Dear Sirs

Qualification in conformance with Figure 4.27 for pipes with outside diameters greater than or equal to 4 in
[100 mm] or Figure 4.27 and Figure 4.29 for box tubes.
Qualification in conformance with Figure 4.28 for pipes with outside diameters less than 4 in [100 mm] or Figure
4.28 and Figure 4.29 for box tubes.
Figure 4.27-CJP groove T-, Y-, and K-connections welded from one side without backing in pipe.( Min 6" in Dia )
'
So, Production Qualification range based on Table 4.11 shall be -
1 - Dia 6" and over  not Dia 4" and over
2 - Thk Range shall be T/2 to 2T

Pls confirm if my understanding is correct. Thanks