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[MW:2409] Re: requirement of purging in CS/SS pipes

By Materials & Welding
Back purging is required for the GTAW and GMAW processes for welding materials having a nominal chromium content greater than 2 1/4% unless the joint is ground or back gouged to sound metal. The purpose is to prevent oxidation or scale formation on the underside of the weld, the purge shall be maintained until at least 1/4 in. (6.3 mm) depth of weld metal has been deposited



On Thu, Jun 11, 2009 at 7:30 PM, prashant pansare <prashantpan_99@yahoo.co.in> wrote:
1) Why purging reqd.while welding with E316 / 316L for SS  pipes?
2) Why purging not reqd.while welding with ER 70-S for CS  pipes?
Pl. reply.

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