Thanks, I feel much the same as the general consensus indicates. But as any devil's advocate might say, and after already having checked 2002's 4.1.1.2, 4.1.1.3 and III3.5, such basically and simply requires only 'that when required, CVN testing needs be done'. D1.1's rqmt's for CVN WPS's, especially in single pass applications, don't seem to give rise to precluding a Fabricator from utilizing the filler Mfgr's prequalified essential variables only due to slightly varying HAZ's for different base metals. But if it is really of issue (in all cases), then the Engr' would certainly and simply disapprove all such WPS's (prequalified or qualified), but until one identifies why it would be disapproved, I can't see why it would or should.
In other words, as Engr's do approve new and/or revised WPS's documenting CVN essential variables (actually tested by a Fabricator), as long as a CVN WPS's variables also abide by Table 4.5 and/or 4.6 as appropriate, as both table's only restrict base metal changes 'outside' one's specifically tested group, then again, why wouldn't he/she also approve a prequalified CVN WPS ?
The filler metal manufacturer impact values and test temperature are derived from the filler metal specifications. Most application requirements for impacts are based upon different criteria. For example, E7018 has a 20/15 ft-lb requirement at -20F. I have a job application for 15/10 ft-lb at -30F. They do not equate and a PQR must be performed to prove out not only the weld metal in the as welded condition but also the welding procedure parameters by checking the HAZ. Once a procedure is qualified then limitations on heat input come into play. Having a manufacturer weld metal test data is next to unless if you are not controlling amperage, voltage, travel speed, preheat, postheat and base metal thickness in your WPS. And your WPS is derived from the original test configuration of your test plate for the PQR. Prequalified welding procedures do not address all of these variables when charpy impact values are required for the weld procedure. That is why the D1.1 welding code leaves it open with the "when required" statement.
What does your job specifications demand? What CVN value and test temperature is mandated? What is the approving engineering asking for? What application will the completed weldment be used in?
It sounds like the specifications are too loose and subject to wide intrepretation. Go back to the engineer and ask what the requirements are and then you can make a determination if prequalified procedures are appropriate. If any CVN requirements are specified then prequalified welding procedures cannot be used. The filler manufacturer makes no claims on HAZ values for their product, they cannot because they do not know if you even purchased a base metal that will support good HAZ values.
As for Tables 4.5 and 4.6, if you look closely at the heat input requirements you will see that you are restricted to less than a 10% increase (except for GTAW) and would therefore require re-qualification. If you have no baseline PQR test results and only a prequalified procedure what are you comparing your increase to? Table 4.5 and 4.6 are there for procedure qualification and therefore you should have started with a tested WPS.