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    Need help understanding Dunham system (66 Posts)

  • Fisher Fisher @ 4:00 PM
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    I am glad you appreciate the post -

    I have learned so much from this thread, and I feel tremendous gratitude to "the Wall" community and to Dan for his work. I will continue to post questions and updates. Please post some pics of your Vari-Vac system - I would like to see it. What vintage is it? BTW - I am about to order some trap repair kits. The vaporstat is in - I plan to install it, and a new pressure gauge tomorrow.
  • Long Beach Ed Long Beach Ed @ 10:44 PM
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    The Differential Controller

    I just received information about that Dunham Differential Controller. It's interesting to note that both the small vacuum heating pump and controller appear to have been introduced by Dunham in 1929 but were gone from their catalogiue # 514 by 1935. A short lived system indeed. The controller was piped between the end on the longest steam main and the return. A greater pressure on the steam side than on the return side is needed to keep the differential conteoller "in balance". The controller is adjusted to turn the pump off when the pressure in the main exceeds the pressure in the return by 1" of mercury, or about one-half pound. Remember that this system operated at about eight ounces of pressure. If the differance in pressure between the two pipes is less than a pound, the vacuum pump turns on. The controller can be adjusted to a higher differential if that is needed "to prevent slugglish circulation at the ends of steam mains". Where more than one zone was used, with motorized valves, additional controllers could be used for each zone. They would be wired in parallel so either one would turn on the pump. I hope this is helpful in your understanding and restoring this fantastic Dunham system. Long Beach Ed
  • Fisher Fisher @ 10:44 PM
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    Remember Uncle Morton's system???

    Last winter we serviced the radiator traps, crossover traps and added a vaporstat. Now it is time for the real fun! I have the DH pump in my shop. To my astonishment, the motor runs!. It was full of dirt, and the brushes sparked like crazy, but it is alive. A local motor/pump shop owner is going to go over it for me. (he is old enough to have experience with an AC motor with brushes). Any suggestions for restoration of the pump are welcome - we havn't really gotten into it yet. I am optimistic that it can be put back into service without any big heroics. Unfortunately I have not found the original differential vacuum controller. Therefore I am looking for info/suggestions. What differential pressure does it operate at? Does anyone have any leads for me to find a suitable controller? I have recently emailed MEPCO. Fisher
  • Steamhead (in transit) Steamhead (in transit) @ 10:57 PM
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  • Fisher Fisher @ 11:21 PM
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    some photos

    Steamhead - here are some shots of the pump. Soon (maybe tonight) I will post some photos from my other steam challenge - Cousin Margaret's system. It is a Webster.
  • Steamhead (in transit) Steamhead (in transit) @ 11:29 PM
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    Looks better already!

    I reread some of the earlier stuff in this thread- you should be able to fit the sight glass on the reservoir with a McDonnell & Miller #67 low-water cutoff. This can be wired to an automatic feeder valve (preferably a newer version using a brass valve body) so you don't have to fill the reservoir manually, and can stop the pump (via a relay if needed) if the level gets too low despite the feed valve. I wonder if the pump died because of low reservoir water? To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Fisher Fisher @ 11:42 PM
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    I think that the pump was OK...

    Steamhead - I have done a lot of speculating on this. I think that the pressure switch failed - not the pump. "Ollie" was the last "dead man" at our company to look after this system. Unfortunately he joined the rest of the dead men about 5 years ago, so I cannot ask him what happened. Eleanor does not have any recollections at all about the vacuum pump. Like I posted earlier - the pump motor runs. I could get proven wrong, but I don't think that there is anything seriously wrong with the pump. Since the differential switch is missing, I believe that the pressure switch failed, and Ollie diconnected the pump and installed an air vent in it's place. I really like your suggestion to add a McDonnell & Miller to the pump reservoir to maintain the water level.
  • Dave in QCA Dave in QCA @ 9:20 AM
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    Bump

    Posting a nul reply to bring this very interesting thread back to the top. 

    I am also hoping that doing so will reactivate the images and attached files that are no longer visible.

    Dave
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • SteamCoffee SteamCoffee @ 3:09 PM
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    Hate to dredge this oldie up.....

    but wondering if any Dunham Differential info has surfaced since this thread?? Anyone know if the poster, "Fischer" every got this all sorted out? Thanks...
  • Dave in QCA Dave in QCA @ 5:49 PM
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    picture of controller

    Boiler Wrestler was out on a job and found this controller, took a picture, and sent it to me. Don't think the vacuum is in use.

