A disposable pump for a liquid dispensing system includes a compressible container and a housing forming a chamber and a dispensing opening wherein the pressure in the chamber may be varied for pumping liquid from the container to the chamber, and from the chamber to the dispensing opening. A regulator is fixedly arranged in the chamber for regulating a flow of liquid between the container and the chamber and between the chamber and the dispensing opening. The regulator includes an outer valve for regulating the flow between the chamber and the dispensing opening. The outer valve is displaceable between a symmetrical position corresponding to a closed position, where the outer valve is in sealing contact with the housing, and a tilted position corresponding to a dispensing position.