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Design of Flow Systems 465

Table 8.4.2 Summary of Flow-System Design

Item Specification Specification

Pipe Size
Discharge Sin 7.62 cm
Suction 4 in 10.2 cm
Pipe Connections Flanged
Pipe Material Carbon Steel
Pipe Construction Welded
Schedule No. 40
Flow Rate 100 gpm 0.379 nrVmin
Total Head 173ft 52.7m
Valve Size (C v) 33
Motor Power 10 hp 7.46 kW
(NPSH) R 22ft 6.71m
39.9ft 12.2m
(NPSH) A
Impeller Diameter 6 'A in 15.2cm

Pump Power

The mass flow rate, m, in Equation 8.35 equals p Q.

62.3 Ibw 100 gal 1 ft 3
m = - - = 832.8 IbM/min (378 kg/min)
1 ft 3 1 min 7.48 gal

Use Equation 8.35 to calculate the shaft or brake horsepower. The pump ef-
ficiency, taken from Figure 8.4, is 62%.
832.8 lb M 1 min 32.2 ft 173 ft

1 min 60 s
- = 7.042 hp (5.25 kW)
550 ft-lb F 32.2 ft-lb M 0.62
2
1 s-hp 1 s -lb F 1
which is the pump or brake horsepower. The pump horsepower is also plotted in
Figure 8.4.2.

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