A flow set comprises one-way valves and enables the sequential administration of two fluids from a pair of containers to a patient. The predetermined cracking (threshold) pressure of the one-way valves, namely an inlet pressure at which the first indication of flow occurs,can be individually set at predetermined values to minimize and/or prevent free-flow of the two fluids. A connecting tube segment is part of both the flow path of the first fluid and the flow path of the second fluid, and a pump can be connected to the connecting tubing segment. By reversing the pumping direction of the pump, the two fluids may be sequentially drawn from the pair of containers and thus sequentially administered to a patient.
