life span of vents?

JimMcS

I have moved into the old (pre-1900) house I grew up in, which has one pipe steam. The radiator vents have not been touched, that I know of, in 50 years. How long do these guys last, not counting painting? And there seem to be two main vents but they are rather tough to reach and if I can avoid fussing with them I'd rather. So far this winter things seemed to work OK, but I did swap out a couple vents on rads that were under-performing. They are Dole, adjustable items, and well stocked with scale - and no "tongue" on any of the three. I replaced them with Hoffman vents from Amazon; any comments?
I only just recently found Dan's books, so I expect to learn a bunch. But I love to learn.

nicholas bonham-carter

The life Span of vents is proportional to pressure and price.
Cheap vents last a season on average, and even expensive, high quality ones like your Hoffmanns will be quickly destroyed by pressures over 2 psi. Most of us here try to keep the pressure below 10 ounces max.
Old ones were well made, and as long as they seem to work, leave them in place.--NBC

Fred

I agree with what Nick said. The only comment I would add is to question what the old vents on the Mains are? More often than not, the old venting on mains are well under the venting capacity needed for the best performance, even if they are working. Vent mains reasonably fast, radiators slow.

JimMcS

It's hard to say what the old mains are; I can't get my head up in the bay to read it. Can you tell from a photo?

BobC

I don't know what brand they are (probably rated at 0.1cfm) but I know they are too small. Do whatever it takes to replace them with Gorton #1's this summer - depending on how long the mains are you may need more than one vent on each main.

Bob

Steamhead

That looks like a cute little Hoffman #4, which has pretty much the same rating as the cute little Hoffman #4A. It's way too small for all but the shortest mains.

Measure the length and diameter of each steam main and post the figures here. We can tell you what you need.

JimMcS

Well it looks like I will learn some plumbing this summer. The mains in question are 2" pipe, and 60-70 feet from boiler to the last riser. If I read the charts in "Greening Steam" correctly, that's 1.6 cu ft to vent. Gorton #2 vents price at $90 on line.
I don't have the space (nor the skill) to put in manifolds.
Have I reached the DIY limit?

BTW, Steamhead, I am in Frederick Co. Do you know Gene Colby?

Fred

Try one of these from Barnes and Jones. They are new. I just ordered 5 of them. Amazon is out of stock right now but they will be restocked soon: http://www.amazon.com/dp/B01F26P13C

Check out this thread to see how these came about:
http://forum.heatinghelp.com/discussion/158197/latest-round-of-air-vent-testing-thank-you-barnes-jones#latest

Steamhead

JimMcS said:

Well it looks like I will learn some plumbing this summer. The mains in question are 2" pipe, and 60-70 feet from boiler to the last riser. If I read the charts in "Greening Steam" correctly, that's 1.6 cu ft to vent. Gorton #2 vents price at $90 on line.
I don't have the space (nor the skill) to put in manifolds.
Have I reached the DIY limit?

BTW, Steamhead, I am in Frederick Co. Do you know Gene Colby?

That name sounds familiar but I can't place it right now.

But we do come out to your area- get in touch and we'll set something up.