Problem 3. A pump with an 8-in diameter impeller from a group of centrifugal pumps with
the characteristics shown below is used to pump water that is at 120 °F. The pump inlet is
11.0 ft above the open water surface, and typical head loss along this section of pipe is 5.00
ft of water. Calculate this system's maximum flow rate in gal/min so that cavitation will not
occur in the pump. 1 atm = 14.7 psia.
11 ft 21
P1= Patm
(1)
(2)
8 in. dia
500
Reference 400 7
plane
300
6
200
100
0
0
40
1
50%
55
60
ε
63
65
65
63
60
55
NPSHR
15
--
40 bhp
50
30
25
20 15
80 120 160 200 240 280 320
Capacity, gal/min
10
5
NPSHR, ft