Have you ever used an industrial air hammer? Have you checked on your automotive starter system at one point or another? Have you ever seen an electric bell assembly? If you answer yes to any of these questions, then you probably know what a solenoid valve is. 
During the 1970s, the chemical industry primarily utilized linear control valves that employed a rising stem. Once automated, these valves required pipe-mounted solenoid valves. Solenoid valves designed initially for linear control valves were, at this point, playing double-duty because they were being used for quarter-turn ball valves as well. However, because standardization was not widespread at the time, each actuator manufacturer tended to have a unique interface configuration. Consequently, solenoid valve manufacturers needed to design five to six different styles of valves to fit onto these various actuators. It was not until the 1990s that the valve industry instituted its own standardization for an interface with the solenoid valve. A solenoid valve is an electromechanical valve for use with liquid or gas controlled by running or stopping an electrical current through a solenoid, which is a coil of wire, thus changing the state of the valve. The operation of a solenoid valve is similar to that of a light switch, but typically controls the flow of air or water, whereas a light switch typically controls the flow of electricity. It is controlled by electrical current, which is run through a coil. When the coil is energized, a magnetic field is created, causing a plunger inside the coil to move. Depending on the design of the valve, the plunger will either open or close the valve. When electrical current is removed from the coil, the valve will return to its de-energized state. Solenoid valves may have two or more ports: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports. Multiple solenoid valves can be placed together on a manifold. In some solenoid valves the solenoid acts directly on the main valve. Others use a small, complete solenoid valve, known as a pilot, to actuate a larger valve. While the second type is actually a solenoid valve combined with a pneumatically actuated valve, they are sold and packaged as a single unit referred to as a solenoid valve. Piloted valves require much less power to control, but they are noticeably slower. Piloted solenoids usually need full power at all times to open and stay open, where a direct acting solenoid may only need full power for a short period of time to open it, and only low power to hold it. Compare with other valves the main features o solenoid valve is: 1 blocking leak stopped, and easy to control leakage, the use of security. 2 The system is simple, then computer-low prices. Solenoid valve itself I simple, low prices, compared to other types of valve actuators easy to install and maintain. It is the more significant component of the control system is much simple, much lower price. 3 Action Express, micro-power, lightweight configuration. Solenoid Valve response time may be as short as a few milliseconds, even in the pilot-control solenoid valve can also dozens of milliseconds. As self-loop control valve more responsive than the other. A common use for 2 way solenoid valves is in central heating. The solenoid valves are controlled by an electrical signal from the thermostat to regulate the flow of heated water to the heating elements within the occupied space. Such valves are particularly useful when multiple heating zones are fed by a single heat source. Commercially available solenoid valves for this purpose are often referred to as Zone valves. Another common use for solenoid valves is in automatic irrigation sprinkler systems. See also Controller (irrigation). In the paintball industry solenoid valves are usually referred to simply as "solenoids." They are commonly used to control a larger valve used to control the propellant (usually compressed air or CO2). In the industry, "solenoid" may also refer to an electromechanical solenoid commonly used to actuate a sear. Solenoid valves are also used for air control, to control fluid flow, and in pharmacology experiments, especially for patch-clamp, which can control the application of agonist or antagonist. Tank farms are an excellent example of how solenoid valve applications have helped systems progress from manual to automatic operation, facilitating finer and safer control in processing plants.
As the world continues to grow smaller and end users become more global, solenoid valve manufacturers will respond with products that have a common electrical enclosure that suits directives and standards worldwide.