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Why does my solenoid valve not shut off / not shut off instantly / not open?
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If you are having trouble with the valve's operation or it does not seem to function properly, please see
Solenoid valve fault locator DO LINK TO LOCATOR
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Are Solenoid Valves affected by the Pressure Equipment Directive (PED)?
The Pressure Equipment Directive (PED) is an EU Directive that becomes mandatory on the 29th May 2002. Danfoss Industrial Controls Division has reviewed its Industrial Valves range and the attached document explains which valves are, or are not, affected by the Directive.
Click here to download document
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Can Danfoss solenoid valves operate by themselves or do I need to buy other things?
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All Danfoss solenoid valves require electrical coils to work. The type of coil we recommend with the valve is noted on the valve product pages. A cable plug is also often required to fit onto the coil and is used for wiring up the electrical supply. In general we recommend using a filter with a solenoid valve, preferably a type with a removable element which can be cleaned. We also recommend a check valve if the solenoid will experience back pressure. All Danfoss solenoid valves have screwed connections so compression fittings are often required when used on tubing. Danfoss would also suggest that pipe work is properly supported and pipe clips are used where needed. Compression fittings and pipe clips can be sourced through your local premier distributor.
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What valve do you recommend for de-mineralised or de-ionised or even sea water?
Any of our solenoid valves with DZR bras are suitable for use on "technical water".
Danfoss offer certain versions of the EV220B 15-50 and EV220B 6-22 in DZR brass with EPDM seals. The new range of EV250B assisted lift (zero differential) valve is in DZR brass as standard, and in both EPDM and FKM seals.
In addition we also have a few larger sizes of the EV220B (direct-operated) valves and also the thermostatic valve AVTA.
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What valves do you recommend for Vacum?
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Many direct-operated valves (types EV210A and EV210B) are suitable for use on rough vacum, as is the lastest range the new assisted lift (zero differential) solenoid valve, EV250B. In our terms, rough vacum is within the range of 0 to 950 mbar gauge. We also specialize in high vacum applications up to 10-6 Torr.
To discuss your application, please call our technical support line on 0870 241 7010.
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When are calculations based on kv invalid?
The published kv refers to a fully open valve and is a measurement related to performance on water. It can be used to calculate performance on other fluids. It will be necessary to correct for different density. It may be necessary to correct for viscosity or for compressibility. Steam/vapour calculations need special consideration.
Note: The kv is only valid if the valve is fully open. Servo operated and assisted lift valves may partially open under some circumstances, and advice should be taken.
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What happened to the code numbers for WRAS (WRc) approved solenoid valves?
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Danfoss used to manufacture two versions of the EV220B 15-50B valve (previously known as EVSI 15-50) with EPDM seals. One of these versions had the WRAS (WRc) drinking water approval. Danfoss are now using the WRAS approved seals in both valves and can now reduce the code numbers but more importantly provide greater availability as it was only the UK which used the WRAS version. Now Danfoss in the UK can use the same version the rest of the world uses and can take advantage of the greater supply of stock and provide a larger quantity of ex-stock valves.
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What kind of valve can I use for potable water? (WRAS approved)
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You can use any of the valves which have the WRAS (WRc)approval for potable water. Danfoss has a huge range of WRAS approved solenoid valves from 1/8" up to 2" in size. The WRAS approved valves can be found within the normal valve product pages.
Only Normally Closed valves are approved for use on potable water, you will not be able to obtain a solenoid valve anywhere which is Normally Open and has the WRAS approval.
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What is the significance of different power ratings of solenoid coils?
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In respect of direct-operated valves, and also some servo-operated valves, the different coil power ratings allow valves to used for different differential pressures. The technical catalogues list the pressure limits that a valve can operate on with the different wattage coils. On some coils, using a higher wattage coil allows a different IP rating to be obtained, for instance IP67 is only available on the 10W, 12W and 20W coils while the 9W can only have an IP65 rating
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Which kinds of media are your valves not suitable for?
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Danfoss manufacture solenoid valves in many different body and seal materials to suit most media. If you are unsure as to the valves' suitability with the medium in question, please contact the Danfoss Controls Technical Team on:
0870 241 7010 or email uk.controls.technsupport@danfoss.com
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What is a kv-value?
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The kv-value is the flow capacity that the valve can handle. Figures quoted are based on water at 1 bar and is measured in m3/h. The kv-value is a more accurate way of comparing flow capacity between valves rather than using the valve orifice size.
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What is more important in selecting a valve size - system pressure / flow rate / port dimensions?
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All are important, although pressure and flow are the most important parameters when selecting a valve. Adapters can always be used to step up or step down to the right size of valve.
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What is the difference between direct and servo operation?
A direct operated valve relies solely on the force generated by an energized coil to open; a servo valve uses the differential pressure in a system to assist in opening.
Direct-operated valves are suitable for relatively low flow applications and with pipe sizes of 3/8" or lower. At this size high pressures can be achieved. At higher pipe sizes and larger flows servo-operated valves should be considered. Servo-operated valves require a minimum pressure or flow to keep the valve open whilst direct-operated valves do not require a minimum flow or pressure to operate.
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Why does the coil on the valve seem to be very hot?
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Solenoid coils do get very hot when energized continuously, this is normal.
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Are Danfoss coils continuously rated?
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Yes, all Danfoss coils are continuously rated
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What if my system has back pressure?
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If your system has back pressure then a check valve has to be installed downstream of the valve, only a few solenoid valves can cope with back pressure. If in doubt please call the Danfoss Controls Technical Team on:
0870 241 7010 or email uk.controls.technsupport@danfoss.com
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What IP ratings do the valves have?
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IP ratings apply to the cable plug which is fitted onto the solenoid coil. Danfoss can supply cable plugs and coils to IP65 or IP67. The IP rating is the plugs protection against mechanical and moisture penetration. The first number relates to mechanical penetration and the second number is the moisture penetration - the higher the number the greater the protection. Our IP67 coils can withstand submersion under water at a depth of 1 m for a period of 1/2 hour.
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Which coil can I use on a valve?
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You can use which ever coil we advise within the valve pages of the product catalogue. If we advise to use a 9W coil then you can use this or any other higher wattage coil. If in doubt please call the Danfoss Controls Technical Team on:
0870 241 7010 or email uk.controls.technsupport@danfoss.com
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I have a coil here - which valve can I use?
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As long as the coil is a Danfoss solenoid valve coil, you can use any valve which is suitable for your application. Danfoss have two main coil systems: Type A, a compact black coil system which fits all valves with A as the 6'th letter of the designation, e.g.. EV220A. Type B coils are blue in colour and fit all valves with the 6th designation as B, e.g. EV220B. Please select a product within the product pages. If you require help in selecting a valve, please contact the Danfoss Controls Technical Team on:
0870 241 7010 or email uk.controls.technsupport@danfoss.com
Also, please see our coil overview.
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Can you supply coils for hazardous areas?
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Yes, Danfoss are able to supply coils to EEx m or EEx d standards.
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Why do I have to order a valve and coil separately?
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Danfoss have decided to supply their valves and coils separately, as it enables us to hold greater stock of each variant possible. This allows Danfoss to be more flexible and provide a quicker delivery service for any requirement you may have.
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