Single pipe vacuum vents

HowardLong

I just ran into a single pipe steam system with two of the returns having dole number 6B vacuum vents. Is it worth getting replacement vacuum vents? Because these ones are definitely not opening. Or should I just get a standard gorton?

HowardLong

It also appears the original boiler it's still working and was converted to gas in the '30s-40's.

Captain Who

What vents do you have on your radiators? If those are not vacuum vents as well then something is out of wack. Vacuum vents aren't supposed to open actually. They should only let air out.

https://cdn.toxicdocs.org/oe/oemk2gBy19gbj8RQ3vBz1Jxd3/oemk2gBy19gbj8RQ3vBz1Jxd3.pdf

If you remove the vent you cannot blow through it?

ChrisJ

https://forum.heatinghelp.com/discussion/comment/1889533#Comment_1889533

I'm pretty certain they need to open in order to let air out and I'm willing to bet the OP meant that.

Jamie Hall

If the "returns" are actually steam main extensions, which I suspect is the case given that this is one pipe steam, then I'd replace those with Gorton #1 or #2, depending on the total length of the main and extension in question.

Unless all the other vents in the building are also vacuum vents…

dabrakeman

6B lets air out, just not back in. As others have said unless all the other vents are also vacuum vents this would be of no benefit, just more likely to get sucking hisses from your radiator vents.

I don't know that you can get vacuum vents for radiators anywhere??

HowardLong

Yeah, the vents are completely stuck and they don't let any air out. I worked on two pipe vacuum systems before that have now been converted to just normal steam. But with a single pipe one I wasn't sure if it was worth trying to keep it a vacuum system or just swap it. But I do need to check the apartment, no one has checked any of those vents in s.

HowardLong

And yes these two returns are actually the extensions of the steam main just like in a two pipe system. The return vent seems to be working fine.

dabrakeman

So let me get this straight. There are two vacuum vents not working and these are where, end of the mains? You mention a "return vent" (singular) that is working. Is that back at the boiler? Shouldn't need vents in both locations but more importantly it seems there should be two returns which if vented should be vented separately since they should not join before dropping below the waterline.

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1889803#Comment_1889803

How's that again Two pipe systems have steam mains and dry returns and often wet returns… but steam main extensions?

HowardLong

Yeah this is a two pipe system. I don't know why I kept saying it was one pipe. Must have been having a long day. I see that I can still get main vacuum vents. But they're pretty expensive. Does anyone have any experience if it's worth installing them versus a normal vent?

Jamie Hall

Ask six people and you'll get 12 answers. No. 18. Yes, no, and maybe.

My own take? I run a Hoffman Equipped vapour steam (two pipe) system (340,000 BTUh power). It has one Gorton #2 main vent at the Hoffman Differential Loop, where it belongs, and works just fine. It originally had a Hoffman #76 vacuum main vent — but there's no noticeable difference in behaviour or fuel use with the Gorton.