Maintaining high pressure in the rail is necessary for the injectors to function properly. It is technically known as a common rail and is basically a pipe (generally, looks similar to a rail) which is used to deliver fuel to each and every fuel injectors on internal combustion engines. The Common Rail system was developed as a prototype in the late 1960s by Robert Huber of Switzerland and this technology further bettered by Dr. Marco Ganser at the Swiss Federal Institute of Technology in Zurich, later of Ganser – Hydromag AG (est.1995) in Oberägeri. Common Rail direct fuel injection (Crdi) is the modern version of direct fuel injection system for petrol and diesel engines. There are some fuel rails which incorporate an attached fuel pressure regulator. They are also used on engines with multi – point fuel injection systems, although some of these systems use a fuel distributor with individual pipes or tubes to feed each injector. It used as gasoline direct injection engine technology in gasoline engines. It has a high – pressure (maybe over 1,000 bars or 100 MPa or 15,000 psi) fuel rail feeding individual solenoid valves, as opposed to low – pressure fuel pump which feeds as unit injectors (or pump nozzles) in diesel engines. Now – a – days the Third – generation common rail diesels feature piezoelectric injectors for increased precision with fuel pressures reaching up to 3,000 bar (300 MPa; 44,000 psi). Solenoid or piezoelectric valves makes it possible for fine electronic control over the fuel injection time and quantity, and the higher pressure which the common rail technology makes available provides better fuel atomisation.