Abstract: A pneumatic regulator in the form of an electro-pneumatic device (an I/P regulaor) in which the pressure of pneuamtic medium is controlled in response to an electrical signal in which the pneumatic pressure regulator incorporates a control volume whose pressure is used to regulate the main pneumatic pressure and the pressure in the control volume being under the control of pneumatic valves, the valves being opened and closed by electrical signals provided by an electrical circuit, which circuit incorporates electrical storage so as to permit the electrical circuitry to operate the valve on currents in the range 4-20 mA so that the electro-pneumatic regulator can be operated directly by electronic control systems without the need of supplementary electrical feeds.