Volute casing for a centrifugal pump and centrifugal pump

A volute casing for a centrifugal pump, the volute casing having a central axis defining an axial direction, comprising:

• a volute chamber configured to receive an impeller for rotation about the axial direction;
• an outlet passage configured to discharge a fluid;
• and
• a first cutwater configured to direct the fluid to the outlet passage,
• the cutwater comprising an inner surface facing the central axis, an outer surface facing away from the central axis and a leading edge joining the inner surface and the outer surface, the cutwater having a cross-sectional contour in a midplane perpendicular to the axial direction, the cross-sectional contour comprising a cutwater starting point at the leading edge, and a cutwater minimum point on the inner surface, the cutwater starting point being defined by a tangent to the leading edge, the tangent intersecting the central axis, and the cutwater minimum point being defined by a location, at which the inner surface has a minimum distance from the central axis, the cutwater being configured such that a straight profile chord located in the cross-sectional contour, and extending from the cutwater starting point to the cutwater minimum point, has a maximum orthogonal distance from the inner surface, the maximum orthogonal distance being at most 15% of the length of the profile chord, and an angular distance between the cutwater starting point and the cutwater minimum point measured on the midplane by an angle between the tangent to the leading edge through the cutwater starting point and a straight line connecting the cutwater minimum point with the central axis is at least 5.5°.