= The 32-in diameter pump has a performance curve as below. The pump is used at 1170 rpm in a system whose head curve is hp 110+ 1.5Q2 (in ft), with Q in units of thousands of gallons of water per minute. Please estimate the brake horsepower (BHP) required for two pumps in parallel installed in the system. n=1170 r/min 800 Total head, ft NPSH 700 36-in dia. " 600 32-in dia. 500 400 28-in dia. 300 1500 bhp 87% 88% %LS: 3500 bhp 3000 bhp 2500 bhp 2000 bhp 200 0 12 16 20 24 28 3500 HP 2300 HP 2000 HP 2800 HP U.S. gallons per minute x 1000 40 30 20 NPSH, ft