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February 27, 2020

When we talk about an aircraft’s engine, we can’t compare it with a regular car engine. There are many differences between the two. In order to manufacture an aircraft engine mount, it is essential that the aircraft engine is studied properly, so the aviation engineers can design, build, and install the aircraft engine mount accordingly. Apart from this, there are many more factors that assure the safety of the aircraft and the aircraft’s engine injectors are among them.


The injectors are responsible for supplying the necessary amount of fuel to the engine for combustion in an aircraft. The injection system provides high-pressure fuel to the engine compression cycle. When in contact with the air in high temperatures, it ignites causing combustion. This system consists of a displacement pump capable of injecting different amounts of fuel, thanks to the pistons that are attached to each injector or cylinder of the engine.

The injectors are, therefore, solenoid valves capable of opening and closing millions of times with a very precise reaction to the electric pulse that drives them, without fuel leaks. They’re responsible for supplying the appropriate amount of fuel to the intake duct or to the pre-combustion chamber, depending on whether it’s a direct or indirect injection system, respectively, in a pulverized manner and without dripping so that the fuel is distributed as homogeneously as possible according to the operating regime of the engine.

Parts And Operations

An injector consists of the following parts: nozzle holder, nozzle, nozzle nut, cap nut, stem, return connector, spring, spring adjusting nut and fuel inlet. The operation of an injector is not as complex as it may seem at first glance. The spring is activated by means of the rod, while the force with which the fuel is sprayed is adjusted by means of the nut attached to it. The fuel circulates from the marked inlet to the perforated duct in the nozzle holder.

The tip of the needle valve, which is attached at the end of the nozzle, is responsible for preventing the passage of liquid through the holes when it travels under pressure through the injector ducts and will rise when you have to atomize the fluid to the chambers of combustion. In the process, a small amount of fuel is released upwards, allowing the needle, the nozzle and the rest of the components to be lubricated before leaving the connection for the return tube and returning to the tank.

The way in which the fuel is discharged is called an atomization pattern, and it will depend on the pressure it carries inside the injector as well as the number, size and angle of the holes in the nozzle. Since it’s the last responsible part for injecting sufficient liquid charge in the combustion chamber so that it can burn optimally. Depending on the type and size of the engine, we can find a wide variety of nozzles, although if what we want is to classify the injectors, the best way to do this is by attending to its operation.

We can divide the types of injectors mainly into two classes:

Mechanical Injectors

These were common in diesel engines until the arrival of single -rail or common-rail injection systems. They work by means of a system of feeding in charge to control the quantity and the moment to pulverize the fuel of mechanical form.

Electronic Injectors

These are most common in gasoline engines. They have multiple sensors that send the information to the control unit so that it approves when and how much fuel must be provided at each moment. Therefore, the control unit activates them and they close by recovering an internal spring. Surely it’s now easier for you to understand the task that the injectors fulfill and the role of the injection system inside our aircraft.

Acorn Welding is an aviation repair and manufacturing specialist based in Edmonton, Alberta. Visit our website to know more or call us for personalized customer service.