A 60 cm diameter, impeller centrifugal pump has the following characteristic at 750 rev min−1:

(a) If the system resistance is purely frictional and is 40 m at 42 m3 min−1 determine the pump operating point and power absorbed.

(b) The pump is used to pump water from one reservoir to another, the difference between levels being 13 m. The pipeline is 45 cm in diameter, 130 m long, f = 0.005 and it contains two gate valves (K = 0.2) and ten 90° bends (K = 0.35). Obtain the volume delivered by the pump and power absorbed.

(c) If, for the system at (b) a geometrically similar pump but of 50 cm diameter is used running at 900 rev min−1, determine the volume delivered and power consumed.