Priming systems and infusion assemblies are provided. For example, a priming system comprises a priming conduit having a priming portion and a pressure portion. The priming portion is in fluid communication with a first fluid source, with an inlet and an outlet for ingress and egress of a first fluid from the first fluid source. The pressure portion is in fluid communication with a second fluid source connected by a connector. Disposed within the priming conduit are a biasing member and a valve having an open position and a closed position. The biasing member is in operable communication with the valve to urge the valve into the closed position such that the valve defaults to the closed position. The open position allows the first fluid to flow from the inlet to the outlet and the closed position prevents the first fluid from flowing from the inlet to the outlet.
