Tube-hole structure for expanded tube-to-tube-sheet joint

摘要

A tube-hole structure for an expanded tube-to-tube-sheet joint which is formed by axially moving a rod within each tube member in each tube hole of the tube sheet by external drive means, thereby imparting an elastic mass placed inside the tube with a sufficient compressive load to expand the tube uniformly in the radial direction to provide a rigid joint between the tube and tube hole, characterized in that each tube hole has at least one circumferential groove with an axial dimension or length of 1.5/ beta to 3.0/ beta ( beta being WHERE R is the mean radius of the tube member to be expanded, t is the wall thickness of the tube, and nu is the Poisson's ratio).