On occasion we get questions from our members who would like to use backing flux in lieu of purging when making welds on stainless steel or other corrosion resistant materials. This bulletin describes an experiment conducted by NCPWB Consultant Walter Sperko where he had a colleague make stainless steel butt welds without any protection of the root of the weld, with inert gas backing, with backing flux and with flux-coated wire.
NCPWB Technical Bulletin: Purge to Protect Stainless-Steel Pipe Welds

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