    Also, I now have a copy of Dunham Handbook No. 514 from 1935. It pictures a much more modern type of controller, but the discussion is very complete in justifying the benefits of using vacuum steam from an efficiency and control standpoint.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Fred Fred @ 7:51 PM
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    Fisher, I have not used photos but will work on it. The system I service is relatively new, about 1950-53? Recently I aquired a D/B catalog circa 1971. It has the info for the Vari-Vac systems. Possibly Dan would like it copied for the library. I do not recall if I mentioned that the boiler,condensate tank and controls were replaced about 8 years ago. However the original differental controller (not used) is still in place. It is piped as you desribed earlier. Actually there are two diff/controllers one for each zone. The two movs are original with original Honeywell actuators.
  • Fisher Fisher @ 9:39 PM
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    Photos

    Gerry, I'll take some photos and post them tomorrow.
  • Fisher Fisher @ 3:43 PM
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    I need help.....

    I am a mechanical contractor, working on a residential steam system (a rarity down here in the South). It is a Dunham 2-pipe gravity system with thermostatic traps, and almost perfectly matches fig 907e in the Dunham Handbook No. 914. c. 1935 I have read "The Lost Art of Steam Heating" cover to cover and I am gaining an understanding of this system. I am also gaining a huge respect for the "dead guys" who installed and serviced this system. My question: There is a connection with a swing check between the end of steam main and the end of the dry return. On my installation, the check valve has a Dunham no. 106 Surge Chamber on the steam side of the check valve and a Dunham no. 107 surge chamber on the return side. This connection apparently provides a path to equalize vacuum when the system cools. Do I have this right? On my system, this path is valved off. Can anyone explain this, and what is the impact of having it valved off?
  • gerry gill gerry gill @ 8:40 PM
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    you got it..

    the equalizer pipe has a check valve that swings toward the steam main and stops the steam main from achieving a partial vacuum or whats probably best described as lower pressure than the return pipe has in it..cold starts, shut down, low fire etc...unsure about surge chambers..none of my dunham literature lists them by that name..can you post a picture? as far as it being closed.. my gut tells me it may have mattered more with coal than gas or oil...but why would anyone close it unless the checks disc didn't hold back the steam? To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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  • Fisher Fisher @ 12:07 AM
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    You guys are incredible!

    Steamhead, you are right on. Guess what - I think that the old vacuum pump is still down there in the basement. I'll check it out tomorrow, and post some more photos. Let me provide some backgound on the house and some brief family history. The house was built in 1820's or 1830's by the first governor of Alabama for his daughter and son-in-law. It is presently owned by my father's cousin, Eleanor. Dad and I manage The Hutchens Co., a family owned business founded in 1886. He is 3rd generation and I have the honor of being the 4th generation at the company. The last of our steam men passed away 5 years ago, so now I don't have him to consult. We are now a plumbing and HVAC contractor. We do some steam work in some local plants, so I have a bit of experence with industrial steam systems, but these pumped condensate systems are really different from the residential systems. I presently know of 3 residental steam systems in Huntsville, and 2 of them are my relatives (we will discuss cousin Margaret's system in another post) Eleanor's parents bought the house in 1926, and her father, Morton Hutchens, was one of the partners in the Hutchens Company in those days. The primary business for the company in back then was steam heating, sanitary plumbing, and Electrical work. It stands to reason that Uncle Morton installed the best system of it's day in his home! Eleanor has lived in the house her whole life, and the house is like a museum. Unlike most of the antebellum homes in Huntsville, she has not restored the house. Most of the house has been unchanged in her lifetime. Her high utility bills have prompted her to ask me about switching from steam to forced air heat. I want to keep this piece of steam heating history working, and I think that she is willing to invest a little in getting the steam system working if I can reduce her gas consumption. It is clear to me now that the system has been suffering from a number of faults: 1. Pressure set too high, and associated condensate return problems 2. Failed crossover traps preventing venting of the steam mains 3. Failed radiator traps. Knowing now that the system was a vacuum system, what should I do now? We have not actually installed the Hoffman 17C crossover traps, so it is not too late to re-engineer the system. Should I abandon the air eliminator and put vents on each steam main (as suggested by Christian)? I have not measured the steam mains or the radiation area yet. I just ordered EDR from Dan Holohan. The house has finned convectors in large metal cabinets. When I get the book, I will attempt to calculate radiation area on each of the 3 steam circuits.
  • gerry gill gerry gill @ 7:24 AM
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    awesome research Steamhead !!

    thats great info..knowing what it is now..there has to be something on the market that can do the same thing to restore the system.. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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  • Noel Noel @ 8:04 AM
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    Heat Timer still has a controller.

    http://www.heat-timer.com/?page=src I'm not sure if Mepco (Marshall Engineering) is still around, they had the Vari-Vac line, last I knew. Check this out... http://www.i-boards.com/bnp/es/messages.asp?MsgID=482&ThreadID=334 Noel
  • Steamhead (in transit) Steamhead (in transit) @ 9:01 PM
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    I found your Surge Chambers

    they were a part of an early Differential Vacuum Controller. This isn't a Home Heating System, it's a very early Differential Vacuum System- later known as the Vari-Vac! This was the smallest version, known as the "DH". Whoever had this put in really went first-class. I've attached several scans from the Dunham Handbook #414, predecessor to your #514 (I have that one too). By the time the #514 came out, the Differential Vacuum system had gone thru several phases of evolution, so it's no wonder we didn't recognize what your system was. The first scan shows the Differential Vacuum Controller itself, including surge chambers. This explains the pipe nipples and elbows screwed into yours. The remaining scans show the little vacuum pump used with this setup and how the whole system fit together. Note how the vent line was piped from the Air Eliminator to the pump. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Steamhead (in transit) Steamhead (in transit) @ 9:08 PM
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    This is how it worked

