Skewness

Dears,

I have vertical fabricated spool which has a 4" flange, the face of flange is skewed to 1.5 mm in east west( due to improper welding of flange to pipe) , the skewness is out of tolerance of B31.3(0.4 mm).
The mating flange on the connected line is also skewed 0.8 mm in north-south direction.


How to model the flange skewness of both flanges to check whether the system can absorb that.Appreciate your help.

Thanks,
Van M

Why not re-do the spool(s)?

That way, it doesnt matter which orientation the fitter bolts the flanges up, you meet code requirements and can be confident of integrity.

(Right first time??)