Abstract: A centrifuge for separation of two liquid phases of different specific gravities to be removed separately; the separation chamber has a first subset of openings communicating with a skimmer and a second subset of openings communication with a collector. In one position, a movable barrier plate covers the inner portion of the first subset and the outer portion of the second subset to direct the heavier liquid to the skimmer and the lighter liquid to the collector. Changing the barrier to a second position where the situation is reversed selectively directs the lighter liquid to the skimmer.