5.9.2. A pump delivers water at 20°C between a reservoir and a water tank 20 m higher. The suction side contains an entrance strainer (Ks = 2.5), three 90° bends (R/D = 2), and 10 m of ductile-iron pipe, 25 cm in diameter. The discharge side includes a 160-m- long, ductile-iron pipe, 20 cm in diameter, and a gate valve. The friction factor for the pipeline is 0.02, the net positive suction head is 7.5 m, and the design discharge is 170 L/s. Determine the allowable elevation difference between the pump and the reservoir water surface to avoid cavitation. Search 4

Fig: 1