Main vents should be here?

MonasDad

This bit of jungle gym is where I think a main vent should be, and maybe once was. There's an extension on the house and these pipes go to radiators in the extension primarily. These radiators hiss horribly and one of them sucks in air at a good clip at the start of the cycle...a little disconcerting when I think I'm paying for all that steam to push the air in the system out and I got a stupid radiator sucking in violently.



So -- do I need main vents in this location? It's at the end of about 45 feet of main right where it drops to the wet return. I have another main that goes in the opposite direction and I've put one gorton No. 1 there but actually that doesn't seem to have done a whole lot. I'm trying to get my ducks in a row before I call a pro.

JStar

Steam

There is no such thing as too much main venting. The radiator sucking air is a symptom of wet steam, or venting imbalance.

Steamhead

What I'd do

is drill and tap the side of the tee for 1/2" pipe thread, install a short nipple and a 90 pointing up, and put on a Gorton #2.



This assumes the runout to the addition radiator(s) isn't too long. If it's more than 8 feet of 1-1/4" pipe or so, I'd look into putting the vent under the addition.



How long is your other steam main? Are they both 2-inch pipe?

MonasDad

Thanks for the suggestion

Other main is just over 35'. Pipe must be 2.5" as circumference is over 9" and outside diameter is almost 3"



The smaller pipe that goes to the sucking radiator is hidden behind walls and under floors. The extension is from the 30's -- and it's cold and not well insulated. From what I read in 'We Got Steam Heat' is seems to me that if pipe travels through a cold space, it gives up it's heat, steam turns back to water and that creates a vacuum -- so it sucks. But I'll take your advice and vent the main as all the other radiators off it hiss loudly.

BobC

insulate

Insulate any piping you can in that crawl space, anything you can do to lessen heat loss will help. After you get the mains venting taken care of insulate all that piping.



Bob

Steamhead

You're still

in Gorton #2 territory. Start with one on each main.