Steam main venting question

patrickc123

Hello, 

I recently purchased a home with a one pipe steam system. In these cold winter months, I am realizing that the system is heating pretty unevenly throughout the house. Some radiators (especially those farther from the boiler) are not getting hot, or only getting hot when the boiler has been on for a while. 

I understand from reading here that proper venting of the steam mains is one of the first steps in fixing this issue. That’s where my question comes in. Is this the steam main vent?

Judging by the looks of it, it seems to need replacement, but just want to confirm this is it, and how to go about replacement. 

I also included two additional photos so you could see where this is in relation to the boiler. 

Thanks!

mattmia2

It looks like it is where the vent should be but I can't tell what it is, looks like some sort of boiler drain. Can you take some closer pictures of the device screwed in to the pipe?

Is that lower horizontal pipe along the wall below the water line of the boiler? It should be but looks a bit high for modern boilers.

bburd

There should be a main vent on the tee just before the steam pipe drops and reduces in size. The white PVC pipe is blocking the view.

steam pipes should also be insulated, which will help to heat all the radiators quickly. 1" thick fiberglass is standard practice. It's not generally available at big box stores, but can be ordered online from many sources.

Jamie Hall

Whatever that turquoise thing on the vertical pipe is, it isn't a vent. There might be one hiding behind the drain line at the T about a foot before the drop to the return -- and that would be the right place for one.

Waher

The green mess of pipes I think was a make up water feed. The original boiler and maybe hot water heater tank would have extended into that area.

There's an iron plug in a tee underneath the PVC pipe that I think was the location of the main vent. The pipe stuck into the wall and wedged under the main to may have been the nipple for the vent in that plugged tee until someone decided to repurpose it as a support.

If the PVC is in the way, you'll have to use a 45 degree street elbow to lateral out away from it and then use another 45 degree elbow to get 8-10" above the main to install some vents on a new antler of nipples & tees.

Long Beach Ed

Yes, a main vent would go into that tee under the plastic pipe. The plug would have to be removed (good luck with that!) and replaced with a vent.

JUGHNE

Short pipe stubs drilled into the wall was a common method of pipe support by the dead men.
That was in the original plan.

2 Lb hammer and "Star" bit would get you there. Unheard amount of labor/work in today's world.
I did use one for 1/4" plastic anchors at one time, real incentive to buy a small hammer drill.

patrickc123

Thanks, all. These replies are really helpful. 

For those who asked, here are a few more photos, an up close of the device I was originally looking at, and some pics behind the pvc drain pipe. 

It makes sense that the device was an older make up water feed, as opposed to the main vent. The current water feed is not too far down this same run. 

The lower horizontal pipe is actually a single return pipe from one radiator. For some reason, though the rest of the system is one pipe with air vents, one radiator has a return. (Anyone have any reasoning for this set up?)

There appears to be just enough room behind the pvc pipe to install a main vent, so this will probably be my next step. 

And the point about insulating these pipes is well taken- that’s going to be one of my next steps too. 

Jamie Hall

They didn't do you any favours on getting that plug out, did they? I think I'd try an impact wrench with a really good fitting square drive socket.

Long Beach Ed

The nickel valve on the pipe is a shower hose or gas lamp cock that was used as some sort of condensate drain. The plug for the vent probably isn't coming out. Usually the tee has to be broken out and replaced, but maybe you'll be lucky.

mattmia2

Long Beach Ed said:

The nickel valve on the pipe is a shower hose or gas lamp cock that was used as some sort of condensate drain. The plug for the vent probably isn't coming out. Usually the tee has to be broken out and replaced, but maybe you'll be lucky.

Maybe it was a try cock for the water level of the old boiler?

pecmsg

Impact gun and Sq socket. Try tightening and loosing. A torch would help. You may want to cut that drain line out of the way as well!

mattmia2

There is always cut the center of the plug out with a hole saw and make 2 saw cuts to almost the threads and pop a wedge out with a chisel too.

JUGHNE

IIWM, I would use a dental pick to cut rust away around the plug threads, then soak several times with PB blaster or Kroil spray.
A little hammering on top of the plug might help between sprays.

An exact fitting 8 point socket with extension on impact driver might unscrew it.
As pecmsg suggested try to tighten a touch and then loosen.

The PVC may swing out of the way away from the wall, nipple up above the PVC for your vent.
That new vent pipe will get steam hot so I would slip a larger diameter nipple over the vent nipple to avoid direct contact with the PVC.

The little "try cock" might have been a manual air vent.
If it was a boiler water level indicator then the old boiler water line must have been high.
I would not try to open it....probably break off.

dabrakeman

Certainly where you are working at the end of the main extension is likely where the main vent was and an acceptable location but I am just curious as to what you have at the actual end of the main just after the last takeoff? Haven't seen any pictures and maybe you have another alternative location. Can barely see what might be there in the attached picture: