Regulating device, comprising a housing providing a first chamber in which a first pressure is present and a second chamber in which a second pressure is present; a flow restriction valve positioned in the housing , wherein the flow restriction valve comprises a valve body acting together with a flow restriction seat ; and wherein the flow restriction valve adjusts the flow from the first chamber into the second chamber ; a servo valve positioned in the housing , wherein the servo valve comprises a valve body attached to a membrane , wherein the membrane defines a servo chamber in which a servo pressure is present, wherein the servo chamber is connected to the first chamber though a fixed flow restriction element , and wherein the servo chamber is connected to the second chamber though an adjustable flow restriction element ; characterized by a stepper motor for moving the valve body of the servo valve , wherein the position of the valve body of the servo valve is direct driven by the stepper motor , wherein the movement of the valve body of the servo valve adjusts the adjustable flow restriction element , wherein the adjustment of the adjustable flow restriction element causes a change of the servo pressure being present in the servo chamber which is used to move the flow restriction valve to a position reflecting a defined flow resistance between the valve body of the flow restriction valve and the flow restriction seat , wherein the position of flow restriction valve is defined and controlled by the position of the servo valve and the equilibrium of axial forces that depend from the pressures in first chamber , the second chamber and the servo chamber , wherein the second pressure within the second chamber is measured by a sensor, and wherein the stepper motor is operated on basis of the pressure measured by the sensor in such a way that the second pressure within the second chamber is kept constant. a housing providing a first chamber in which a first pressure is present and a second chamber in which a second pressure is present; a flow restriction valve positioned in the housing , wherein the flow restriction valve comprises a valve body acting together with a flow restriction seat ; and wherein the flow restriction valve adjusts the flow from the first chamber into the second chamber ; a servo valve positioned in the housing , wherein the servo valve comprises a valve body attached to a membrane , wherein the membrane defines a servo chamber in which a servo pressure is present, wherein the servo chamber is connected to the first chamber though a fixed flow restriction element , and wherein the servo chamber is connected to the second chamber though an adjustable flow restriction element ; characterized by a stepper motor for moving the valve body of the servo valve , wherein the position of the valve body of the servo valve is direct driven by the stepper motor , wherein the movement of the valve body of the servo valve adjusts the adjustable flow restriction element , wherein the adjustment of the adjustable flow restriction element causes a change of the servo pressure being present in the servo chamber which is used to move the flow restriction valve to a position reflecting a defined flow resistance between the valve body of the flow restriction valve and the flow restriction seat , wherein the position of flow restriction valve is defined and controlled by the position of the servo valve and the equilibrium of axial forces that depend from the pressures in first chamber , the second chamber and the servo chamber , wherein the second pressure within the second chamber is measured by a sensor, and wherein the stepper motor is operated on basis of the pressure measured by the sensor in such a way that the second pressure within the second chamber is kept constant. <EOS>