Research Of Metal-to-Metal Contact Type Flange Joint Design

Metal-to-metal contact (MMC) type flange joint has good performance of sealing, and it is different from FLT type flange in structure and mechanism. But, traditional method can only calculate the gasket with single ring loaded, it can not fit the MMC type flange. Besides, traditional method is only based on the principle of integrity, it has defects in theory.In order to make the calculation of MMC type flange joint more accurate. CEN proposed prCEN/TS1591-3 to fit the calculation of this flange in 2006. This design meet the principle of integrity and sealing performance, take consideration of factors entirely, will reflect the mechanical behavior of MMC type flange joints in practical work. But there is still no reference of the MMC gasket parameters.This article research the parameters of MMC gasket and their test methods, use the compression/recovery test, gasket relaxation test and leakage test to determine the calculation parameters of MMC gasket, including the stress-strain curves, gasket relaxation factors, gasket surface pressure of MMC, unloading modulus and the minimum level of surface pressure required for leakage rate, research both mechanical and tightness performance of MMC gasket at ambient and high temperature, provide the data for calculation. Besides, this article introduce the detail of pr CEN/TS1591-3 method, including the mechanical model, calculation sequences and calculation parameters, and make a calculation example of DN80 MMC type flange, which is based on the method of prCEN/TS1591-3, use FEA to compare the result of gasket stress, decrement, flange rotation, bolt loads and load ratio, and build a experimental device to prove the applicability of the calculation method, provide a reference for MMC type flange design.