What is this?

pjyorks · July 3

Does anyone know what this is?

My wife and I recently purchased a Victorian house that has single pipe steam. I was looking for the main vents, (which there aren't any) and found this at the end of a main line.

Any help is appreciated, thank you.

20240703_100254.jpg

dko · July 3

EBEBRATT-Ed · July 3

Just a tee with a plug in it. A vent could go there but they are supposed to be located back on the horizontal main about 18". But better in the tee than no vent at all.

ethicalpaul · July 3

I'm not sure I've ever seen an example of a main vent NOT located at this location, and IMO it's fine there (the reasoning behind positioning it away from the end is sound in theory but in reality it's not a problem unless your boiler is surging like crazy).

You or your plumber can add the vent there (The original installers put the tee there for the vent then someone removed it at some point).

Let me guess, north Jersey?

pjyorks · July 3

Thank you very much for your help.

Central Pennsylvania. The system worked better than I would expect considering I could not find any main vents, only a few radiators were not performing well. We did not have a ton of hissing, although balancing the house took some effort using radiator air vents.

mattmia2 · July 3

Looks like there is a lot of asbestos and maybe some sort of encapsulant in that area.

EBEBRATT-Ed · July 3

Putting main vents in will make it perform much better. But it may require balancing after they are installed.

KC_Jones · July 3

https://forum.heatinghelp.com/discussion/comment/1805311#Comment_1805311

Balancing was hard because of the lack of main vents. With main vents, it's honestly fairly easy. Without them you are asking radiator vents to do the work of main vents and it can create challenges.

I'd add the main vents and rebalance if necessary, it will perform much better.

I'm in south central Pennsylvania and there is a tremendous lack of steam knowledge in my area, I suspect you are in a similar boat.

ChrisJ · July 3

https://forum.heatinghelp.com/discussion/comment/1805309#Comment_1805309

None of mine are at that location.

They're located about a foot back from it in a 2x2x3/4 tee on each main.

Ironman · July 3

Putting the main vents on a manifold like this will help.

EBEBRATT-Ed · July 3

I would certainly try putting vents on the existing tee before cutting into the main. If they spit water the pressure may be too high. I usually like the vents raised as high as possible up to the underside of the sub floor.

Either way asbestos may be an issue.

Mad Dog_2 · July 3

I find the most common locations of the main vent tees are like the OP's pic...on a Heel Tee. It's not ideal, but as Paul said, should only be a problem with a surging boiler or clogging wet returns. Mad Dog 🐕

Mad Dog_2 · July 3

I would suggest you spray down all the nearby insulation (likely asbestos) with 3 M #77 Encapsulating spray to bind any friable or loose fibers, before you put a wrench on that plug. Soak it real good for a few days with WD 40. You may get lucky. Mad Dog 🐕

ChrisJ · July 3

@Mad Dog_2 and @ethicalpaul agree?

I need to find a chair.....

ethicalpaul · July 4

https://forum.heatinghelp.com/discussion/comment/1805324#Comment_1805324

was yours re-done, or old skool?

ethicalpaul · July 4

https://forum.heatinghelp.com/discussion/comment/1805335#Comment_1805335

We agree on way more than we disagree, as do, I think, any of us here. But the disagreements are just more noticeable!

I've even recommended Matt to people offline!!

ChrisJ · July 4

https://forum.heatinghelp.com/discussion/comment/1805350#Comment_1805350

DanHolohan · July 4

We can tell by the stains on the pipe that main vents were once there, but someone replaced the vents with plugs when they began to leak steam and water.