A pump delivers water to a pipe network of diameter 40 mm and length 25 m. The pipe section has six 90°-elbows and a gate valve at the exit. The system uses schedule-40 steel pipes with threaded...

A pump delivers water to a pipe network of diameter 40 mm and length 25 m. The pipe section has six 90°-elbows and a gate valve at the exit. The system uses schedule-40 steel pipes with threaded fittings. (i) Obtain the system curve when the valve is fully open. What is the ideal work input to the pump when the flow rate through the pipe network is 3.4 Lsí1 ? (ii) If the loss coefficient of the gate valve when it is partially closed is 1.2, obtain the new system curve with the valve partially closed.