Engineers devised the fuel shutoff solenoid, an electromagnetically-operated valve to turn off an engine's fuel supply remotely. Used on diesel vehicles, it prevents fuel from leaking from the infusion fuel pump once the engine is turned off. The engine's starting procedure necessitates the momentary activation of a pull-in coil connected to the solenoid.

Standard solenoids have a valve body and solenoid assembly that are the same, with the solenoid attached to a valve stem. Activating the solenoid causes its plunger to move, releasing the spring-loaded poppet out of its seat and allowing fuel to flow through the valve.

Returning the poppet to its core once the solenoid is turned off, the fuel flow is shut off. A human operator or the engine management system may trigger the solenoid that turns the engine off.

 

How does a fuel shutoff solenoid function?

 

In response to an electric current, a standard solenoid valve generates a magnetic field that causes the valve to close or open. The fuel shutoff solenoid in an engine is hardwired to the machine's power supply. The battery supplies electricity to the solenoid valve, which opens to let diesel fuel flow from the reservoir to the engine.

While functioning normally, diesel fuel flows through an inlet pipe and into a solenoid that controls fuel flow. There is a rubber plug at the end of the input pipe, and it is secured in place by a metal spring connected to the rear of the plug and a metal bar that runs perpendicular from the plug to a metal pin close to the solenoid coil.

When an electric current flows through the solenoid valve, a magnetic field is created, and the pin is retracted, the valve's stopper is pulled away from the inlet pipe. When the plug is removed, the fuel line may provide the engine with fuel. However, a fuel shutoff solenoid is distinguished from a standard solenoid by its capacity to receive and process signals from the vehicle's electrical system.

The gasoline shutoff solenoid's power source can be operated manually, automatically, or by combining the two. The solenoid can be employed to disable the engine, as is the situation in most jet aircraft, or as part of an automatic safety system. Typically, these valves will open during the startup sequence of a system and close if an unsafe state is identified. It instantly shuts off the fuel supply to the engine or burner, eliminating the potential for worsening the situation. When installed as part of a vehicle's security system, these valves cut off fuel in the event of a theft.

 

Applications

 

Solenoid valves are widely utilized in several settings and are among the most popular types of remote fluid flow devices. One such device is the fuel shutoff solenoid, which you can use to remotely and, in certain situations, mechanically turn off fuel to a motor or burner.

These valves are often constructed as a single unit incorporating two parts. The gasoline shutoff valve is the first and is usually standard, brass poppet-style. In most cases, a solenoid will be placed on top of a valve body, with the operational stem attached to the plunger.

A powerful magnetic field is generated around the solenoid coil when an appropriate electric current flows through it. The solenoid plunger is swiftly drawn into the coil by this magnetic field. Fuel can flow through the valve because the solenoid's moving plunger is coupled to the valve stem and lifts the poppet off its seat.

When the gasoline shutdown solenoid loses power, the poppet is returned to its seated position by the valve spring, sealing the valve and activating the solenoid to its subsequent duty cycle.

 

Take away

 

In contrast to pumps, diesel fuel shutoff solenoids do not use mechanical means to drive diesel fuel via the valve. A pressure difference between the input and outlet pipes of a  fuel shutoff solenoid is crucial.

The intake pipe pressure must be greater than the outlet pipe pressure to push diesel fuel via the solenoid valve. Even though the solenoid is open and the stopper is in place, diesel fuel won't flow through the valve if the pressure inside the solenoid has been equalized.