When the piping seismic design rules of the ASME Boiler and Pressure Vessel Code, Section III, Division 1 Subsections NB, NC, and ND were updated in 1994 a strain based criterion was incorporated in Article NB-3200. Due to objections to this criterion by the USNRC they were subsequently removed and replaced by guidance which stated that for Article NB-3200 for Service Level C and D reversing dynamic loads use the simplified design rules of Article NB-3600. The use of simplified Article NB-3600 rules in the NB-3200 design by analysis Article is inconsistent with the philosophy of NB-3200 and precludes the analyst from using detailed analysis methods for piping for Service Level C and D reversing dynamic loads. In 2012 an effort was undertaken to develop a more detailed design by analysis criteria for reversing dynamic loads. This paper provides the background and basis for changes that are anticipated to be implemented in the near future in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for the design by analysis rules of Article NB-3200 for reversing dynamic loads in piping systems.

This content is only available via PDF.
You do not currently have access to this content.