Hi, I am modeling a tee with the fallowing inputs, run 18" std and branch 14" std, the type of tee for my model is Fitting, with Radius rp = 8.281, after running the model validation, I have the warning W2164-147:B31 App J: SIF values for the tee(s) below are not valid, as the ratio of branch mean diameter to run mean diameter is greater than 0.6
per ASME B31J 2017, 2.6 Integrally Reinforced Branch Welded-on Fittings [Notes (1), (7), (10)]
(7) The flexibility and stress intensification factors apply only if the following conditions are satisfied:(a) The branch pipe axis is normal to within 5 deg of the surface of the run pipe unless otherwise noted.(b) R/T ≤ 50(c) d/D ≤ 1(d) r/t ≤ 50
According to note 7 the value of branch mean diameter to run mean diameter is less than or equal to 1, in the case of mi model the ratio of branch mean diameter to run mean diameter is 0.7. This value is less than 1, and valid according to note 7 (c), therefore values between 0.6 to 1 are not valid, according to warning W2164-147:B31 App J, please explain.
Hello Boris, thank you for your question.
Note 7 of table 1-1 continues further stating that Stress intensification factors can be used for sketches 2.2, 2.3, 2.5, 2.6 [...] provided d/D <= 0.6. AutoPipe is following this statement with respect to SIF's. Please note that this warning does not affect the SIF calculations; AutoPipe will continue to produce the requested B31J SIFs.
Answer Verified By: Mike Dattilio