Venting Wet Returns

cdm

I have seen several posts on venting wet returns on one pipe steam systems - What advantage does this add one pipe steam system.

cdm

nicholas bonham-carter

Large vents on the dry returns allow the air to escape so the steam can get in. The radiator vents are too small to handle this job, without burning excess fuel to force the air out.—NBC

Jamie Hall

But there's no point to venting a wet return -- if that is what it really is.

Fred

@cdm , I think those posts you refer to are from someone who thought/thinks venting a wet return helped their situation. Don't vent a wet return. It is a waste of a good vent and likely will spew water. Serves no purpose.

cdm

Thanks for the response - Since the wet returns are at the end of the main last feed. I also could also not see why an additional vent was required.

cdm

Fred

Let's make sure we are really talking about a wet return. A wet return is a return that is below the water level in the boiler. Any returns above the water line or at the end of a main, after the last radiator run out is basically a "Dry" return and can benefit from venting. Once it drops down and is below the boiler water level, it is filled with water and there is no benefit from venting those wet returns.