The purpose of this report is to align stress intensification and flexibility factors for metallic pipes used in ASME’s Pressure Piping Codes (B31) and Boiler and Pressure Vessel Code (B&PVC) Section III Class 2 and Class 3 Piping. The alignment recommendations are provided with examples along with major features of the aligned and updated equations. Validation is provided by comparison to existing Codes, alternate guidelines and test data in the supporting annexes.
https://www.asme.org/products/codes-standards/stppt073-2014-stress-intensity-factor-kfactor
See B31J