Need help with main vent selection...

John_141

Please help me pick new main vents, single pipe steam, about 15 rads of varying size. Lately I'm having pressure issues and I want to look at the mains first, waiting for my plumber to help look at te ptrol.





2 mains, each 2.5" pipe

Short main is about 30'

Long main is about 60'



Presently have Hoffman 4a on each and I think they

are too small. I was looking at Gorton 1 & 2, big price diff.

Also, my vent risers are 3/4".



Thanks!

BobC

Buy what you can afford

A 30 ft 2.5" main has about a cubic foot of air in it and you want that to leave quickly. A Gorton #2 would be optimum if you have the room for it, you need 7-8" of headroom for it. Three ea Gorton #1's are almost as good as one #2 but that costs about as much as the #2 so you might just as well go for the #2. You would need 2 #2's on the 60ft main.



If things are really tight put a #1 on the 30ft main and 2ea #1's on the 60 ft main, it won't work as well but about 2.5X better than a 4A. But a Gorton #1 is only about 27% that of a #2.



Remember Gorton #2's have 1/2" threads while #1's have 3/4" threads so you have to allow some height for a thread reducer.



Bob

John_141

thanks.,

thanks for the quick reply Bob...i still cant get over how much the gorton #2 is...pretty expensive for what it does...but if this helps my gas bill then im all for it...my gas bill is already doubling by the month and its not that cold yet...

John_141

thanks.,

thanks for the quick reply Bob...i still cant get over how much the gorton #2 is...pretty expensive for what it does...but if this helps my gas bill then im all for it...my gas bill is already doubling by the month and its not that cold yet...

John_141

question about

when i went to measure the clearance for the gorton 2s, i realized that while the vent on the long main is at the end of the line, its AFTER 2 branch lines going to radiators.  there looks to be a 3rd branch line that was cut and capped, probably due to a renovation.  should i relocate the vent to where the capped branch is?  it would then be located in front of three radiator branch lines...

BobC

vent is in the right place

That existing vent is where it belongs, it just needs to be bigger. the vent wants to be after all the radiator takeoffs and before the line drops down towards the boiler.



i agree the Gorton #2 is very expensive but the other option besides the Gortons (for about the same venting capacity) is to use 2ea Hoffman 75's and those are just as expensive as the Gorton #2 and you need two of them so it would cost twice as much.



The good thing is they last a long time.



Bob

John_141

last question...on the vents that is

does anyone here know if there is a retail store in manhattan or nassau county long islnd that sells these?

BobC

If you can't find them locally

Try pexsupply.com



http://www.pexsupply.com/Gorton

John_141

tks...

didnt realize Pexsupply was locatedin Farmingdale NY..not far form me at all, may have them tomorrow. 

So the theory is to put the large vents on both mains, and then all or most of the radiators should get the same size vent like the gorton C or an equivalent? 

If there is still one room that needs to vent faster, which rad vent would you recommend?  due to a renovation whjere we removed a non load bearing wall, one bedroom in my house had to have the stame pipe redirected up an outside wall and i dont think the contractors installed sufficient insulation on the pipe, they used the rubber stuff, not the 2" thick fiberglass wraps.  So that bedroom not only has a long branch run to the radiator, but it goes up an outside wall about 10 feet or so before going back into the bedroom to the radiator.