Welding 1/2" black pipe?

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I'm a plumber.  We do lots of screw pipe, usually, in 1/2" to 2" id, schedule 40 black or galv.  Sometimes I see welded installations where the pipe is welded almost all the way to the appliance, such as a boiler, etc.  I've seen welded fittings as small as 1/2" id in black pipe, and I'm wondering what the procedure is to weld something that small? Seems like it would be hard to fit a root and cover pass on something so tiny.  I'm assuming these are stick welded?
Reply:Originally Posted by StelthI'm a plumber.  We do lots of screw pipe, usually, in 1/2" to 2" id, schedule 40 black or galv.  Sometimes I see welded installations where the pipe is welded almost all the way to the appliance, such as a boiler, etc.  I've seen welded fittings as small as 1/2" id in black pipe, and I'm wondering what the procedure is to weld something that small? Seems like it would be hard to fit a root and cover pass on something so tiny.  I'm assuming these are stick welded?
Reply:Socket weld fittings are the way to go.  Just be sure to pull the fitting and pipe apart just a small amount to avoid weld cracking when things shrink up..  7018 seal weld.Dan D.Manipulator Of Metal
Reply:I'm aware of socket weld fittings, and have even used them, although not for anything mission-critical.  My local industrial plumbing supply carries them, as well as butt weld fittings down to 1/2".  Plus, I've seen butt welded 1/2" in the field.  So I'm wondering how you would make a decent weld on something that small.
Reply:5P+ ....6010....3/32"  Personally I've only welded down to 3/4" ( butt-weld)  Now if your talking weld/ thread o-let's  or fittings like mentioned before , yes........Only 1/2" I've done was in plant using TIG.......Best way to weld it...IMHO......
Reply:I've welded many, many,  nuclear 1/2" inconel pipe butt joints with tig.Rich
Reply:Originally Posted by SmoothOperator5P+ ....6010....3/32"  Personally I've only welded down to 3/4" ( butt-weld)  Now if your talking weld/ thread o-let's  or fittings like mentioned before , yes........Only 1/2" I've done was in plant using TIG.......Best way to weld it...IMHO......
Reply:TIG.. Where I work ( manufacture  natural gas processing equipment) We have had to  weld 1/2 SCH 160 nipples on butt weld tees.. Those sucked.
Reply:Where I work everything 2'' and below is 100% TIG. I sure wouldn't want to stick weld half inch butt welds,but I suppose it can be done. 1/2'' schedule 160 ain't too bad, we had one job 1/2'' schedule 10 stainless. Last edited by TimmyTIG; 02-12-2016 at 08:21 PM.
Reply:Originally Posted by StelthHow many passes with stick on that 3/4" butt weld?
Reply:Originally Posted by StelthI'm a plumber.  We do lots of screw pipe, usually, in 1/2" to 2" id, schedule 40 black or galv.  Sometimes I see welded installations where the pipe is welded almost all the way to the appliance, such as a boiler, etc.  I've seen welded fittings as small as 1/2" id in black pipe, and I'm wondering what the procedure is to weld something that small? Seems like it would be hard to fit a root and cover pass on something so tiny.  I'm assuming these are stick welded?
Reply:The old days we used to gas weld [ oxy/act weld]  everything that small. One hospital job ALL of the radiant ceiling panels were gas welded. I didn't do it but talk about never ending welds !
Reply:It's really easy to butt weld 1/2 inch pipe with the acetylene torch.  And speaking of gas pipes I believe this is PG&E's preferred method.
Reply:I forget the exact situation but yes, pg&e does a gas weld for certain pipe connections.esab 260 multimasternew tech 150 invertorlincoln 140 cheapo
Reply:Originally Posted by steelsurgeonI've welded many, many,  nuclear 1/2" inconel pipe butt joints with tig.Rich
Reply:Originally Posted by TimmyTIGThat sounds like tons of fun...NOT!!!
Reply:they make threaded weld-o-lets in 3/8",I have some kicking around someplace