    More scans from the #414 handbook. For the steam main vent traps, I'd use either replacement Dunham units (they're still made) or Barnes & Jones #122 traps. These will pass a lot more air than Hoffman #17C traps, and will help maintain the system balance. For details, get a copy of Gerry Gill and Steve Pajek's e-book on balancing steam systems. You can find it on the Books and More page of this site. Dan, feel free to add this to the Library. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Christian Egli Christian Egli @ 11:49 PM
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    Sweet Steamhead

    Beautiful detective work. Now we know. There is a missing vacuumizer in this home. Thanks It seems all the surge chambers do is act like very fancy pigtails by keeping a plug of water to protect the control gauge and diaphragm from steam. Your pictures even show M a 3/4 plug to prime the very fancy pigtail surge chamber.
  • Rodney Summers Rodney Summers @ 9:17 AM
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    Not in #214

    Just as information, those chambers were not mentioned in the Dunham Handbook #214 which is from 1922. I'm surprised. Thems was the glory years of that stuff. LB Ed
  • Fisher Fisher @ 8:01 AM
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    Testing Radiator Traps

    Yesterday I finally spent some sustained time with the system. I was assisted by my best HVAC serviceman. We installed the Hoffman 17C's as temporary vents on the ends of the steam mains, and for the first time in years, she had 3 hot steam mains. The "dry" return was locked up full of water - we removed one of the dead crossover traps and got a lively geiser of water and steam out of the "dry return". We set the existing pressurestat as low as it would go - 0.5 cutin, 1.5 cutout. With a little elbow grease, we shut off all of the radiator valves except one stubborn valve. Our test vent on the dry return was now quiet-no discharge at all. I used a Flucke 52 with the pipe clamp probe to measure inlet and outlet temp for each trap as we turned the radators on. Out of 24 radiators, we found 4 that had failed wide open - there was no temperature difference, and the test vent shot steam out when they were opened. There were only 2 stuck closed. The rest were harder to judge, although I felt that around half of the traps were working OK, and the rest were leaking slightly. Now my questions: What outlet temperature should I expect from these old traps? They are all Dunham 1E's and 2A's. What is the trick to getting the cap off of these traps? Steamhead, you recommended Barnes and Jones #122 for the crossover vents - should I use there traps for replacements? What about cage units? I discussed $$ with Eleanor, and she did not want to spring for replacement of all traps if I could identify the bad ones.
  • Steamhead (in transit) Steamhead (in transit) @ 8:51 PM
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    My first choice

    would be to rebuild the Dunham traps, but if you need more venting capacity on the crossovers the 122 traps would work well. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Fisher Fisher @ 7:32 AM
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    Here is the house

    This is the house, and Great Uncle Morton is calling to me....
  • Fisher Fisher @ 9:52 AM
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    More info..

    Steamhead, Thanks for your response. The vent on top of the Dunham air eliminator is a Hoffman no. 76. It takes a long time to vent the system. I will do a little measuring and I will appreciate help in selecting a bigger vent. The air eliminator is very rusty and I don't expect to get it apart unless we wait 'til summer and make a restoration project out of it. My photos may not be clear - there is one dry return and 3 steam mains. The 3 steam mains all have Dunham 1E traps crossing over to the dry return. We had one removed and capped in the photo(waiting for replacement). We are planning to replace these with Hoffman 17C's since I could get them locally. I did not find a patent no. or date on the surge chambers. As Gerry suggested, I will take a look inside. I made a typo in my original post - My only Dunhman handbook is No. 514, dated 1935. If there is any better handbook info, please post or guide me to a source. What pressure should I run? The existing pressurestat is in 1 PSI increments with a minimum differential of 1 PSI - I think that I will need a different device if we need to run down below 1PSI. Fisher
  • gerry gill gerry gill @ 7:47 PM
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    put a vaporstat on,

    and run it a say 4 ounces and see how things work.. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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  • Christian Egli Christian Egli @ 11:40 PM
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    Brain surge -- need surge chamber here

