A centrifugal pump assembly includes a pump housing that encloses a rotor unit that includes an impeller. The pump housing includes an inlet that defines a first passageway that is aligned with the rotor rotational axis, an outlet that defines a second passageway that is aligned with a second axis, and a volute that is provided on an inner surface of the pump housing. An exit opening of the volute faces the outlet and at least a portion of the fluid exiting the volute moves along a volute discharge axis. The volute discharge axis is tangential to a portion of fluid flow exiting the volute at the volute exit opening and is offset relative to the rotational axis. When viewed in a direction perpendicular to the first axis, the second axis is acutely angled relative to the volute discharge axis.

A plain bearing (410) is fixed to a shaft hole (401) of an impeller (400) of the pump (100) so as to rotatably support the impeller (400) with respect to the shaft (300), and is restricted from moving in an axial direction by an annular restrictor (310) fixed to the shaft (300). On an end face (411) of the plain bearing (410) facing the restrictor (310), a lubrication groove (412) connecting a radially inner side and a radially outer side of the end face (411) to supply cooling water onto the end face (411) for lubrication, and a dynamic pressure generating groove (413) that introduces a flow of cooling water created by rotation of the impeller (400) to generate a dynamic pressure, are provided. The present bearing suppresses an increase in rotation torque of the impeller (400) during high speed rotation.

A technique facilitates operation of a pump, such as a submersible pump in an electric submersible pumping system. The pump has a sequential diffuser and impeller which are operationally engaged via a thrust device. In some embodiments, the diffuser and impeller also are operationally engaged via a front seal. A bypass channel is used to route a flow of fluid from a tip region of the impeller to an inlet region of the impeller without passing through the thrust device during operation of the pump.

It is an object of the present invention to provide a sealing structure for a casing that can reduce the number of used gaskets and achieve further weight reduction, with the sealing function of the gaskets secured. The object is solved by including: a case 2 having an opened top; a cover 3 attached to the top of the case 2 to form a fluid flow path therein; a center plate 5 interposed between the case 2 and the cover 3 and partitions an inner space into the side of the case 2 and the side of the cover 3; and a gasket 4, which is disposed between the case 2 and the cover 3, and forming the center plate 5 so as to have a size that is within an inner peripheral side relative to a sealing line 41 of the gasket 4 and stacking this center plate on the gasket 4, and attaching the cover 3 to the top of the case 2 with the stacked gasket 4 and center plate 5 sandwiched there between to compress the gasket 4 with the mutual butting surfaces between the case 2 and the cover 3.

A pump system for high pressure, high volume applications is presented. The pump system includes a turbo-shaft engine having a drive shaft and a high pressure, high RPM centrifugal pump coupled to the drive shaft. In certain embodiments the pump system further includes a second low pressure, high RPM centrifugal pump coupled to the drive shaft.

A housing element for a pump or of a pump has a housing inner wall defining a flow channel for a fluid medium extending along a central axis. The cross section of the flow channel is greater in a main flow direction and the housing inner wall has a surface structure configured such that it counteracts a return flow counter to the main flow direction along the housing inner wall of the fluid medium. The housing element can act as a pump housing and be combined with a pump.

Technologies are generally described for pump devices that include an adaptive cutwater and impeller arrangement. The power end of the pump device can be coupled to a motor to drive an impeller. The primer plate and impeller of the pump device are removable from the pump casing such that the primer plate and impeller can be replaced or modified as desired for different applications. In some examples, the pump casing includes a primer plate that is removable from the pump casing, where the primer plate includes a discharge cutwater tongue that is specifically spaced and sized to service an impeller of a desired design. The discharge cutwater tongue and impellers in the pump device may thus be serviced for replacement parts, as well as to modify the pump device for different fluids of different fluids properties or hydraulic requirements as may be needed in different applications.

The present invention has an object of providing a sealing structure for a casing that suppresses the deformation of a center plate of a laminated gasket on a partition wall and ensures the compression amount of a bead on the partition wall, without the center plate being thickened. The object is achieved by a sealing structure including: a case 2, the interior of which is partitioned by a partition wall 25 into an upstream chamber 23 and a downstream chamber 24; a cover 3, which forms a flow path for a fluid that causes the upstream chamber 23 and the downstream chamber 24 to be communicated inside; and a laminated gasket 4, in which a first gasket 41, a center plate 43, and a second gasket 42 are laminated, and that is provided between a butting surface 22a of the case 2 and a butting surface 32a of the cover 3, in which the first gasket 41 and the second gasket 42 respectively include beads 41b and 42b along the butting surfaces 22a and 32a, and the first gasket 41 and the center plate 43 respectively include partition-wall sealing portions 41a and 43a along the partition wall 25, the partition-wall sealing portion 41a of the first gasket 41 includes the beads 41b, and the cover 3 is provided with a contact portion 34 that applies a contact force to the partition-wall sealing portion 43a of the center plate 43.

A back-to-back centrifugal pump comprising a pump inlet, a pump outlet, a pump shaft, a set of first stages, and a set of second stages in a back-to-back arrangement. Between the two sets of stages an intermediate crossover module is arranged. The first and second sets of stages comprise respective first outer diaphragms and second outer diaphragms. The outer diaphragms and the intermediate crossover module are stacked together and form a pump casing. The intermediate crossover module forms at least one axial transfer channel between the two sets of stages, and a fluid connection between the set of second stages and the pump outlet. The second diaphragms comprise each at least one peripherally arranged through aperture. The through apertures are aligned to form at least one passageway, which fluidly connects the axial transfer channel with a most upstream one of the impellers of the second set of stages.

A heater pump includes a motor and a pump assembly. The pump assembly includes a pump housing having an inlet and an outlet. An impeller and a heater are disposed within the pump housing. The heater includes a heater housing having an inner wall, an outer wall, a lower wall and an upper wall forming a heating chamber. A heating element is disposed within the heating chamber. The inner wall defines an inlet channel connecting the impeller with the inlet of the water pump. Water flowing through the pump is heated by contact with the heater housing and/or the heating element.