Multifactorial Coupling Enhancement Testing and Research on Improvement of Control Mode of Nuclear-grade Electric Shut-off Valve

As the key active equipment in the nuclear reactor system, the reliability of valves directly determines the safety of nuclear reactors and personnel. In this paper, aming at the common valves (electric shut-off valve) in nuclear power plant, and based on the analysis of previous fault data and structural characteristics, it is found that the main fault of the electric shut-off valve is that the position indicator does not match the travel position, resulting in internal leakage of the valve. On this basis, the coupling enhancement test scheme was designed to simulate the vibration strengthening effect under comprehensive conditions. The failure of electric shut-off valve was stimulated in a relatively short period of time in the test. Finally, it was proposed to change the drive control mode to solve the problem of internal leakage of electric shut-off valve according to the cause of fault. The test results show that after improving the control mode, the torque control mechanism is used to control the closing, and the valve is closed normally without leakage.