Solenoid Valves

Solenoid Valve Replacement Coils.

A solenoid valve coil is designed to convert electrical energy into lateral motion and typically consists of copper wire wound around a hollow bobbin or tube so when electric current flows through the coil, a magnetic field is generated. By placing a solenoid valve coil over a ferromagnetic core (usually magnetic 430F stainless steel armature) the magnetic field generated causes this ferromagnetic core or plunger to slide further up towards the magnetic field (into the coil) thus allowing a valve opening to be created.

This in turn can be utilised to either to control direct acting solenoid valve, connected to a diaphragm to produce an assisted lift Solenoid Valve or put into an external pilot to produce a servo or pilot assisted solenoid valve.

Solenoid valve coils come in a huge range of sizes, voltages, IP protection levels, temperature ratings and power levels in watts or VA. Care needs to be taken when replacing solenoid valve coils because all these factors must be considered.

Solenoid Coil Sizing.

When measuring a coil you need to measure accurately the internal diameter of the coil. Some solenoid coils may be fitted with a top plate with a reduced diameter to aid secure fitments to the armature / core tube. Then the depth of the internal core needs to be measured. If this matches up you are at the first step of finding the right coil.

Helpful hint - when buying solenoid valve coils try to replace according to brand.

Solenoid Coil Voltages.

Coils are manufactured for specific voltages, it is very rare that a coil will work on more than 1 voltage weather it be AC or DC. There are some instances of "Dual voltage coils" which can work on for example 12v DC or 24v AC, 48v DC or 24v AC but these are quite rare and this cannot be relied on to over come spares shortfall's.

Helpful hint - check your supply voltage rather than guessing or trying to read the coil voltage.

Solenoid Coil Temperature Ratings.

Coil winding have several temperature classes and are usually designed depending on the media, ambient temperatures and duty cycle (duty cycle being the power on time and power off cool down time) as all coils generate heat when energised a bit like a light bulb the more power they consume the hotter they will get. Standard coils are available for insulation
classes E, F and H. The insulation class determines the coil’s maximum operating temperature for a specific life:

  • Class H: 30 000 hours
  • Class F: 20 000 hours

Class F coils are rated to 155°C, basically the copper wire windings can withstand a working temperature up to but not exceeding 155°C. This are the most common form of solenoid coil and are ideally suited to working ambient temperatures up to 20°C and media up to 100°C.

Class H coils are rated to 180°C, basically the copper wire windings can withstand a working temperature up to but not exceeding 180°C. This are the most common form of solenoid coil and are ideally suited to working ambient temperatures up to 50°C and media up to 180°C.

Class N coils are rated to 200°C, basically the copper wire windings can withstand a working temperature up to but not exceeding 200°C. This are the most common form of solenoid coil and are ideally suited to working ambient temperatures up to 80°C and media up to 200°C.

Helpful hint - replace brand like for like if experiencing short life check supply voltage and application parameters.

Power Levels for solenoid coils

Solenoid coils come in a range of power levels, DC coils are measured in Watts, AC coils measured in VA (Volt Amps) and will have a higher Inrush current and lower Holding Current. Its a bit like weight lifting lifting a weight, it requires more energy to lift or move the weight than it does to hold in position.

Helpful hint Watts = volts x amps, Amp = watts divided by volts and finally volts = watts divided by amps so knowing any 2 you can work out the third.

You need to pay attention the the power ratings, under rated coils will over load and burn out and too higher power rating may well do the same.

Helpful hint - try to stay with the same power level (watt or VA) unless the coil fails quickly then check voltage supply and current availability then if need be consult your supplier.

Some standard solenoid coil types are shown below, read more about solenoid coils here...

solenoid valve replacement Coil system 8

Standard DIN 43650B IP65 Rated coil Rectangular DIN connector required

8 to 11 mm bore 22 mm wide various power levels from 1 to 7 Watts.

Usually used on Small Miniature solenoid valves and primarily in the pneumatics industry.

solenoid valve replacement Coil System 13/30

Standard DIN 43650A IP65 Rated coil Square DIN connector required

14.6 mm bore 30.0 mm wide various wattage or VA power levels from 1 to 15 Watts.

Usually used on general purpose solenoid valves. 

solenoid valve replacement Coil System 13/36

Standard DIN 43650A IP65 Rated coil Square DIN connector required

14.6 mm bore 36.0 mm wide two power levels either 15 Watts or 18.5 Watts.

Generally used on Shako general purpose solenoid valves.

solenoid valve replacement Coil 11630 T30

Typical Italian Standard coil DIN 43650A IP65 Rated Square DIN connector required

13.5 mm bore 30.0 mm wide various power levels from 8 watts to 10 Watts.

Usually used on Small Miniature solenoid valves and primarily in the pneumatics industry.  

solenoid valve replacement Coil 31400 T36

Typical Italian High Power coil DIN 43650A IP65 Rated Square DIN connector required

13.5 mm bore 36 mm wide various power levels from 14 to 20 Watts.

Usually used on Small Miniature solenoid valves and primarily in the pneumatics industry.

solenoid valve replacement Coil M16 Queen

Typical Italian Very High Power coil DIN 43650A IP65 Rated Square DIN connector required

13.5 to 16.0 mm bore 37.5 mm wide various wattage power levels. This one 26 Watts used on our MD solenoid valves also found on hydraulic solenoid valves.

Usually used on large solenoid valves and primarily in the hydraulics industry.

solenoid valve replacement Coil System 8 ATEX Coil
ATEX encapsulated EExmIIT4 IP65 Solenoid Coil

8.0mm top 11.0 mm bore 22 mm wide various power levels from 3.8 to 5.1 Watts.

Usually used on Small Miniature solenoid valves and primarily in the pneumatics industry, ideal Zone 21 and 22 ATEX application coil.

Fitted with 3 meter 3 core cable but can be found with 5 meter or terminal junction box. 

solenoid valve replacement Coil system 13 ATEX Coil
ATEX encapsulated EExmIIT4 IP65 Solenoid Coil

10/14.6 mm bore 36 mm wide various power levels from 8.5 to 10.1 Watts.

Usually used on standard hazardous area solenoid valves and primarily in the Oil and Gas and Food Industries, ideal Zone 21 and Zone 22 ATEX application coil.

Fitted with 3 meter 3 core cable but can be found with 5 meter or terminal junction box.

solenoid valve replacement Coil IP54

Typical American and Asian IP54 coil with 30 cm flying lead no DIN connector required

8 to 16.0 mm bore various widths various power levels from 8 to 26 Watts.

Usually used on large imported US and other non European solenoid valves.

Solenoid Coil Ingress Protection Levels.

Solenoid coils come with a wide range of IP (Ingress Protection) ratings according to general protection and Dust and Water Ingress. Please find below a basic IP Protection chart.

IP protection levels explained

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