Abstract: The tube plug comprises a substantially cylindrical sheath closed at one end and having a relatively smooth outer surface and a central cavity. An expandable shell is received within the central cavity of the sheath. An expander member is adapted to expand the shell from within by being axially translated within the shell, the expander member also being adapted to grip the inner surface of the shell to retain the expander member in the expanded position. The outside surface of the shell is preferably provided with a plurality of lands. A second embodiment of the tube plug comprises a sleeve, a closed shell member adapted to be inserted within the sleeve, and an expander member contained within the shell. Upon axial translation of the expander member within the shell, the shell is expanded into contact with the sleeve and the sleeve is expanded into contact with the tube, thereby sealing the tube.

Abstract: A process for the controlled expansion of a conduit against the walls of a circumscribing structure is disclosed herein. The process generally comprises the steps of applying a radially expansive force to the conduit, while monitoring a variable associated with the elastic and plastic properties of the particular conduit being expanded in order to determine a final swaging force which will complete the expansion process. The process of the invention is particularly useful in eliminating the clearance between heat exchanger tubes and baffle plates in a nuclear reactor, and in sleeving operations wherein an internally inserted sleeve is plastically deformed against a heat exchanger tube in order to affect an interference joint therebetween.

Abstract: An apparatus for expanding a tube against the walls of a circumscribing bore, or a sleeve within a tube to effect an interference joint therebetween, is described herein. The tube expansion apparatus generally comprises a fluid mandrel connected to a hydraulic expansion unit for applying a radially expansive force to the tube or sleeve, and a control circuit electrically connected to the expansion unit and fluidly connected to the mandrel for sensing fluctuations in the pressure of the fluid discharged from the mandrel during the elastic and plastic deformation of the tube or sleeve during the expansion process, computing a final swaging pressure on the basis of these pressure fluctuations, and deactuating the hydraulic expansion unit when this final swaging pressure is attained within the tube or sleeve. The invention is particularly adapted for minimizing or eliminating the clearance between the heat exchange tubes of a nuclear reactor, and the baffle plate bores through which they extend.