GB896985A - - Google Patents

Abstract

896,985. Expansion joints. INTERNATIONAL COMBUSTION (HOLDINGS) Ltd., and BENNET, E. F. P. March 18, 1959 [March 19, 1958], No. 8861/58. Class 99(1). An expansion joint for a pressurised fluid circuit is provided with a secondary seal 5 adapted to permit flexure of the joint and such that in the event of failure of the expansion joint the rate of leakage of pressurised fluid is substantially reduced. As shown in Fig. 1, a flexible bellows joint 1 is disposed between portions 2, 3 of a high-pressure gas ducting of a gas-cooled nuclear reactor, the end portions of the ducting being formed with overlapping extensions 6, 7 pivotally connected together about an axis 4. The seal 5 comprises overlapping extension sleeves 10, 11 secured to the extensions 6, 7 and a resilient strip 12 of heatresistant rubber which in the event of failure of the bellows joint, is forced against the gap 15 between the sleeves 10, 11. In modifications, the seal comprises (a) split rings 17, Fig. 3, and a rubber ring 18 are held in a rebate 19 in an extension member 16 secured to the extension 6, and (b) a number of spaced springy strips bolted alternately to the extensions 6, 7 to form a labyrinth passage.