Question: ( 3 0 points ) A Peerless Type 4 AE 1 1 centrifugal pump ( Fig . 1 below ) is tested at 1 7

(30 points) A Peerless Type 4AE11 centrifugal pump (Fig.1 below) is tested at 1750 rpm using a flow system with the layout shown in Fig. 2. The water level in the inlet reservoir is 3.5 ft above the pump centerline; the inlet line consists of 6 ft of 5 in . diameter straight cast-iron pipe (=0.00085ft), a standard elbow, and a fully open gate valve. Kinematic viscosity of water at 80F is v=0.92710-5ft2s. Kinematic viscosity of water at 180F is v=0.38010-5ft2s. The total minor losses coefficient is K=2.5. The vapor pressure for water at 80F is pv=0.507. The vapor pressure for water at 180F is pv=7.51. Calculate:
a. The net positive suction head available (NPSHa) at the pump inlet at a volume flow rate of 1000 gpm of water at 80F.
b. Compare with the net positive suction head required (NPSHr) by the pump at this flow rate (Fig.1). SHOW YOUR WORK ON THE PLOT. SHOW YOUR WORK ON THE PLOT. Will cavitation occur at 80F and 1000 gpm?
c. Plot NPSHa and NPSHr for water at 80F and 180F versus volume flow rate (this is the suction head vs flowrate plot outlining the NPSHa and NPSHr curves). Will cavitation occur at 180F and 1000 gpm? TIP: Take NPSHr curve (longer one) from the Fig. 1. The NPSHr is the same in the two plots with different NPSHa. Think about how to construct curves based on the energy equation and suction head at flowrates ranging from 0 to 1500 gpm.
( 3 0 points ) A Peerless Type 4 AE 1 1

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