Critical Internal Pressure in the Sealing Performance of New Gasketless Flange Having Different Flange Nominal Size

This paper deals with a new seal system between two flanges without using gaskets. The system includes a groove and an annular lip that is held by one of the flange with its highest point in contact with the other flange to form a seal line when the flanges are assembled. The critical internal pressure for leak in the sealing performance of this system is investigated through an experiment and FEM analysis with varying flange nominal size. The analysis indicates that the critical pressure is controlled by the maximum contact stress appearing at the highest point of the annular lip when the flanges are assembled even the flange nomimal sizes are different.