1) PQR is qualified with 1.6 mm diameter(filler wire), but sub vendor is mentioned 1.2 mm and 1.6 mm diameter both in WPS.( as per D1.1 Table 3.7 clause No- 7) A change in nominal electrode diameter(s) is essential Variables),How can they use 1.2 mm in WPS?
Ok... Table 3.7 is deals with prequalified WPS's and you mention up front that your WPS is qualified by testing; meaning you should be getting your guidance via Clause 4.
Look to Table 4.5 (10) and you will see that any *increase* in filler metal diameter triggers WPS requalification. But It appears that your new WPS is a reduction in electrode wire diameter... So if all other essential variables are in order, this should be compliant.
Is the PQR for a PJP square groove weld? or is the production WPS for a PJP square groove weld?
It is notable that if your PQR is being used to generate a WPS with a prequalified square groove joint detail that the maximum base metal thickness is 1/4" for the two detail options available (B-P1cGF BP1bGF)