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Opinions about Copper Piping in Steam Systems....Boilerpro

Boilerpro Member Posts: 410
Was wondering what fellow wetheads' opinions are about using copper piping for wet returns and near boiler piping below the water line. My chief concern is with the strength of copper piping if something goes wrong in the system and you get water hammer. Steamhead, under another thread, suggested its use for wet returns to help keep them from plugging up. Makes sense to me. I have seen it used for both supply and return on a two pipe system and it was hammering and survived. Would save alot of time on steam boiler installs and changes. Also, how about CPVC?



  • Earthfire
    Earthfire Member Posts: 543
    copper steam lines

    I wouldn't use copper anywhere on the header or any other near boiler piping. Especially it it was soft soldered . I do believe in the principle of swing 90's and threaded fitting, give to handle extreme temp fluctuation ( ambient in a cold damp basement to full load of steam)For dry return I'd consider ( haven't done it yet) silphosed joints with threaded fittings at expansion loops. Have used copper for a wet return replacement and repairs and haven't had any problems. But I wouldn't use copper in the return any closer to the boiler then the Hartford loop connection and then I install a dielectric union at both ends of the copper . Pricing and availability for dielectrics gets interesting above 1". As for cpvc, in an buried application if well bedded with fines and properly backfilled it might survive (brittle?) Depending on the wet returns temps. I would look at something like EcoFlex . Pipe and insulation in one
  • Steamhead
    Steamhead Member Posts: 16,733
    I only use copper on WET returns

    where theyre always filled with water. I wouldn't use it on dry returns as steam might get into them- and NEVER on a pipe that normally carries steam.

    Of the copper steam piping jobs I've seen, about half leaked and half did not. That's not a very good percentage.

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  • Copper on steam ???

    I don't understand why the use of copper at all !
  • keith
    keith Member Posts: 224

    on wet reurns yes on every thing else no. Any steam boiler I have ever seen after 2 or 3 years the joints are leaking. The sodder cant take the expansion and contraction like steel joints.
  • From a boiler manufacturer's standpoint

    We may well be the first manufacturer to address this in the Installation Manual for the boiler. We advise against the use of copper piping within the steam system for the following reasons:

    1.) Expansion and Contraction problems related to the soldered joints.

    2.) Possibility of an electrolytic or galvanic reaction that can cause corrosion within the boiler.

    3.) Difficulty in purging leftover chemicals and oils that solder flux can deposit within the pores of the fittings and boiler.

    I hope that I never see plastic used on a steam system, but I'm sure that I eventually will. Hope this helps.

    Glenn Stanton

    Burnham Corp.

  • Glenn

    Will using copper on return pipes become an issue on the warantee of a steam boiler from Burnham ? Will it void the warantee ?

    And what about that issue if the boiler is installed in a house with existing copper return lines ?

    I think we are going to be switching to an all Burnham line very soon , we just had 2 reps in to our office going over all the details of the V8 and the RSA models . I am very impressed .
  • ScottMP
    ScottMP Member Posts: 5,884

    No one has addressed the issue of the copper leaching/flaking due to the corrosivness of condensate. I was under the idea that it can coat the inside of the boiler ???

    I have to agree with others.. It just dosn't belong on a steam system due to expansion and contraction action on the joints.


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  • The warning

    is simply that....a warning. There is no mention of anything related to warranty. Use of copper below the water levels is not as big an issue. We are simply covering this issue for those cases where use of copper can possibly become a contributing factor in a situation such as fittings expanding apart and some sort of physical harm being done and/or harm to the boiler. This does not normally occur on return lines. It is yet another precaution neccessary to ensure a safe and nuisance free installation.

    Happy to hear you liked the product line. You have a couple of great representatives calling on you out there. They are second to none in the industry. They are hands-on when it comes to any sort of nuisance issue and always there when they are needed. I am sure that you folks will enjoy working with them. Hope this helps.

  • canuckDale
    canuckDale Member Posts: 77
    Water Treatmant Programs

    I have many systems with copper parts. After all, 1 1/4" wall fin is hard to find here in steel.

    Perhaps my systems are bigger than residential ones where I wouldn't recommend it. But, the valving is usually brass (copper). And I have a treatment program for >460 stm/hwh systems. With the steam systems we use molybdenum as an anodic inhibitor...sulphite on some and DEA, morpholine, cyclohexamine and other condensate pH adjusters.

    We experience no copper plating as long as the treatment levels, water chemistry and boiler operation are closely monitored.

