Header and boiler riser size

CherylR

I am going to be installing a new Peerless 63-04L boiler, and I have a question about the size of the header and boiler risers.  I am considering either two 2 inch risers with a 2 1/2 inch header, or two 2 1/2 inch risers with a 3 inch header.  Is there an advantage to using the larger size when my steam main is 2 1/2 inches?

Steamhead

The larger size

will slow down the steam and do a better job of separating out any water that gets that far. The specified header is 2-1/2", but it can't hurt to go with 3". That's what I'd do if it were mine.

CherylR

Thanks

Okay, thanks!  I will go with the larger size.

Hap_Hazzard

Header and Risers

From what I've seen, the pros usually make the header at least 1" pipe size larger than the risers. I think this is because they want the cross-sectional area of the header to be as big as that of the two risers combined.



NPS cross section

2" 3.356

2 1/2" 4.788

3" 7.393

3 1/2" 9.887

Long Beach Ed

I'm with Steamhead

I'd go with the larger size too. 



While the improvement between the two may sometimes be nearly immeasurable,  on some systems it will make a large difference.   By dividing the added cost, which is generally only in materials, over the years of the boiler's life, it's negligible.  



I think the larger header is probably a good investment if you can do it.