The ranges listed by the manufacture are typically greater than those permitted by AWS. The person writing the prequalified WPS is tasked with determining the "best" parameters for their situation, then limit the range per the code requirements.
Consider if you will, one project involves all shop welding were the positions are limited to flat grooves and flat and horizontal positions. The arc voltage, wire feed speeds, etc. may trend toward the high end of the ranges recommended by the electrode manufacturer. In contrast, another contractor is welding in all positions, they may opt to use the midrange for the parameters, or if the material is on the thinner side, may opt to use the lower end of the recommended ranges.
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