Steam sizing, any charts out there

McSteamer22

I’m sizing a steam boiler for a Church in lower CT, my edr is 638. Existing header is 4” with two 3” mains. Whenever sizing comes into play I use the color of steam by peerless. Most of the time things are sized accurately , in this case I believe the 4” header to be oversized, im curious to the pros and cons, as my book says I can get 1163 edr from 3”.

I’ve always wanted other material on sizing, just because I use one manufactures numbers who’s to say that they are right on general steam sizing, Anything would be apritiated.
Thanks.
(Cough cough, J Hall)???

AMservices

The color of steam is probably saying a 3" main can support 1163 edr, with the right configuration, at the appropriate pressure.

neilc

no disrespect,
what does boiler manual spec?

McSteamer22

I’m putting in a peerless etc04, 650edr. Manual says 3”. But someone long ago thought it was a good idea to go 4”. Header is getting re piped regardless, just deciding on 3” or 4”.
Existing boiler has 744 edr output

Jamie Hall

We'll make the assumption that the EDR is correct, and the boiler is properly sized. What is important to remember is two things: first, the manufacturer's recommendations are minimum. Second, the bigger the header the better the separation of steam and water will be. As I read that boiler, it takes two 2 inch risers. A three inch header would have the same steam velocity -- but there is a lot to be said for having a lower velocity in the header than in the risers.

So... I'd go with the four inch header.

McSteamer22

McSteamer22

nicholas bonham-carter

I don’t think you can be ever be oversized with the risers and header of a boiler. Keeping the steam velocity down low is so important in keeping the steam dry, and not flinging a lot of water up into the mains. In addition, pay attention to how the air is pushed out, whether it might be from two-pipe or one-pipe.
The choir, and congregation will be so appreciative to have a quiet system!—NBC

newagedawn

id go 4" and a great reference book for any steam job is " the lost art of steam heating" by dan holohan, tells you why a 4 " header would be better and shows all kinds of piping and anything else you'd wanna know about piping steam boilers,.....good choice on the peerless , i use them all the time for steam jobs, never had a problem with them!!!!!!!!