    The Lost Art, Page 252, Topic 6 and figure 23 shows exactly your layout minus the surge chambers and minus the anti-deeper-vacuum-in-the-boiler equalizer line, so I would reasonably say that operating your Dunham system with the special equalizer valve shut is not too big a deal. Here's one reason why: The special equalizer line is very important on systems that have condensate pumps and accumulating tanks (of which you have none) because of the risk the boiler might suck everything out of the condensate pump holding tank and flood itself. This causes problems when the boiler comes back on. Does the system get messed up with the valve closed? The purpose of those surge chambers eludes me so far. What do you think was connected to both the capped bottoms, just dirt pockets? In one picture there seems to be an abandoned union on the upper left. Look at Page 192, upper left picture It shows a vaccumizer and the special equalizer line. Note how the check valve is saddled at the bottom of a valley of elbows. This is to help the check valve function positively, without shatter or leakage or banging (or so we hope). Perhaps those surge tanks are meant to do the same thing as the valley of elbows. I predict the innards of the surge chamber will show a parting baffle running down the middle of the chamber, stopping at some height before the bottom. Please tell us more. From the rust on the air eliminator (which is nothing else than a float valve that closes when the B stack of condensate rises too high) I would guess at two problems, 1) the float valve does not work as good as it is supposed to, and 2) you are running your system at too high a pressure. Measure the B height from the boiler water line to the air eliminator and you'll know your maximum allowable pressure. Likely less than 1/2 a PSI, you'll need a vaporstat, and you'll have much less problems. As you'll note on figure 23, there is no Hoffman 76, or other, on the air eliminator (sometimes there is an optional check valve for creating a vacuum) This hole should be wide open. If water comes out, your pressure is too high If more than just whiffs of steam come out, then one of your radiator traps needs care immediately. The most important thing to do is to fix / replace all the traps. An optional end of main venting arrangement: instead of the crossover trap, you can use Gorton 2's, this might make your piping work simpler. What I suspect happened to your system is when it was converted to natural gas, it was fitted with a pressuretrol (rather than the vaporstat) This caused excessive B stacking (4 PSI turns to about 9 ft !!!) which led to floods in the returns and poor steam distribution. With defective traps this could cause serious banging. Traps likely clog themselves shut with dirt when kept flooded. But short cycling could mask all these problems. Adding on to the system... someone might have thought that adding a whole equalizer line and surge chambers would improve things... Why not?... But it seems the air eliminator has been leaking for a long time. You're likely to improve lots of things for this homeowner. Everyone will be happy.
  • Fisher Fisher @ 10:05 PM
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    Here are some photos

    Here are 4 photos. I included a couple of shots of the end of the steam mains and the end of the return. This system has been virtually untouched for many decades. The owner believes that the steam system was upgraded in 1926 when her mother purchased the home. The boiler is not nearly that old. Fuel is natural gas. The system is heating, but "not like it used to", and her gas bills are high. No water hammer reported. All radiators are heating to some degree. So far, I turned the pressurestat cutout down from 4 PSI to 2 PSI. Differential is 1 PSI. We have diagnosed 2 bad traps on the end of steam main. They failed closed so 2 of the mains were not venting. These will get replaced Saturday. Next we will go hunting for bad radiator traps. Any suggestions?
  • Steamhead (in transit) Steamhead (in transit) @ 10:52 PM
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    That looks like a Dunham Home Heating System

    a real Vapor gem. In your #414 manual, this system is covered on pages 87-93. The equalizer connection itself appears on page 93- and as usual Gerry's description is spot-on. The system has definitely been added to. Those two steam mains ending with main vents to the left and right of the dry return definitely aren't Dunham, and the older of the two main vents (on the right) looks like it dates back to the 1920s (unless it's actually a pipe elbow- can't tell from the pic). The Dunham crossover trap we can see that vents the steam main looks like the pipe coming out of the bottom might be welded onto the dry return (pic not quite clear enough to tell for sure)- an almost-certain sign that it was added later. So the "upgrade" you mention might have been to Dunham-ize an older system. I've reattached the photo so we can take another look. The first thing I'd look at is the air eliminator attached to the dry return. This is the vent for all the air coming back from the radiators via the traps- also for air from the original steam mains that was vented into the dry return thru those crossover traps you fixed. It has a port on the top maybe 1/2-inch or 3/8-inch, that probably originally had a vacuum check screwed into it. The vent that's in that port now looks like a Hoffman #5 or #6, which is not only too small to handle all the air from a houseful of Vapor radiators but is probably stuck closed. Change this to a Gorton #2 and I'll bet you see a huge difference. About those two mains that look as if they've been added on (the ones with vents on them) are these steam mains or dry returns? If the former, I'll bet the vents are too small- measure the length and diameter of each and we can tell you what's needed. If the latter, they might still be too small- how many rads are on each one? Not sure about the surge chambers- they don't appear in my book either. BTW, the #414 manual I have was printed in 1929. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • gerry gill gerry gill @ 10:55 PM
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    i think i would

    just have to remove one of those surge chamber caps and look inside with a flashlight to see if its hollow or whats in there..i would think that system should be running in ounces instead of pounds..that must be a fascinating house..is there any patent #'s or dates on those surge chambers? To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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  • Fisher Fisher @ 1:20 PM
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    Come on down!

