SOLENOID VALVES

                     Solenoid valves are electrically operated devices that control the flow of liquids. Solenoid valves are   electro-mechanical devices that use a wire coil and a movable plunger, called a solenoid, to control a particular valve. The solenoid controls the valve during either the open or closed positions. Thus, these kinds of valves do not regulate flow. They are used for the remote control of valves for directional control of liquids. Solenoid valves have two main parts: the solenoid and the valve. After the coil receives a current, the actuating magnetic field is created. The magnetic field acts upon the plunger, resulting in the actuation of the valve, either opening or closing it.

                        There are two general types of solenoid valves: direct-acting and pilot-operated. Direct-acting solenoid valves have a plunger that is in direct contact with the primary opening in the body. This plunger is used to open and close the orifice. The pilot-operated solenoid valve works with a diaphragm rather than a plunger. This valve uses differential pressure to control the flow of fluids. The air-venting valve is opened to allow the pressure to equalize and permit the fluids to flow through.

The design of solenoid valves allows them to have many applications. Their most common use is the control of water, oil, gas, steam, solvents, cryogenics, air and vapors, as well as many other hydraulic and pneumatic applications. Typical environments for solenoid valves are in medical and biomedical equipment, analytical instrumentation, semiconductors, HVAC and other industrial OEM environments. A unique feature that solenoid valves have is the automatic triggering from remote locations by different voltages, making them useful in rough or hazardous locations.

                     Important items to consider when looking at solenoid valves are proportionality, linearity, frequency response, repeatability, power consumption, leakage, life expectancy and cost. With so many types of solenoid and related valves, the application requirements are very important. Because solenoid valves are designed to perform operations, such as restrict, meter and maintain the flow of liquid and gaseous materials, they are widely used in vastly different fields and industries.