Abstract: Disclosed herein are embodiments of a valve assembly for providing selective flow communication between a plurality of fluid flow conduits. The valve assembly may comprise two valve members disposed coaxially in fluidly sealing contact and relatively rotatable to provide valving action of at least two port tracks. At least one valve member may comprise a fluid pressure loading means, and the fluid pressure loading means may span at least two port tracks. The valve assembly may further comprise a drive means for driving relative rotation of the valve members in order to enable cycled interconnection and fluid flow through the fluid flow conduits.