    Ed, I like your attitude. Are you really in Long Beach? That is a little too far to ask you to stop in and give me a hand! As a matter of fact, she does not have an unlimited budget, and I am also quite busy with other work - her system has become a labor of love, and I don't expect to profit, but I do need to cover my costs. I would like to get Eleanor's systems "walking" before I ask it to "run". We badly need to find and replace the bad radiator traps, and I would like to do that right away. I don't want to invest in 3 vents for the steam mains until we decide whether the system is going to vacuum or vapor. Here is my plan, please comment: 1. I already bought 3 17C traps, so we will install them as temporary vents on the steam mains, with them venting to atmosphere. This will allow the steam side to vent(which only one circuit does now) 2. I will need a vaporstat for either course of action, right? I would like to purchase that right away. Where do I find one, and what pressure range am I looking for? What steam pressure is right for the vari-vac system? My end-of-main and dry return is 55" above the water line in the boiler - what pressure should I run if it is a vapor system? 3. The radiators have steam shutoff valves, so we will shut them all off, bring on the steam, and start testing traps one by one. (I got this idea from a previous post on the wall) Being in the AC business, we have a number of digital thermometers and I am hoping that we can diagnose the bad traps by looking for hot discharge from the bad ones. Unfortunately there are between 20 and 30 radiators, and I think that a few of them are leaking by, so the return piping is going to heat up as the return gets pressurized. If we remove the Hoffman vent on the top of the air eliminator, will this relieve enough pressure to find the bad traps? We have not done this before, so I am open to suggestions. Steamhead, we will also measure the steam piping size and length. When I have this info, you can help me determine if the system will work as a vapor system or not.
  • Fisher Fisher @ 1:24 PM
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    Come on down!

    Ed, I like your attitude. Are you really in Long Beach? That is a little too far to ask you to stop in and give me a hand! As a matter of fact, she does not have an unlimited budget, and I am also quite busy with other work - her system has become a labor of love, and I don't expect to profit, but I do need to cover my costs. I would like to get Eleanor's systems "walking" before I ask it to "run". We badly need to find and replace the bad radiator traps, and I would like to do that right away. I don't want to invest in 3 vents for the steam mains until we decide whether the system is going to vacuum or vapor. Here is my plan, please comment: 1. I already bought 3 17C traps, so we will install them as temporary vents on the steam mains, with them venting to atmosphere. This will allow the steam side to vent(which only one circuit does now) 2. I will need a vaporstat for either course of action, right? I would like to purchase that right away. Where do I find one, and what pressure range am I looking for? What steam pressure is right for the vari-vac system? My end-of-main and dry return is 55" above the water line in the boiler - what pressure should I run if it is a vapor system? 3. The radiators have steam shutoff valves, so we will shut them all off, bring on the steam, and start testing traps one by one. (I got this idea from a previous post on the wall) Being in the AC business, we have a number of digital thermometers and I am hoping that we can diagnose the bad traps by looking for hot discharge from the bad ones. Unfortunately there are between 20 and 30 radiators, and I think that a few of them are leaking by, so the return piping is going to heat up as the return gets pressurized. If we remove the Hoffman vent on the top of the air eliminator, will this relieve enough pressure to find the bad traps? We have not done this before, so I am open to suggestions. Steamhead, we will also measure the steam piping size and length. When I have this info, you can help me determine if the system will work as a vapor system or not. I will also try to calculate total radiation area when we get a count of the radiators.
  • Long Beach Ed Long Beach Ed @ 5:33 PM
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    The Pump

    ...is definately my domain. Love rebuilding that old stuff. Wrap it up ans send it up here to New York. We're right next to Coney Island. I'm sure the others have more experiences with the Dunham system. I've never even seen one like this and it isn't in my books. They'd be best to answer your questions. I'd suspect you might find pipes a bit undersized to run without the pump, but if you don't expect too much, it should work. Again, those with the book could look this up for you. 20 - 30 radiators? What's this, a little summer cottage? Simply LOVE reading about this stuff. Go get 'em. There's a place in heaven for guys like you. Probably heated with electric. Long Beach Ed
  • LKE LKE @ 11:45 PM
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    what is the differential

    Could a vapor system be converted to vacuum, it looks like it could be more economical to heat with. What would be the correct values for the differential, would .3 to 1 inch water column do it? If so I just found the switch.For a vacuum pump could you use a water pump with an eductor?
  • Al Al @ 11:19 PM
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    This is an incredible thread. I don't know how I missed it last winter, but thanks for bringing it back.
  • gerry gill gerry gill @ 8:54 AM
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    thats great work on saving that system..

    i use two different tools to remove the covers of traps..both will work.. one is a tool called a torque multiplier that i got from MSC Direct co. around 4-5 hundred bucks..the other i just got for christmas and its really good at removing covers, its a milwaukee electric impact wrench/gun..both work exceptionally well..haven't had a cover not come off with either of these yet..your next question, yes, by all means use the cage units..they work very well..i use barnes and jones brand cage units and am very pleased with them..oh, and when i'm testing traps i usually look for a pipe surface temperature of around 205 entering the trap on the pipe surface, and around 180-185 pipe surface temp after the trap..seems to be about 15-20 degree difference is what i usually see on a good trap.. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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  • Fisher Fisher @ 9:54 AM
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    Trap covers

