A fluid delivery Y-site is described that is configured to receive and control delivery of two or more fluid flows. Fluid flow is controlled within a chamber by a valve and float. Flow of a primary fluid into the chamber is reduced or halted by the movement of a valve. The valve may occlude a first flow port into the chamber in response fluid flowing from a second flow port into the chamber. A float is moveably disposed within the chamber and configured to engage the valve in response a fluid flow into the chamber from the second flow port. As fluid flow from the second flow port into the chamber is reduced or ceases, the valve and float allow the flow from the primary flow port to once again enter the chamber and exit from an outlet port.