I have written a prequalified WPS for a 5/16 fillet weld using A709 GR.70W with 90 K wire per Sec.3. All our welder quals and PQR's are done for A572 Gr. 50, A36, A588, A53-B, A500-B. Sec.4 Part C references Table 4.11 essential variable changes requiring welder requalification, which does not list material or wire tensile strength. Table 4.5 PQR essential variable changes requiring WPS requalification lists increase in filler metal class strength,change from one electrode class to any other class, and change in base metal not listed on PQR. Since the WPS is prequalified is Table 4.11 the only table I need to reference for welder qualification ? It seems that Table 4.5 is for WPS's that may need to be requalified due to changes in essential variables. I hope that someone can understand my questions. It seems a bit confusing to me. Thanks David Smith