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Hanging a glass cryostat from a metal support

  1. Oct 24, 2012 #1

    I'm looking to hang a glass cryostat that has a glass bevelled flange at the top. If the cryostat stands vertically, the flange is angled at 45 degrees. Like this (more or less; the silver underscore is just a place holder to get the shape approximately right):


    Liquid helium will be put into the cryostat but lower in the cryostat than the flange. The company that has quoted me for the glass piece doesn't have an economical solution to hang it, so I'm hoping to have this made in a shop here.

    I believe the hanging support, which is like a collar that encircles the flange and then connects to the rest of our system above it, is made from cast iron. There's also a piece of foam that goes between the glass and the metal, which I'm not sure how to obtain if we have a machine shop here make the cast iron piece (the foam should be ring shaped and sit comfortably in a surface that is angled at 45 degrees).

    The idea is that we bring the metal collar up, which brings the cryostat up, and presses the o-ring against a flat surface.

    Can anyone offer advice? Is cast iron proper? Is there a company that makes these parts off-the-shelf? The flange won't be custom but rather NW120 or some industry standard. If our machine shop makes the metal support, where can I find this piece of foam and are there any other components I'm missing?

  2. jcsd
  3. Oct 24, 2012 #2


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    Hi Matt. I take it you have a vacuum insulated, glass cryostat? I've seen them in academia before but they are typically bathed in liquid nitrogen because the latent heat of boiling for LHe is so low. In industry we use a vacuum jacketed and copper shielded, stainless steel container. A conventional vacuum jacketed container used for liquid nitrogen for example, doesn't have sufficient insulating properties.

    Should we would assume the ring supporting this is on the outside of the insulation so it won't get cold? In which case, it doesn't much matter what you make it from.
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