The exploration of centrifugal pump function is important for knowing its features viz. efficiency, discharge, specific discharge, relationship of efficiency vs. discharge and head vs. discharge. These relationships characterize the performance of pump and play an important role in selection of pump to lift water for different purposes. To address this purpose testing of two pumps such as Milton pump (4″, 1500 RPM) and KSB pump (4″, 2200 RPM) assess performance at different operating conditions at constant suction and delivery lift. The maximum efficiency and maximum specific discharge of the pumps represents the same operating condition, but specific discharge offers accurate scope of measuring discharge with respect to energy consumption in reckoned form. The difference of percent maximum efficiency of tested pumps was 0.54%, which is equivalent to the difference of highest specific discharge of 0.35 m3/ kWh. Operation of the pump at maximum specific discharge saves specific discharge up to 22.30% for KSB pump and 29.04% for Milton pump, which is economic, and energy saving for minor irrigation scheme.