I have another centrifugal pump question if anyone is willing. If pump curves are plotted for a particular shaft rpm, then the velocity of the fluid exiting the impeller must stay approximately constant. (Just stop me when I make a mistake). I am confused as to why, as the flow rate increases on a pump curve the brake horsepower does as well, (much slower mind you). This suggests that the torque applied to the shaft is increasing with flow rate. It seems to me, if the speed of the impeller is constant, the torque should be as well. Perhaps someone could shed some light on the subject.