Radiators full of Condensate

Chris K_2

Hello, I work for a small engineering firm in upstate NY. I dont have much heating experience, but I'm trying to learn as much as I can. My company allowed me be the lead desinger on my first project last spring, and the contractor intalled it this summer.

The system is a One pipe steam system, with 2 new Weil Mclain 688 boilers. Resized and replaced all the piping per chapter 7 in dan's book, the original system was gravity fed, but I put in a boiler feed set, with a 120 gal resivour to make up for the low water content of the new boilers.

I trapped every radiator with F&T, but the thermostatic element removed.

The system was started last week, and the feed set was blowing steam out of the vent, so we trapped the end of the mains as well. All seemed fine, but then I was called by the contractor and told that the radiators had stopped heating, and that they were totally filled with condensate.

The radiators are no bigger than 100Sq Ft EDR, and the traps were sized for 390 Lbs/hr of condensate. The contractor thinks the traps are undersized, and that they can not drain fast enough....

I dont think this is the case. Should I have left the thermostatic air vents in the traps? I think it must be some problem with the venting, kind of like putting your finger over a straw....

Please Help!!!!
Thank You

Chris K_2

Radiators full of Condensate

Hello, I work for a small engineering firm in upstate NY. I dont have much heating experience, but I'm trying to learn as much as I can. My company allowed me be the lead desinger on my first project last spring, and the contractor intalled it this summer.

The system is a One pipe steam system, with 2 new Weil Mclain 688 boilers. Resized and replaced all the piping per chapter 7 in dan's book, the original system was gravity fed, but I put in a boiler feed set, with a 120 gal resivour to make up for the low water content of the new boilers.

I trapped every radiator with F&T, but the thermostatic element removed.

The system was started last week, and the feed set was blowing steam out of the vent, so we trapped the end of the mains as well. All seemed fine, but then I was called by the contractor and told that the radiators had stopped heating, and that they were totally filled with condensate.

The radiators are no bigger than 100Sq Ft EDR, and the traps were sized for 390 Lbs/hr of condensate. The contractor thinks the traps are undersized, and that they can not drain fast enough....

I dont think this is the case. Should I have left the thermostatic air vents in the traps? I think it must be some problem with the venting, kind of like putting your finger over a straw....

Please Help!!!!
Thank You

Steamhead (in transit)

\"I trapped every radiator with F&T\"

on a one-pipe system the rads don't need traps. Where did you put these F&Ts?

Normally if you change a one-pipe system to pumped return, the trap at the end-of-main drip handles all the condensate. If you didn't plug the thermostatic elements' openings, steam can get right past the trap. Depending on how you piped it, this could pressurize the returns to the extent that condensate won't flow.

Take some pics and post them here.