We are welding some product that needs to conform to D1.1  We are working on the WPS for the welding and the following question came up after observing different weld settings for tacking than the final weld on initial production. Does a tack welder need to be set to the same values the WPS specifies?  Or in other words, does a second WPS and PQR need to be performed to tack at different weld settings? 

My initial feeling is that the tack weld becomes a part of the finished weld and it must conform to the same criteria when the joint is completed. That said, it should be welded with the same settings as the finish weld WPS or at a minimum a Seperate WPS for the tack weld settings developed and evaluated using the same quality criteria as the finish weld.

Thanks in advance for your feed back.