The rail distributes the fuel compressed by the high-pressure pump to the injectors and also serves as a high-pressure fuel accumulator. Due to the increasingly higher pressures involved in gasoline direct injection, brazed rails are gradually being replaced by forged ones. The design possibilities of hot forging allow a single-piece component to be produced which, in addition to being able to withstand higher pressure, also has advantages in terms of leak tightness (hydrocarbon emissions), stiffness and dimensional accuracy. Due to the ethanol content in the fuel, stainless steel grades are used.

At the customer’s request, Hirschvogel can assume responsibility for development, including all validations and tests. Hirschvogel is also already prepared for further increases in operating pressures and can draw on its experience with diesel rails. Within the framework of a development project, a gasoline rail made of stainless steel was designed, produced and tested. This verified the fatigue strength of the rail at an operating pressure of 1,000 bar.