What Is a Diesel Fuel System?

Over the past few decades, scientists and engineers have experimented with different types of fuels for use in cars, trucks, construction equipment, planes and other machines. Although fuels such as electricity and hydrogen have been developed or considered for this purpose, the most common fuels are still derived from petroleum. Gasoline is the most common type of fuel used in fuel systems. Another common type of fuel system, however, is the diesel fuel system.

Definition

A diesel fuel system is any fuel system (regardless of design) that runs on diesel. The purpose of the system is to inject specific amounts of fuel (diesel) into every cylinder of the engine at a specific time. Diesel fuel systems are regarded as being among the most efficient fuel systems and thus are applied in many freight or heavy industry machines. They usually include the base components of a fuel tank, fuel transfer pump, fuel filters, injection pump and injection nozzles.

Tank

Fuel tanks in diesel fuel systems usually are made of sheet metal or an aluminum alloy. The main function of this part is simply to hold the diesel.

Fuel Transfer Pump

The transfer pump transfers the diesel out of the fuel tank. It most commonly is placed outside of the fuel tank, but it also can be within the fuel tank or on the rear of the injection pump.

Fuel Filters

Fuel filters in a diesel system filter out any dirt or other contaminants that may enter the fuel system. All fuel passes through these filters. The filters are put into the system to protect the injector pump and injector parts, which would be damaged easily by dirt or contaminants.

Injection Pump

The injection pump of a diesel fuel system is the part that supplies the high pressure fuel for injection. There are many different types of these pumps.

Injection Nozzles

Injection nozzles spray diesel fuel into the combustion chamber of every cylinder.

Differences

The main difference between a gasoline engine system and a diesel engine system is that the diesel system injects the fuel directly into the cylinders. However, another difference is that diesel is more efficient (gets better mileage) than gasoline. It is heavier and oilier than gasoline and evaporates more slowly because of its weight. Additionally, a diesel system emits fewer compounds related to global warming than a gasoline system, although the diesel system is associated with higher emissions of nitrogen compounds related to acid rain and smog.