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 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 ).