The injector in a common rail system consists of the nozzle, an actuator for Piezo injectors or a solenoid valve for solenoid valve injectors, as well as hydraulic and electrical connections for actuation of the nozzle needle.
It is installed in each engine cylinder and connected to the rail via a short high-pressure pipe. The injector is controlled by the Electronic Diesel Control (EDC). This ensures that the nozzle needle is opened or closed by the actuator, be it solenoid valve or Piezo. Injectors with Piezo actuators are somewhat narrower and operate at a particularly low noise level. Both variants demonstrate similarly short switching times and enable pre-injection, main injection and secondary injection to ensure clean and efficient fuel combustion at every operating point.