A centrifugal pump for handling abrasive-laden fluid is described. A centrifugal pump system for handling abrasive-laden fluid includes an impeller including an annular balance ring extending longitudinally on a top side of the impeller and an annular skirt extending longitudinally on a bottom side of the impeller, one of the annular balance ring, the annular skirt or a combination thereof having portions defining a plurality of apertures, wherein the plurality of apertures form an abrasive-media relief path that bypasses at least a portion of a clearance gap and merges with a primary working-fluid flow path. A centrifugal pump impeller includes a bottom shroud, an annular skirt extending longitudinally upstream from the bottom shroud, the annular skirt encircling a central hub, and the annular skirt having an aperture extending through a thickness of the annular skirt.

A low-cavitation impeller for a centrifugal pump is provided. The impeller provides a smooth flow path from the inducer section through to the outlet section. Continuous main blades run from a leading edge at the inlet eye to a trailing edge at the impeller outlet, and continuous secondary blades run from a leading edge in the transition region to a trailing edge at the impeller outlet.

A centrifugal fluid machine includes an impeller (4) that has a front shroud (41) arranged on one side in an axial direction, a rear shroud (42) arranged on the other side in the axial direction, and a plurality of blades (43) provided side by side in a circumferential direction between the front shroud and the rear shroud and is rotatably supported within a casing (2); a suction passage (2A) that allows a fluid to be sucked therethrough in the axial direction toward the impeller with the rotation of the impeller; a discharge passage (2B) that allows a fluid delivered under pressure by the impeller with the rotation of the impeller to be discharged in a direction intersecting the axial direction of the impeller; and a first flow path (5A) that communicates with the discharge passage, leads to the suction passage through a gap between the casing and the rear shroud, and an opening (5Aa) that opens toward the downstream side of the suction passage in a suction direction of a fluid. The opening area of the opening is set so that the ejection speed (Vs) of a fluid ejected from the opening to the suction passage is matched with the suction speed (V) of a fluid sucked into the suction passage.

An electrical submersible pump (ESP) assembly. The ESP assembly comprises an electric motor having a first drive shaft; a seal section having a second drive shaft that is coupled to the first drive shaft; a third drive shaft that is coupled to the second drive shaft; and an axial flow centrifugal pump stage, wherein the centrifugal pump stage comprises an impeller coupled to the third drive shaft and a diffuser, wherein the impeller defines a plurality of impeller vanes attached between an impeller hub and an impeller shroud, wherein the impeller shroud is a straight-walled cylindrical shape, wherein the diffuser defines a plurality of diffuser vanes attached between a diffuser hub and a diffuser shroud, and wherein the diffuser shroud is a straight-walled cylindrical shape.