Fuel injection systems

Fuel injection systems

Due to one of the most complete ranges of products available on the stainless steel market, Valbruna is able to offer and meet the numerous and complex technical and quality requirements that normally characterise the selection of the steels used in injection systems.

Steels that are used in the majority of cases for safety components in contact with the propellant of the motor (be it petrol, diesel, LPG or other) require adherence to high standards that only cutting edge processes can satisfy, especially in the field of non-destructive testing (eddy current and ultrasonic). Thus, the important and continued investments in recent years allow us to satisfy the most stringent requirements for many ranges of product, such as ultrasonic testing of 100% of the cross section of the bar.

Another very important technical aspect for these applications is the level of micro cleanliness required. Due to the fact that we have very important and sophisticated primary (continuous casting and ingot casting) and secondary casting (ESR and VAR) available, Valbruna is able to satisfy any requirement, supporting the customer in choosing the most appropriate form of casting, often must represent the correct synthesis between the needs of the designer and that of production. A very common example is the use of AISI 304 with improved machinability (Valbruna MVAISL) ensures high productivity during machining, however, high machinability comes at the expense of micro cleanliness.  In such cases, the customer must use an AISI 304 with manufacturing processes targeted at obtaining a high micro cleanliness (Valbruna AISL).

Many choices of material are available for these applications and materials used range from ferritic steels to austenitic or precipitation hardening steels (steels known as PH) to duplex, depending on the technical requirements preferred by the engineer that characterises that particular injection system.

The injection systems can be fundamentally divided into three main types of products: the injector, the injection pump and the rail.

Ferritic steels are more commonly used in the components that make up the injector due to the magnetic characteristics that distinguish this type of steel. Martensitic steels are instead preferred for the pump due to the improved mechanical properties that they can provide. Finally the most common austenitic steels are normally used for the rail but with very strict requirements in the field of non-destructive testing and micro cleanliness.

As already mentioned, the use of one steel over another depends on the engineer. Therefore, there is (such as for steel for engine valves) a list of typical steels used for injection systems. Although we list the most commonly used in this area below, please contact us directly if the steel that you are interested in is not present in this list.