Study on the gasket parameters and the calculation of MMC flange joint according to XP CEN\TS 1591-3

Metal-to-metal contact type flange joints (bolted flange joint with metal-to-metal contact) have a constant gasket sealing stress during service, so it is extensively used for “zero leakage” design in petrochemical, chemical, or nuclear power industry. XP CEN\TS 1591-3 provides a calculation method for metal-to-metal contact flange joints but the gasket parameters needed in this calculation and their test methods are not given. To determine the gasket parameters of metal-to-metal contact type flange joints, the procedures of the compression–resilience test, the stress relaxation test, and the sealing test at different temperature were described here, and the main mechanical properties and sealing property of a metal-to-metal contact type gasket were obtained from these tests. The methods to determine the metal-to-metal contact gasket parameters were introduced. And then, the calculation for a DN80 PN5.0 metal-to-metal contact type flange joint was carried out with two methods, one was the method according to XP CEN\TS 1591-3, the other was finite element method. In these calculations, the assembly condition and service condition were considered. The results of the two methods coincided well. This showed the test methods and test results of metal-to-metal contact type gasket parameters suggested here were available. So, they could be applied for the calculation of metal-to-metal contact type flange joints.