Drop Header Questions

MikeyB · August 2012

Is there a list of rules to play by when building a drop header? or is it based on field conditions or personal preference? Are there certain pipe diameters to go by when laying out the spacing between the take offs from the header? do you have to leave a certain amount of space between the last take off and the elbow to the equalizer (if room permits)? I'm looking to build a drop header on a Burnham IN4, utilizing both tappings from the boiler running 2" inch risers up to at least 24" above the top of the boiler, elbow, close nipple, elbow (facing down) close nipple down (or longer nipple) into a 3" header. It looks like the header only needs a little bit of pitch to drain the condensate, and by using 3"X 2" tees for the take offs I can come right off the top of the 2" Bull to connect to the mains and not really notice that the vertical take offs might be a bit out of plumb? and does the elbow that connects to the equalizer really need to drop straight down without rolling it on a 45? would offsetting it to make it plumb cause too much resistance (my old boss was real particular about risers/drips being plumb)? And is it a better to run a 3" nipple on the equalizer line and reduce to say 2" before the Hartford Loop tee? or just reduce to 2" at the elbow? and why? And does that larger size nipple need to be a certain length? Sorry for all the questions but I'm trying to understand all that goes into a Drop Header, the 2 different shops i used to work for never built drop headers. Thanks for your input guys.

Charlie from wmass · August 2012

Field conditions and budget rules many of your choices

I prefer a full size elbow and nipple leading to a reducing coupling on small headers. If the header is a size or 2 large and the equalizer is large then a reducing elbow will be fine. I use drop headers when the rise to the main is low or I am installing onto a counterflow system. In my local area drop headers are a 1 out of 10 thing, when I am farther from home it is a 9 out of 10 thing. I think it is more the type of systems I work on locally are basic everyday systems and those away from home are not or the local guys would already be doing them. Be practical and mindful to not go to over board as it is simply wasting material, adding excess air to be vented and increasing radiation losses by going too large. If the boiler is sized well and the system is vented well a 3 inch header is not needed on such a small boiler, that said I have not seen the job even in a picture so I am just talking in general terms.

Hap_Hazzard · August 2012

Other Threads

I got some good advice on my drop header in this thread, when we weren't talking about drawing programs, FeatFlow, snow blowers, Les Paul and Mary Ford. :-)

http://www.heatinghelp.com/forum-thread/140885/How-High-The-Header

You can probably find other discussions on this subject here if you search for them--not that it's not worth bringing it up again. Something new always comes out whenever a topic comes up again.

gerry gill · August 2012

You can probably answer most of your questions

by a careful study of this picture. See how the water backs up into the header due to the turn and size of the equalizer.. And this is a properly piped boiler..See how the water is still being lifted into the takeoff..In my opinion, the header should drip to the equalizer vertically, and it should be at least 2'' and preferably have a larger drop out the equalizer elbow than the equalizer itself to act as a 'reservior" so to speak.

MikeyB · August 2012

Drop Header

Great advice guys, thank you

The Steam Whisperer (Formerly Boilerpro) · August 2012

Other helpful ideas....

When piping your takeoffs off the top of the header, make them oversized and then reduce down to the main size. I often just make the takeoff tees the same size as the header then go up with a 6 inch nipple and then use a concentric reducer. This will greatly reduce the velocity going into the takeoff and allow the water to stay down at the bottom of the header. Also the spacing matters....at least 3 header diameters from the last boiler riser to the first take off, at least 2 diameters between takeoffs and between the last take off and the drip/ equalizer. These spacings halp make sure the water settles in the bottom of the header after each high velcity transition.

Drop Header Questions

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