A dual-stream filling system (12) is used in a packaging machine to introduce at least two flowable materials into a container. The dual-stream filling system (12) defines a material flow path therethrough. The system (12) includes a primary filling tube (38) having an inlet end (50) and a discharge end (42) and defining a primary filling tube internal flow region. A secondary filling tube (40) has an inlet end and an outlet end and defines a secondary filling tube (40) internal flow region. The secondary filling tube (40) is positioned at least in part within the primary filling tube (38) internal flow region, penetrating the primary filling tube (38) through the first opening. The dual-stream fill system (12) includes a valve plug (54) that includes a portion that is movable relative to the secondary filling tubes (40) between an opened state wherein flow communication is established between the internal flow regions of the primary and secondary filling tubes (38 and 40) and a closed state wherein flow communication is terminated between the internal flow regions of the primary and secondary filling tubes (38 and 40). An actuator (56) is provided for moving the valve plug (54) portion between the opened and closed positions. The actuator (56) is disposed fully external of the secondary filling tube (40) flow region.