A component that controls fluid flow direction through a system, possessing two inlets/outlets and one common port. Its primary function is to direct flow from one source to either of two different destinations, or, conversely, to select flow from one of two sources to a single destination. An example would be in a bypass system where fluid is either routed through a processing unit or directly around it.
This type of valve offers system designers enhanced flexibility in fluid management, allowing for simplified plumbing and reduced component counts. Its utility extends across various industries including chemical processing, HVAC, and manufacturing. Historically, variations of these control mechanisms have been employed to optimize process efficiency and reduce operational costs by streamlining fluid pathways.