The performance characteristics of a certain centrifugal pump are determined from an experimental setup similar to that shown in Fig. 12.10. When the flowrate of a liquid \((S G=0.9)\) through the pump is \(120 \mathrm{gpm}\), the pressure gage at (1) indicates a vacuum of \(95 \mathrm{~mm}\) of mercury and the pressure gage at (2) indicates a pressure of \(80 \mathrm{kPa}\). The diameter of the pipe at the inlet is \(110 \mathrm{~mm}\) and at the exit it is \(55 \mathrm{~mm}\). If \(z_{2}-z_{1}=0.5 \mathrm{~m}\), what is the actual head rise across the pump? Explain how you would estimate the pump motor power requirement.

Figure 12.10

Transcribed Image Text:

(1). Valve for varying system resistance Flowrate meter (2) I 22-1 Behind pump (out of sight): Drive shaft and motor with speed and power measurement