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Brazing copper LP lines

Solid_Fuel_Man Member Posts: 2,597
Is it acceptable to braze copper (opposed to flare) propane lines? This would all be for 10 psi or less.

I believe NFPA states 1,000 degree F connections, which a braze would be. I've never seen it done, but curiosity has me. I suppose if you purge with nitrogen and treated the whole system like refrigeration.

Just for discussion, I'm not actually considering it!
Serving Northern Maine HVAC & Controls. I burn wood, it smells good!


  • GroundUp
    GroundUp Member Posts: 1,573
    Will depend on local codes, but here in MN we braze a large percentage of gas lines that are indoors. Always type L and always purged with nitrogen, like refrigeration.
    EBEBRATT-Ed Member Posts: 13,440
    MA allows brazed oil lines but not soldered and the same 1000deg applies. Never seen that done and never seen gas lines brazed but it may be legal
  • Leonard
    Leonard Member Posts: 903
    edited May 2019
    Sounds easier to carry a lightweight hand flaring tool in than a heavy acetylene tank, even if it is a small "B" tank.

    Unless you have metal scrapper BUMS that sheered the line off flush with cement wall,,,,,,,, had that happen with restaurant walkin coolers
  • Intplm.
    Intplm. Member Posts: 1,443
    It is ok to solder and braze in some parts . But! The thing to do is contact the local building official as they may not allow it in your area.
  • Jellis
    Jellis Member Posts: 228
    Local code here requires brazing vs flare in enclosed spaces so yes it is "acceptable" but as others stated. check with your local AHJ
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,597
    Thanks all, I would certainly consider a brazed joint superior to any mechanical flare.

    Good discussion!
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • Big Ed_4
    Big Ed_4 Member Posts: 2,239
    Just curious , I know the reason for refrigeration , carbon contamination from burnt oxygen , buy why nitrogen for a gas line ?
    I have enough experience to know , that I dont know it all
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,597
    I'd think to avoid the flaking inside the pipe from oxidation. Those wouldn't be good for gas valves.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!