A centrifugal pump and an impeller thereof

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).