Main Vent Question

johnw

Sorry that this may be a bit long but anyway: I need to replace the main vent down in my basement. Hopefully I can explain this right - coming up off the furnace is, let's say, a 3 inch iron pipe that after coming up off the furnace does a 90 degree angle and begins the Hartford Loop (I believe). Anyway, after going about 3/4 of the way around the piping drops about 6 inches. At the drop is a 90 degree elbow and this is where the main vent is located. After it drops the piping becomes 2 inch piping. But back to this main vent location. Since it's on the elbow that's dropping down the vent hole is not on the top of the piping but on the side. This might sound confusing but what this does is this - I ordered a Gorton valve #2 air eliminator. This valve is not angled so it seems that it should go into the top of a pipe and stick straight up. The way my vent is will make it stick, let's say, parallel (sp?) to the ceiling. I don't know if that matters or not. On another note, the main vent hole is just about 1/2 inch. The Gorton #2 says 1/2 inch but really is bigger than that b/c their just measuring the hole in the vent and not including the threads which makes it about 3/4 inch. So I took the old one off (which, by the way, comes out of the hole and makes a 90 degree angle and goes straight up)and it says # 3 on it. I couldn't tell what brand as it may be 50 years old but I can see the # 3. Sorry, I can't include pics but I hope someone gets this.

Christian Egli

Like a rising moon

The Gorton #2 must be installed vertically with the outlet pointing to the sky where air belongs. There is a float inside that just won't work flat.

It seems the current hole in your main is not the same size as the Gorton. You'll either have to drill and tap a new hole, or play with reduction fittings. At any rate you'll need an elbow for pointing the vent the right way. Use black iron fittings.

Also, you want to put the vent on top of an (6 to 12 inch) extension to protect the vent from possibly banging water near the end of the main.

You're talking about a location 3/4 down the way along your main. Does this mean it goes further another 1/4?

If so, what kind of vent is at that end?

Here is a current post that has helpful pictures.

http://forums.invision.net/Index.cfm?CFApp=2&Message_ID=187625

You've got the good idea maintaining your steam system. Good luck.