Danfoss EV220W Compact Servo-Operated Solenoid Valve

EV220W compact servo-operated 2/2-way solenoid valve, G3/8 to G2

The Danfoss EV220W is a range of compact indirect servo-operated 2/2-way solenoid valves with brass bodies and connections from G3/8 to G2 (DN 10 to 50). It is designed for installations where space is limited and the medium is water, air, oil or a similar neutral fluid, and the EPDM version carries WRAS approval for drinking water. Seven Star LLC supplies the EV220W in Oman and the GCC as an independent supplier in Muscat. This page explains the version structure, technical limits and what to include in an RFQ.

EV220W technical specifications

How the EV220W servo operation works

In the normally closed version, the armature spring presses the armature onto a small pilot orifice. Pressure builds up above the diaphragm through the equalising orifice until it matches the inlet pressure, and the diaphragm then closes the main orifice. Energising the coil lifts the armature and opens the pilot orifice, which is larger than the equalising orifice, so pressure above the diaphragm falls and the line pressure lifts the diaphragm clear of the main orifice. The valve stays open as long as the minimum differential pressure and coil voltage are present. The normally open version works the other way round: it is open without voltage and closes when the coil is energised.

Opening and closing times by size

These times are indicative for water; the exact times depend on the pressure conditions. Longer closing times at the larger sizes reduce the risk of water hammer but must be considered in process timing.

Versions, seals and coils

The ordering program lists NC and NO bodies in EPDM and NBR for every size, in combination with coil voltages including 230 V 50/60 Hz (8 W), 24 V 50/60 Hz (9.5 W) and 24 V DC (6.5 W). Choose EPDM for water, drinking water and WRAS applications and NBR for compressed air and oil. The standard clip-on coil is suitable for dry and humid environments. A hot-coil warning applies for continuous power-on time, so keep flammable material away from the coil and do not touch it with bare hands.

Selection and ordering checklist

• Medium: water, drinking water, compressed air or oil, which decides EPDM or NBR.
• Function NC or NO and the fail-safe position required.
• Size and connection from the required flow and Kv value.
• Differential pressure available: servo valves need a minimum of 0.2 to 0.3 bar.
• Coil voltage: 230 V AC, 24 V AC or 24 V DC.
• WRAS approval needed or not for the application.
• Medium temperature and ambient temperature limits.

Installation, commissioning and maintenance

Fit a 50-mesh (297 micron) filter in front of the valve. In water applications, exercise the valve at least once every 24 hours to reduce sticking risk from calcium carbonate, zinc or iron oxide build-up. For water quality, the datasheet recommends hardness 6 to 18 °dH and conductivity 50 to 800 µS/cm to avoid scaling and dezincification, and advises against stagnant water above 25 °C inside the valve. Observe the permitted mounting angle shown in the datasheet and the flow direction arrow.

Where the EV220W fits among related valves

The EV220W is the compact alternative to the larger EV220B 15-50 servo valve range and can be considered where the installation space is tight. For very small flows or dirty media the direct-operated EV212B with isolating diaphragm is the better match, and the EV220W 10-50 WRAS series suits drinking-water service. All of these use clip-on Danfoss coils, so a stock of 24 V and 230 V coils can serve several valve types.

Typical applications in Oman and the GCC

Compact servo valves of this class are used on process water, cooling water, humidifier and irrigation lines, compressed-air drain and control circuits, and light oil lines in plant rooms. In hot climates, check that the ambient temperature at the coil stays within −40 to 50 °C, and use the filter and exercise routine in hard water.

Information to send with an RFQ

• Size, connection and NC or NO function.
• Seal material and coil voltage.
• Medium, pressure and temperature.
• Quantity and delivery location in Oman or the GCC.

Site conditions in Oman for the EV220W

Valves and their accessories in Oman work in demanding conditions: high ambient temperatures, direct sun on outdoor pipe racks, dust, and corrosive coastal air at many oil, gas and water sites. When you specify the EV220W, confirm the pressure and temperature ratings, body and trim materials and any sour-service or hazardous-area requirements against the actual line data, and check that seals and soft parts suit the process medium and the full temperature range.

For reliable operation, plan access for maintenance, define which spare parts are kept on site, and record the configuration of each installed EV220W. Sending the complete process data sheet with your RFQ allows the selection to be checked before the order is placed.

Documents and quotation

A Danfoss datasheet for the EV220W solenoid valve is attached on this page.

Send the size, function and coil voltage and we will confirm the matching valve.