Problem:

The following is displayed when using AutoPIPE

• • • W2261-113:B31 App J: Tee header legs are not collinear. B31J Flexibility factors and SIF requirements are not satisfied by the tee.  

Why and how to avoid it?

Solution:

Generally, this warning is issued when the tee header outgoing pipe is not completely aligned with the incoming tee header pipe at least at one node before / after a tee node point.

The solution is simple, make sure the tee header incoming and outgoing pipes are completely aligned. 

In March 2026, a case was recorded regarding this message appears for an aligned tee header. This case is currently under investigation. Meanwhile, please be aware that this is merely a warning and should not impact the analysis or results. This warning message can be disregarded after verifying that the header piping surrounding the tee node point is properly aligned.