Assuring Tube-to-Tubesheet Joint Tightness and Strength

Abstract

This paper describes preparing mockup tubesheet specimens for visual examination using a digital microscope to determine that tube-to-tubesheet joint welds are of the specified size and that expanded joints are satisfactory for the intended purpose. It discusses nondestructive examinations (NDE) of the tubesheets and tube joints intended to assure achieving sufficient tightness and strength to satisfy the uses to which the exchangers will be put. This paper refers to the ASME Boiler and Pressure Vessel Code (Code) paragraphs that apply to tube joint welds and expanded joints including shear load testing when the Code requires it [1]. The discussion also addresses the need for manufacturers to have qualified tube joining procedures and personnel qualified to use the qualified procedures. The work concludes with a summary of ways to assure tube joint tightness and strength.