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copper piping a commercial steam boiler

jim_51 Member Posts: 69
Is there any danger in piping the steam header in copper (4") pipe?.


  • Paul Pollets
    Paul Pollets Member Posts: 3,656

    Steam boilers (low pressure) should be piped with sch 40 black steel pipe and steam fittings, rather than black malleable. Copper will not hold up when soldered, to the pressures and expansion of steam. Besides, 4" copper is extremely pricey, when compared to steel pipe.

    I suggest you purchase Dan's book, "The Lost Art of Steam Heating". This issue comes up frequently on this site. The answer is always steel pipe NOT copper.

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  • copper pipe ?

    everyone here says that the difference in thermal expansion between copper and cast iron boiler sections will cause a stress between them resulting in a boiler leak, a pipe joint leak, or just a bad hair day.also the chemical action of the copper flux residue could be a source of corrosion.

    however maybe there could be some emergency situations [nursing home occupants 90+ years old,-20 deg., long holiday weekend, have copper on truck] which would warrent taking a chance with copper piped a certain way.
    certainly the drop headers now favored might provide the extra pipe length needed to provide some copper equivalent to the "swing joint".
    our old boiler lasted from '72--'07 with copper. of course we might have got 10 more years out of it if it had been done with iron pipe.
    it certainly difficult to thread the bigger sizes of pipe on site.
    any thoughts?--nbc
  • Don't do it, Pat

    you'd be asking for trouble. I know a gentleman who was in a commercial boiler room when a copper header let loose. Not a pretty sight.

    The ability to work with 4-inch threaded black pipe is one thing that separates the men from the boys.

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  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314

    this is why it is usually welded for larger pipe now. Some dinosaurs ( read us) still have the dies for up to 4 inch even up to 6 inch. We still thread for up to 4 inch but not much call for it as of late.
    Cost is what you spend , value is what you get.

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  • dinosaurs R us

    that rig to thread 4 in. pipe must be enormously heavy!
    welded pipe seems to have the same problems as copper--a rigid structure; unless there is a method of incorporating some sort of swing joint.maybe lots of flange joints whose threaded connections with the welded pipe will absorb the stress of thermal expansion.
    i have seen the victaulic connections, but they are held in low esteem.perhaps the gaskets are the problem.--nbc
  • MrHVAC Mechanic
    MrHVAC Mechanic Member Posts: 7

    I havent seen LP boiler headers piped with copper

    I have seen jobs with LP copper baseboard piped with copper! The risers are black, but when they tee off to the baseboard its copper. Does code allow this?
  • oil-2-4-6-gas
    oil-2-4-6-gas Member Posts: 641

    come on guys just get out the gear head hook it up to the 300 machine and start threading//// so you need a 4ft wrench a 5ft chain wrench and some equalizer pipes --dope and wicking ,, at least we aren't talking about 10" mains --anything over 4" we have welded now a days anyway --
  • jim_51
    jim_51 Member Posts: 69
    I was framed!

    Somebody musta got my cookie by mistake. Thanks to the info I've picked up around here, I'd never let some knuckle head pipe in my steamer with copper.

    The Real Patrick North
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