In transporting water, the inner pipe diameter is assumed to be constant, and thus the velocity of water is also constant. The energy loss derived from the friction between the water and the pipeline is calculated by the lost hydraulic head, h (m), estimated from the Darcy-Weisbach equation below. Since frictional and sudden expansion losses at the inlet and outlet are inevitable, the inlet loss coefficient, ζi, and exit loss coefficients, ζe, are considered 0.5 and 1, respectively.