Sec. 12 does not apply here since it is manual SMAW, sec. 5 Qualification of Welding Procedures for Welds Containing Filler-metal Additives does. And this really depends on how the procedure was written. Pipe diameter is not an essential variable requiring a re-qualification test under sec. 5.4.2. Wall thickness MAY be, depends on the ranges your company listed. The ranges in sec. 6.2.2 are for welder qualification and also may be applied to procedure quals, but doesn't have to be. So if the procedure in question lists a wall thickness of .250 only, for example, then yes this procedure would need to be qualified by testing again to allow the suggested revision.