The media constructed by the solenoid valve enters the valve through the inlet port (port 2 as mentioned above) the media must flow through closed and opened by the plunger.
The valve picture mentioned above is normally closed valve use a spring which pushes the plunger tip against the opening of the orifice. The sealing material at the tip of the plunger keeps the media from entering the orifice, until the plunger lifted up by an electromagnetic field.
Solenoid offers fast and safe switching, high reliability, long service life, good medium capability of the materials used low control power and compact design.