Verfahren zur Herstellung einer vakuumdichten Abdichtung

摘要

1,244,948. Joint-making packing; pipe joints. PHILIPS GLOEILAMPENFABRIEKEN N.V. 4 March, 1970 [7 March, 1969], No. 10408/70. Headings F2B and F2G. A vacuum-tight seal (for use between ducts in the heat insulation of cryogenic apparatus) is formed between the cylindrical surfaces of metal members by providing the inner member 2 of a metal having a lower coefficient of thermal expansion than that of the metal of the outer member 1, the members being a sliding fit at room temperature and an 0-ring 6 and a layer of grease being provided between the surfaces. At high temperatures the seal is formed by the 0-ring and at low temperatures it is formed by shrinkage of the outer member (brass) on the inner member (copper) in combination with the layer of grease (silicone grease).