GB834003A - Improvements in pressure relief valves - Google Patents

Abstract

834,003. Pressure relief valves. VISCHER, A. May 16, 1956 [June 2, 1955], No. 15290/56. Class 135. A pressure relief valve for pressure cookers and other thin-walled pressurized vessels comprises a valve member 20, Fig. 1, mounted on the outside of the vessel so as to co-operate with a seat formed about an aperture 11a formed in a wall 11 of the vessel, and means for resiliently urging the valve member against the seat, such means engaging the opposite side of the wall to the seat throughout an area which is directly opposite the seat defining surface. The wall 11 may be the cover of the vessel. The valve member 20 is of cap-like form and has an external flange 26 grooved to receive a resilient sealing ring 28. The means acting resiliently on the valve member comprise a sleeve 13 and a spring 25. The sleeve 13 which has an upturned flange 15 engaging the under side of the cover 11 projects through the aperture 11a into the valve member. The spring 25 is arranged between an inwardly projecting flange 16 on the sleeve and the head of a screw 22 threaded into a boss 19 depending from the top of the valve member. Apertures 30 in the sleeve 13 facilitate the rapid release of fluid. In a modification (Fig. 3), the valve member 113 has a truncated conical extension 113a passing through the seat aperture 112 and is urged to its seat by a truncated conical spring 115 engaging the under side of the cover 111 and a flange 121 on the extension 113a. The flange 121 has an inclined slot to facilitate assembly of the spring 115 and also has grooves 123 to permit fluid to pass should the end of the bore 124 become obstructed by a large item of food. A threaded bore 126 open to the bore 124 may be provided to facilitate the attachment of a pressure-indicating device 116.