Abstract: A centrifuge for separating first and second liquids having different specific gravities includes a container supported for rotation about an axis, a drive arrangement for rotating the container, a supply arrangement for introducing a mixture of the liquids into the container, a valve arrangement supported on the container and in fluid communication with and responsive to fluid pressure in a radially outermost portion of the container for discharging quantities of the first liquid from such portion of the container to the region external to the container during rotation of the container, and an arrangement for removing from the container during rotation thereof quantities of the second liquid.