Abstract: A separator for separating a first fluid from a second fluid through rotation about an axis of rotation, the first fluid having a density less than the density of the second fluid. In one embodiment, the separator includes a separation chamber mounted for rotation about the axis of rotation. A first weir is positioned in fluid communication with the separation chamber. A second weir is positioned over which the second fluid may pass to exit the separation chamber through a collection chamber. A fluid pressure chamber is positioned radially outwardly from the crest of the second weir to receive the second fluid as it passes over the second weir. The fluid pressure chamber is partially defined by an exit weir over which the second fluid may pass.