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Question for the steam guys

Ken_8
Ken_8 Member Posts: 1,640
in THE MAIN WALL
water's backing up the return from excessive steam pressure? If you run that bad boy at over a pound the main vent (which IS the Moline thingy you describe) the water will piss out instead of air.

Set the pressuretrol as low as you can and make the diferential '1'. If the problem continues, give us a shout and we'll walk you through the land of vapor and vacuum.

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Comments

  • Tom_29
    Tom_29 Member Posts: 1
    Question for the steam guys

    I don't do alot of steam work but I got a call to replace a couple of rusted out return lines which isn't a problem. But there is a saucer shaped disc about 12" in diameter which is piped with a 3/4 line from the top of possibly a steam trap which has moline on the outside casting. This disc is leaking water from a hole in the top of it. Can anyone give me any information about this as to what its purpose is or can it be replaced with something else. I asked the supply house but they have no idea what it is. Thank you Tom.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,600
    If you give me a fax number

    I'll send you the Moline literature.
    Retired and loving it.
  • Tom_30
    Tom_30 Member Posts: 4
    Fax #

    Dan, I sent you the fax #. Thank you, Tom.
  • Mad Dog
    Mad Dog Member Posts: 2,595
    Sometimes...the old check valves are all clogged

    up...and keep the condensate from returning to boiler. They may need to be taken out. Had this problem with a Webster a few months ago. Mad Dog

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  • Tom_30
    Tom_30 Member Posts: 4
    Moline info

    Dan, thanks for the info. Tom
  • Tom_30
    Tom_30 Member Posts: 4
    check valves

    There was only one check valve that I seen. Four return lines that dropped down to a single line perpendictular to the four with a check valve between line two and three. This has been an ongoing problem for years which has gotten steadily worse from what they told me. Maybe I can get some pics to post. Tom
  • Mad Dog
    Mad Dog Member Posts: 2,595
    Pics always help

    We'll get you thru it. Mad Dog

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  • Boilerpro_3
    Boilerpro_3 Member Posts: 1,231
    Actually the disc is the vacumn valve

    See my other post "Vapor lovers, look what I found today". The taller cyclinder is the old main air vent that vented all the mains and the rads in the system. Pressure should be kept below 8 ounces for this system. If you aren't running a coal fire anymore, I'd remove the vacumn valve. I've been told by wiser heads here that it can cause problems with steam distribution. And while you're at it replace the air vent with a couple of Gorton # 2s. What ever you do don't insulate the condensor pipe attached to the vent or/ alternataively remove its radiator. The brass fitting the condensor is connected too is a steam powered venturi that sucks the air out of the system, when everything is right. You can now get rid of the other vents on the system.

    Moline's are my favorite steam/ vacumn system and I intend to apply the same concepts and equipment to improve some plain one pipe and two pipe systems as I get the opportunity.

    Boilerpro
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,600
    Hope

    it helped, Tom. Thanks.
    Retired and loving it.
  • Tom_30
    Tom_30 Member Posts: 4
    Some more questions

    Well, I changed the rusted return lines today. Fired boiler up and mains heated up very quickly. Ran for a while and then an excessive amount of water came out of the vacuum valve. Probably a gallon or so. Pressure is set at .5 cut in and 1# differential, as low as it goes. Does this system need a vaporstat? Can the vaccum valve be removed and if so what does it have to be replaced with or can you just plug it. The system works very well except for the leaking vacuum valve. I forgot my camera today but I have some other work to do there and can get some pics then. Any thoughts? Thank you Tom.
  • Boilerpro_3
    Boilerpro_3 Member Posts: 1,231
    Some answers, I hope!

    The condensor pipe or rad on the ceiling can only condense enough steam to prevent water or steam from exiting the vacumn valve if the pressure is kept below 8 Oz pressure. Also if the pressure gets too high the water will back up in the condensor pipe drip and the dry returns and come out the valve. I would defintely put on a vaporstat on the system. With a vaporstat set properly, you can just have an open pipe in place of the float type vent and vapor valve. Some folks still like to put on some big main vents just in case the pressure gets too high and the steam makes it all the way to the vacumn vent. See attachment.

    Boilerpro
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