The reason why the single-stage centrifugal water pump in the pump station does not produce water after being turned on is usually due to the following reasons:
(1) The inlet valve, outlet valve or maintenance valve of the water pump unit is not opened or the valve automatically closes due to mechanical or electrical failure. Before starting the pump unit of the pump station, the inlet valve, outlet valve, and maintenance valve are all fully closed. Whether operated locally or remotely, the inlet valve and maintenance valve must be opened to fill the pump body with water, and the outlet valve must be closed to start (in order to reduce the starting power). If the inlet valve and maintenance valve cannot be opened during the starting operation, the pump body may not be filled or the outlet valve may not be opened in a timely manner after the unit is started, resulting in no water flow from the pump.
(2) Gas accumulation in pipelines and pump casings. When the accumulated gas in the pipeline and pump body is not discharged, the water pump unit is started. Due to the inability to reach a vacuum state in the pump body, there is no water flow discharged from the pump.
(3) Air leaks into the suction pipe. The suction pipeline of the water pump unit or the vacuum pump pipeline connected to it is not tightly sealed, resulting in air entering the pipeline and unable to completely fill the liquid, and the water pump has no water flow to discharge.
(4) The inlet or blades of the water pump are blocked by foreign objects. When there are large foreign objects such as tree roots, firewood, film, drowning animals, or concrete blocks falling off from the bottom of the water intake tank in the pump station's water intake channel or water intake tank, they may block the inlet valve and pump impeller inlet and blades, causing the pump to have no water flow discharge or interrupted operation.
(5) The suction stroke of the water pump is too large. During operation, the liquid level in the inlet pool of the water pump fluctuates. When the length of the pipeline, the number of bends, and the number of fittings are determined (i.e., the local resistance loss remains unchanged), if the water level in the inlet pool is too low, it will cause an increase in the suction stroke of the water pump, resulting in no water discharge after startup or flow interruption during operation.
(6) The impeller rotates in reverse. In the maintenance of water pumps, installing the impeller in reverse or reversing the phase sequence of the motor will result in no water flow discharge after the unit is started.
