Solenoid Valves

Fuel Solenoid Valve: Working Principle, Specifications and Selection

Learn how fuel solenoid valves shut off flow on burners and fuel lines by electrical signal, and how to choose the right seal material and specifications.

ORFA Technical TeamUpdated: Oct 30, 20264 min read

Fuel solenoid valve – electromagnetic valve for burners and fuel lines

Safe and precise fuel control in industrial plants is critical for energy efficiency, process continuity and safety. A fuel solenoid valve is an electromechanical valve that opens and shuts off the fuel supply to burners and fuel lines on an electrical signal. A correctly selected fuel solenoid valve cuts the fuel instantly on command from the control system and protects the plant against potential hazards.

This article covers how fuel solenoid valves work, their advantages, typical specifications and the often overlooked question of seal material selection.

What Is a Fuel Solenoid Valve?

A fuel solenoid valve consists of an electromagnetic coil (solenoid) and a movable core (plunger) and is used to control the flow of liquid fuels such as diesel and fuel oil, or gaseous fuels. It is usually connected to the burner control, boiler automation or fuel supply unit. For natural gas lines, natural gas solenoid valves designed specifically for that medium are used.

Working Principle

Coil energised: A signal from the control system sends current through the coil.
Magnetic field: The electromagnetic field overcomes the spring force and moves the plunger.
Valve opens: In a normally closed (NC) valve, the plunger movement opens the orifice and fuel flows.
Coil de-energised: The spring pushes the plunger back, the valve closes and fuel flow stops.

A normally closed (NC) valve closes automatically when power is lost. This fail-safe behaviour is the main reason NC valves are the standard choice for burner and fuel applications. Normally open (NO) valves stay open when de-energised and are only used in special circuits where that behaviour is required.

Advantages of Fuel Solenoid Valves

Fast, precise control: They open and close instantly on an electrical signal.
Safety: NC valves close automatically on power failure.
Easy automation: They integrate easily with burner controls, PLCs and boiler automation systems.
Application-specific options: Different body and seal materials, connection sizes and coil voltages adapt them to different fuels, pressures and temperatures.
Reliability: Correctly selected and used with clean fuel, they provide long, trouble-free service.

Typical Specifications

Typical specifications of the fuel solenoid valves supplied by ORFA are summarised below. Exact values vary by model and series, so please check the technical data of the specific product before selecting.

Feature	Typical value / option
Connection	Threaded 1/8″ – 1/4″ for burner-type valves (e.g. Parker-Lucifer E121/E122, Tork S40); 1/2″ and larger models also exist for bigger lines
Operating pressure	Depends on model; e.g. Tork S40 series direct-acting 0 – 30 bar
Body material	Brass (stainless steel tube and internals); stainless steel body on some models
Seal material	NBR (standard), FKM/Viton (optional)
Maximum temperature (by seal)	Depends on model and seal; e.g. Parker-Lucifer E121 K 63: -10 … +80 °C, Tork S40 (FKM/ruby seal): -10 … +160 °C
Protection class	IP65
Coil voltage	220 V AC standard; 24 V, 12 V AC/DC and other options depending on model
De-energised position	Normally closed (NC); normally open (NO) optional

Seal Material Selection

One of the most common mistakes in fuel applications is choosing a seal material that is not compatible with the medium:

NBR (nitrile): Good resistance to diesel, fuel oil and mineral oil based media; the standard choice for fuel lines.
FKM (Viton): Preferred for higher temperatures and more aggressive fuels.
EPDM: Suitable for media such as water and steam; it is not resistant to mineral oil based fuels and must not be used with them.

Tip: Installing a fuel filter upstream of the solenoid valve keeps dirt away from the valve seat and pilot orifices, reducing the risk of leakage and malfunction.

Applications

Oil-fired burners and boiler systems
Industrial heating systems and furnaces
Generators and fuel supply units
Fuel distribution and transfer lines
Industrial production processes

Frequently Asked Questions

Why are normally closed (NC) solenoid valves used on fuel lines?

An NC valve closes by itself when power is lost or the control system de-energises it, so fuel flow stops automatically in the event of a fault or power failure.

Can an EPDM-sealed solenoid valve be used on a diesel line?

No. EPDM swells and degrades in contact with mineral oil based fuels. For diesel and fuel oil, choose valves with NBR or FKM (Viton) seals.

Can a fuel solenoid valve be used on a natural gas line?

Natural gas lines require natural gas solenoid valves designed and approved for gas service. Always check the medium compatibility of the product when selecting a valve.

Conclusion

Fuel solenoid valves are essential components that control flow on burners and fuel systems safely, quickly and in an automation-friendly way. Choosing the right de-energised position, seal material, pressure rating and coil voltage directly affects system safety and performance. You can explore the options in our fuel solenoid valves product group and contact our technical team for help choosing the right valve.

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