Drop header length

hi

im redoing my near boiler piping and was wandering if there is a minimum length that the header should be?

in other words I'm using 3 inch pipe and have a 6 inch nipple between the two boiler risers then another 6 inch nipple then comes the risers to the mains, there are two risers with a close nipple in between then another close nipple to the equalizer.

Rod

Dropheader Layout

I've seen a figure of  "15 inch minimum" between the boiler riser and the riser taking steam to the mains. This would make sense as it allows the steam to travel a bit horizontally and let the water droplets in the steam precipitate out before rushing up into the risers to the mains. On of the advantages of a dropheader is being able to have tall boiler risers. Dan suggests 24 inches above the top of the boiler cabinet.  Having boiler risers is a big first step in filtering out water from the steam.

If you want ideas on dropheaders take a look at Gerry Gill's website http://www.gwgillplumbingandheating.com/

- Rod

hi

How signifecant

Is that 15 inch? (I am very tight on space)

I've made the risers as tall as I possibly can (it's over 40 inches tall!!).

JStar

Header

We very rarely have enough space to implement the 15" rule. We usually stick the main riser tees right next to the boiler riser tees with a close nipple. The drop-header is VERY forgiving (if it's upsized), and will still produce dry steam. We've never seen any operational deficiencies with the header this way.

Jamie Hall

I'll go with Joe

on this one -- assuming the drop header is upsized -- at least, one, two is better -- the water droplets are never going to make the corner to get into the risers to the steam mains.  Mine works beautifully, and it is less than 15 inches (haven't measured it) -- but it's a 4" header with 3" risers off the boiler and over to it.

hi

Up sized

What do you mean when you say upsized?

JStar

Upsized

At least one size bigger than recommended.



I ignore the manufacturer's suggested header size; they are always way too small. I made a post here with a chart for header sizes based on an acceptable steam velocity.



http://www.heatinghelp.com/forum-thread/146979/Steam-Formulas