Abstract: An axial flow-type pump for separating immiscible fluids having different specific gravities and a discharge manifold fluid connected to the fluid pump for drawing of the fluid having the heavier specific gravity. The fluid pump employs a rotatable impeller mechanism having a hollow core and a decreasing axial pitch in the direction of fluid flow. The fluid interface between the pump and the discharge manifold is adjustable, so that the discharge of the fluid having the heavier specific gravity can be adjusted. The fluids are introduced into the inlet end of the rotatable impeller to produce a high velocity swirling action in the fluids and a low pressure area along the longitudinal axis of the flow line, to generate a high centrifugal force as the fluids move axially and cause the fluid having the heavier specific gravity to migrate to the perimeter. The discharge manifold is then used to draw off the fluid having a heavier specific gravity.