In the present work, the annular static gaskets are considered as porous media and the Darcy’s law is written for a steady radial flow of a compressible gas with a first order slip boundary conditions. From this, a simple equation is obtained that includes the Klinkenberg’s intrinsic permeability factor kv of the gasket and the Knudsen number Kno defined with a characteristic length l. The parameters kv and l of the porous gasket are calculated from experimental results obtained with a reference gas at several gasket stress levels. Then, with kv and l, the inverse procedure is performed to predict the leakage rate for three different gases. It is shown that the porous media model predicts leak rates with the same accuracy as the laminar-molecular flow model (LMF) of Marchand, Derenne and Masi. However, the new model has the advantage of furnishing phenomenological information on the evolution of the intrinsic permeability and the gas flow regimes with the gasket compressive stress. It also enables quick identification of the part of leakage that occurs at the flange-gasket interface at low gasket stresses. At low gas pressure, the behavior of the apparent permeability diverges from that of Klinkenberg’s, indicating that the rarefaction effect becomes preponderant on the leak. Finally, it is demonstrated that the porous media model could be very useful in predicting gasket leakage with liquids.

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