1 pipe steam returns hot?

Kjmass1

Is it normal for the returns after the main vents to get warm during long cycles like we are having now with the cold in the northeast? I had re-pitched a return that had some obvious sags and low spots, I’m noticing the return pipes must be getting some steam traveling back through them?

Radiators are filling fully, no signs of pressure.

Paul S_3

Dry and wet returns will get warm and eventually hot. It's water that condensed from the steam. Are you having issues with the system like water hammer etc

Jamie Hall

If these are steam main extensions — sometimes called returns — that is to say they are directly connected to the steam mains, no traps or whatever — of course they will get steam in them. Slowly, perhaps, if there are no vents, but inevitably.

Kjmass1

thanks- no traps, just a step down in pipe size from the main to the smaller return extension pipe back to the boiler.

Guess I was surprised they would get that hot even all the way back to the boiler. Worth insulating those?

EBEBRATT-Ed

@Kjmass1 I am assuming this is overhead piping. Is your vent located at the end of the main where it joins the return? Or back by the boiler?

Kjmass1

https://forum.heatinghelp.com/discussion/comment/1836925#Comment_1836925

correct, ceiling of basement. Vent is located at end of 40’ steam main (a couple of big gorton vents). No venting at the boiler. The other 20’ main doesn’t have a main vent to try and slow that side down.