any pipe fitter/welders

[Shield Arc]

I guess it comes from having to be in Seattle by 6:00 AM every day. I've always got up early!:thumbdown::thumbdown:

 

[Jorville]

What's with the cast steel caps? Must it be cast? Why not reg. mild steel caps. That's your problem, the cast steel.

The caps look to be cast steel, there are also reducing couplings, they look to be cast steel, maybe they are not. Is there a way to tell what they are without doing a grind test on them? Maybe I can ask the company that I bought them from what they are made of. Maybe they are mild steel, hope so.

 

[Mysfyt]

The end use of this job is a new hot water heating system in my boiler room. What is there now is a 1970's design that I put in, in 1983. I since added two rooms and want to heat them so I need to re-plumb my boiler room. I am using 2016 design and ideas. So there will be a little pressure 12 psi cold and a few more pounds when the water is hot. I would like it to look nice, even though I will probably insulate the piping. All the piping will be welded on the bench so it can be rolled.



I have not done pipe in 30 or more years, did O/A on small pipe and arc on the larger stuff. I did not do a lot of it. I know on SS there need to be an argon purge. Do you think a purge needs to be done on mild steel?

I purge everything when practical. Especially where pressure and leakage is a concern.

 

[chuck172]

I doubt they are cast. All you need to do is 6010 root, hot pass, fill it out with 7018. Really, I'd just use 6010. That's all you need.

 

[Tractor Seabee]

Steel butt weld fittings fittings are forged steel not cast. I assumed the OP was really using those type. Shield Arc; there is a big difference in the various venues for pipe welding. Navy marine work is even more technical than commercial ship work. Navy, nuclear, high tech process piping, power piping, are all 100% tested and cost is not a big factor. Highly competitive commercial/industrial work which the OPs project is based on price hence labor cost is precious.

Ron

 

[nybirdman]

40+years as a union pipefitter/certified nuclear welder.I would Tig the first pass and hot pass with Tig and 7018 out.You could Tig all the way if you chose.Maybe four or five passes.No need to purge on carbon steel.

 

[Arc weld]

I realize this is for your own system but I see a potential problem. You're asking questions about purging mild steel and thinking the caps are cast steel. Are you using seamless pipe suitable for welding a pressure sytem? This is a pressurized boiler system so I have to ask, are you a certified pressure welder? I believe anything over 7 psi requires a pressure ticket(s). 12 psi cold is certainly going to be higher when heated. If something went wrong you could be in a lot of trouble. Not trying to discourage you, just asking. If you roll the welds, get some wheels to roll the pipe. Trying to roll it on a piece of angle iron isn't going to roll smooth enough.

 

[Shield Arc]

If you roll the welds, get some wheels to roll the pipe. Trying to roll it on a piece of angle iron isn't going to roll smooth enough.

Or get one of these. This thing makes my welds look good! :cool2:

 

[Arc weld]

Or get one of these. This thing makes my welds look good! :cool2:

Yes, especially for TIG.

 

[Shield Arc]

Yes, especially for TIG.

Oh yeah!