The equilibrium distribution of methane between the liquid and vapour phases of oxygen

✍ Scribed by R.J. Hodges; R.J. Burch

• Publisher: Elsevier Science
• Year: 1967
• Tongue: English
• Weight: 173 KB
• Volume: 7
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(67)80043-2

✦ Synopsis

J

g Rgure 1. Arrangement of high vacuum seal for low temperatures

The satisfactory operation of the seal described over a wide temperature range is explained by the thinness of the washer. Although there is a large difference between the coefficients of linear expansion of bronze and PTFE, the relative change in thickness of the washer with temperature is insignificant and the elastic deformation of the bolts which tighten the flanges appears to be sufficient to compensate for these changes in dimensions.

The seal described was tested over the whole range from room temperature to 1-5 ° K. On immersing the seal into liquid helium-4 the vacuum in the system became 10-s-10 -6 torr and did not change when the liquid helium became superfluid by pumping. It was established that the seal does not need tightening after tens ofcoolings and the same sealing washer can be used many times.