PURPOSE: To provide a method and device for predicting fault of ball tap type constant water level valve with which the fault can be predicted before any serious accident such as filling with water or water supply stop occurs.
CONSTITUTION: The number of times of operations to open/close a ball tap type constant water level valve 11 of a water receiving tank 2 is calculated from the water level read by a water level detector 8, the area to limit the detection just for prescribed time is set near the lower limit and upper light water levels so as to prevent malfunction caused by waving on the surface of water, when the accumulated number of times of opening/closing reaches the allowable number of times of use, the fault of the ball tap type valve 11 is predicted, and a fault predictive signal is outputted.
MATSUI TAKAYUKI
OHIRA YOSHIHIRO
ARIMIZU KOJI
