Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Header Piping

denick Member Posts: 10
edited November 2021 in Strictly Steam
I'm installing a new boiler and there is a 2 1/2" riser on the new boiler. The existing header is 4". The mains coming out of the header are 2".

Can I increase the riser to 3" at the boiler nipple?
Make the drop into the header with 3"?
Keep the 4" header ?
Do the 4" to 2" T's in the header to the mains cause any increase in steam velocity?


  • Jamie Hall
    Jamie Hall Member Posts: 23,324
    Yes. Yes. Yes. Yes. Make sure (it's pretty obvious!) that the two mains come off vertically up, or no more than 45 degrees off vertically up, from the header, and that they are after the boiler riser. Make sure that the reduction in size on the equalizer is on the vertical part after dropping from the header.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EBEBRATT-Ed Member Posts: 15,544
    As long as the take offs to the mains from the header are at least the size of the mains your fine. Ditto everything @Jamie Hall

    In this case bigger is better. as long as you meet the MFG minimum you are fine if you exceed that your fine as well. Just follow the piping diagram