METHOD OF DETECTING ABNORMAL WEAR AT ROTARY PART OF SUBMERGIBLE MOTOR PUMP

PURPOSE:To enable to detect abnormal wear at the rotary part of a submergible motor pump, by turning the rotary part as a turbine by passing liquid through the pump while increasing the flow rate of the liquid gradually, and measuring the flow rate of liquid or the pressure difference on the opposite sides of the pump at the time when the turning part beins to turn. CONSTITUTION:A liquid is passed through the inside of a submergible motor pump while increasing the flow rate of liquid by opening a valve 10 gradually, a runner 7 begins to turn as a turbine at the time when the torque imparted to the runner 7 by liquid overcomes the static frictional torque of rotary parts. Here, if the rotation of the runner 7 is detected by a non-contact type rotation detector 13 and the flow rate of liquid passed through the inside of the pump and discharged from a discharge pipe 9 at the time when rotation of the runner 7 is started is measured by a flow meter 11, the static frictional torque can be measured from the flow rate of liquid. Further, if comparison is made between the actual static frictional torque thus detected and the value measured beforehand under normal conditions, it is enabled to judge whether abnormal wear is caused or not actually at the rotary parts of the pump.