A port assembly includes a valve housing with an inlet opening, a valve disposed in the valve housing to control access through the inlet opening, and a base joined to the valve housing and having a bore therethrough. The bore has a closed end defined by a frangible barrier, and a pushrod is disposed in the bore between the valve and the frangible barrier, axial movement of the pushrod causing rupture of the frangible barrier. The port assembly may be used in a fluid container that includes a receptacle for retaining a fluid, and at least one conduit in communication with the receptacle. The at least one conduit is defined, at least in part, by a port assembly.