A solenoid valve is an electromechanical controlled valve. The valve features a solenoid, which is an electric coil with a moveable ferromagnetic core in its center. This core is called the plunger. In rest position, the plunger closes off a small orifice. An electric current through the coil creates a magnetic field. The magnetic field exerts a force on the plunger. As a result, the plunger is pulled toward the center of the coil so that the orifice opens. This is the basic principle that is used to open and close solenoid valves.
Solenoid valves are amongst the most used components in gas and liquid circuits. The number of applications is almost endless. Some examples of the use of solenoid calves include heating system, compressed air technology, industrial automation, swimming pools, sprinkler systems, washing machines, dental equipment, car wash systems and irrigation systems.