Solenoid valves are used in industrial applications to control and direct the flow of fluids. These valves are also known as mechanical or electrohydraulic valves. Since they use electromechanical actuators, they are more rugged than other types of valve mechanisms. This article will teach various solenoid valve problems and their solutions with troubleshooting steps.
A solenoid is one of the main components of a valve. Unfortunately, the solenoid valve’s failure rate is higher than other valve accessories. If you’re experiencing problems with your solenoid valve, these troubleshooting steps will help you get it back up and running.
Below are the troubleshooting steps of solenoid valve：
- The first thing to do is make sure that the air supply is established. To do this, check the pressure of the AFR at the solenoid valve with a gauge or other measuring device (like a thermometer). Ensure that there is enough pressure for your valve’s requirements listed in its datasheet (which should be available online).
- You should also check that all electrical connections are good and tight. This includes connecting pipes or hoses to the valve’s fittings, using wire nuts on connectors or bolts that hold parts together, and ensuring all parts are correctly attached (including replacing missing parts).
- It is essential to check the AFR bowl (bottom) because this can tell you if there is the moisture content in the system. If there is, then flush the entire system. This action may operate the valve.
- If any of these checks fail, there may be an issue with your wiring or connections between components within your system, which could create problems during operation.
For doing this, take clearance from Plant Operation for operating the solenoid valve.
- Check for any obstruction in the solenoid valve, whether it is a blockage, a bent or broken vent tube, or something else. It is better to check this at every shutdown and start-up to avoid any problems later.
- The air solenoid valve controls air flow in and out of the air compressor’s system. When the manual latching system is present, it can be operated manually by pulling on its handle or giving a command through the control system to operate the valve. During this time, the valve will open and close, and air should come out with good pressure and flow because the actuator’s one compartment will empty out its air.
- Now remove the tubing from the actuator side, and during command changeover (ON/OFF) from the system side, a clicking sound should come from the solenoid valve. That means that its coil is energizing. Also, air should start flowing through another port, or if only one outlet port exists, it should reverse its condition by stopping or reversing flow.
- If you hear a click during command changeover (ON/OFF), the air path is not changing, and the solenoid valve may have issues. To open the body of the solenoid valve as per instructions from your vendor manual, do so and service or replace the piece if necessary.
- If continuous venting comes from the vent port during command changeover (ON/OFF), it’s likely a problem with either the solenoid valve or its actuator. If true, remove the tubing and check for problems with each component.
- If you don’t hear a clicking sound while giving a command from your system, check to see if there’s any change in voltage while switching between ON/OFF states. If there are no voltage changes during this period, check to see if anything is wrong with any wires or connections in your junction box.
- If all connections are found ok, it is time to check the marshaling cabinet and the fuse in the marshaling cabinet. If the fuse is blown, we can replace it with a new fuse of the same rating. We then proceed to test the solenoid valve.
- If still no voltage is received in the field, we can check whether the DO—digital output—is turning on or off when we give commands from our engineering system. If it isn’t happening as expected, we’ll need to consider whether the cable resistance from the marshaling cabinet to the field is high or open. If it’s high or open, change one of your cables with a spare one—and keep an eye on that magnetic field!
- If a solenoid valve is making a clicking sound, but the voltage is present, disconnect the cables and check the coil resistance.
- Coil resistance should be as per vendor manual specifications (it should not be high resistance in megaohm or very low single digit ohm). If the coil is not ok as per its resistance, replace it.
The most important thing that you need to remember when using solenoid valves is to follow the instructions carefully. If you do not follow these instructions, your equipment may fail or even explode. So make sure that you understand what each part does before you put it together.