Abstract: The present invention provides a motor driven, helical screw conveyor having an impeller wheel at one end thereof. The screw conveyor is immersed in the liquid to be transferred and lifts the liquid so that the impeller may drive it through a first conduit and a first valve into a utilization device. The valve has three separate positions, the first of which permits delivery of a major portion of the fluid to the utilization device with a minor portion of the fluid being returned to the container via a second conduit. A second position of the first valve provides for flow of fluid from the container, through the first conduit, through the first valve and then directly back to the container via the second conduit.