| 摘要 |
A seal apparatus is disclosed for sealing an outlet of a pressurized chamber from fluid loss from the chamber and contamination to the chamber. The apparatus includes certain combinations of (a) a chamber outlet structure; (b) a removable cover; (c) means for reversibly connecting the cover to the chamber outlet structure; and (d) a compressible self-energizing ring having a surface which consists essentially of a material selected from the group consisting of noble metals, noble metal alloys and polytetrafluoroethylene, which has a hardness selected to substantially avoid deformation when the cover is sealed to the chamber outlet structure. Also disclosed are certain pressure vessels for hydrothermal crystal growth using a crystal growth media, which comprise (a) a vessel base and (b) a removable vessel cover. The vessels include (i) certain said combinations employing a compressible self-energizing ring with a surface resistant to corrosion by the crystal growth media and a hardness lower than the hardness of the seal surfaces of the base and cover; and/or (ii) (in an aspect of this invention especially suited for the growth of crystals of the formula MTiOXO4 wherein M is selected from the group consisting of K, Rb, Tl, NH4 and mixtures thereof and X is selected from the group consisting of P, As and mixtures thereof) vessel bodies of a nickel alloy essentially free of titanium.
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