A pump delivers water at 20°C between a reservoir and a water tank 24 m higher. The suction side consists of a strainer (ks = 2.5), three 90° bends (R/D = 4), and 50 m of ductile-iron pipe, 35 cm in diameter. The discharge side includes a 155-m-long, ductile iron pipe, 20 cm in diameter, and a gate valve. Assume the friction factor throughout the pipeline is 0.018, the NPSH required is 5m, and the design discharge is 300 L/s. Determine the allowable elevation difference between the pump and the reservoir water surface to avoid cavitation. Assume the strainer coefficient includes the entrance loss coefficient.