Answer Happy

Water is pumped, at a rate of 50 L/s, from a large-diameter supply main into a reservoir at a higher elevation as shown in Figure P28. The elevation difference between the centerline of the supply main and the free surface of the reservoir is 10 m (see figure). The galvanized iron pipe used in the application has a diameter of 15 cm. The pipeline connecting the supply main to the inlet (suction side) of the pump has an unknown length and contains a sharp-edged entrance. The pipeline connecting the exit of the pump to the upper reservoir is 60 m long and contains one long radius 90° threaded elbow, 1 threaded union and one 3/4 open gate valve. The pressure inside the large supply main is maintained at 125 kPa. Determine the maximum length of the pipe connection the large-diameter supply main for which no cavitation occurs at the inlet of the pump and the corresponding power required to operate the pump. 10 m Large-D supply main NDU - pump