It has been recognized for some time that the current B31 Codes are inconsistent in the values they use for stress intensification factors for piping design. ASME has undertaken a project to align the Stress Intensification and Flexibility Factors in the various B31 book sections via the ASME ST-LLC 07-02 Project which is being managed by the Paulin Research Group. The intent is neither to decrease nor to increase conservatism but rather to improve the accuracy of piping analysis as it attempts to model the real world. The supporting research is based on literature reviews, recent testing (within the last 25 years), new testing, advanced analysis techniques and interviews with industry and research personnel. The results are intended to be eventually included in a non-mandatory appendix to ASME B31J.
In this paper the scope of the changes and visual representation of some of the current information from the Project is provided to acquaint the piping analysts in general terms. Since flexibility changes are more fundamental to piping analysis, some discussion is provided as to how to incorporate them and some of the possible effects on piping design.