The net positive suction head required (NPSHR) by a pump may be expressed approximately as a parabolic function of volume flow rate. The NPSHR for a particular pump operating at 1800 rpm is given as Hr = H0 = AQ2, where H0 = 10 ft of water and A = 7.9 ft / cfs2. Assume the pipe system supplying the pump suction consists of a reservoir, whose surface is 22 ft above the pump centerline, a square entrance, 20 ft of 6-in. (nominal) cast-iron pipe, and a 90( elbow. Calculate the maximum volume flow rate at 70(F for which the suction head is sufficient to operate this pump without cavitation.