Patent GB-1239916-A (GB)
Title: Improvements in or relating to pressure vessels
Inventor: MORRIS MICHAEL
IPC: F16J13/10
Filed: 1967-05-26
Abstract: 1,239,916. Pressure vessels. BABCOCK & WILCOX Ltd. 24 May, 1968 [26 May, 1967], No. 24760/67. Heading B1X. [Also in Division F2] The peripheral portion of a closure member for closing an aperture of a pressure vessel is provided with a flange which is adapted to be disposed within the aperture and which carries a plurality of shear members, each shear member being movable between a position in which it projects from the outer face of the flange into a recessed portion of the vessel surface defining the aperture, whereby the shear members prevent movement of the closure member from the aperture in a direction away from the vessel, and a position in which it is retracted so that such movement of the closure member is not prevented, the movement of each shear member between its projected position and its retracted position being effected by actuating means which extends from each shear member through the flange to project from the inner face thereof. As illustrated in Figures 1 and 3, end 16 of pressure vessel 10 has an aperture 12 adapted to be closed by closure member 14 in the form of a domed cap having a peripheral flange 26 adapted to be located by a shoulder 18 formed on the internal surface of the pressure vessel. The internal vessel surface 20 defining the aperture is provided with an annular recess 22 for receiving eight shear members 24 which are housed in a groove 30 provided on the outer face 28 of the flange. The radially external face of each shear member is profiled to have portions 24 interconnected by surfaces 36, the opposed surface of the 'annular recess provided in the vesel surface being profiled correspondingly in order to mate with the profiled shear members. Each shear member is connected to at least two, for example three, parallel actuating rods 40 each of which extends with close fit through a bore 44 formed in the flange; the inner ends of the actuating rods of each shear member preferably are interconnected. The actuating rods enable the shear members to be moved, for example by means (not shown) introduced through aperture 50 provided centrally in the closure member, between a projected position (as shown) and a retracted position in which they may lie end-to-end in an annulus in the groove provided in the flange. The shear members may be associated with means for locking each shear member in its projected position, the means also indicating when the shear member is in its projected position. As illustrated, the flange is provided with vertical bores 52 in each of which is located a locking member in the form of a part-threaded bar 78 the threaded portion of which cooperates with a threaded portion 74 of the bore. Each shear member is provided with two such bores and associated bars. When a shear member is in its projected position (as shown), the end portion of each locking bar occupies part 62 of the arcuate space defined by the shear members and the groove provided in the flange. The head of each locking bar is sealed to the flange by a sealing ring 76 housed in a groove 80 formed in the flange. Forming a seal externally of the closure member between the pressure vessel and the closure member is sealing means 64 which may consist of an annular bridge member 66, annular sealing bands 68 and 70 (each for example in the form of a metal ring) and clamping rings 72.