A device for controlling a liquid flow by means of a gas pressure. The device comprises a pressure chamber (5), in which an overpressure, an underpressure or atmospheric pressure may prevail. The pressure in said pressure chamber (5) can be used for allowing the liquid flow to pass or for stopping said liquid flow. Furthermore the liquid flow can be limited to a predetermined rate of flow. The device may interalia be used in sewage systems, hydraulic engineering works and irrigation works.