"Be sure to determine whether the question is dealing with procedure qualification or welder qualifications. That will determine what variables are considered to be essential variables. the essential variables, if changed or if changed beyond permitted ranges will require requalification of the WPS or the welder."-Al
The exam writers love to try to trip you up with WPS vs Welder qualifications and which set of essential variables are to be used for various things. I have run into that very thing when discussing different views of opinions in the field among inspectors. It shouldn't be so, but I have discussed/argued with very seasoned CWIs over these same types of issues.
ie. Welder qualified on 3G & 4G 1"coupon with E7018 with an A/C machine and the proper WPS back at the office. A CWI (with a "79" in his certification number) on a job threw out the welder's certs. and told him not to weld on the job until he was recertified on a D/C machine. I tried my best to lead the seasoned CWI by the hand and show him the path through the code and read out the essential variables regarding the welder, but he refused to listen and said that guy will not weld on his job.