A two-stage valve comprises a housing fitted with an inlet port extending to an inlet chamber and configured for coupling to an upstream liquid supply line, and an outlet port extending from an outlet chamber and configured for coupling to a downstream supply line; a high flow-rate path extending between the inlet chamber and the outlet chamber fitted with a hydraulic element configured for selectively admitting liquid flow therebetween at a demand position defined by substantially high flow; a pressure regulating unit configured for controlling a pressure regulating flow path providing direct or indirect flow communication between the inlet chamber and the outlet chamber for allowing liquid flow therebetween at a leak position defined by substantially low flow rates.