Abstract: A non-refillable valve is provided that allows for an initial filling of a container, but prevents subsequent refilling of the container. In one embodiment, the valve includes a valve core having a retaining means for maintaining the valve core in an open or non-sealing position to allow flow through the valve and filling of the container. The valve core may then be advanced to seal the container, and subsequently selectively operated to discharge the container as desired. Further refilling of the container is prevented by the force of fluid reentering the valve which forces the valve core to its seated engagement with the valve seat.