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Rookie to steam - don't laugh!

Just bought a foreclosed 1880's 2-flat in Chicago with what I have just determined is a one pipe steam system.  It has a relatively new Weil McLain boiler.

Closing on the house tomorrow, fired up the boiler yesterday and everything seems fine.

However, where the 1 1/2" main returns to the boiler room, it has a vertical T.  The leg going down feeds the boiler return.  The leg going up has been totally broken off (I am literally looking at a broken 1 1/"2" x 3/4" bushing that I need to carefully break out).  I presume that this is the location of the main vent.  What do I get for the main vent?   Available at a good plumbing supply house?  Also, should I install a y-strainer as well?


  • The Steam Whisperer (Formerly Boilerpro)
    edited July 2010
    You're probably right..

    the main vent probably used to be there.  However, typically  it is a poor location because water hammer can beat it up really easily in that spot.   As to what vent, that is determined by measuring all your steam main and figuring out how much air you need to vent and then sizing the vent accordingly.  If you are interested in me stopping by I could look over the system more thouroughly and provide some input to help you get it running well and keep it that way.  I will be in Chicago in the next week or so on some other consulting work in Lincoln Park for a couple of days.  I may be over in Beverly too during my time there.  I
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • Rod
    Rod Posts: 2,067
    edited July 2010
    New to Steam

    Hi-  First of all -  It would rather bother me that a part had "broken off" my steam system and it would make me wonder what else could be wrong.  There maybe items, such as parts and safety issues that may not be readily apparent to someone who is new with steam so I think you'd be well advised to get a real "steam pro" to take a look at your steam system as they could tell you immediately exactly what shape your system in in and what needs to be done to rectify the problems. You be far ahead both economically and from a safety standpoint to find these problems out now than by trial and error, especially when winter comes on and it gets cold. Luckily you have some very good steam pros in the Chicago area like Dave Bunnell, "Boiler Pro", who can help you out.

    He's an expert on steam heating and squeezing the maximum efficiency out of a steam system

    You also might want to get some of Dan's books on steam which are available in the "Shop" section at the top of this page. Read "We Got Steam Heat" first as it is a good introduction to residential steam heating

    Also you might want to take a look "off the wall" as Dan has posted a lot of info on steam other places on this website. Look  in "Resources" section at the top of the page. 

    - Rod

    Edit: LOL-  I see "Boiler Pro" has already responded to your post. As I said your lucky you're in his service area!
  • Steamhead
    Steamhead Member Posts: 14,700
    I agree

    if you can get Boilerpro to come, do so.

    If the house was foreclosed, the main vent may have been broken off by a disgruntled former owner, or someone stealing copper or brass. It might take some doing to get the remaining piece out, but you can't get by without it.

    BP, bring a good selection of main vents.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • I just ordered some more Gorton..

    main vents and Hoffman 1A's for another deknuckling project in Chicago.   I may need to add a few more. 
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • steamfitter
    steamfitter Member Posts: 156
    main vent

    Looks like you have help on the way. Just thought I would add that Holohan's book," Lost Art of Steam Heating" is another great steam book. If I remember correctly the main steam air vent needs to be approx. 12 to 18 inches before the last elbow that looks down into your return. In your case, they put a tee there with the vent on the run of the tee instead of the bull, common mistake that will guarantee water hammer. You need to install a tee back before that existing tee using a union in order to install it. If you get that bushing out you would just put a 3/4" plug in it or better yet, just change that tee to an elbow, as long as you install the new vent tee in the correct place. Also put a long nipple or 12" piece with a coupling in the bull of this new tee before you install the vent. This too will help protect the tee from potential water hammer. Hopefully you have the room. Good luck with your new home!
  • JoelL
    JoelL Member Posts: 4
    Similar issue

    I've got a similar issue with main vent placement. In my case, three of the mains have vents placed in the run of the tees, except that the tees and vents are at the very end of the dry returns right at the boiler just before the return drops the a short wet line into the boiler. It seems to me that this doubles the volume of air that has to be vented in addition to the issue with water hammer. Only one or two vents (all are Vent-Rite #77's) have failed over 25 years or so and no water hammer is audible. Still, I'm planning on replacing all of these with "antler" type arrangements of, say, 4 or so Gorton #2's to maximize the venting rate. Is it worth it to move the vents to the standard location just back from the elbow at the end of the main, or will the extra venting from the multiple Gortons be enough? Thanks for any help!
  • Rod
    Rod Posts: 2,067
    Main Vents

    Hi- You didn't mention whether your system was one pipe or two pipe.  Why don't you just try new main vents at the present location.  You can always change the  location later if you want.  Just using larger vents should make a BIG difference. (A Gorton # 2 has about 6 times the venting capacity of a Ventrite 77 and a Gorton # 1 almost twice the capacity of the 77.)

    If you are going with an "Antler" arrangement, use a pipe union to connect the "antler" as this way you can make/modify the "antler" up on a bench and then attach it with one fitting.

    -  Rod
  • JoelL
    JoelL Member Posts: 4
    Total venting time the issue....

    Sorry - it's a one-pipe system. As I thought about it more, this makes sense. As far as I understand it, moving the vent location from near the boiler to about the mid point of the main would roughly halve the time to vent the air from the portion of the main supplying steam to the risers, leaving some slightly compressed (~ the 1 psi of the steam pressure) air in the dry return. If this takes it from, say, 10 minutes to 5 minutes, then it might be worth moving the location. If it changes it from 40 seconds to 20 seconds, it's probably not worth it. Either way I should increase the venting rate first, which will have a much larger effect, then see if it pays to move the location. Sound reasonable?

    And the union sounds like a great idea. Thanks!

  • Charlie from wmass
    Charlie from wmass Member Posts: 4,192
    It will not change the vent time to reach that point

    It will only change the time to reach the vent. Moving the vent should be limited to only being within a couple of feet from the end of the dry return. The Vent gets moved back to protect it from the water hammer at the end of the return. Venting is sized by the system volume and preferred venting time. Best thing I did to get precise on venting was to buy Gerry Gills book.
    Cost is what you spend , value is what you get.

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  • Rod
    Rod Posts: 2,067
    Venting Book

    Steam moves very quickly if you get the air out of its way.  Adequate venting does this.rather than location. As Charlie mentioned, Gerry Gill's venting book is what you need.. It explains all this thoroughly and has venting tables for the different types and sizes of you can compare them.

    - Rod
This discussion has been closed.