Reliability Factors and Tightness of Tube-to-Tubesheet Joints

Abstract

The main purpose of this paper is to provide an applicable method to establish reliability factors for expanded tube-to-tubesheet joints. The paper also reports on the results of a preliminary study to validate experimentally the reliability efficiencies listed in Table A-2 of Appendix A of Section VIII, Division 1, of the Boiler and Pressure Vessel Code (ASME, 1986), and tightness of expanded tube-tubesheet joints. A comparison between the actual reliability factors fr determined from testing the damage strength of the joint and calculated according to Appendix A-4 of the ASME Code and those of Table A-2 is carried out. The results are discussed in light of the restrictions inherent in Table A-2. It is confirmed that some existing values of fr are conservative, while others are less so.