DIAGNOSTIC METHOD FOR SWING CHECK VALVE

摘要

PROBLEM TO BE SOLVED: To provide a diagnostic method for a swing check valve which can accurately predict the occurrence of deterioration by diagnosing the detailed operation state of the swing check valve, and diagnoses the degree of deterioration of the swing check valve.SOLUTION: A diagnostic method for a swing check valve for diagnosing the operation state of the swing check valve storing a check valve unit performing arcuate motion with a valve rod as a support shaft in a valve box comprises: a position determination process which makes an ultrasonic wave incident into the valve box from an ultrasonic sensor installed in the valve box and determines the position of the check valve unit on the basis of the ultrasonic wave reflected by the check valve unit; a behavior determination process which determines the state of the behavior of the check valve unit on the basis of the change of the peak position of the ultrasonic wave measured by the ultrasonic sensor for each measurement time; and a collision determination process which detects the collision noise generated in the valve box by using an AE sensor installed in the valve box and determines the presence/absence of collision between the check valve unit and the valve box on the basis of the detected collision noise.