The centrifugal pump is for the delivery of fluid and gas mixtures with a high gas content, and is of the single or double flow type. Either large rough surfaces, radial ribs (6, 7) or blades are positioned on the housing wall in the area of the wheel side chambers and there are smooth outer surfaces on the boss disc (1) and cover disc (3) of the running wheel. Due to the thus formed gaps in the wheel side chambers, the pressure gradient in the latter caused by the rotating fluid-gas ring is small. Gas from the pump housing (4) does not penetrate the wheel side chambers.
