I'm working on trying to qualify a pulsed GMAW process in accordance with D1.3, as specified by our customer.  The parts all use a 18 gauge carbon steel tube and have carbon steel components (brackets, flanges) welded onto them with thicknesses up to .500".  Table 1.1 of D1.3 states that when welding a material less than 1/8" thick to a material greater than 3/16" thick, D1.3 still applies, as specified by Annex A.  I know D1.3 states that when joining materials of differing thicknesses, the thinner material controls.  My question is essentially this: because the tube thickness is constant regardless of the component thickness and is always the thinner material, can I qualify a WPS that will cover all thickness of the other components?  Or, am I subject to Table 4.2 Item 10, which states that requalification is required when changing to a sheet thickness less than .5t or greater than 2t, where t is the thickness of the thinner material? 

Any help would be greatly appreciated.