Well diameter (D): Well equipped pipe diameter (mm)
Static Level: Prior to taking water from wells, distance between the water and well mouth
Dynamic Level (Ds): It is the level of water decrease and remains constant, when well efficiency is equal to pumping water.
Well flow rate (Q): It is the amount of water that can be received from the well.
L: is the depth of well.
H1: It is the geometric altitude from the well mouth up to the warehouse.
Friction Loss (hs): It is the loss of pipe friction, valve, bend, check valve from the pump to the flow of water (Refer to Table of Losses).
V: is the speed of the fluid.           

Correct Motopomp Selection Criteria 

1 - Pump diameter must be smaller than well diameter.                       

D Pump < D Well

2 - The pump flow rate must be smaller than the well flow rate           

 Q Pump < Q Well

3 - Pump compression height must be greater than the total system manometric height.                       

Hm Pump > [Ds + h1 + Hs + (V² / 2g)]