Is there a table somewhere with X feet of Y diameter pipe needs Z number of Gorton #2?

agurkas

My system still gets up to 2PSI (and would go hire if not for cut-off). So I need to audit my venting. Is there a table somewhere that would tell me how many Gorton #2 I need for say every 20 feet of 2" pipe?

My issue is that one main is 75% 2" and 25% 1", the other two mains are mostly 1.5". It would be good to have rule of thumb stuff that does not require a lot of calculation.

Fred

Yes there is. If you get Gerry gill's ebook, at the store on this site, called "Balancing Steam Systems Using a Vent Capacity Chart" That gives you the venting capacity of various vents as well as the amount of air, per foot, in a variety of pipe diameters. It costs only $10.00, which is donated to charity and is immediately downloadable.

agurkas

Oh wait. I did buy that one. Completely spaced.

Paul48

Venting will not change the fact that your system gets up to 2 psi.It will change what is hot and when it is hot as your system reaches 2 psi. If everything within the system gets hot rapidly and evenly but the pressure builds to fast, then you have "Two gallons in a one gallon pail".

agurkas

I am sure is it "holistic" issue. From overfired boiler (which will be fixed with conversion) to vents being too big or too small on the rads and on the mains.

agurkas

OK, so just to doublecheck I got the number right, my 3 mains have:
#1. 1.925cu ft of air to vent
#2. 0.47cu ft of air
#3 0.32cu ft of air

So for #1 1 Gorton #2 is enough
For #2 Gorton #1
For #3 also Gorton #1

Am I right?

BobC

Some consider that under vented, be prepared to add more. I have 12 ft of 2" main and am using 2ea #1's on it (1ea Gorton #! and 1ea maid o mist #1).

Bob

KC_Jones

I agree with Bob those numbers get you into the ballpark. I did the same exercise on my replacement and came out to 1 Gorton#1 on each main. My bigger main still takes almost 6 minutes to fill. While I am not building pressure I think I can get it faster. I will probably add another #1 to each. It is still MUCH better than what was there before (single hoffman 4A i think it was).

Paul48

That theory flies in the face of balancing a system with proper venting. Venting appropriately moves the path of least resistance where you want it. With that approach, you are inviting an imbalanced sytem. IMHO

agurkas

I hear ya. Challenge now is that vents on two mains are half way through the system right before say 1.5" supply is reduced to 1" return. At the top of the branches I have no way of getting wide open pipe happening, since I can't even remove the servicable parts of the shut-off valve

KC_Jones

Paul48 said:

That theory flies in the face of balancing a system with proper venting. Venting appropriately moves the path of least resistance where you want it. With that approach, you are inviting an imbalanced sytem. IMHO

I agree. The idea as I read it in Dan's books is to take advantage of the 1700:1 expansion rate. Any pressure no matter how small of a pressure resists this expansion and slows the steam down. Gerry's venting chart is showing what a vent can move at given pressure yes, but he was moving air not steam. Just because a vent allows more air at a given pressure doesn't mean you want pressure to move steam faster. If you make pressure the vent has the ability to vent faster, but you have slowed the steam down so overall you have slowed things down not sped them up. Pressure always slows the steam down. Mine doesn't show much pressure when moving down the main either, but with the vent removed it goes faster. The only pressure I see on the gauge is a bit of bouncing at fractions of 1 ounce, but like I said no vent made it faster that is proof even that little bouncing is slowing it down.

BobC

If you know how long it takes to fill the main with the vent, try unscrewing the main and see how long it takes then - just be ready to kill the boiler when the open pipe starts to spew steam.

Then you can make an educated guess on adding more venting.

Bob

Paul48

That's a great idea, but also take the system out of the equation, to ensure you are gauging only the main. Turn your vents over. I understand that those are always present, but that does not mean that they are correctly sized. You want to avoid sequential heating, and that may be what you are gauging, your way. I believe (and I may be wrong) the chart was developed to compare apples to apples, and there is no other way to test venting capacity, other than to apply a given amount of pressure and volume to produce a number.

Fred

I would go with 2 Gorton #2's on Main #1 and 2 Gorton #1's Main
# 2 and 1 Gorton #1 on Main #3.

agurkas

Question: how many Gorton #2 can I vent via 1/4" tapping? Two of the mains only have 1/4" tappings.

Fred

You can only vent 1 Gorton #2 with a 1/4 inch tapping. You can vent 2 or 3 Gorton #1"

KC_Jones

One of the few things that was good on my system. I have a 1" tapping on the longer (30') main and a 3/4" tapping on the short (23') main.

Abracadabra

BobC said:

If you know how long it takes to fill the main with the vent, try unscrewing the main and see how long it takes then - just be ready to kill the boiler when the open pipe starts to spew steam.

Then you can make an educated guess on adding more venting.

Bob

I add a ball valve temporarily to the antler I'm making. Leave the ball valve open. See how long it takes to get steam there. Add main vents until it's about the same amount of time.

Abracadabra

bc3510 said:

Paul48 said:

That's a great idea, but also take the system out of the equation, to ensure you are gauging only the main. Turn your vents over. I understand that those are always present, but that does not mean that they are correctly sized. You want to avoid sequential heating, and that may be what you are gauging, your way. I believe (and I may be wrong) the chart was developed to compare apples to apples, and there is no other way to test venting capacity, other than to apply a given amount of pressure and volume to produce a number.

I'm not understanding "turn your vents over".

Please explain. Tks.

I think he means to flip the vents on the radiators to take them out of the equation. Not sure I'd do it that way tho.

Paul48

Sorry.....I was out.....That is what I meant.Or any other way you can shut the radiators off.