Gas feeding system for an internal combustion engine, having a pressure reducing valve controlled by a pilot pressure

In a gas-supply system for internal-combustion engines, a pressure-reducing valve (7) is set between the reservoir (3) of the gas and a distribution manifold or rail (2) that feeds the gas to a series of electromagnetically controlled injectors (1) associated to the various cylinders of the engine. The pressure-reducing valve (7) brings about a pressure drop which depends upon a pilot-pressure signal that is sent thereto by a pilot solenoid valve (83). The electrical supply to the solenoid (99) of said pilot solenoid valve is controlled by an electronic control unit (C) according to the signal issued by a sensor (8) of the pressure in the rail (2) for the purpose of regulating the pressure in the rail (2) at a desired level, according to the operating conditions of the engine.