Boilermakers/tube welding, anyone?

admin

The UA steward put me in touch with the local boilermakers for a 4 week outage. Since I'm a pretty fair hand at tig he figured I would do alright, and get to make a bit of money during the down time here. So anyway, I've never done tube welding before. My understanding is it's thick pipe, and that I don't really do anything different than I would a regular pipe. I've heard things like, one guy holds the filler wire and one guy welds. Something about having to "catch the puddle" when it gets to my side... (how does one do that, exactly?)Anyway. Just looking for any information that might be had about what to expect and what I should prepare for.
Reply:Will they be hiring C list weldors?Lots of weird things go on with welding water walls.  Window welds, weldors on either side of the wall, and the such.
Reply:I had a situation welding superheater panels.  One guy on each side of the wall.  So one guy would use the tig while the other one fed the wire into the joint.  Weird stuff.
Reply:Picture your wall of tubes, maybe 1.5" apart             Me( 0-0-0-0-0-0-0-0-0-0)            You One guy is on one side of the wall, and the other guy on the other side.  Starting the weld at 180 degrees (at the dashes) might seem logical, but starting and ending an arc between the tubes is dangerous, cause you can't see what is going on as well you can when the puddle is more on one side or the other.So you don't start and stop at the halfway point, the guy on the second side is feeding wire into the first guy's puddle, till the first guy can't reach the puddle any more, then it becomes the 2nd guy's puddle, and he has gotten his torch into position to take over the puddle, all without there being a point when neither has control of the arc, or puddle. Of course the first guy at some point will have to feed wire when his partner no longer can get his wire in front of the puddle.Builds trust and comradery!
Reply:Of course both weldors disappear in a puff of smoke if their arcs come in contact with other.HahahaJust kiddingHobart Beta-Mig 2511972 Miller AEAD-200LEMiller 250 TwinNorthern Ind. Hybrid 200Longevity Stick 140Longevity Migweld 200SThermal Arc Pak 3XR
Reply:Bit of difference between pipefitters and boilermakers but if they need the manpower, they'll find something you're used to.  Some tubes and downcomers are out in the open, but as mentioned above, the biggest difference would be the two man wall tubes.  Around here, each take turns doing quarter tube from tangent to front.  Used to be your partner would be able to feed filler for starting in tangent but nowadays safety rules require so much ventilation on the inside of the boiler that draft past tubes cause porosity problems.  Your partner usually has to back you up to stop this air flow.Sometimes you tig out, sometimes stick.  I think the 'catch the puddle' you mentioned might refer to putting in a stick cap.  One machine with a 'y' to two stingers.  First welder welds into tangent and then the second picks up the puddle without breaking the arc, covers his front to opposite tangent and then the first picks him up again.  Less chance of porosity.  http://weldingweb.com/vbb/showthread.php...aps&highlight=I've included a pic of a wall tube mockup but most likely these tubes will go to the experienced.  Lot's of associated work though, the actual butt welding is a small percentage of any tube replacement.  Some designs have sheet/plate casing that has to be gouged off.  Also the tubes themselves may have 1/2" to 1" membrane between them that also has to be removed and then replaced.   Also there's usually some water treatment or emissions vessel work during each shutdown. Attached Images
Reply:Thanks for pointing out my oversight, oldsparks. it has been so long  I flat out forgot about the stick process using one machine, split out with a y.Great fun.It seems I remember once we got started, we would go round and round without stopping till the cap was completed.Ahh, the good old days - 7 12's for weeks on a shutdown.