Abstract: An impeller for a centrifugal pump includes a hub, a shroud extending outwardly from the hub and dividing the impeller into front and rear sides, a working vane on a first face of the hub and the shroud at the front side, a rear vane on a second face of the shroud at the rear side, and a balancing conduit extending through the hub from a first opening at the first face to a second opening at the rear side of the impeller. The first opening is disposed closer to the axis than the second opening, and the first opening is located within a circle formed by a radially innermost part of the working vane, while the impeller is rotated about the axis, and the second opening or the balancing conduit at the rear side of the impeller is located at a smallest diameter of the shroud.

Abstract: An impeller for a centrifugal pump, the impeller includes a front shroud, a rear shroud, and one or more working vanes therebetween, the front shroud having a front face opposite to the face having the working vanes, the rear shroud having a rear face opposite to the face having the working vanes, the front shroud having an outer circumference and a plurality of front pump-out vanes attached to the front face of the front shroud, the rear shroud having a plurality of rear pump-out vanes attached to the rear face of the rear shroud, the front pump-out vanes being dimensioned in accordance with an equation: ?i=1z(li)/D>8, where Z is the number of front pump-out vanes, l is the vane length measured along the leading surface of each front pump-out vane, D is the outer diameter of the front shroud.

Abstract: The present invention relates to a sealing arrangement for attaching a side plate often used with a pump volute of a centrifugal pump and an attachment screw used therewith. A characterizing feature of the sealing arrangement for attaching the side plate of a centrifugal pump, comprising at least a pump volute (10) and a side plate (130) with attachment screws (132) and flanges (164) of the screws (132) arranged in communication with the volute (10) or the cover of the casing, is that an annular seal (180) is arranged between the screw (132) and the volute or the cover of the casing.

Abstract: The present invention relates to a sealing arrangement for attaching a side plate often used with a pump volute of a centrifugal pump and an attachment screw used therewith. A characterizing feature of the sealing arrangement for attaching the side plate of a centrifugal pump, comprising at least a pump volute (10) and a side plate (130) with attachment screws (132) and flanges (164) of the screws (132) arranged in communication with the volute (10) or the cover of the casing, is that an annular seal (180) is arranged between the screw (132) and the volute or the cover of the casing.

Abstract: The present invention relates to a centrifugal pump and an impeller thereof. The present invention especially relates to modifying an impeller of a centrifugal pump in such a way that the pump may be used without a risk of damaging a shaft seal or the like at capacities higher than that at the optimal operating point. A characterizing feature of a centrifugal pump, comprising a pump volute (2), a rear wall (4) of the pump, an impeller (20) having a shroud (22) and balancing holes extending through the shroud, the impeller being attached on the pump shaft (6) and rotating inside the volute (2), is that the balancing holes (26) are arranged through the shroud (22) in such a way that an opening (30) of the holes (26) in the front face of the impeller shroud (22) is both in the rotational direction and ahead of an opening (32) located in the rear face of the impeller shroud (22) and closer to the axis (8) of the pump than the opening (32) in the rear face of the impeller shroud (22).

Abstract: The present invention relates to a sealing arrangement for attaching a side plate often used with a pump volute of a centrifugal pump and an attachment screw used therewith. A characterizing feature of the sealing arrangement for attaching the side plate of a centrifugal pump, comprising at least a pump volute (10) and a side plate (130) with attachment screws (132) and flanges (164) of the screws (132) arranged in communication with the volute (10) or the cover of the casing, is that an annular seal (180) is arranged between the screw (132) and the volute or the cover of the casing.

Abstract: The present invention relates to a centrifugal pump and an impeller thereof. The present invention especially relates to modifying an impeller of a centrifugal pump in such a way that said pump may be used without a risk of damaging a shaft seal or like at capacities higher than that at the optimal operating point. A characterizing feature of a centrifugal pump, comprising a pump volute (2), a rear wall (4) of said pump, an impeller (20) having a shroud (22) and balancing holes extending through said shroud, said impeller being attached on the pump shaft (6) and rotating inside said volute (2), is that said balancing holes (26) are arranged through the shroud (22) in such a way that an opening (30) of said holes (26) in the front face of the impeller shroud (22) is both in the rotational direction in ahead of an opening (32) located in the rear face of the impeller shroud (22) and closer to the axis (8) of the pump than the opening (32) in the rear face of the impeller shroud (22).

Abstract: The present invention relates to a sealing arrangement for attaching a side plate often used with a pump volute of a centrifugal pump and an attachment screw used therewith. A characterizing feature of the sealing arrangement for attaching the side plate of a centrifugal pump, comprising at least a pump volute (10) and a side plate (130) with attachment screws (132) and flanges (164) of the screws (132) arranged in communication with the volute (10) or the cover of the casing, is that an annular seal (180) is arranged between the screw (132) and the volute or the cover of the casing.