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on pipe root pass welds? Navy & Air Force are requiring GTAW or GMAW on root pass for fuel piping. Fill and cap passes are almost alway SMAW unless you have a WPS for FCAW. I think GTAW is slow on 10" and up for the root. Contractors employing the GTAW are required to purge with argon, but lets not open that can of worms.Anyway, I want to set up a WPS for downhand GMAW root, .035 solid wire (E70S-3), argon/CO2 shielding gas, and FCAW (.035 E71T) out. I have three LN25's to work with. I ordered some 200 amp magnum guns and the corresponding drive wheels for this set up... only I have never welded GMAW downhand on open butt pipe. Anybody here been there, done that?Why they changed root procedure is beyond me. For years passed, we always used 6010 in, 7018 out. A minimal amount repairs over the years with that combo. Arguing with the inspector is not highly recommended.
Reply:Cut some practice cans and work up a process. then practice.Don't forget to change polarity when switching wire. 0.035 wire, try 16 to 18 volts. 230 to 270 ipm 72/25 gas. co2 add 2 volts. |
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发表于 2021-8-31 22:09:18