During normal operation of the centrifugal pump, the suction pipe sucks water and the drain pipe drains water! If I close the outlet valve of the drain pipe and the motor is still working, what will happen?
During the normal operation of the centrifugal pump, if the outlet valve of the drain pipe is completely closed, the motor is still running normally, the pump does not output water, and only the friction loss of the disc remains in the pump. Other items can be ignored. Therefore, the motor will be damaged. Shaft power is minimal.
-For centrifugal pumps, it is required to close the water outlet valve and start, and then gradually open the valve after reaching the normal speed, so that the motor will not be burned.
-For mixed flow pumps, it should be determined according to its characteristic curve.
-For axial flow pumps, the valve must be opened to start.
If you close the pump outlet valve when the centrifugal pump is working, it is a very dangerous operation to hold back the pressure at the pump outlet pipeline. It is easy to burn the motor of the pump, because the resistance received by the impeller of the pump head when it rotates is too much different than the normal use, so it is easy to cause the motor to burn.
If you close the outlet valve when the pump is off, and then start the pump to run, in this case, you need to open the exhaust valve of the pump head (usually a very small valve), so that the inlet pipeline After all the internal parts are discharged, the pump head will suck the water out and rush to the pump outlet. During this time, the water will be sprayed out from the exhaust valve. At this time, the valve at the pump outlet can be opened. Then close the exhaust valve of the pump head.
