Method and apparatus for sealing radially expanded joints

Abstract

Connectors and connections that enhance mechanical and sealing engagement between the ends of tubular bodies that are radially expanded by a forging tool. The connectors are designed to maintain or restore mechanical and sealing engagement following expansion. The connections are made by joining components that exhibit different spring back characteristics following mechanical deformation. Dissimilar material may be used for the connectors or the connected components can be made of the same materials but dimensioned and configured to exert an interfering force between engaged components following expansion. In operation, a material or component with a high spring back characteristic is positioned adjacent a material or component having a lower spring back characteristic. Following passage of a forging tool, the expanded components spring back differently toward their original unexpanded dimensions to produce the enhanced seal or mechanical engagement. The materials of the end connectors are selected and positioned such that a compressive or locking force is exerted between the different component of the connectors due to the difference in the spring back of the materials or components.