Abstract: A horizontal pumping system has a motor, a suction chamber and a pump driven by the motor. The pump includes a primary stage assembly and a low NPSH stage assembly connected between the primary stage assembly and the suction chamber. The low NPSH stage assembly is external to the primary stage assembly. The low NPSH stage assembly includes a diffuser connected to the pump housing and a low NPSH impeller contained within the diffuser. The diameter of the low NPSH stage assembly is optionally larger than the diameter of the primary stage assembly.

Abstract: A horizontal pumping system has a motor, a suction chamber and a pump driven by the motor. The pump includes a primary stage assembly and a low NPSH stage assembly connected between the primary stage assembly and the suction chamber. The low NPSH stage assembly is external to the primary stage assembly. The low NPSH stage assembly includes a diffuser connected to the pump housing and a low NPSH impeller contained within the diffuser. The diameter of the low NPSH stage assembly is optionally larger than the diameter of the primary stage assembly.

Abstract: A pump for pumping a multiphase fluid includes a housing and a rotor with an outer surface. A plurality of inducer vanes are attached to the rotor hub, each having a leading edge and a trailing edge where the leading edge of one inducer vane overlaps the trailing edge of an adjacent inducer vane by a first overlap angle. A plurality of impeller vanes are also attached to the hub. The impeller vanes each have a leading edge and a trailing edge where the leading edge of one impeller vane overlaps the trailing edge of an adjacent impeller vane by a second overlap angle larger than the first overlap angle. The pump includes a rotor flow channel extending between the hub outer surface and the housing inner surface. The rotor flow channel has an inlet area and an outlet area, whereby the outlet area is smaller than the inlet area.

Abstract: A pump for pumping a multiphase fluid includes a housing and a rotor with an outer surface. A plurality of inducer vanes are attached to the rotor hub, each having a leading edge and a trailing edge where the leading edge of one inducer vane overlaps the trailing edge of an adjacent inducer vane by a first overlap angle. A plurality of impeller vanes are also attached to the hub. The impeller vanes each have a leading edge and a trailing edge where the leading edge of one impeller vane overlaps the trailing edge of an adjacent impeller vane by a second overlap angle larger than the first overlap angle. The pump includes a rotor flow channel extending between the hub outer surface and the housing inner surface. The rotor flow channel has an inlet area and an outlet area, whereby the outlet area is smaller than the inlet area.