the best way is to connect the air source directly to judge whether the air leaks. If there is no air source, you can send out the gas Close the mouth and blow it down. In addition, the universal meter can be used for coil inspection.
- 1. Power on the solenoid valve, pull off the plug, and use a multimeter to measure whether there is electricity;
- 2. When the solenoid valve is energized, use a thin steel wire close to the coil to see if there is suction.
- 3. Solenoid valve power on – power off reverse retest, with a very thin hexagon wrench poke solenoid valve axis brass “small hole”, see if it can be sucked – ejected.
Common faults of solenoid valve
1. Coil short circuit or open circuit:
Detection method: first use a multimeter to measure its on-off, the resistance tends to zero or infinity, which means that the coil is short circuit or open circuit. If the measured resistance is normal (about tens of Ohm), it does not mean that the coil must be good (I once measured that the resistance of a solenoid valve coil is about 50 ohm, but the solenoid valve can not act, and everything is normal after replacing the coil), please carry out the following final test: find a small screwdriver and put it near the metal rod in the solenoid valve coil, and then power on the solenoid valve If there is magnetism, the solenoid coil is good, otherwise it is bad.
Treatment: replace the solenoid valve coil.
2. Problem with plug / socket:
Fault phenomenon: if the solenoid valve has a plug / socket, there may be problems with the metal spring of the socket, the wiring of the plug (for example, the power line is connected to the ground wire), and other reasons, so the power can not be sent to the coil. It’s better to form a habit: after the plug is inserted in the socket, screw on the fixing screw, and after the spool rod, screw on the fixing nut.
If the plug of solenoid valve coil is equipped with LED power indicator, the DC power supply should be used to drive the solenoid valve, otherwise the indicator will not be on. In addition, do not replace the power plugs with LED power indicator of different voltage levels, which will cause the led to be burnt out / short circuit of power supply (replace the plug with low voltage level) or weak light emission of LED (replace the plug with high voltage level).
If there is no power indicator, there is no need to distinguish the polarity of the solenoid valve coil (unlike the transistor time relay with DC coil voltage and the intermediate relay with DC coil voltage of diode / resistor leakage circuit in parallel on the coil < this kind of intermediate relay is mainly from the original Japan >, which needs to distinguish the polarity).
Treatment: correct wiring error, repair or replace plug and socket.
3. Valve core problem:
Fault phenomenon 1: when the medium pressure of the solenoid valve is normal, pressing the red manual button of the solenoid valve, the solenoid valve has no response (the pressure medium has no change of on-off), indicating that the valve core must be bad.
Treatment method: check whether there are problems in the medium, such as whether there is a lot of water in the compressed air (sometimes the oil-water separator does not play a very important role, especially when the pipeline design is poor, there will be a lot of water in the compressed air to the solenoid valve), and whether there are many impurities in the liquid medium. Then remove the water or impurities in the solenoid valve and pipeline. If you can’t, please repair it (if you have time, patience and need to) or replace the valve core, or replace the whole solenoid valve.
Fault phenomenon 2: after inspection, the coil is the original coil, and the magnetism of the coil is normal when it is powered on, but the solenoid valve still does not act (at this time, the function of the manual button of the solenoid valve may be normal), indicating that the valve core is bad.
Treatment: please repair or replace the valve core, or simply replace the entire solenoid valve.
How to judge the quality of solenoid valve quickly?
First, the solenoid valve is connected with the controlled medium (liquid and gas with pressure air , and the pressure value is the middle value of the pressure range of the solenoid valve), and then the solenoid valve coil is energized. If the controlled medium changes from on to off or from off to on, then the solenoid valve is good, otherwise there is a problem.
First, check whether the solenoid coil of the solenoid valve is faulty?
In the DCS to the two valve to open or close the signal, and then see whether the solenoid valve power, generally in the field to listen to the sound. If not, there must be something wrong with the coil. Is there something wrong with the solenoid valve itself? (explanation below)
If there is a problem with the solenoid coil, first check the wiring to see if there is virtual connection or short circuit. If there is no problem with the circuit, the solenoid coil is burnt out. Remove the wiring of the solenoid valve and measure it with a multimeter. If there is an open circuit, the solenoid coil is burnt out. The reason is that the coil is damp, causing poor insulation and magnetic leakage, causing excessive current in the coil and burning, so it is necessary to prevent rainwater from entering the solenoid valve. In addition, if the spring is too hard, the reaction force is too large, the coil turns are too few, and the suction force is not enough, the coil can be burned.
If the coil is good, it is the problem of the solenoid valve itself.
Generally, the valve can be adjusted from 1 to 0 in the manual adjustment position, so that the valve can be opened. If it can be opened, it means that it is indeed a coil problem. If it can’t be opened, remove the solenoid valve to see if the valve core is stuck or there is debris blockage. CCl4 should be used for correct cleaning. However, considering that there are no conditions on site, gasoline can be used, and there is no water Yes, after cleaning, it can be dried with field instrument air. When dismantling, be sure to remember the sequence of each component. If you don’t pay attention, it’s easy to make mistakes when installing. If you remember the wrong sequence, even if you clean the solenoid valve well, even if the solenoid valve is connected, it still can’t be opened.
The solenoid valve generally has a manual button. If it is pressed manually, the solenoid valve can act. When it is powered on, the solenoid valve does not act or the power supply trips, which indicates that the solenoid valve coil is broken. Of course, it is necessary to determine whether its working voltage is correct.
The quality of the solenoid valve mainly depends on two aspects, one is the coil, the other is the valve body, so the test mainly tests these two aspects. You can find a 24 V power supply and connect it to the coil. If you can hear the sound, it means that the coil and valve core of the solenoid valve are normal, and can absorb and connect normally;
Then check whether there is air leakage. If there is a gas source, it is best to connect the gas source directly to judge whether there is air leakage. If there is no gas source, plug up the air outlet and blow it down with a nozzle. In addition, the coil can also be checked with a multimeter.
Source: China Valves Manufacturer – Yaang Pipe Industry Co., Limited (www.pipelinedubai.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
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