Patent Number: 043127088
Section: claims

1. A reactor stud hole plug unit comprising: A. a compression plate having an outer surface, an inner surface, a peripheral edge, a central opening therethrough and an annular rim extending from the inward surface and spaced inward of the peripheral edge, said peripheral edge defining a lip adapted to rest on a reactor surface about an opening to be closed with said rim extending into said opening;  B. a mandrel having a central threaded stud extending outward therefrom through the compression plate central opening, said mandrel plate having a cylindrical upper section dimensioned to fit within said annular rim, a cylindrical lower section of larger diameter than the upper section and a frustoconical section connecting the upper and lower sections;  C. an elastomeric seal ring having a rectangular cross section and dimensioned to snugly fit about the cylindrical upper section of the mandrel plate and engage the compression plate rim in aligned relationship; and  D. a nut threadably engaging the stud so as to maintain the unit in assembled relationship and upon turning adapted to draw the mandrel plate toward the compression plate between a noncompressed state where the compression plate is spaced from the mandrel and a compressed state where the seal ring substantially fills a space defined by the annular rim, the mandrel and a wall of the opening being plugged. 2. The unit of claim 1 wherein the compression plate, when resting on the seal ring, is spaced from the mandrel a distance substantially equal to an axial extent of the frustoconical and lower sections of the mandrel and the seal ring is so dimensioned that in the compressed state the compression plate inward surface engages the mandrel and the seal ring extends to a position substantially even with a bottom surface of the mandrel lower section. 3. The unit of claim 1 wherein the stud includes means for being restrained from rotation as the nut is turned. 4. The unit of claim 3 wherein the restraining means includes a threaded tap at a distal stud end, said tap threads being the opposite of the threaded stud. 5. The unit of claim 1 wherein the stud is positioned within a central opening in the mandrel and welded thereto. 6. The unit of claim 5, said stud extending a distance into the mandrel to leave a recess between a stud end and a bottom of the mandrel, said weld positioned in said recess. 7. The unit of claim 1, said stud having an axial vent passage extending therethrough. 8. The unit of claim 1, said seal dimensioned to extend outwardly beyond the cylindrical upper section in the noncompressed state.