false water line

mstrbill

Need help w/false water line on existing system , Boiler was replaced 5 yrs, apartment build, w/21 units , gravity system , old system had two mains ending 60 feet away from boiler to drip into wet returns horizontally back 50 feet or so to boiler room . Near boiler room there are 15 inch inverted U's which used to keep the old pipes under water, now that there is a new water line LOWER than the old the water line is right at the line of where the U s connect to the return near the boiler . there is an equalizer at this return off the main , there is water in the U traps , there is old manual vents on each U elbow , and there is 28 inch at end of main and like i said 15 inch rise up to new boiler water line , my question is to Dan why need 48" inch inverted U s and how can I improve the return flow from the 50 foot horizontal returns , what signifigense is the 48 inch rise in false water line , I barely have 15 and the longest return stays cold . Any help ?

Jamie Hall

First and obvious question is...

is it working as it stands?  In particular, are the wet returns still wet -- that is, full of water when the system is steaming?  The 48" is nice to have -- but the A dimension -- from the top of the U to the lowest steam carrying line -- is much more important.  That's the 28" Dan quotes.  You don't absolutely have to have the 48"; the idea there is to help avoid a situation where the inverted U for some reason gets dewatered.



But if your wet returns are wet, and water is able to return along them to the boiler, and the system is working OK... leave 'er be.