Seismic Test Result of Motor-Operated Butterfly Valve Actuators for Nuclear Power Plant

Seismic tests were carried out to confirm the operability limit acceleration for a standard motor-operated butterfly valve actuator in three excitation directions. Based on the results, seismic brackets that can operate valves even in three directions at 20 × 9.8 m/s² or more were designed in three representative models. For the model subjected to the seismic test, we mounted the designed seismic bracket and confirmed the operability of the butterfly valve actuator by carrying out vibration tests in three directions at 20 × 9.8 m/s². We used these results and previously reported motor-operated valve actuator seismic test results to creat a revision (draft) of the earthquake resistance evaluation methods.