Abstract: A self-priming assembly for a multi-stage pump is provided. The self-priming assembly includes a first diffuser with a first central portion, a first diffuser axis, a first arcuate channel within the first central portion, and a first arcuate passage extending through the first central portion and a first peripheral portion having a first ledge. The self-priming assembly also includes a second diffuser with a second central portion, a second diffuser axis, a second arcuate channel within the second central portion, a second arcuate passage extending through the second central portion, and a second peripheral portion having a second ledge. The first ledge abuts the second ledge. Further, the self-priming assembly includes an impeller with an impeller axis. The first diffuser and the second diffuser are configured to be combined and to receive the impeller therebetween with the first diffuser axis, the second diffuser axis, and the impeller axis aligned.

Abstract: Single suction centrifugal pumps, pump casings, pump systems and vehicles for using pumps which include a single piece casing having a first cut-water wall and a second cut-water wall, corresponding joint-water paths communicating with respective discharge nozzles, the second cut-water wall spanning less than 180 degrees from a leading edge of the second cut-water wall to a trailing edge of the second cute-water wall, and in aspects, the discharge nozzles are offset from a horizontal centerline of a center opening of the casing, the cut-water walls define a diameter which is greater than 1.07 times the impeller diameter, and the diameter is constant for a portion of the walls and transitions to a varying diameter at trailing ends of the walls.

Abstract: The present invention relates to a reinforcing structure for a casing accommodating an impeller. A double-suction centrifugal pump includes: a rotational shaft (1); an impeller (2) secured to the rotational shaft (1); a casing (3) that accommodates the impeller (2) therein; and legs (5) secured to the casing (3). The casing (3) includes a suction volute (20) that communicates with a suction port (6), the casing (3) includes an upper casing (3a) and a lower casing (3b) fastened to each other, at least one rib (28A, 28B, 28C) is provided on each of both side surfaces of the lower casing (3b) constituting the suction volute (20), the rib (28A, 28B, 28C) extends in a radial direction of the rotational shaft (1) when viewed from an axial direction of the rotational shaft (1), and the rib (28A, 28B, 28C) is separated from the legs (5).