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vacuum system

I am a licenced plumber that does case research and investigative work for attorneys and insurance companies. A new case that I am working on involves what I am told to be is a closed vacuum steam system. The basis of this case involves damage to property caused by water. One side is arguing that a large puddle of water about three feet in diameter was seen emanating from under the radiator on and off for several days during operation. A plumber that was hired by the building is going to testify that a closed vacuum system is designed to completely avoid leaks and to minimize if not entirely negate the collection of moister and condensation.  He explains that steam enters the radiator via a feed pipe and is sucked through the radiator into the return pipe by the vacuum system. he also says that the steam trap on the return catches condensation and prevents leaks.He says that because the steam is being sucked through the pipes and radiator that it would not be able to escape the system even if there were a crack in the radiator.He says that even if the radiator was cracked that the amount of steam that would escape would only produce an ounce or two of condensation not nearly enough to produce a large puddle of water. Now I have worked on quite a few steam systems in my career but admittedly not that many vacuum systems. Without getting to technical I thought the steam trap is normally open until steam reaches it at which point it would close trapping the steam which would then turn to condensate. If this is the normal function of the system isn't it then possible for the condensate to leak from the system if there is a break in either the radiator, a nearby fitting, the steam trap itself or the return piping? Please advise because I have never heard of this plumbers explanations in my life.


  • gerry gill
    gerry gill Member Posts: 3,078
    Why don't they just turn on the system and go look

    at the radiator? do they think the ''leak'' fixed itself? if there was a leak, would it not still be present? your description sounds accurate to me as far as the system operation..i also think if there is a radiator leak, water is coming out vacuum or no vacuum..a 3 foot puddle should be a good leak tho..i would think it would be cheaper to fix it than to pay lawyers and others.
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Henry
    Henry Member Posts: 998
    Vacuum systems

    You would still get a leak. The other guy does not understand a vacuum system. Is it a one pipe steam/condensate system with a 3/8 inch vacuum pipe attached wher you would normaly have an air vent? Or is it a two pipe system that the vacuum is through the return lines?

    One system is used to speed up the steam getting into the rad. The other is used to control the steam temperature. In both cases, a split rad will cause a puddle untill it is shutoff the steam.

    You can pm me pictures etc..
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