Single Pipe Vacuum System

Steamhead

so you definitely have some main-venting issues. But these are easily fixed by a good steam man. The "steam main" is the pipe leading away from the boiler header until it feeds the last radiator. That's the length we need to size main vents. If there is more than one main, we need the length and diameter of each.

If there is more than a few feet of pipe past that last radiator takeoff before it gets to the drip, that's the "dry return".

The vent on the right side of page 8 is a Hoffman #75, which may or may not be the right size. The other one is a Gorton #1.

There are plenty of good steam men in New England- try the Find a Professional page of this site to locate one.

Paul Ashton

Single Pipe Vacuum System

We just bought a house that was built in 1937. Based on what a plumber friend and my oil company tell me, we have what started out as a single pipe vacuum system that has been altered some over the years. There's eleven radiators, four of which have had vents added. Based on what little I can find on the subject (and understand since I'm not a professional) a well working vacuum system is a desirable thing. If that's true than I'd like to try to get it back to it's original working order. My friend, who has a good reputation as a plumber and also told me about this website, thinks it's worth a try. My oil company repairman, who doesn't seem to share my facination with the system, just shrugged and said we should just vent the rest of the radiators. That's my story and I'm trying do figure out what to do. I'd appreciate any advice. What should I be looking for? What questions should I be asking? Etc. Thanks.

Dean_7

steam

I'm just a homeowner who restored our single pipe steam system 2 years ago. If you really want to restore your system first educate yourself. Buy Dan's books "We got Steam Heat" and "The Lost Art of Steam Heating". They explain how and why your system works in detail. Perhaps more importantly they explain what to do and what NOT to do to these systems to make them function as they should. Second if steamhead or mad dog replies LISTEN to these people. Third find a professional to work on you system. If you have the books you will be able to talk to them intellegently and you will scare the hacks away.

Steamhead

Thanks, Dean

for the kind words!

Paul, if there is only one pipe connection (usually with a valve) to each radiator, it's definitely a one-pipe system. If there are no visible air vents on radiators, you probably have "In-Airid" vents installed in the top tapping on the end of the radiator opposite the pipe connection. These worked the same as standard air vents but were more decorative. I scanned a description and pic of the In-Airid from the 1929 American Radiator Co. "Ideal Fitter" catalog.

In-Airids are no longer made. If radiators do not heat well, just add standard air vents to them. No need to remove the In-Airids unless they leak.

Unfortunately, vacuum vents on steam only worked well with coal firing. The shorter cycles on oil or gas can result in air left in the system when the vacuum forms, which can block steam circulation. This is the reason vacuum vents are no longer made.

Also look at the vents at the ends of your steam mains. If there aren't any you need to add them. If there are, they may be too small or not working. Main vents are crucial to fast, even steam distribution. Measure the length and diameter of your steam mains and we can tell you what you need.

What area do you live in?

gerry gill

do you mean,

a one pipe air line (paul) system? if so by all means restore it.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Paul Ashton

In-Airids and air vents

Steamhead,

Thanks for your response to my posting. I just got Dan's book (the homeowner's guide)and I'm still reading it. We definitely have a one-pipe system. You were right about the In-Airids. There on eight of the eleven radiators, having been replaced on three.

It appears that we have air vents on two of our three mains. (They look like the ones in the photo on the right on page eight in Dan's book). You asked us to measure the length and diameter of the mains. This is where I get confused. Using the diagram in Dan's book (pg 40), The supply main (above the header?) is 3 1/2" in diameter. The vents sit on top of a one and one half inch pipes at the end of what I think is the dry return. The whole system has 150 feet of pipe. I'm not clear about what you mean by length.

By the way, we moved in in mid-May so we have limited experience with the system running. Our oil compnany repairman came over and ran the system. Most of the radiators were hot within 20 minutes. A couple took over 40 minutes.

By the way, we live in Willimantic, CT. thirty miles east of Hartford.

Thanks, Paul

Paul Ashton

In-Airids

Steamhead,
Thanks for your most recent response. I've got a call in to one of the folks listed on this site. One corection though. I wrote in my last posting that three of the In-Airids had been replaced. I was wrong. They are still in place. Vents were added about half way up on the same side of the radiator. In Dan's book he talks about In-Airids being easily painted in. I'm looking forward to what the guy I called has to say. Thanks again for your help.

Paul