The primary function of electromagnetic diaphragm valves is to close and open the flow of the working medium. They only operate in fully open or fully closed position. They are most often installed in compressed air, heating and water installations, both for domestic and industrial applications. Their opening and closing times are very short. Solenoid valves can act as executive device which, based on the current signal from the controller, open or close the flow of the medium. They are electrically controlled devices. There are two basic types of solenoid valves:
- Normally closed NC - the valve is closed without electricity, does not let the medium pass through when idling - it opens only when the power reaches the coil.
- Normally open NO - the valve is open without electricity, it lets the medium through when it is idling - it closes when the power reaches the coil.