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Low-Loss Header ASME or Non-ASME

space Member Posts: 3
edited June 2021 in THE MAIN WALL
Hi, when does a low-loss header need to be ASME rated? Thanks


  • dopey27177
    dopey27177 Member Posts: 873
    Typically only when ASME items are specified, government work and when you liability insurance covers errors of omission, errors of commission and the insurance company does not have qualified inspectors.

    EBEBRATT-Ed Member Posts: 12,131
    Only if ASME considers it a pressure vessel. The size may have something to do with it. That is the reason large water heater are 119 gallons and not 120 gallons
  • Zman
    Zman Member Posts: 7,355
    It is dictated by the BTU rating and design pressure of the system.
    Some more details as well as the local codes would help answer the question.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • space
    space Member Posts: 3
    edited June 2021
    Thanks everyone for the replies

    Building is in Saskatchewan Canada, which adopts the National Building Code.
    2 condensing boilers (input = 280 MBH each).
    Typical boiler pressure (between 12 - 30 PSI).
    Low-loss header flow rate is 132 GPM.

    Please let me know if you need any more info and thanks again for all the help
  • Dave T_2
    Dave T_2 Member Posts: 64
    edited June 2021
    you can always build a low loss header with fittings for multiple boiler injection. A 3" header will give you 132 gpm and each boiler will need 2 - 3x1.25 closely spaced tees.

    I would question why you need 132 gpm through the header? Sounds high considering the total input.
  • space
    space Member Posts: 3
    Closely spaced tees will work.
    Yes, the low-loss header is larger than what is needed and we may use a smaller one.

    However, I am still unsure when an ASME low-loss header is required.
  • Zman
    Zman Member Posts: 7,355
    I am not familiar with Canadian codes.
    Perhaps @Henry would know.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Henry
    Henry Member Posts: 995
    The provinces are the AHJ. Loss headers are are not required to be ASME in Canada.
  • hot_rod
    hot_rod Member Posts: 16,518
    They do need a CRN number. I think if it as the CRN it also has ASME, don't quote me on that.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream