Abstract: The invention relates to a cyclone separator for separating oil and water and removing suspended solids. It comprises a generally cylindrical first portion with an open end and a closed end. A generally axial overflow outlet is provided in the closed end and a moveable member is associated with this closed end having a plurality of orifices of progressively smaller diameter than the overflow outlet. This moveable member may be moved such that any selected one of the plurality of orifices may be axially aligned with the overflow outlet. The separator includes at least two radially balanced feed injection ports in the cylindrical first portion adjacent to the closed end thereof. A converging tapered second section with open ends is axially flow connected to the open end of the cylindrical first portion and a converging tapered third portion with open ends is axially flow connected to the tapered second portion. A fourth generally cylindrical portion is axially flow connected to the third tapered portion.