Abstract:In ASME standard,strengthbased gasket factor M and gasket prestressing stress y satisfying the leak rate grade are adopted,however,the leak rate requirement of joints is not taken into account.The leakage rate based gasket coefficient m(L),gasket prestressing stress y(L),and the minimum stress of the gasket at installation and service conditions based on leakage rate proposed in EN1591-1 were studied.The test of gasket coefficient based on leakage rate was carried out with metal wound gaskets,and a test method ofm(L) andy(L) based on leakage rate was recommended.According to the test method and the method in EN13555,the gasket coefficient was tested and compared.The result show that the values ofm(L) and y(L) obtained by the test method based on leakage rate are reliable under the low leakage rate requirement level,which is available for practical engineering.