Product Overview

© Danfoss | DCS (az) | 2017.12
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Data sheet | Solenoid valves for water shut off and leak detection, Types EV220T, EV220W, EV220B, and EV228B
IC.PD.200.S1.02 | 3
Function, NC
Coil voltage disconnected
When voltage is disconnected, the armature
spring (2) presses the armature (3) down against
the pilot orifice (4). Pressure builds up over the
diaphragm (5) via the equalizing orifice (6). The
diaphragm closes the main orifice (7) as soon as
the pressure over the diaphragm equals the inlet
pressure. The valve stays closed for as long as
voltage remains disconnected.
Pos. no. Description
1 Coil
2 Armature spring
3 Armature
4 Pilot orifice
5 Diaphragm
6 Equalizing orifice
7 Main orifice
Coil voltage connected (open)
When voltage is applied to the coil (1), the pilot
orifice (4) is opened. Since the pilot orifice is
larger than the equalizing orifice (6), pressure
over the diaphragm (5) falls and the diaphragm
is lifted clear of the main orifice (7). The valve
stays open for as long as the required minimum
differential pressure is present and voltage is
applied to the coil.