Placement of Main Vent

NancyQueensNY

Want to get professional opinion. I want to replace the rusted and inadequate old vent but it is so badly rusted that it is very hard to get to; bushing is also rusted. Even if we were able to get it off, it is too close to the ceiling so is most likely picking up runoff and debris. The plumber who did the conversion from oil to gas did not replace this decades old vent. That section of the pipe is cold and we have cold radiator issue on top floor. So this has to be fixed as immediate next step. The location of this vent makes it very hard so looking for creative solution here. See attached diagram of current and proposed.

What I am thinking is that I have a vent installed not at the elbow but slightly below the bend. The final drop is a copper pipe so should not be too hard to tap/weld and put a Gorton #2 vent there.

Questions:

1- How high should the vent be above the water line?
2- Any other considerations for the vent in terms of some basic steam principles that I should keep in mind?

Thank you!

Steamhead

I've seen this done, but it's better to have the vent above the steam main if possible. We would use an impact wrench with a right-angle attachment to get the bushing out, then elbow over to where we have more room, making sure the piping slopes back to the main so water wouldn't collect in it.

How long is that steam main, and what pipe size?

nicholas bonham-carter

Are you sure this is a parallel flow system, with that being the dry return?
If your only option is to mount the vent on the vertical drop, then it must be as high as possible above the waterline. The water level in the returns rises 1.75 inches per ounce of pressure above the waterline of the boiler. This rising return water level can block the vent connection if it is not high enough.--NBC

New England SteamWorks

You can also install the vents at the end of the supply main(s) after the last radiator take-off and just before the return begins, rather than at the end of the return. May not be any easier depending on what's there, but something to look at.

NancyQueensNY

Steamhead said:

I've seen this done, but it's better to have the vent above the steam main if possible. We would use an impact wrench with a right-angle attachment to get the bushing out, then elbow over to where we have more room, making sure the piping slopes back to the main so water wouldn't collect in it.

How long is that steam main, and what pipe size?

Its a bit of a mystery - I'd guess 80-90ft steam main (2" supply, home is 33 ft in length and approx 15 ft across.)

Steamhead

OK, so the main wraps around the basement, then? You'll need to start with at least two Gorton #2 vents.

NancyQueensNY

Yes it wraps around the basement, i do see two supply mains come out of the boiler. I cannot trace them all the way. I see there are 4 risers that go from 1st floor to the 2nd floor. Could be two lines going out merging into a single return. In which case it would be 1.5x my estimate.

What is shocking is that the return currently has a very tiny valve, which is corroded and rusty and none of the plumbers who came diagnosed that cold pipe to be the issue, so i had to do the research and i hope i am on the right track...

Steamhead

You may be right. What would it take to trace those pipes out? That way you'd know for sure.

NancyQueensNY

No clue how to trace out the pipes... what would you suggest? I can remember the planet of the apes TV show where they would click on the pipes to communicate... I could do that.

Home is Two floors, 3 bedroom per floor residential - two Gorton #2s?! Ok, I'm on it... since the return pipe at the end if 1" there may be diminishing returns beyond 2 vents too...