    I was hoping that an impact wrench might work - I guess that I will have to buy one today (oh Bummer). The 4 really bad traps are very accessible. All of the "working" traps were 205-209 inlet temp. I didn't have any traps with that much DT on the outlet. Quite a few were 197-199.
  • gerry gill gerry gill @ 12:54 PM
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    hmmm,

    with that little temp difference i'd think they are leaky thru at least to some degree..but they may not be bleeding past enough to cause any harm..perhaps do the 4 you know blow thru badly, and run the system to see if then any others are really bad..if you get the system down to a few ounces, you may not blow thru either..just a thought. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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  • Fisher Fisher @ 2:02 PM
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    Here it is!

    Here is the vacuum pump. It was right there all along, but I did not know what it was. I could not find a nameplate on it. I looked around the basement and could not find the missing differential switch. I spoke to Eleanor and she does not recall when the pump was taken off line. She recalled that her father took great pride in the state of the art oil burning boiler installed in 1926, but a shortage of heating oil forced him to switch to a coal fired boiler which was used for many years. The present boiler is gas fired (nameplate attached). She also did not know when the present gas fired boiler was installed. Has anyone rebuilt/serviced one of these pumps? I don't know whether to attempt to fix it and restore the differential vacuum system or not. On my next trip to the house, I will try to sort out the power and see what happens when I apply juice to the motor. I expect the motor to be bad(why else would it be abandoned), but who knows? Fisher
  • antique steam heat road show

    Regards to Steamhead, Gerry and Christian, I searched our archives and found the Dunham Bulletin #634, 1946. Still has the differential vacuum heating system listed, with a few more bells and whistles, but no surge protectors. It would be great to be able to restore this top-o-the line system to its former glory, but could it be more practical to set it up as a vapor system? With the repair of all thermostatic traps (necessary anyway) and the increased venting capacity recommended (mo venting - mo better) this could be a quiet, even heating, and efficient system. I guess the cost and/or ability to restore the vacuum pump will determine the direction. Now if we could get a film crew in to document it all, and Ken Burns to produce, and Holohan to narrate..... Best regards, Pat
  • Steamhead (in transit) Steamhead (in transit) @ 10:10 PM
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    The pump may have been abandoned

    because someone didn't understand what it did. I wonder if the system would work properly without the pump. The piping was sized for the vacuum differential the pump produced. Without that, the steam may not distribute properly. Pat, you're right- a Steam Trek to Huntsville with cameras is in order. Hard to believe it's only 700 miles from Baltimore...... To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Long Beach Ed Long Beach Ed @ 10:33 AM
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    Controller

    Fisher, You've got a nice project there. Look around for the controler that sat at the bottom of those two surge chambers. There are lots of ways to control the vacuum today but it would be really kean to have the old stuff. You gotta restore that pump. Send it here if you don't want to and I will. The hardest thing will be getting it open without breaking off the bolts. This is all really basic stuff and parts should be easy to find or make. Hay, you've got nothing better to do with you time and the client says price is no object, right? They can open that basement to Steam Pilgrims and charge admission when you're done! Long Beach Ed
  • Christian Egli Christian Egli @ 10:08 AM
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    Oh Uncle Morton

    What a wonderful history, with all these steam systems connected to your ancestors this seems like a family most of us would want to marry into. Ahem, you mention Aunt Eleanor and Cousin Margaret... You also mention there still is a vacuum pump, that's got to be the sweetener. If your plans might involve restoring the vacuum, you'll need to keep the crossovers. Good reasons to restore the vacuum: it greatly accelerates start up distribution time, which improves comfort and reduces boiler on time, and fuel usage. In your case, there is also a sentimental value. The air eliminator float assembly should be easy to restore. The pump might be much more work. Any brand new pump could be substituted. If you run into difficulties finding replacement parts, let me know how I can help, we do operate a machine shop and repair lots of old stuff. Thanks for this fascinating post.
  • Fisher Fisher @ 1:44 PM
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    Here it is!

