Crude oil (μ = 40 cP, SG = 0.87) is to be pumped from a storage tank to a refinery through a series of pump stations via 10-in, schedule-20, commercial-steel pipeline at a flowrate of 2000 gpm. The pipeline is 50 mi long and contains 35 90° elbows and 10 open gate valves. The pipeline exit is 150 ft higher than the entrance, and the exit pressure is 25 psig. What horsepower is required to drive the pumps if they are 70% efficient?