Centrifugal pump in operation, can not be a long time to close the outlet valve:
When the centrifugal pump outlet valve is closed, if the flow is too small, it is only the efficiency of the centrifugal pump will be decreased, the cost of electricity, the centrifugal pump device has no effect. Once the valve is closed to a certain limit, will lead to noise and vibration caused by centrifugal pump, centrifugal pump performance will be unstable phenomenon. But also long time operation of centrifugal pump under the condition of closing the valve to the temperature of the liquid inside the pump body to rise, once in the small flow centrifugal pump closed under the operation or no flow operation, the water in the pump cavity through the water high-speed rotation of the impeller in the pump cavity rapid cycling friction with the pump will cause the pump body the sharp rise in temperature, the outlet pressure will rise, if the pump temperature is too high or even lead to dangerous pump burst, the motor current will rise, current will lead to failure of the motor burned. Therefore, the centrifugal pump can not be closed for a long time to run the valve.
