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Vent at end of main

HeatingHelp
HeatingHelp Administrator Posts: 688
in THE MAIN WALL
This discussion was created from comments split from: main vent on return piping.

Comments

  • Laars66
    Laars66 Member Posts: 9

    what type of vent should I put at the end of a return line ?a gorton? What size?

  • Jamie Hall
    Jamie Hall Member Posts: 25,292

    What kind of "return" line? Some need no vent at all… some need a full size main vent…

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • alanm
    alanm Member Posts: 95

    thanks….it is a return line /cast iron…and right now there is a valve…. see at top upper right…valve is "green".

    thanks alan

    P1010370a.JPG

  • ethicalpaul
    ethicalpaul Member Posts: 7,002
    edited October 2024

    The recommended size depends on the size and length of your main. Your current one is a Hoffman which I think makes a terrible main vent in terms of bang for buck.

    One similar to that capacity is a Gorton #1 but depending on your main a Gorton #2 would be better. See this article by Gerry Gill and Steve Pajek

    What size and how long is that main?

    You seem to have a second main as well. Does that one have a vent?

    NJ Steam Homeowner.
    Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
    See my sight glass boiler videos: https://bit.ly/3sZW1el

  • alanm
    alanm Member Posts: 95

    thanks…..i think a unique system!…….one run handles all radiators except 3… that other run just handles 3 radiators (one on the first floor, one on the 2nd and one on the 3rd). the run that handles just 3 radiators does not have any return/valve. the main run about 85'….and i attached another photo…Hoffman 75 vent at the end of the main on that run. any insight will help! thanks

    vent 1.jpg
    vent 2.jpg
    vent3.jpg

  • delcrossv
    delcrossv Member Posts: 1,581

    Both returns should have vents. for the short one with only 3 rads, the Hoffman 75 would work well on that. There's a convenient union on that one to place a tee with a riser for another vent.

    The other main, that runs everything else, should have a larger vent.(which should also be on a riser)

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • alanm
    alanm Member Posts: 95

    ok….cant picture where to put that vent on the short one….piping from boiler for that short run….pipe heads off to the first floor radiator and then it continued to the 2nd/3rd floor ….see diagram…where would i put the vent?

    thanks

  • delcrossv
    delcrossv Member Posts: 1,581
    edited October 2024

    Diagram?

    If it's just one outgoing pipe that doesn't come back, it's counterflow . If it just feeds the riser, I'd put a vent at the top of the riser before the 3rd floor rad. That way you can make sure you're not overheating the rad while getting the air out of the pipe.

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
    ethicalpaul
  • alanm
    alanm Member Posts: 95

    ok….is that why those 3 radiators dont seem to get hot unless i have temperature up high….and then it drops off when heat is on…is that because of no vent?

    delcrossvcanstaff
  • ethicalpaul
    ethicalpaul Member Posts: 7,002

    Yes that is a likely cause. All the air in the main pipe has to be expelled through the radiator vents which can take some time

    NJ Steam Homeowner.
    Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
    See my sight glass boiler videos: https://bit.ly/3sZW1el

    delcrossv
  • delcrossv
    delcrossv Member Posts: 1,581

    Yep. and you don't want a big vent on the top radiator because that room will roast. Hence the two vents.

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • delcrossv
    delcrossv Member Posts: 1,581

    And get some insulation on those copper pipes. 😉

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • alanm
    alanm Member Posts: 95

    thanks…anything special…what type of insulation should i use? besides making my basement cooler (!)….what does that do to the rest of the system/radiators? thanks again Alan

  • delcrossv
    delcrossv Member Posts: 1,581

    I inch paper backed fiberglass pipe insulation. The more you insulate the faster steam gets to where you want it (instead of heating the basement)

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • delcrossv
    delcrossv Member Posts: 1,581
    edited October 2024

    See pic below. You can ignore the numbers pointing at the rad vents as they may not apply.

    20241016_130528.jpg

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
    ethicalpaul
  • alanm
    alanm Member Posts: 95

    thanks….

  • alanm
    alanm Member Posts: 95

    about the pipe insulation….besides wrapping the copper….should i also wrap the iron? thanks

  • RTW
    RTW Member Posts: 166

    QUOTE above "And get some insulation on those copper pipes".

    Every competent pro on this site abhors the use of copper in piping a boiler, but it shows up in new boiler replacements on this site time and time again. And, I've read there is "no code" to prohibit its use - perhaps its time a "code" was instituted nationwide

    Regards,

    RTW

  • alanm
    alanm Member Posts: 95

    thanks…..i will wrap the copper…is it worth it to replace the steel piping? what effect is the steel having on the system that i may notice…..

  • alanm
    alanm Member Posts: 95

    question….see photos….so as a reminder….i had to mains from teh boiler…one did 98% of the house…and the other run….a quick run to a radiator on the first floor and off that run…it went to a radiator on the 2nd floor and one on the 3rd. you mentioned about putting a vent on the piping before the 3rd floor vent….can i try , before that, to add a vent on to that radiator on the 3rd floor. seems there was a spot for one….the reason is that both the 2nd floor and 3rd floor radiators off that seperate run dont get that hot and dont stay hot when they do. seems i really have to raise the temperature to get heat in them. see photos….

    heater 3.jpg
    heater 1.jpg
    heater 2.jpg

  • Jamie Hall
    Jamie Hall Member Posts: 25,292

    On the vent on the third floor radiator. Keep in mind that vents on radiators control the performance of that specific radiator. Vents on mains — or risers — allow steam to reach the radiator rapidly.

    So… in this case, a vent somewhere on that riser — the closer to the top the better — will be the most help. A faster vent, or extra vent, on the radiator may help that one radiator, but isn't what is needed.

    On copper. in response to @RTW . It is absolutely true that iron (NOT galvanized, by the way — that's the worst choice) is preferred for steam piping. However, copper can be satisfactory — if it is installed properly. The problem isn't the metal by itself, but expansion, and if provision is made in the piping for expansion to take place without putting stress on things, it's fine. This does mean using ProPress or similar fittings, rather than sweating. It also means arranging for true swing joints (drop headers, by the way, do this inherently) or for expansion loops.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • alanm
    alanm Member Posts: 95

    thanks…so if no problems leaking/etc on the copper….and it has been like 10 years…..then i dont have to do anything……..on the vent….you are saying on photo 1…which shows pipe coming otu of the wall (this is the 3rd floor radiator)…i should put in a valve there…before it gets to radiator and this will help that 2nd floor and the 3rd radiator to get hot?

    thanks alan

  • alanm
    alanm Member Posts: 95

    follow up….see diagram (i am not an artist)….the one main run goes to about 15 radiators and there is a return with a Hoffman 75 vent at the end…this diagram shows the other run…….one goes to a radiator on the 1st floor and then it shoots off and then the run goes to radiator on the 2nd and then the 3rd….those two dont seem to get hot unless i really set the temperature high…like 74. still think the best bet is putting in vent on the pipe right before it goes into the radiator on the 3rd floor? thanks

    diagram.jpg

  • RTW
    RTW Member Posts: 166

    On the use of copper in near boiler piping, my thought is the installers used copper because it was "easier to install" than conventional malleable steel/iron. I thought pros dont use copper, but I could be wrong - at least back in the day

    Regards,

    RTW

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