Steam Vent ID - Dole 2B?

cnjamros

Hi there!

Has anyone ever heard of a Dole 2B vent?

Just moved into a new house and evaluating the steam setup. Haven't yet been able to track down specs and venting capacities for these vents.

Thank you in advance!
Chris.

nicholas bonham-carter

First locate the main vents, usually on the return piping close to the boiler. Verify that they are working, and large enough.
When that is done, then pay attention to the radiator vents, which usually last much longer than the main vents.—NBC

cnjamros

Thanks, NBC!

The main vent is a Hoffman 76. On the main leg I've got 33' of 2" main, so I think .75 cu ft. By the Vent Capacity Chart this looks to vent in about a minute.

the 2nd leg of the main has no vent. It's only 17', so about .391 cu ft.

75% of the vents in the house, both upstairs and down, are this mystery Dole 2B.

(diagram attached)

Here are the issues I'm trying to fix:
- Living Room radiator, nearest the boiler, makes a bit of hissing noise. It has a USAV vent, so that will be my first contender for replacement. Pressuretrol appears set to 2PSI, which may contribute to hissing as well.
- Upstairs is a bit cooler than downstairs, though not cold.

No other parts of the system make any noise, so I'm looking to make modest adjustments to get more heat upstairs without otherwise affecting the system.

If I can find out the venting capacity of these mystery Dole 2B vents, that will help me determine if I should buy smaller vents for downstairs, or buy larger vents for upstairs.

Unlike my gargantuan problem system from 2 years ago, this system is small and straight forward and I think a minor tune-up is all that's needed.

Here is the layout:

nicholas bonham-carter

The advice we usually give is to put large main vents on the dry returns, and slow ones on the radiators, which will fill all the pipes first, and then when they close, will let the rads fill all together. The Hoffman 76 Vacuum vent is too slow for 33 feet of 2 inch pipe. The air must be let out, with minimum resistance. A couple of ounces backpressure is all it needs. The rule of thumb is one Gorton #2 (or a big mouth), for each 20 feet of 2 inch pipe.
You may need one larger radiator vent on the last radiator on the short main, if there is no main vent on it, but a real vent would be best..—NBC

cnjamros

I was looking at the venting capacity for a Big Mouth, being about 1.5x that of a Gorton #2. With 33' of 2" Main, do you think one Big Mouth would be sufficient for venting that side of the Main?

Steamhead

The 2B is a vacuum vent as well. I'd replace it. But do your main vents first. How long is each main, and what pipe size?

luketheplumber

save the vents the older vents if you do replace them they tend to last much longer than any new ones just like everything today

cnjamros

Hey, @Steamhead. check out the diagram up higher in the thread for more details. I've got 2 main runs. 1@ 33'x2" and 1@17'x2". Only the longer run is vented, but it looks like I have a location to easily add a vent to the smaller run, where an old radiator was removed.

cnjamros

P.S. @Steamhead, thank you for helping me identify that vent. It's been driving me crazy!

gfrbrookline

Go with 2, it is better to over vent the mains than under. I would also turn your pressuretrol down to cut out at 1.5 and in at .5, 2 is too high.

Steamhead

cnjamros said:

Hey, @Steamhead. check out the diagram up higher in the thread for more details. I've got 2 main runs. 1@ 33'x2" and 1@17'x2". Only the longer run is vented, but it looks like I have a location to easily add a vent to the smaller run, where an old radiator was removed.

I missed that. A Gorton #2 on the long main and a Gorton #1 on the short one should work well.