Abstract: A liquid supply system comprising of a source of liquid, at least one storage (325,326,312) at an elevation, supply pipe line (305) connecting the source of liquid to the said storage, a device to raise/move the liquid from the said source to the said storage, at least one outlet (370, 380) at or below the level of said storage; wherein the said storage is hermetically closed and is capable of holding the liquid under air pressure. The delivery pipeline is connected to the various outlets to supply pressurized liquid to the user after opening of the outlet (s) at any time including the period when the pump is not supplying to the closed storage facility. A one way valve (314) connected to the closed facility is activated by building up of liquid in the intermediary buffer line which creates a low pressure which forces the one way valve to open when the pressure in the system falls below atmospheric pressure.