Help identifying, replacing main air vent

KenF

Hi,

We have a single pipe steam heating system with an oil boiler in a 100 year old three-story Victorian home in Philadelphia. It has had an assortment of ailments, including serious water hammer at morning start-up, leaking air vents, and excessive hissing. I got a copy of Dan's book "We Got Steam Heat" and have been trying to address what issues I can before calling an expert.



Increasing the pitch of the largest radiator on the second floor has greatly improved the water hammer and leaking issues, but we still get excessive hissing, and my guess is that it's a malfunctioning main air vent in our basement. When the system is at full blast, I can't hear or see any evidence that air is venting, and the pipe is very hot just before and cold after the vent. It's about 5" tall from the base to the top, and around 3/4" where it screws in. (I've attached a couple of pictures) How can I identify which exact model and size to replace it?

Thanks!

BobC

No pictures

The pictures didn't post, they have to be jpg files and they shouldn't be huge.



Bob

KenF

Pictures of the air vent

Apologies for the double (triple) posting. My original post had huge image files and I wasn't getting confirmation of submission. I would delete the extra posts if I could figure out how to do it. Compressed pictures are attached.

BobC

How long and how big?

I'm not sure what kind of a vent that is but someone here will recognize it. In the meantime how long are the steam mains and what size pipe (pipe circumference is fine)? That will tell us the volume of air we are dealing with and tell what size vent you should have.



While your measuring the main take some pictures of the boiler and the piping around it so we can see what your working with.



Bob

KenF

Steam Main Measurement, Boiler Pics

The steam main (I'm pretty sure just one) measures about 55 feet long from the front to back of the house. The pipe is about 7 3/4" around. I've also attached a couple pictures of the boiler. There are radiators on three floors of the house. The boiler is a Weil-McLain Gold Oil.

BobC

That's a 2" pipe

and 55feet contains about 1.2 cu ft of air. I would install a Gorton #2 vent and be prepared to add another using an antler if you have to. The Gortons are not cheap but they will save you money in the long run through fuel savings.



That copper header is not good, steam boiler should be piped in threaded steel pipe. For now I would put in the new vent and see how she plays, you can think about the piping after the heating season.



What is that pressuretrol set to? Steam systems work best when the pressure is below 2 PSI.



Bob

KenF

Boiler PSI

Thanks for all your help on this. The boiler is set to less than 1 PSI. I will definitely order the Gorton #2. I see it says half-inch on the product listing. Any chance it won't fit in the main pipe? I measured 3/4" at the bottom of the current vent, but I assume the 1/2 inch is the inside thread or something (or my measurement was just off)?

nicholas bonham-carter

Philadelphia venting

When you mount the new vent, do so on an antler, so you can add more vents if needed.

If your radiator vents are making any noise, then the main venting is not adequate, and you are burning extra fuel.

Make sure you have adequate insulation on the main supply pipes, and keep the pressure low. If you hade a vaporstat, your house could be heated with 2-8 ounces of steam, and naturally, there is less fuel burned at those low pressures.--NBC

JStar

Vent

You can install a reducing fitting to fit the vent onto the existing opening.

BobC

Height

The Gorton #2 is a great vent but they are probably 7" tall overall so make sure you have the room. If you come off the main with a 90 and use a pipe nipple you can place the vent in a joist bay and that would also make it easy to add a second vent if you use a T with a plug in the outlet side for now.Just make sure this all has a little slope so it can drain any water back to the main.



Bob