GB718547A - Improvements in and relating to high temperature expansion joints - Google Patents

Abstract

718,547. Pipe joints. BRITISH THOMSONHOUSTON CO., Ltd. April 24, 1952 [April 24, 1951], No. 10330/52. Class 99 (1). In an expansion joint for connecting a thinwalled conduit to a relatively massive casing, e.g. for connecting a steam inlet pipe 1a to the inner shell of a double shell turbine casing 2, 3, a sleeve 14 surrounds the end of the pipe with a clearance 15 and is secured thereto at 13, a metal sealing ring 11a disposed in a recess in the shell 3 closely fits on the sleeve 14 and has radial clearance 17 with the wall of the recess, and a second ring 11b bearing against the ring 11a fits closely in the recess and has clearance with the sleeve, whereby the steam pressure acting on the ring 11a maintains the side surfaces of the rings in tight engagement, and the clearance 15 and the restricted heat conduction path between the sleeve and pipe restrict the rate of temperature rise of the sleeve, the slow expansion of which involves no excessive stretching action on the metal rings. Additional rings 11c ... 11g may be provided, all the rings being held in place by a split ring 12 and a lip 3a on the casing 3. The outer surface of the sleeve 14 may have a bearing surface 16 of a high-temperature-resisting material such as " Stellite " (Registered Trade Mark), and the pipe 1a, sleeve 14, casing 2 and rings 11 may be made of specified stainless steels. The rings may be of the composite structure and retained in position by the means described in Specification 718,534. An expansion joint is provided between the pipe and the shell 2, the opening in the shell being surrounded by a flange 4 connected by studs 7 to a fitting 5 having a thin-walled annular part welded to the pipe at 6. A gasket 8 between the flange and the fitting is compressed by a tongue 9, and nuts 7a are tightened while the studs are hot.