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 | 19
Function, NC
Coil voltage disconnected (closed):
When the voltage is disconnected, the valve plate
(3) is pressed down against the pilot orifice (4) by
the armature spring (2). 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 diaphragm is
equivalent to the inlet pressure. The valve will
be closed for as long as the voltage to the coil is
disconnected.
Coil voltage connected (open):
When voltage is applied to the coil (1), the pilot
orifice (4) is opened. 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 is now
open for unimpeded flow and will be open for as
long as the minimum differential pressure across
the valve is maintained, and 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