Centrifugal compressor

A centrifugal compressor includes an impeller of a make-up (compressing) pump stage, a first balancing ring for generating axial thrust on an impellar shaft for balancing the axial thrust generated by the make-up pump stage, an impeller of a recycle stage and a second balancing ring disposed between the make-up pump stage and the recycle stage. The impellers and balancing rings are fixedly mounted on the same impellar shaft in a common casing. The diameters of the first and second balancing ring and a liner ring disposed at a suction side of the impeller of the recycle stage are substantially identical with each other.