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Can you have 2 separate mains and returns?

Is it possible to pipe each riser separate from one another and have separate equalizers and returns? I have never done this before and would work great as far as piping ease is concerned.


  • Rod
    Rod Posts: 2,067
    Stick to the Boiler Manufacturer's Recommendations

    The only way I can think that you would figure it was less work was if

    you weren't planning on using a header and planned going straight from the

    boiler to the main.

    You need the steam risers coming out of the boiler to go into a header with the equalizer

    attached to the end. This helps separate water from the steam to produce dry steam which is much more efficient. Using a header is the standard configuration that you see in the manufacturer's installation drawings. What you are proposing differs tremendously from the typical manufacturer's recommendations so if there is any trouble with the system and you end up in court, you'll lose big time.

    If you don't have a copy you might want to get this book as it has explanations as to why piping needs to be done a certain way and also shows what variations will work and what won't. http://www.heatinghelp.com/products/Books/Books-by-Dan-Holohan/11/68/Lost-Art-Of-Steam-Heating

    If you don't use them already, you might want to look into using dropheaders in your steam installations. They use a few fittings more but are MUCH easier to install than the standard header plus they produce really dry steam.

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

    you can not.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Rod
    Rod Posts: 2,067
    A Real Steam Pro Speaks!

    Charlie has given you a far better answer than mine.... in 3 words!!
  • Charlie...

    Charlie, does it come down to an imbalance in steam rise/return? I am not trying to cut corners by doing so because it would actually involve more time and material...but it sounds like doing a regular style header is the way to go. I just wanted to see if anyone had experimented with separating the risers and returns before...
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    I have remove systems piped the way you suggest

    The new systems were quieter, and more even in heating when piped properly. I also have a client who thinks their boiler is just fine and it is piped as you want but it has swing checks and no Hartford loop. It is gurgly, and I am sure their fuel bill is far higher than it needs to be. They also has several rooms that never quite heat the same and their steam vents last about 3 years and fail, they replace them themselves with ones from home depot. So if that kind of system appeals to you then go for it. I will stick to the manufacturer recommended piping.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Dave in QCA
    Dave in QCA Member Posts: 1,785
    Imbalance and many potential problems

    The experts have commented, and have in polite yet strong terms,  recommended ----- Don't do it! ----

    I think there are several things to remember here.  1.  The boiler and its close boiler piping operate as a single unit.  The close piping is critical to the boiler's proper operation.  While you may have separate branches in your building, many buildings do, you can't split your boiler in half and have it act as if it were two boilers.  That won't work.  There is one water line, one vessel of water, and one steam chest.  The steam risers, how ever many there are, the equalizer, and the return port to the boiler must be piped as recommended to assure that all pressures in the boiler are equal as can practically be, so that good dry steam can be produced from the boiler system and sent out into your building piping.  Also, this assures that external pressures won't be affecting your water line, and that an equal amount of steam will be exiting the boiler through each riser.  There is 100+ years of experience and engineering in the specific requirements of the close boiler piping and that piping design has been VERY well thought out.

    If for some reason that you really need to supply each of your steam mains separately, the only way to do that is to install 2 separate boilers, with their own independent close boiler piping setups.  

    With all of that being said, I must commend you for asking why.  My brain works the same way.  I too have observed some "rules" in steam systems and have supposed that an alternative might work.  After very close study and reading the reasons why the "rule" is there in the first place, I begin to realize all of the factors that I had not considered.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
  • I just wanted to know for sure

    Thanks for the feedback guys...much appreciated.
This discussion has been closed.