Hoffman 75 Main Vent

Brian_31

Can a hoffman 75 steam vent be cleaned and reused? I have a two pipe steam system with two Hoffman 75 vents. One vent on the Main steam return, and the other on the dry return. Can multiple vents help with the lifetime of the vents?

Brian_31

Hoffman 75 main steam vent

Can a hoffman 75 steam vent be cleaned and reused? I have a two pipe steam system with two Hoffman 75 vents. One vent on the Main steam return, and the other on the dry return. Can multiple vents help with the lifetime of the vents?

Steamhead

How long

is your steam main and what pipe size? If the main has old insulation, don't disturb it- measure its outside diameter and subtract 2-1/4 inches to get the likely pipe size.

How much radiation does the system have? Is it cast-iron radiators or fin-tube convectors?

The answers to the above questions will tell us if those #75 vents are the right size.

This is probably a Vapor system. Have you located any manufacturer's info?

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Brian_31

Thanks for the reply.

Hope this information helps. The steam boiler is a Weil-Mclain EGH-85 steam supply is 875 ft3. It has two supply headers feeding two separate loops which connect near the steam return. The supply pipes are 2 1/2". The first loop is 57 ft, and the second is 78 ft.

I have both cast iron radiators and fin tube convectors.

I have 16 sections of 2ft X 8in X 2in fin tube convectors. The cast iron radiators have plates which are 24in X 8in X 2in. I have a total of 144 plates between all the cast iron radiators in the house

The cast iron radiators

Steamhead

That's what I needed

the object of steam main venting is to fill the steam mains quickly and evenly. The steam mains should be vented with Gorton #2 vents. If the steam takes more than about 30 seconds to reach the end of the longer main than for the shorter one, install a tee in the vent riser on the longer main and add one of your Hoffman #75 vents to even it out.

On the dry return, install a Gorton #2. If you have trouble finding Gortons in your area, go to Gorton's site and get in touch with Ken Kunz. Tell him I sent you. He will see that you get what you need.

The manufacturer's info I was referring to can be found on the radiator valves and traps (if used). You're looking for names like Dunham, Hoffman, Marsh, Trane, Webster etc. Since your system uses standard main vents I'm guessing it's a Trane, unless it's been modified over the years. Weil-McLain only made the boiler.

www.gorton-valves.com



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Brian_31

Tanks again for the information.
The majority of the valves are 3/4" Trane, with a few replaced by Dunhum. The traps are 1/2" mouat. The two steam loops return together in a common pipe. Would 1 Gorton #2 be sufficient or should I place two Gorton #2 together?

Do the Gorton #2 vents allow for better venting than the Hoffman 75?

In a 2 pipe system, should tube-fin radiators have vents?
Thanks for all the help.

Steamhead

Looks like you have a hybrid

with parts from several different makers.

If the "common pipe returning the steam loops" is above the boiler's waterline, and the existing vent is mounted thereon, I'd first try putting two Gorton #2 vents on a tee at that location. As long as steam fills both mains completely (as far as the last radiator takeoff) you should be OK.

The Gorton #2 vents about 4 times faster than the Hoffman #75. You'd need 8 #75 vents to equal the two #2 vents. Since one #2 costs about the same as one #75, the economic advantage is obvious.

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Brian_31

Thanks again Steamhead for the information.

I will get some #2 Gorton vent valves.

I was wondering what kinda of consumption in makeup water for a steam boiler through the winter months would be?

Steamhead

You shouldn't have to add water

more than once every couple weeks or so. If you have to add every day, you have a leak somewhere.

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Brian_31

Thanks.
Will the #2 Gorton vent valves stay cleaner longer because of their ability to vent faster, and have lower velocities?

I was replacing the Hoffman vent on the main steam line every year.

In a two pipe system, are main vents the only venting required? Have you seen vents on radiators on a two pipe system?

Steamhead

Check the pressure

to make sure it's not too high. The lower velocity in the Gortons will help.

On Vapor, the radiators do not have vents. The air goes out the traps, thru the dry (overhead) return and out the return vent.

The first two-pipe system did use vents on the radiators but not on the return. It was rather hard to control, which led to the development of Vapor.

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