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# end of main vent(s)

Member Posts: 272
Once I figure out how much venting I need, where is the best place to put them- at the end of the main (top-left) before the first "T"  or near the end of the dry return (the short nipple below the "T's")?  Keep in mind, it appears I will be completely dissembling what you see and redoing it in larger pipe to handle the EDR I am running through it, so where ever is best, is what I will do.

Thank you,

Mike

• Member Posts: 65
Might want to take a look here.

Hoffman Specialty

Literature

Steam System Manual

HS-901A

Page 10

Hope it helps
• Member Posts: 272
Hoffman specialty

I did look.  What is a high pressure vent and what is its purpose?

My system, when complete, will run on vapor, so do I even need a high pressure vent?

Thank you,

Mike
• Member Posts: 14,476
How long is your steam main

and what pipe size is it?
All Steamed Up, Inc.
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting
• Member Posts: 272
Length of main

Total measurable length of main is about 11 1/2 feet at 1 1/2" diameter.

It has two ells at 90* that add a frictional equivalent of 7 more feet.

Do frictional allowances matter when figuring venting?

Thank you,

Mike
• Member Posts: 272
Venting needs

Looking at the Gill/Pajek "Venting Steam Systems Using A Capacity Chart", and if my math is correct, the above main has 0.161 cubic feet of air to vent (not including frictional equivilents).  To vent that volume of air in 3 minutes (arbitrary figure from chart text) I would divide that number by three(minutes) and size the venting pipe and vent accordingly.

If so, then I could use 1/8" pipe and a single Dole #5 Quick Vent, but would likely use a Gorton #1 and 1/2" pipe to vent this main in three minutes (or less).

Noting I am using all math for this, these numbers do not make sense in my head.  Am I doing this correctly?

And what is the best location for the vent?

Thank you,

Mike
• Member Posts: 272

Is my math correct or am I not smarter than a fifth grader? :~)

Thank you for the help,

Mike
• Member Posts: 8,479
venting question

i don't think that the dry/wet return will have to be changed because of the EDR of the system, as only the steam-carrying pipes are effected. you could certainly put the vent on the horizontal [mounted up as high as your ceiling allows]. that nipple could be easily removed with the classic "thread-collapse" treatment, with a hacksaw cut through the pipe close to the fittings on both ends. then the stubs, sticking out of the fittings [1/4 in.] can be cut from inside towards the threads of the fitting , very carefully so as to weaken the remains of the pipe, without cutting into the threads of the fitting, and to enable its collapse using a hammer and punch. i have a few bracelets left over from that operation still hanging on the wall!

don't skimp on the main venting. if you think you need a gorton #1, then get a #2. remember, you can never have too much venting!!!!!!!!!!!!!!!!!!! just as your pressure can almost never be too low.--nbc
• Member Posts: 272
vent size & location

I am replacing all of the wet returns and some dry returns, so if adding a vent(s) at the end of the horizontal return is the best location, that is where I will put it/them.

Per pexsupply.com, a G1 costs \$19.00 and a G2 costs \$53.00 (retail).  If a G1 will vent all of my air quickly, because of the cost difference, that is what I prefer to use.  I am not being cheap, I just do not want to spend more money than I have too.  I am also "king-venting" at least two risers from this main, so that should take care of any air in the up-feeds.  I have another, larger, main to vent as well and I may "king-vent" some of the risers off that main, too.  So I will be purchasing several more vents.

Now that you know all of this, does that change your suggestions at all?

Thank you,

Mike
• Member Posts: 14,476
For a main described as

"11 1/2 feet at 1 1/2" diameter", you don't need much venting. A Hoffman #4A will do, or a Gorton #6.

Installing the vent at the end of that miniature horizontal dry return is fine.

Is that the only steam main in the system?
All Steamed Up, Inc.
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting
• Member Posts: 272
another main

The main at 11 1/2 feet in length and 1 1/2" ID is the second and smallest main (more like a horizontal run-out?).  Is this an incorrect description??

The other and larger main is 2" and without fittings is approximately 30 feet in length, parallel-flow before changing into, well, I guess you would call it another horizontal run-out that feeds one rad, is counter flow and is 9' 6".  There is a condensate return a few inches before this intersection of main & run-out and the pitch changes here as well.  I can provide a digital picture if you like, as my description does not seem very good.  Also, I have a colored drawing of the entire system I can upload, if that will help too.

Thank you,

Mike
• Member Posts: 14,476
That longer main

is where you'd install the Gorton #2. It could go near the intersection of the parallel-flow and counter-flow mains.
All Steamed Up, Inc.
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting
• Member Posts: 272
Gorton #2 location

Will do.  Thank you Steamhead and everyone else who has helped. I cannot wait to complete this, test it, and post pics.

Mike
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