Product Overview
© Danfoss | DCS (az) | 2017.12
7
Data sheet | Solenoid valves for water shut off and leak detection, Types EV220T, EV220W, EV220B, and EV228B
IC.PD.200.S1.02 | 17
Function, NO
Coil voltage disconnected (closed):
When the voltage to the coil (2) is disconnected,
the pilot orifice (4) is open. As the pilot orifice is
larger than the equalizing orifice (7), the pressure
across the diaphragm (5) drops and therefore it is
lifted clear of the main orifice (6). The valve will
be open for as long as the minimum differential
pressure across the valve is maintained, and for as
long as the voltage to the coil is disconnected.
Coil voltage connected (open):
When voltage is applied to the coil, the valve
plate (3) is pressed down against the pilot orifice
(4). The pressure across the diaphragm (5) is built
up via the equalizing orifice (7). The diaphragm
closes the main orifice (6) as soon as the pressure
across the iaphragm is equivalent to the inlet
pressure. The valve will be closed for as long as
there is voltage to the coil.
Pos. no. Description
1 Coil
2 Armature spring
3 Valve plate
4 Pilot orifice
5 Diaphragm
6 Main orifice
7 Equalizing orifice