Patent Number: 054266769
Section: abstract

Extrusion-resistant seal assembly for sealing a gap defined between a first structure spaced-apart from a second structure, which first structure and second structure may be an annular first flange and an annular second flange belonging to an instrumentation column of the kind typically found penetrating nuclear reactor pressure vessels. The seal assembly includes an annular retainer disposed in a gap defined between the first flange and the second flange, the first flange and the second flange capable of being moved into close proximity to reduce the gap therebetween. The retainer includes a first surface thereon having a first recess extending therearound. The retainer also has a second surface thereon having a second recess extending therearound. An annular first gasket is retained in the first recess and an annular second gasket is retained in the second recess. The first gasket intimately engages the first flange as the second gasket intimately engages the second flange to seal the gap when the first and second flanges are brought into close proximity and clamped together. The first and second gaskets resist extrusion as they are compressed between the flanges and as they are subjected to high fluid pressure because the gaskets are constrained within their respective recesses and because the retainer bears the compressive load. In this manner, the seal assembly seals the gap as the first and second flanges are brought into close proximity and clamped together.