Diesel nozzle is one of the main components of fuel injection system, it regulates the flow of fuel to the ultimate ignition Compartment. The main function of nozzle is to convert the diesel into the diesel vapours and spray it on the piston. in another word, the main purpose of the diesel injection nozzle is to direct and atomise the metered fuel into the combustion chamber. The design of combustion chamber dictates the type of nozzle, the droplet size and the spray required to acheive complete combustion within a given time and space.Multi-holes long stem nozzles (DLL-S,DLLA-S, DLLA-P) are used on direct injection modern diesel engines fitted to commercial vehicles, industrial & agricultural applications. BlueStars Disel use GCr15 steel to replace high speed steel (HSS) and 18Cr2Ni4W steel for diesel injection nozzle assembly. - Page 87