BMOORTY,
Per UG-80, permissible out-of-roundness for cylindrical shells is 1% of nomimal diameter at cross section.
Pipe specifications also generally limit out-of-roundness to 1%, though some specs for fusion welded pipes allow 1.5%.
Lacking other direction, I have used the 1% criteria of UG-80.
You may also investigate whether there is a Code Interpretation on this subject