The pump is an in-line, radially split, single-stage centrifugal pump with connecting flanges according to international standards. The pump is designed for mounting with electric motors having different international flange dimensions. The pump casing is equipped with a replaceable sealing ring. The impeller is made with double-curved blades to ensure low NPSH-values and high efficiency. The bearing unit is equipped with sturdy ball bearings and the small types are fitted with lifetime-lubricated bearings. In the larger types the lower bearing is a double bearing for which a lubrication point is provided.