The flow system used to test a centrifugal pump at a nominal speed of 1750 rpm is shown. The liquid is water at 80 F, and the suction and discharge pipe diameters are 6 in. Data measured during the test are given in the table. The electric motor is supplied at 460 V, 3-phase, and has a power factor of 0.875 and a constant efficiency of 90 percent.

Calculate the net head delivered and the pump efficiency at a volume flow rate of 1000 gpm. Plot the pump head, power input, and efficiency as functions of volume flow rate.

Transcribed Image Text:

Rate of Flow (gpm) Suction Pressure (psig) Discharge Pressure (psig) Motor Current (amp) 0 0.65 53.3 18.0 500 0.25 48.3 26.2 800 -0.35 42.3 31.0 1000 -0.92 36.9 33.9 1100 -1.24 33.0 35.2 1200 -1.62 27.8 36.3 1400 -2.42 15.3 38.0 = 1 ft 1500 -2.89 7.3 39.0 Pd z=3 ft