Tubular passage closure

摘要

860,013. Nuclear reactors. ATOMIC ENERGY OF CANADA Ltd. July 24, 1959 [Aug. 4, 1958], No. 25518/59. Class 39(4). [Also in Group XXVIII] A closure for a reactor fuelling passage 2 comprises a cylindrical body 4 for insertion into the passage and carrying a rod 14 on which is mounted a radially expansible, metal disc 17 carrying a soft metal, sealing element 18 overlying and having an annular surface disposed outwardly of the periphery of the disc. The latter which has a peripheral portion thereof bearing upon the head 5 of the body is radially expansible in response to pressure thereon against the head to cause radial outward movement of the annular surface of the sealing element. As shown, a body support 7, carrying a piston ring 13, is screwed on to the body 4 and is provided with blocks 9 for passage through complementary grooves 10 in the tube 1; spacer rings 30, variable in number, allow the piston rings 13a on a new closure body to seal upon an undamaged surface of the passage 2. The rod 14 is axially movable but non-rotatable in the head 5, and carries a nut 16 by means of which the disc 17 is expanded into contact with the passage, the edge 25 of a shoulder 24 on the disc forming a secondary seal with a conical recess 26 in the body. Leakage of fluid past the element 18 drains through a passage 27, and the pressure drop due to such leakage is equally divided between the rings 13a and is achieved by providing orifices 28 in the rings. In a modification, the element 18 is replaced by a layer of soft metal in the peripheral region of the disc 17 and the passage 27 terminates behind at least one of the rings 13a; in place of the orifices 28, the body 4 has therein a passage which communicates by radial holes with the lands of the rings.