Abstract: A device for regulating the pressure of a tire on a moving vehicle includes an inlet channel to be linked to an exterior pressure supply, an outlet channel on the tire and normally closed by a valve head, as well as a mechanism which, responding to the pressure from the supply line, pushes against the valve head to open it. This mechanism includes, within a chamber directly communicating with the supply channel, a moveable assembly one of the surfaces of which is directly submitted to the pressure of the chamber, while the other surface is submitted to the same pressure by means of a calibrated outflow channel or restriction outlet introducing a delay in the establishment of the pressure.