why drop headers?

steve_6

on a previous posting , I believe mad dog was talking about how drop headers produce great quality steam. does anyone no why and how they do it? thanks

David Efflandt

You want dry steam

There is a chapter in "The Lost Art of Steam Heating" book that explains near boiler piping and what happens if headers are too small, not enough (1 if mfr recommends 2) or not enough rise. Excessive steam velocity can blow water into the mains and result in uneven boiler level which can falsly affect LWCO. Basically READ and FOLLOW manufacturer's directions. Do not assume that what worked for an old boiler will work for the new (nor that somebody else piped it correctly).

David Efflandt

You want dry steam

There is a chapter in "The Lost Art of Steam Heating" book that explains near boiler piping and what happens if headers are too small, not enough (1 if mfr recommends 2) or not enough rise. Excessive steam velocity can blow water into the mains and result in uneven boiler level which can falsly affect LWCO. Basically READ and FOLLOW manufacturer's directions. Do not assume that what worked for an old boiler will work for the new (nor that somebody else piped it correctly).

Jamie Hall

I'll bet Noel

will chime in on this, but I'll give it a shot, too...
The whole idea is to get carried over water (if any) or immediate condensate (sure to be) separated from the steam before the steam gets into the mains... anything that helps do this is helpful! Steam gets carried over from the boiler under several conditions: if the risers are too small, or too few in number, the velocity will be high enough so that water droplets can't fall back into the boiler and wind up in the header -- so use the risers, and riser height, the manufacturer wants (do follow the manufacturer's directions on piping... !). If the header itself is too small, the velocity will be high enough to keep the water in the steam; same problem -- the velocity may even be high enough to entrain more water (oops...). If the risers enter from underneath, rather than from the top (or sides, on very big headers), the steam coming up will blow water droplets from the condensate on the bottom of the header up with it. This is where drop headers are helpful.
Does that help any?

Unknown

Hi

Check these posts from down below, about dropped headers.

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=4919&mc=6

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=4866&mc=9