Why Does The Head Of The Fountain Submersible Pump Decrease?

Reasons for the reduction of the head of the fountain pump.

We can see many beautiful fountains in our life. The lift of the fountain pump will decrease during operation. 

So what are the reasons for the decrease of the lift of the fountain pump? 

Reasons for the reduction of the head of the fountain pump:

• Blockage of the impeller channel

• Internal leakage

• Cavitation at the inlet

• Speed reduction

• Motor reverse rotation

• The operating point shifts toward high flow and low lift

(1) Blockage of the impeller channel: It affects the work of the impeller of the fountain pump and causes the outlet pressure to drop.

(2) Internal leakage: When the gap between the rotating part and the stationary part in the fountain pump pump exceeds the design range, it will cause internal leakage, which is mainly reflected in the drop of the discharge pressure of the pump.

(3) Cavitation at the inlet: If the suction pressure of the pump is too low, cavitation will form when it is lower than the saturated vapor pressure of the pumped medium.

(4) Speed reduction: The important factors affecting the pump head are the outer diameter of the impeller and the speed of the pump.

(5) The operating point shifts toward high flow and low lift: In general, centrifugal pumps have a continuous downward performance curve, and the flow gradually increases with the decrease of the lift.

(6) Motor reverse rotation: due to wiring reasons, the rotation of the motor is opposite to the actual rotation required by the pump.

What happens to a pump with a high head when it works at a low head？

Under normal circumstances, high-lift water pumps will have over-current phenomena when they work at low lifts, and severe thermal overload protection will occur, and even the motor will be burned out. In actual work,

the outlet valve should be properly closed, and its operating condition can be adjusted to operate near the rated head, and the outlet valve can also be adjusted according to the current change.

For example ,Your water pump head is only 8 meters, and the static head is 3 meters. The actual deviation is very small.  According to experience,  generally there will be no negative effects. In order to ensure that there is no problem in operation, you can measure the current during operation. If not superfluid, rest assured to use.