Centrifugal volute pump with discontinuous vane-island diffuser

A centrifugal pump includes a casing containing a volute channel having a cutwater at an entrance thereof. An annular vane-island diffuser is fixed in the casing concentrically within the volute. The diffuser is arranged to be separate and discontinuous from the cutwater of the volute. An impeller rotatably mounted on a shaft is disposed concentrically within the diffuser. The diffuser can be formed, e.g., by an investment casting process, integrally with the casing, or alternatively, independently of it. By arranging the diffuser to be independent of the cutwater of the volute, the diffuser can be "clocked" or "overturned" relative to the cutwater to minimize radial loads on the cutwater and dynamic loads on its leading edge. Additional advantages of the novel design include reductions in pump weight, radial loads, friction loss, design and modeling time, and the energy of outgoing acoustic waves at the pump discharge.