Profile: Online Pump Supplies.com specializes in providing different types of pumps. Horizontal multistage pump is a variety of centrifugal pump that uses a rotating vane impeller to draw in liquid and pressurizes it. Liquid enters through the suction port to the center of the first impeller and is directed along a horizontal pump shaft to successive multi-stage impellers, usually two or four – and thence to a discharge port. This type of pump design is used in heavy duty applications.