mains venting

Steamhead (in transit)

below the top floor, I'd just drill 1/8" pipe-thread holes near the ceiling and put Gorton #C vents in them. If some risers are slower to vent put Gorton D vents on them- you'd get pretty much the same throughput as with the #1 for a lot less work.

If you vent the risers, you may need to add a second #2 to the main, so it will vent at a slightly lower pressure than the risers. This will insure that steam fills the main completely before it enters the risers.

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Bernard Smith

mains venting

I had terrible problems with heating my house until recently. Basically, I hace a 50' main which was vented with a Hoffman 45(totally inadequate I know). I replaced this with a Gorton 2 and the difference is fantastic. The main heats up in about five minutes now as opposed to twenty minutes before. My question is this: Coming off the 50' main, at different locations are four other what I would call sub-mains. They also run horizontally at a slight pitch and at right angles to the 50' main. They are each about 25' long (the width of the house) and 2" in diameter and they of course lead to the risers, or are they actually the risers? I wondered if I was to put a main vent at the end of each of these 20' runs would I doubly assist the steam on its way to the rads or is this wrong? None of these horizontal runs are vented. Am I correct in my line of thinking or not? If I am correct what would be the correct vents to install on these lines? Thank you.

Bob W._3

If it was my system, I would consider putting a Gorton No. 1 at the end of each of those horizontal runs.

Steamhead (in transit)

If those sub-mains

feed more than one radiator apiece, and the various rads take off from different points on the sub-mains, I'd vent them. But if they only feed one rad each or all the rad takeoffs are at the ends of the sub-mains, you might not need to.

How long does it take for the sub-mains to fill with steam?

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Dean_7

vents

Listen to Bob and Steamhead. My situation was similar to yours. I followed Steamheads advice from some time ago and vented my submains. Now my main and submains are vented in about a minute and a half once the steam is up.

Bernard Smith

Thanks guys. Gorton #1 for all those sub-mains. Will let you know how I get on.

Bernard Smith

One more thing guys. The risers at the end of these sub mains extend vertically about 20'. Is this nonsense or would it be feasible to put those Gorton #1s up near the end of the risers. Wouldn't this clear the air much quicker than rad vents only?

Bob W._3

Yes it would, and its a good idea as well. Then you can slow the venting rate on the rads to control noise, spitting, etc.

Bernard Smith

So Bob, am I better to put those Gorton #1s up near the top of the risers and forget about putting them at the end of the horizontal runs altogether? This steam heat is like a neverending journey

Bob W._3

No expert, but that is probably what I would do if feasible. Depends on whether the rads at the top of the runs can be moved. You may have to remove the angle valve, install at T at the top of the riser, move the radiator over and install a gate valve. Fair amount of work - is it worth it? I suppose you could drill and tap a 1/8" hole somewhere near the top of the riser and put in a Gorton D angle vent, which is equivalent to a No. 1, but it probably won't vent as much air because of the small tap. Hopefully Mssrs. Gill and Pajek will do a test on a 1/8" open pipe the next time they run tests on vents.

Bernard Smith

To Steamhead

Rads can easily be moved- all free standing cast iron rads. I think I will try it on one riser first to see how well it works. Seems to me the object of the exercise is to get that steam as fast as possible to the rads. My boiler can be running up to 45 mins. til furthest rads heat up. Any thoughts steamhead?

shawn_11

That's just what i was thinking about...

re: Bob's post,
I just posted a similar question about using gorton Ds to vent a vertical riser, except using a radiator tapping instead of going right off the pipe--here's the thread:

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=31822&mc=7

EDIT:
[Working backwards from the infamous gill/pajek charts, very rough calculations suggest that an open 1/8 inch pipe would vent at .5, .65, and .91 cfm at 1,2, and 3 oz of pressure respectively. We also know that an angled vari-vent will pass .516 cfm at 1oz. This all suggests that the 1/8 hole will not be the limiting factor.]