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. Solenoid valves are useful in converting electrical energy into mechanical energy. Most solenoid valves come in various styles namely 2-way, 3-way and 4-way valves. Two-way valves have 2 ports, an inlet and an outlet. The basic 3-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 2 solenoids in them. Solenoid valves are usually made up of stainless steel, Teflon, and brass materials that have different corrosive and heating properties.
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 coil burn out. In any of the mentioned cases, you must try to narrow down the problem. Try to diagnose the problem before making any moves to remedy the problem. The most important parts that you must assess in this process are the valve diaphragm, diaphragm spring, coil power, flow control adjustment, valve inlet port, solenoid outlet port and the valve bleed port.
Valves Partly Close
Valves can fail to close at times. This can be due to a manual over ride, pressure difference, and residual coil power, damaged armature tube, inverted & damaged valve seats, and some missing components. Be sure you thoroughly check your wiring, lead connections, components and diaphragm. You can also try to lift the coil slightly to check if 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.
Erratic Valve Sounds
Every time a valve closes or opens up, you may hear a disturbing hammering sound. In other cases, a buzzing sound can be 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 inserting 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.
The coil may be burned, melted or can stay cold even with power on. These coil problems can be caused by short circuit, slow 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 with the power supply. Check for moisture and replace as necessary. Replace any damage armatures and check media compatibility with your valve. Bent armatures should be immediate replaced. Soiled armatures are cleaned with Y-type strainers. Don’t forget to move solenoid valves into cooler areas or you may increase ventilation around valves and coil.