Danfoss EV250B Data sheet

Data Sheet

Solenoid valve
Type EV250B

Assisted lift operated 2/2-way valve program is use in closed circuits with low dierential pressure

EV250B with assisted lift can operate from zero
and up to 10 bar dierential pressure.

This 2/2-way valve program is especially to use
in closed circuits with low dierential pressure,
but demanding moderate ow rates.

Valve body in dezincication resistant brass for
ensuring a long life even in connection with
aggressive steam media.

EV250B is compatible with the broad Danfoss
coil program with enclosures from IP00 up to
IP67. Medium temperatures up to 140 °C (low
pressure steam).

Features and versions:

• For water, oil, compressed air and similar
neutral media

• Clip on coil

• Ambient temperature: Up to 80 °C

• Coil enclosure: Up to IP67

• The valve can be used for rough vacuum

• Water hammer damped

AI236986441319en-001001

Features

EV250B

Body material

DZR Brass

DN [mm]

10 - 22

Connection

G⅜'' - G1''

Sealing material

EPDM, FKM

Function

NC, NO

Kv [m3/h]

2.5 - 7

Dierential pressure range [bar]

0 - 10

Temperature range [°C]

-30 - 140

Solenoid valve, type EV250B

1 Portfolio overview

Table 1: Portfolio overview

© Danfoss | Climate Solutions | 2021.06 AI236986441319en-001001 | 2

1

2

3

4

5

6

7

8

9

123456789

Coil

Armature

Closing spring

Valve plate

Pilot orice

Diaphragm

Main orice

Equalizing orice

Assisted lift

Solenoid valve, type EV250B

2 Functions

2.1 Function NC

Coil voltage disconnected (closed):

When the supply voltage to the coil (1) is disconnected, the valve plate (4) is pressed down against the pilot orice
(5) by the closing spring (3). The pressure across the diaphragm (6) is built up via the equalizing orice (8). The
diaphragm closes the main orice (7) as soon as the pressure across the diaphragm is equivalent to the inlet
pressure below, due to the larger diameter of the upper side and/or the tension of the closing spring (3). The valve
will be closed as long as the voltage to the coil is disconnected.

Coil voltage connected (open):

When voltage is applied to the coil, the armature (2) and the valve plate (4) are lifted clear of the pilot orice (5).

If there is a dierential pressure across the valve, the pressure above the diaphragm (6) drops as the pilot orice is
larger than the equalizing orice. Therefore the diaphragm is lifted clear of the main orice (7). If there is no
dierential pressure across the valve, the armature (2) draws the diaphragm (6) clear of the main orice (7) using the
assisted lift (9). The valve will be open for as long as there is voltage to the coil.

2.2 Function NO

Coil voltage disconnected (valve is open):

When the supply voltage to the coil (1) is disconnected, the valve plate (7) are lifted clear of the pilot orice (9) if
there is a dierential pressure across the valve. The pressure above the diaphragm (10) drops as the pilot orice is
larger than the equalizing orice. Therefor the diaphragm is lifted clear of the main orice (12). If there is no
dierential pressure across the valve, the opening spring (5) draws the diaphragm (10) clear of the main orice (12)
using the assisted lift (8). The valve will be open for as long as there is no voltage to the coil.

Coil voltage connected (valve is closed):

When the supply voltage to the coil (1) is connected, the armature (3) will compress the opening spring (5) and the
closing spring will push the spindle (4)/ valve plate down against the pilot orice (9). The pressure across the
diaphragm (10) is built up via the equalising orice (11). The diaphragm closes the main orice (12) as soon as the
pressure across the diaphragm is equivalent to the inlet pressure below, due to the larger diameter of the upper side
and / or the tension of the closing spring (2). The valve will be closed as long as coil voltage is connected.

© Danfoss | Climate Solutions | 2021.06 AI236986441319en-001001 | 3

1

2

3

4

5

6

7

8

9

11

10

12

123456789101112Coil

Closing spring

Armature

Spindle

Opening spring

Armature stop

Valve plate

Assisted lift

Pilot orice

Diaphragm

Equalising orice

Main orice

Solenoid valve, type EV250B

© Danfoss | Climate Solutions | 2021.06 AI236986441319en-001001 | 4