Consideration on ConFlat Seal Mechanism Based on the Stress Analyses in Gasket.

The “capture” model, which is dependent on the compression of a gasket between the knife edge and the retaining counter of the flange, has been the rationale of ConFlat seal mechanism. Our numerical analyses of stress distributions in a tightened gasket indicate that the capture increases the seal pressure less than 2%. The seal pressure is mainly related to the compressive stress between 20° tapers of a pair of flanges. Numerical results also show that maximum stress in the conventional disk gasket can be over 3 times larger than that in the taper-seal gasket. This fact implies that excessive high stresses in the conventional disk gasket prevent achievement of a wide seal area, resulting in a gasket creep during baking. Newly designed taper-seal gasket realizes highly stable seal pressure even under a lower tightening torque and consequently shows a good seal performance as expected.