Steam Boiler Headers

Boston Standard

I go back and forth with the guys from work... We try to all install top-notch steam heating systems and pay respect to the Dead Men. I feel that some guys are taking it a bit too far though.
As an apprentice I worked under a guy who always installed smaller steam boilers (5 sections or less w/Weil-Mclain) with one 2" steam header. He located vents properly, skimmed the boiler and all was quiet & orderly.
I now prefer to pipe the same boiler with dual 2" headers, but otherwise, I feel the install was great and leave it the same.
The guys at work are pressing for the use of dual 3" headers, up until the equalizer where it goes to 2". I just finished one of these boilers earlier, and it operates beautifully.
I think that the use of 3" on boilers of this size is overkill though. I've been around boilers in Boston for 8 years and do not see any residential boilers piped with 3" headers, let alone two of them! The stock cost increases as well as the labor, and I don't think it is justified.

What do you think? Thanks.

gerry gill

bigger is better

why be mr. minimum?

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Brad White_200

A 3-inch dropped header and/or riser

is a gift. I had a 3-inch riser installed (by Norm Harvey), rolling to a 2-inch dropped header on a Burnham IN-4 which, years ago, was improperly piped in a number of ways.

(This one would fire for 40 minutes before half of the closest radiators got halfway warm, the addition would see little heat for an hour and the banging was a chorus.)

The dropped header coupled with other improvements we all know, got that steamer working VERY quickly and quietly as you can imagine.

This of course does not single out the header as the entire reason, but the Owner and his tenant are glad it is.

Yes, up-size risers too.

Now, fine to say that the net size pipe will work, of course it usually will. Competition demands that consideration of course. But on some systems, any system actually, the issues are compounded, "small things not perfect" which have a ripple effect. Marginal heights, limited A dimension, etc.

If I were to insist on leaning to the smaller piping, I would endeavor to make it "better than spec" by using a dropped header, generous riser heights and so-on. But a larger header and more generous risers, if my own system that is what I would do.

My $0.02

Brad

nicholas bonham-carter

does size matter?

nice piping! i would be more concerned that there appears to be no vaporstat, or low pressure gauge on this boiler. a way to drain things directly to the floor drain [if only a good hose] would be nice also.--nbc

V8toilet

The way to determine if piping as large as that is needed is to calculate how fast the steam will travel through those pipes. All you need is large enough pipe to slow the velocity of the steam down to 15 ft per second or less. It is explained in Dan's book on how to calculate it; this is also how the dead men sized there near boiler piping.

Steamhead (in transit)

The manufacturer's minimum specifications

should always be followed. But these are bare minimums. We routinely upsize headers from these minimums, and we get drier steam as a result. The drier the better.

Drop headers make lots of sense where there are two or more risers from the boiler to the header, since the extra swing joint makes the header much easier to assemble. Also where you want to make these risers higher than the steam mains, as in a basement with a low ceiling and counterflow mains.

It's true the pipe and fittings are a bit more expensive, but the labor seems to be about the same. It really doesn't take much more time to build a header using 3-inch nipples and fittings than it does with 2-inch ones, except the 3-inch stuff is a bit heavier.

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