Figure 15  Common 15 – Submerged Pump

In Pipe Flow Expert a pump is automatically positioned at the start of a pipe. The elevation of the node or tank at the start of the pipe effectively defines the elevation of the pump inlet.


A submerged pump can be modeled by defining a tank with its elevation set to the elevation of the pump inlet. The liquid level in the tank is set to the height of fluid above the pump inlet.

 

In this example, we assume that the pump inlet is at the same elevation as the impeller and the pump discharge line. The tank elevation is set at 1m relative to some 0m baseline. The liquid level in the tank is set at 2.03m (giving 2.03m height of fluid above the submerged pump inlet).


Since the pump is submerged we assume there will be minimal losses through any suction pipe. The pump is placed on a pipe that runs horizontally under water before rising vertically to the surface of the water (ground level). The pipe then continues horizontally to the point of discharge.


The pump is set to a fixed flow rate of 20m3/hour.

The calculated result shows the required pump head is 4.86m.