Closure seal for high pressure vessel.

摘要

Sealing between an access opening (15) in a pressure ves- set (11) and a closure member (20) fitted in the openings is provided by an O-ring (38) of perfluoroelastomer in an annular groove (39) formed in a surface of the closure member. The sidewall (42) of the groove on the low pressure side of the seal has a concave curvature in cross section so as to form a «hook» or lip which retains the O-ring in the groove and prevents creeping extrusion of the O-ring under prolonged exposure to high temperature and pressure fluid on the high pressure side of the seal, even with a clearance between the closure member and the access opening of up to approximately 1 percent of the diameter of the O-ring cross section.