    Guys, Here is the pump.
  • Steamhead (in transit) Steamhead (in transit) @ 3:58 PM
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    I think it should be possible

    to restore this system. MEPCO still has Vari-Vac on their site, here's the link: http://www.mepcollc.com/VV.htm The Differential Controller they show is obviously much more sophisticated than the little diaphragm unit on your DH system. But if a suitable diaphragm switch can be located that can handle high temperatures,you should be good to go. It should also be possible to rebuild the pump, but we may have to have parts made up specially for it. In the Dunham Handbook #414, it says the Differential Vacuum Systems shown therein were the very latest. This book came out in 1929 so that confirms the time frame this system was installed. Your Uncle Morton must have marvelled at the latest from Dunham the same way we do now. Long Beach Ed- does the #214 book mention the Differential Vacuum system at all? I think we need to locate a #314 book right now! To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Long Beach Ed Long Beach Ed @ 4:29 PM
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    No DH in 214

    Steamhead, There's no Differential Vacuum system in the 1922 book. There's only the Durham Vacuum Heating System that mentions a steam driven vacuum pump. No detailed pump pictures and no pumps in the catalogue section. The only vacuum device is a Vacuum Pump Governor that had a diaphram and adjustable counterweight controlling a steam valve that operated the pump. More books!!! I need more books!!! Long Beach Ed
  • Fisher Fisher @ 1:48 PM
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    Here it is!

  • Steamhead (in transit) Steamhead (in transit) @ 1:07 AM
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    Vaporstats

    are available from any supply house. You want the one that maxes out at 1 pound. It will probably be a special order but you need it, so go for it. When looking for bad traps, you might have to let the dry return cool down a few times. Use a fan to help you do this. Change the trap elements you found bad while you're waiting. Or, it might be best to change all the trap elements anyway since they're all the same age. That's what I'd do if it were mine. Ed- let me know if you go down there to pick up the pump, after seeing the shipping cost. You can pick me up in Baltimore and I'll help with the driving. I'm familiar with about 75% of the way there from here. It's a real pretty drive. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Fisher Fisher @ 4:26 PM
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    Trap repair! and pump restoration?

    Our new impact wrench easily opened the caps. I am planning to rebuild 7 traps - 2 stuck closed, 4 wide open, and 2 that are "slight" leakers. I don't have source for Barnes and Jones yet, although I do have a local supply house that is trying arrange to get them for me. Is there any distributors that will ship them down here to me? Hopefully, the remaining leakers will not cause problems. As recommended, I will turn the pressure way down when I get the Vaporstat. I hope that Eleanor will "let" us restore the vacuum pump this summer. Therefore I will run the system as a vapor system for the rest of this winter. I would like to avoid the expense of buying Gorton vents for the 3 steam mains - What is the downside of using the Hoffman 17C's as vents on the steam mains?
  • gerry gill gerry gill @ 9:43 PM
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    your talking crossover traps right?

    1/2'' you cand beat the barnes and jones...monash 38 is nice too.. To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.
  • repair kit availability

    Hi Fisher, I work at a supply house with easy access to Barnes & Jones or Tunstall repair kits, 800-576-2142, and I'd love to discuss your restoration plans. Downside to 17c might be vent rate, don't have my Gill capacity chart here at home, left it at the office. Best regards, Pat
  • Long Beach Ed Long Beach Ed @ 4:29 PM
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    Road Trip!!!

    I'll leave the wife and five kids here with the Dunkirk and drive down. Bring beer. Ed
  • Fred Fred @ 5:45 PM
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    Fisher,thanks for the updates, I am vicariously helping with this system. Mainly I am learning from the responses of others and the pictures you post. If I could justify (with the CEO here at home) I would ripout my system and install a steam system. The more sophisticated systems now being installed are constantly being replaced by the latest,not always the greatest new innovation. While a properly maintained steamer just quietly keeps on steaming year after year. Fortuneatly, I have a Dunham Bush Vari-Vac system in my church that I get to check and maintain. And thanks to Dan and others here, I am able to ask questions regarding the system operation. Learned a lot in the site Library. The original controls and boiler have been changed. However, the system seems to work well. Thanks again Fred
  • Fisher Fisher @ 5:35 PM
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    Eleanor's complement to Dan

    Dan - I gave a copy of "We got Steam Heat!" to Eleanor and she borrowed my copy of "The lost Art". She is a PHD and retired English Professor. She reported to me: "I like the way that man writes".
  • Long Beach Ed Long Beach Ed @ 9:45 AM
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    Pump

    I am surprised that the vacuum pump ran whenever the boiler fired.
  • Long Beach Ed Long Beach Ed @ 4:24 PM
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    Here's what I see...

    Fisher, Yes, the pump did nothing but circulate water from its tank around and around through a venturi. This nozzle, called an exhauster, shot water through a venturi, just like the one in an auto carborator, creating a suction that sucked air from the top of the steam system's "#220B air eliminator". The air eliminator is nothing more than a float trap. It probably has a steam vent stuck in it now where the 1/2" or 3/4 line to the pump hooked up. The pump tank was filled wither with a funnel or with a 1/4" pipe and globe valve to a cold water line. You added water when the sight glass ran low. The other tap on the pump was an overflow that ran to a drain. I don't have the data sheet on the Controller, but should be getting one in a few days. From what I read, it appears that the system worked electrically this way: The pump turned on with the boiler when the thermostat called for heat. It ran until the thermostat was satisfied, which on a mild day, would cause 133 degree steam vapor to be made at down to 25 inches of vacuum. I doubt it ever went that low. They told the operator to "lower the gas flame" on mild days. What an opportunity for a two-stage burner!! On a cold day, pressure would build up to eight ounces, overcoming the vacuum and increasing the temperature of the steam. Upon pressure building, the pressure in the return (which is right at the pump's suction) would be overcome by the pressure in the end of the longest main, operating the differential switch and turning off the pump. If I'm correct on this (someone add their opinion, please) you could just connect the pump to a vaporstat set to turn off the pump on some pressure less than the burner shut-off. I'd be tempted to put that vaporstat on the end of the main (?). WHile it woun't actually be measuring the differential between the return and the main, it should give you some control until you find some better way. Not a very sophisticated contol, but Dunham claimed it saved 30% to 50% when using gas as a fuel. Go get 'em!! Or send me that beast pump!! Long Beach Ed
  • Fisher Fisher @ 5:20 PM
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    Plans

