Reliability and Life Research of Certain Autonomous Emergency Solenoid Valve

Objective To achieve the autonomous control and safe application of emergency solenoid valves, a reliability and accelerated life test research on autonomous emergency solenoid valves is carried out. The existing design is improved through test results and failure analysis, and its life performance is verified. Method FMMEA（failure mode, mechanism, and effects analysis） method is used to analyze the failure mode, mechanism, and sensitive stress of solenoid valve; Working limits of the solenoid valve and the performance gap with imported parts are determined through HALT（highly accelerated life testing）; Life characteristics of the solenoid valve is evaluated based on Weibull distribution and ALT（accelerated life testing） of Arrhenius model; Combined with the failure analysis results of the faulty parts, a design improvement plan is proposed and the life characteristics are re-verified. Result ＆ Conclusion FMMEA analysis shows that the key failure components of the solenoid valve are the check valve and the sealing ring, and the main sensitive stresses are temperature and electrical stress; HALT results show that the high-temperature performance of the autonomous solenoid valve is comparable to that of imported parts, but there is a gap in low-temperature performance（with a limit temperature of-40 ℃ vs.-60 ℃）; The initial ALT test shows that the activation energy of the solenoid valve is 0.59 eV, with an equivalent lifespan of 5.97 years, failing to meet EMU requirements（7.5 years）. Through failure analysis, it is found that the content of vulcanized rubber copper powder in the check valve（it should be reduced from 60% to 5%） and process defects are the main causes of failure. After improvement, the re-verification of ALT shows that the equivalent life is increased to 10.83 years, significantly exceeding the life requirements of subway（6.0 years） and EMU（electric multiple units）（7.5 years）, this provides a reliable basis for the engineering application of autonomous solenoid valves.