Patent Number: 051679051
Section: claims

1. An apparatus for sealing a conduit having an open end, the conduit disposed in a steam generator comprising: (a) an annular bracket surrounding the open end of the conduit, said bracket defining an opening transversely therethrough and having a periphery portion sealingly attached to the open end of the conduit, the periphery portion having a plurality of spaced-apart holes transversely therein;  (b) a cover plate mounted on said bracket for covering the opening of said bracket, said cover plate having a periphery portion having a plurality of spaced-apart bores transversely therethrough;  (c) a plurality of elongated fasteners engaging the holes of said bracket and the bores of said cover plate for tightly connecting said cover plate to said bracket; and  (d) an extrusion-resistant seal member interposed between said bracket and said cover plate for providing a fluid-tight seal therebetween, said seal member having a periphery portion having a plurality of spaced-apart transverse apertures for receiving said fasteners therethrough, said seal member forming parallel strata of differing hardness at the periphery of said seal member, so that said seal member is extrusion-resistant for resisting extrusion away from said fasteners as said cover plate is tightly connected to said bracket so that the conduit is sealed thereby.  (a) the first layer has a hardness between approximately 40 and 60 durometer; and  (b) the second layer has a hardness between approximately 60 and 80 durometer.  (a) the first layer has a hardness of approximately 50 durometer; and  (b) the second layer has a hardness of approximately 70 durometer.  (a) the first region has a hardness between approximately 40 and 60 durometer; and  (b) the second region has a hardness between approximately 60 and 80 durometer.  (a) the first region has a hardness of approximately 50 durometer; and  (b) the second region has a hardness of approximately 70 durometer.  (a) an annular bracket surrounding the open end of the nozzle, said bracket having a top surface and having a centrally disposed generally circular transverse opening for passage of the fluid therethrough and having a periphery portion therearound sealingly attached to the rim of the nozzle, the periphery portion having a plurality of spaced-apart threaded transverse holes disposed circumferentially therearound;  (b) a generally circular foldable nozzle dam mounted on said bracket for covering the opening of said bracket, said nozzle dam having a periphery portion therearound having a plurality of spaced-apart bores transversely therethrough coaxially aligned with the holes in said bracket;  (c) a plurality of elongated bolts having a threaded shank portion threadably engaging the threaded holes in said bracket, said bolts passing through the bores of said nozzles dam for tightly connecting said nozzle dam to said bracket; and  (d) an extrusion-resistant seal member interposed between said bracket and said nozzle dam for providing a fluid-tight seal therebetween, said seal member having a periphery portion having a plurality of spaced-apart transverse apertures for receiving said bolts therethrough, said seal member forming parallel strata of differing hardness at the periphery of said seal member, so that said seal member is extrusion-resistant for resisting extrusion away from the shank portion of said bolts as said nozzle dam is tightly connected to said bracket.  (a) wherein the laminated layers define a generally annular first layer having a hardness between approximately 40 and 60 durometer; and  (b) wherein the laminated layers define a generally circular second layer having a hardness between approximately 60 and 80 durometer, the second layer adhesively bonded to the first layer.  (a) wherein the laminated layers define a first layer having a hardness of approximately 50 durometer; and  (b) wherein the laminated layers define a second layer having a hardness of approximately 70 durometer, the first layer adhesively bonded to the first layer.  (a) wherein the molded regions define a first region having a hardness between approximately 40 and 60 durometer; and  (b) wherein the molded regions define a second region having a hardness between approximately 60 and 80 durometer, the second region integrally molded with the first region.  (a) wherein the molded regions define a first region having a hardness of approximately 50 durometer; and  (b) wherein the molded regions define a second region having a hardness of approximately 70 durometer, the second region integrally molded with the first region.  (a) a generally arcuate-shaped first side section;  (b) a generally arcuate-shaped second side section hingedly connected to said first side section by a hinge assembly, said first side section and said second side section capable of being pivoted about the hinge assembly and into a planar configuration; and  (c) a generally rectangular center section removably connected to said first side section and to said second side section for rigidly fixing said first side section and said second side section in the planer configuration.  (a) wherein the top surface of said bracket has a multiplicity of grooves therein; and  (b) wherein said first layer of said seal member intimately engages the grooves in the top surface of said bracket for providing obstructions to fluid flow across said grooves so that said nozzle dam is fluid-tight. 2. The apparatus according to claim 1, wherein said seal member is elastomeric for sealingly engaging said bracket and said cover plate. 3. The apparatus according to claim 2, wherein said strata of said seal member are laminated layers. 4. The apparatus according to claim 3, wherein the laminated layers define a soft first layer for intimately engaging said bracket and a second layer of greater hardness than the first layer for resisting extrusion, the second layer being bonded to the first layer. 5. The apparatus according to claim 4, wherein 6. The apparatus according to claim 4, wherein 7. The apparatus according to claim 2, wherein said strata of said seal member are integrally molded regions. 8. The apparatus according to claim 7, wherein the molded regions define a soft first region for intimately engaging said bracket to seal surface imperfections and leak paths and a second region of greater hardness than the first region for resisting extrusion, the second region being integrally molded with the first region. 9. The apparatus according to claim 8, wherein 10. The apparatus according to claim 8, wherein 11. The apparatus according to claim 3, wherein said seal member is an EPDM. 12. The apparatus according to claim 11, wherein said seal member has "NYLON" fibers homogeneously dispersed therein. 13. The apparatus according to claim 3, wherein said seal member is "NYLON". 14. In a heat exchanger defining a plenum chamber therein and having a nozzle of predetermined inside diameter integrally attached thereto for passage of fluid into or out of the plenum chamber, the nozzle having an open end in fluid communication with the chamber and having a rim surrounding the open end of the nozzle, the heat exchanger having an access port therethrough of predetermined diameter in communication with the plenum chamber for providing access to the plenum chamber, the access port having a diameter smaller than the diameter of the open end of the nozzle, an apparatus for sealing the open end of the nozzle, comprising; 15. The apparatus according to claim 14, wherein said seal member is elastomeric for sealingly engaging said bracket and said nozzle dam. 16. The apparatus according to claim 15, wherein said strata of said seal member are laminated layers, said layers being disposed parallel to the top surface of said bracket. 17. The apparatus according to claim 16, 18. The apparatus according to claim 16, 19. The apparatus according to claim 15, wherein said strata of said seal member are integrally molded regions. 20. The apparatus according to claim 19, 21. The apparatus according to claim 19, 22. The apparatus according to claim 16, wherein said seal member is an EPDM. 23. The apparatus according to claim 22, wherein said seal member has "NYLON" fibers homogeneously dispersed therein for resisting extrusion. 24. The apparatus according to claim 16, wherein said seal member is "NYLON" for resisting extrusion. 25. The apparatus according to claim 14, wherein said nozzle dam comprises: 26. The apparatus according to claim 25, wherein said rectangular center section has arcuate end portions so that said center section, said first side section and said second side section define a generally circular cover plate for covering the generally circular opening of said bracket as said center section fixes said first side section and said second side section in the planer configuration, whereby said first side section and said second side section are capable of being hinged inwardly for passage through the access port and hinged outwardly for placement on the top surface of said bracket. 27. The apparatus according to claim 17,