    Then there was the high school humidification 100% make-up boiler. We used an existing forced draft DHW heater to pre-heat the feedwater. We use corossion coupons too. After construction warranty, we put mild steel coupons in the boiler, pulled them after 3 months to check our treatment. They looked like copper coupons and I took them to the water treatment supplier. As the rep looked at it, he said, "Ya, nice looking copper coupon". Then his jaw hit the ground when he noticed the mild steel stamping on the coupon. I said, "Ya, your product is so good, you 'add' metal to the coupons!" Turned out to be a lesson about the corossive effect of heated and softened water above 120*F on copper. We plated the WHOLE boiler! The remedy - acid clean with Thorium-thiosulfate and sched 80 iron from the heater to the boiler.

    My point is that any metals can be 'mixed' in a system. But
    when you do that water chemistry and treatment monitoring is crucial.

    As for residential, yes, keep it mild steel.

    I love meeting folks around here with similiar operations and when I ask about their WT program and they say - "We don't need those chemicals and don't have one of those programs". I smile and say, "I bet you have a boiler replacement program. Don't you?" ;-)
  • ScottMP
    ScottMP Member Posts: 5,884

    explain to me what a coupon is ?? I have never heard the term.

    New Englander Scott

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  • Tony Conner
    Tony Conner Member Posts: 549

    Local water conditions, combined with the specific mechanical situations for a given installation can cause all kinds of weird and wonderful corrosion/deposit situations. What makes perfect sense in one application is often totally wrong just a short distance away. Not very often that anyone can say "This is always the cause..." The next factory, or town over, it's not.

    A lot of people with mechanical backgrounds suffer for their lack of awareness regarding chemistry. And a lot of chemical-types have an astounding lack of mechanical knowledge. Corrosion & deposits are often an interlocking of mechanical and chemical factors. Mechanical people don't have to be chemists, but they need to have some awareness of chemistry. I know lots that don't, and it costs them, both in terms of time and money.

    As far as copper in steam systems goes, there are copper tubes in steam coils for air intakes, etc. And these are brazed into carbon steel headers. There's no water (there had BETTER not be any water, or the coil will freeze and split) contacting these joints, so they won't corrode. There are yellow-metal tube bundles in shell & tube heat exchangers. Steam is usually on the outside of the bundle. But again, if it's piped correctly, no water to connect the steel shell & copper bundle.

    I don't like copper piping in condensate service. You can get copper being pulled off by the condensate, and it'll wind up back in the boiler. If it gets back to the boiler, it'll plate-out, and form a galvanic cell. This is bad news. It doesn't nearly always happen, though. Some systems have had loads of copper return lines for years, without problems. Some other factor, in addition to the copper lines needs to be present, like a lot of carry-over (wet steam) from the boiler, etc. But if you have copper returns, half of the equation is already in place.
  • PJO
    PJO Member Posts: 140
    Corrosion Coupons

    I believe Dale is referring to the use of a small piece of metal "hanging" in a representative part of the water for indications of corrosion. They are put there for a set period of time, then removed and tested. it's a good gauge for corrosion in large systems.

    My own experience with these was in a cooling tower system years ago.

    Hope this helps, PJO
  • canuckDale
    canuckDale Member Posts: 77

    Patrick is there Scott.

    Try the link.

    A controled flow or 'coupon "rack"' is essential to negate errosion and cavitation effects.

  • Mad Dog
    Mad Dog Member Posts: 2,595
    Good question Jr.......

    That could settle the argument once and for all. CPVC?????? Never on one of my jobs? How about you???? Mad Dog

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  • Boilerpro
    Boilerpro Member Posts: 410
    Lots of opinions

    I think with the issues of copper plating a boiler,etc., it sounds alot safer to stick with steel and just deal with some of its problems. Haven't seen copper showing up around here in boiler replacements, so at least there is not the cost issue to deal with. I found Glenn Stanton's comments interesting, as I would think they could apply to hot water boilers too. Does Burnham also not recomend the use of copper piping with hot water boilers? All this is very interesting!

  • Bill @ Boro
    Bill @ Boro Member Posts: 27
    Don't suffer like I did

    Had a sub using copper on steam about 15 years ago. He always said "don't worry it evens cost more than steel". Boy was I a fool trusting a sub, now anything that is givin out of house must meet my specs, or no $. But my staff techs got very good at heating copper and pulling it apart. leaks leaks leaks and did I mention leaks.
  • Not an issue with Hot Water

    This is not an issue with hot water boilers. They are a closed system and the water is starved of oxygen. Nor is the oil and debris from soldering a problem because we are not concerned about surging in a hot water boiler. These recommendations are only for steam boiler applications. By the way, I will be conducting the seminar at W.L. Engler next week. Hope to see you there!

This discussion has been closed.