Collapsed arc definition in ASME B 16.9

[QCJT]

Greetings to all

B 16.9 in paragraph 7 refers to so called "collaped arcs". It reads as follows:
7 SURFACE CONTOURS
Where adjacent openings in fittings are not in parallel
planes, they shall be joined by a circular arc or radius
on the external surfaces. The arc or radius may be terminated
in tangents. Except as provided for block forgings
(see section 5), the projected profile of external surfaces
of fittings shall not have sharp intersections (corners)
and/or [highlight #FCE94F]collapsed arcs.[/highlight]

We have a major argument over a fabricated elbow and this wording with an end user who claims that, what seems to us as a dent in pipe, is actually a "collapsed arc" that lead to an internal misalignment at root of the weld for about 2.5mm and wasn't tapered properly. Our qc visited the joint and stated that there are no sharp edges and it is not a "collapsed arc. Please note that ASME VIII or other codes were not specified on PO except ASME B16.9. So here is my question(-s):
-1 Where can I find a definition of collapsed arc? I am a qualified welding inspector and a welding engineer and such word is not in my books for welding defects. I know how the arc may collapse during welding but can't imagine how this can lead to a misalignment. For this case in particular I think that the misalignment was there already when they started welding and as a result the capping in those parts is slightly lower than adjacent areas and it makes it look as a dent.
-2 What and where is B16.9 requirement about misalignments?

 

[KevinNZ]

This sentence applies to the external surfaces of fittings, I am guessing a collapsed arc is just a hollow like structure.

I can not see how a clause about the external surfaces has anything to do with internal surface misalignment at the weld prep. B16.9 Table 13 has tolerances for the well prep.

 

[QCJT]

KevinNZ, thank you for your feedback.

In that table they don't mention anything about misalignment though. I am wondering if the Note 5) belonging to Fig.1 "Maximum Envelope for Welding End Transitions" is referring to angular misalignments. Here is the text: Note 5) "Where transitions using maximum slope do not intersect the inside or outside surfaces within the transition region, as shown by phantom outline, maximum slopes shall be used. Alternatively, radii lying within the envelope may be used"

I am not sure though if I understand this statement correctly - so the two ends shall meet at the "phantom outline" right? and if they do not then "maximum slopes shall be used". But what maximum slopes do they mean? Bevel angle or what? And what is in this case the minimum slope?
Sorry for too many, perhaps, stupid questions but I haven't been exposed to manufacturing standards so much in the past.

P.S. I am writing this from home where I don't have the latest version of ASME B 16.9 so the figure number and note number mentioned above may differ in latest version of the code and that's why I noted down the text here for clarity.

Thank you for reading this post and would appreciate any feedback