Low-Loss Header ASME or Non-ASME

space

Hi, when does a low-loss header need to be ASME rated? Thanks

dopey27177

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.

Jake

EBEBRATT-Ed

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

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.

space

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

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

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

I am not familiar with Canadian codes.
Perhaps @Henry would know.

Henry

The provinces are the AHJ. Loss headers are are not required to be ASME in Canada.
Henry

hot_rod

They do need a CRN number. I think if it as the CRN it also has ASME, don't quote me on that.