Abstract: A device for the control of the delivery of the gas in self-propulsion gas systems, in methane gas systems in particular. The system includes a gas cylinder under high pressure, a pipeline which conveys the gas from the cylinder to the engine and devices for controlling the flow and pressure of the gas in the pipeline. A device includes a manual valve or cock (18) per cylinder, at least one pressure reducing valve (19) and one solenoid valve (20), which are integrated into one unit (16), which has a body with channels for the gas between an inlet (I) of the gas under high pressure and an outlet (U) for the gas under the desired reduced pressure. The unit is attached, as a single entity, at the inlet, to the cylinder, and, at the outlet, to the gas pipeline directed towards the engine to be fed.