A pump draws a solution of specific gravity 1.2 with the viscosity of water from a ground-level storage tank at 50 psia through 3.5-in, schedule-40, commercial-steel pipe at a rate of 12 lb/s. The pump produces 4.5 hp with an efficiency of 75%.

The pump discharges through a 2.5-in, schedule-40 commercial steel pipe to an overhead tank at 100 psia, which is 50 ft above the level of solution in the feed tank. The suction line has an equivalent length of 20 ft, including the tank exit. The discharge line contains a half-open globe valve, two wide-open gate valves, and two 90° elbows. What is the maximum total length of discharge piping allowed for this pump to work?