    Ed-Thanks for the explanation of the pump operation. The old differential switch with the surge arrestors was connected between the end of one steam main and the end of the dry return, so it would shut off the pump based on reaching a setpoint of pressure difference between the steam supply and the mains. I don't see how it would know the difference between a mild day and a cold day. BTW - I am expecting the Barnes and Jones cage units soon. We will repair the known problem radiator traps and evaluate the system at that time. We reduced the pressure to 8oz cutin and 12 oz cutout based on Patrick's recommendation over the phone. Eleanor is reporting that the room temp is 65 upstairs and 70 downstairs at the thermostat(which is set at 70). The radiator in the room with the thermostat has a leaking trap so I hope that fixing that trap will help with balance. Steamhead - I have a hunch that you are correct in suggesting that the piping was sized for vacuum and will be too small to work well as a vapor system. There is so much piping that I have not been able to allocate time to measure pipe sizes (and spend all that time with friable asbestos). During a normal daytime cycle, the steam mains are venting in about 2-3 minutes and getting hot, but the end of the return doesn't get hot. I don't want to pass judgement until we fix the radiator nearest the thermostat, but I've got a feeling that the system will need the vacuum to perform. I suggested to Eleanor that we fix the radiator traps now and plan on a pump restoration project sometime between now and next winter.
  • Steamhead (in transit) Steamhead (in transit) @ 6:04 PM
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    The dry return lines

    are not supposed to get hot- warm, but not steam-hot. The traps keep steam from leaving the radiators and going into the returns. You mentioned that the system was "upgraded" when your uncle bought the place- wonder if he added the DH and vacuum-capable traps to an existing Vapor system? To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Long Beach Ed Long Beach Ed @ 5:39 PM
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    You may be surprised...

    I know a selling point of most vacuum systems was the reduced pipe sizes (and costs) necessary when using a vacuum. Most of the Dunham literature raves that their system can be added to any regular two-pipe system. While I have much of their material, they didn't appear to advocate the usual reduced vacuum piping sizes. Maybe you'll be lucky and the thing will work fairly well without the pump and its noise. But what fun would that be? Long Beach Ed
  • fireside fireside @ 12:04 AM
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    dunham system

    if there is excessive steam coming out of the overflow of the vari vac what causes that is it a bad trap or vaporstat or anything else
  • fireside fireside @ 12:04 AM
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    dunham system

    if there is excessive steam coming out of the overflow of the vari vac what causes that is it a bad trap or vaporstat or anything else
  • Fred Fred @ 8:45 AM
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  • Long Beach Ed Long Beach Ed @ 6:44 PM
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    Dunham DH Spec Sheets

    Here are some spec sheet for the DUNHAM DH Home Vacuum Heating System. Excuse the big file size, but there's much detail here. This is from the 1929 Sweet's Directory. Check out how that pump works! Long Beach Ed
  • Fisher Fisher @ 1:22 PM
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    The pump

    Ed, Thanks for the good scan of the sheets on the pump. I could blow them up to read all of the details. Apparently the pump itself is a water pump, and it creates a vacuum with a venturi? What maintains the water level in the tank? I still have not found the differential controller. Do you have a suggestion for what I can use? What vacuum levels are we looking for? Fisher
  • Steamhead (in transit) Steamhead (in transit) @ 9:34 PM
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    Nice find, Ed

    I've never heard of Sweet's Directory- what is/was it? To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Long Beach Ed Long Beach Ed @ 5:13 AM
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    Sweets...

    ...was and still is a multi-volume set of manufacturers' catalogues and data sheets. Most suppliers printed and inserted entire sections into the books. Dunham's contribution was about 40 pages, probably right out of the Handbook, perhaps with a little added sales fluff. I believe Sweet's is now about a 50 huge volume set. Some big libaries have them and certainly they are now on CD. They are published for the architectural/engineering gang to help them select and specify everything from windows to tile. Back in the 1930's they had a whole volume related to heating. A little "social engineering" will get you a new set if you have the place to put it and care about asphalt floot tile designs. Long Beach Ed
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