A solenoid valve is a device used to control the flow of liquid or gas in a system. It is usually powered by electromagnetic energy in a coil. These valves are useful in converting electrical energy into mechanical energy, and they come in various styles, namely two-way, three-way, and four-way valves. Two-way valves have two ports, an inlet, and an outlet. Basic three-way valves are specifically designed for operating cylinders and air-operated control valves. Four-way solenoid valves can also be useful in operating valves that have two solenoids in them. Solenoid valves are usually made up of stainless steel, Teflon, and brass materials that have different corrosive and heating properties.
Here are some common problems that can occur in these parts.
1. Valves Do Not Open
Solenoid valves may not open because of power failure, uneven pressure, wrong voltage, dirt under the diaphragm, corrosion, missing components, or a burnt coil. However, since there are so many causes, you must try to narrow down the problem in order to fix it. The most important parts that you must assess in this process are the power source, valve diaphragm, diaphragm spring, flow control adjustment, valve inlet port or outlet port, and the valve bleed port.
2. Valves Partly Close
Valves can also fail to close at times. This can be due to a manual override, pressure difference, residual coil power, damaged armature tube, inverted or damaged valve seats, and some missing components. Be sure you thoroughly check your wiring, lead connections, components, and diaphragm to see what the specific issue is. You can also try to lift the coil slightly to check if an electromagnetic field is present. If ever you have an inverted diaphragm, it would be wise to refit the item correctly before replacing it with a new one.
3. Erratic Valve Sounds
Every time a valve closes or opens up, you may hear a disturbing hammering sound, or in other cases, there can be a buzzing sound heard upon the operation of solenoid valves. These errant valve sounds can be due to the difference in the inlet or outlet pressure inside the system. Water hammering upon valve opening can be due to high liquid pressure traveling through a small pipe bore. Installation of a T-piece pipe before the air can help dampen the noise and reduce the impact. You may also increase the dimensions of your pipe to reduce the speed of your liquid components. Increasing pipe size would be a nice way to reduce inlet pressure on the valves as well.
4. Coil Problems
The coil may be burnt, melted, or can stay cold even with power on. These coil problems can be caused by a short circuit, dragging coil armature, wrong voltage, and high media (gases, liquids, etc) temperatures.
To avoid erroneous voltage supply, be sure to check the compatibility of your coil's voltage and if it's AC or DC, with the power supply. Check for moisture within and replace if necessary. Replace any damaged or bent armatures as well, and check media compatibility with your valve. Don’t forget to move solenoid valves into cooler areas or you may increase ventilation around valves and coil.