History and Current Status of Expanded Tube-to-Tubesheet Joints

Abstract

This paper narrates the history of expanded tube-to-tubesheet joints. After summarizing a theoretical analysis based upon a uniform-pressure expanding model, it reviews the progression of mechanical tube expanding equipment and techniques. In so doing it covers sectional manual expanding , manual rolling, development of automatic torque-controlled rolling and controlling and optimizing the degree of roller expansion. The article traces development of hydraulic and rubber uniform-pressure expanding, hybrid expanding , and kinetic (explosive) tube expanding. After discussing the benefits of two-stage expanding, it gives examples of uses of the Hydroswage system of hydroexpanding. The paper closes with a discussion of the role and status of expanded and rolled tube-to- tubesheet joints in tubulars stamped in accordance with the ASME Boiler and Pressure Vessel Code (Code).