• 1. The significance of filling the pump with water is to establish a vacuum.
• 2. Be sure to close the valve on the outlet, so that the pump does not establish the flow, which can reduce the current during the operation of the motor, which is conducive to the smooth operation of the pump, and the valve should be opened slowly in time with the smooth operation of the pump.

The centrifugal pump is based on the vacuum water absorption caused by the centrifugal force of the impeller. therefore, when the centrifugal pump is running, the outlet valve must be closed for irrigation. The water level is higher than that of the impeller, and the air is discharged in the centrifugal pump, which is operable. After operation, a vacuum is set around the impeller to absorb water, which can be opened automatically and water is raised. Therefore, be sure to close the valve at the mouth first.

Second, why to drop the outlet valve when the centrifugal pump is running?

When the centrifugal pump is in operation, the pump outlet pipe is not water, so there is no pipe resistance and rising resistance. After the centrifugal pump is running, the centrifugal pump head is very low and the flow rate is very high.

Before the operation of the pump, the pump body is filled with transported liquid; after operation, the impeller is driven by a high-speed rotating shaft, and the liquid between the blades must be accompanied by rotation. Under the action of centrifugal force, the liquid is thrown from the center of the impeller to foreign aid to get your energy. In the volute, the liquid slows down from the gradual expansion of the flow channel, and part of the kinetic energy is converted into static pressure energy, which flows into the discharge pipe with higher pressure and is sent to the important place. When the liquid is from the outer edge of the flow passage in the center of the impeller, a certain vacuum is set in the center of the impeller. Because the pressure above the tank is greater than the pressure at the inlet of the pump, the liquid is constantly pressed into the impeller. It can be seen that as long as the impeller continues to rotate, the liquid will continue to be inhaled and discharged.

If the use of axial flow pump is the opposite, it is necessary to open the valve operation, the power of the motor in the short term by and no resistance, will be excessive flow, often pump vibration, noise, or even motor overload operation, will burn out the motor. Close the outlet valve, equal to the artificial resistance pressure, with the normal operation of the pump, the valve runs slowly, so that the pump gradually works normally along its performance curve.