Patent attributes
A pressure retained gasket seal provides enhanced resistance to hydraulic unloading by including a notch formed in a rear face of the gasket groove, thereby reducing intrusion of process fluid behind the gasket and improving hydraulic retention of the gasket seal. Embodiments increase the process fluid pressure limit of the gasket seal by a factor of two or three compared to gasket seals of the prior art. In embodiments, the gasket groove has a dovetail cross-section, thereby increasing resistance to process fluid pressure by requiring compression of the gasket before it can be dislodged from the groove. Embodiments form the gasket from flexible graphite, which can be initially shaped as an annulus and then forced by an applied load into the gasket groove in conformance with the notch. Embodiments include compressing the graphite to within 50% or even 70% of its maximum density during installation thereof.
