Abstract: A centrifugal pump may include plural pump stages, each comprising an impeller assembly, a stationary disc assembly and a diffuser assembly, all disposed about an impeller shaft that is driven by a motor. The impeller assembly may include upper and lower impeller shrouds having facing surfaces, and a plurality of impeller vanes extending between the surfaces of the shrouds to define a plurality of flow passages for liquid to flow outwardly from a central hub of the impeller assembly. To assist in pressure recovery of the pump, the distance between the surfaces of the impeller shrouds may increase as the radial distance from the central hub increases.