I don't have any ASME codes to look at,
This may be comparing apples(ASME Section IX) and oranges(D1.1), but in D1.1:2002 Table 4.1 if the weldor qualified in 2G,3G and 4G plate tests the weldor can weld pipe CJP, PJP, and fillets in F,H,V,& OH but is restricted to 24" or greater in nominal outer diameter(note #2) or has to weld along a line parallel to the axis of circular pipe(note #1).
If the weldors test on pipe then there are loads of other things to consider, wall thickness, diameter, etc....
John Wright