Abstract:Gaskets are the core components of bolted flange connection systems.Predicting the life of gaskets can improve the reliability of the bolted flanged connection,while reducing the experimental error of gasket life evaluation devices can improve the accuracy of gasket life prediction.Taking flexible graphite spiral wound gaskets as example,the influence of flange and gasket thickness deviation,loading coaxiality deviation and gasket installation deviation on the stress distribution of the gasket of the multi specimen gasket accelerated life test device were studied.The load ratio under different temperatures and pre-tightening stress was obtained,and the maximum allowable deviation of the test device was determined.The influence of temperature and pre-tightening stress on the pre-tightening stress error of the test gasket was revealed,and the method of controlling the pre-tightening stress error was put forward.The results show that the pre-tightening stress error decreases with the increase of temperature,the pre-tightening stress error caused by the thickness deviation of the flange and gasket decreases with the increase of pre-tightening stress,and the coaxiality deviation of test device loading and the pre-tightening stress error of the gasket caused by the gasket installation deviation increases with the increase of preloading stress.Taking the pre-tightening stress error of the test gasket of 1% as the index,it is obtained that the thickness deviation of the flange and gasket should be controlled between -0.02 mm to 0.005 mm,the coaxiality deviation loaded by the test device should not be greater than 0.33 mm,and the installation deviation of the test gasket should not be greater than 1.24 mm.For other types of gaskets,the range of thickness deviation between flange and gasket,coaxiality deviation loaded by test device and installation deviation of test gasket can also be determined by the method established in this paper.