Steamhead or Noel HELP!

Jeff_23

Hi Guys,
I am trying to size my main vents. I have two mains...each 2 inches in diameter. One travels 25 feet to the last rad riser...bends 90 degrees into a 1 1/2 return that is 15 feet long...where it dips into the wet return. Just where it dips is where my main vent is located.
The other travels 16 feet to the last rad riser bends into a 1 1/2 inch return that is 20 feet long which dips into the wet return. Just where this one dips is where the other main vent is....How many Gortons should I use...or what size!? Thanks..I have a concotion of main vents on t's that I do not think are enough. I need the MOST ou of my gas this year! Jeff

Mad Dog

I Don't have the genius of either Noel or Steamhead

But I am a Deadman. At a minumum, use a Gorton #1 at each location. If you really want to do it right...use the #2s. Either way Gorton is the way to go with main vents. Mad Dog

Unknown

Both mains could use a Gorton #1

But #2s would be faster, though more money.

The first Main contains 0.785 cubic ft of air.

The second, 0.648.

A number 1 Gorton vents 1.4 CFM at 2 ounces.

A number 2 Gorton vents 5.5 CFM at 2 ounces.

Hoffman 75, and 76 are the same as the Gorton #1.

All the others that I know of are equal to or less than .75 CFM.

Noel

Jeff_17

What's vents more quickly

the 75? or the 76?

I am assuming the 76?

Unknown

They are the same, 1.4 CFM

I think the 76 is for vacuum. I haven't seen one installed in a while.

Noel

Jeff Krawic

vents

Hey didnt anyone remind him of the minimum riser on the air vent to keep it dry? Just thinking,....hmmmmmmmmmm.....

Mad Dog

He didn't ask...................................

I don't always have the time for all the details. Mad Dog

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john_27

vents

where in "Lost Art" is the calculation do determine cubic feet of air in a main?...I can't find it....Hoffman 76 is a vacuum vent,the 75 is not...John

Unknown

Dead Men's Steam School workbook

But Steamhead put the tables together. I keep that table taped to my file cabinet. I use it a few times a week!

Thanks, Dan and Steamhead!

Noel

Steamhead

Thanks, Guys

I don't often get referred to as a "genius"....... ;-)

You guys are right on. Gorton #1 will handle those mains. It might not be a bad idea to use two #1s on each since the vents are at the ends of the dry returns, and there's some air in the dry returns that needs to be vented before steam can start rising to the radiators.

Hoffman's #75 and 76 vents will work here too, but they cost a lot more- especially the 76 since it's a vacuum vent. You really don't need a vacuum vent on this system.

Ideally the vents should be installed on nipples 6 to 10 inches tall. But if you don't have the headroom for these nipples, and if the steam is dry, the wet returns aren't plugged and the pressure is kept low like it should be, you should be OK.

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