The issue with pump head pressure
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The new pump is being tested with clean water. The pump’s nameplate indicates a capacity of 50 cubic meters per minute, a head of 50 meters, and a power rating of 18.5 KW, classified as grade 2. Yet the outlet pressure gauge shows only 3 kilograms of pressure, even though all valves are fully open. I seek help from everyone; thank you.
For a pump with such high flow rate and head, the outlet pressure is normally around 0.3 Mpa under normal conditions. What outlet pressure do you need?
It is usually unrelated to the pump. Check whether there is air in the inlet, poor water inflow, motor reversal, etc. If the current exceeds the limit, it may be because the pump head has been set too high.
Shouldn’t it be around 0.5?
Is the flow rate high? A higher flow rate results in lower pressure
If the pressure gauge is functioning properly, the pressure indicated by the outlet pressure gauge should be determined primarily by the system pressure. In other words, when the system pressure and system resistance are close to the pump’s head, the pressure should be around 5 kilograms
With the outlet valve fully open, it means your system requires a pressure of 3 kilograms. The flow rate is much higher than 50 cubic meters
Look at the pump’s curve graph: a higher flow rate corresponds to lower pressure, while a lower flow rate results in a higher head. When the valve is fully open, the pressure at the pump outlet equals the pressure in the piping system. To achieve a pressure of 5 kilograms, it is necessary to close the valve more or use a pump with a higher capacity.
It must be that the flow rate is greater than 50 cubic meters, which is why the head is much lower than 50 meters; as a result, the outlet pressure is low. The parameters listed on the nameplate represent those specified at the time of ordering, but to determine whether the actual operating parameters of the pump match these specifications, it is necessary to consult the process engineers regarding the operating conditions (inlet pressure/flow rate). Only after that can the condition of the pump be assessed
Keep testing the vehicle; by doing this more times, I’ll be able to buy a new motor.
The water pump should operate at a higher flow rate; it is recommended to reduce the valve opening or shrink the impeller