APPLIED FLUID MECHANICS System Curve US: CLASS I SERIES SYSTEMS
Objective: System Curve Reference points for the energy equation:
Ex. Problem 13.1 Pt. 1: Surface of lower reservoir
Fig. 13.33 Pt. 2: Surface of upper reservoir
System Data: U.S. Customary Units
Volume flow rate: Q = 0.5011
ft 3/s Elevation at point 1 = 0 ft
Pressure at point 1 = 0 psig Elevation at point 2 = 80 ft
Pressure at point 2 = 35 psig
If Ref. pt. is in pipe: Set v 1 “= B20” OR Set v2 “= E20“
Velocity at point 1 = 0.00 ft/s –> Vel head at point 1 = 0.00 ft
Velocity at point 2 = 0.00 ft/s –> Vel head at point 2 = 0.00 ft
Fluid Properties: May need to compute: n = h/r
lb/ft 3Kinematic viscosity = 1.21E-05 ft 2/s
Pipe 1: 3 1/2-in Schedule 40 steel pipe Pipe 2: 2 1/2-in Schedule 40 steel pipe
Diameter: D = 0.2957 ft Diameter: D = 0.2058 ft
Wall roughness: e = 1.50E-04 ft Wall roughness: e = 1.50E-04 ft [See Table 8.2]
Energy losses-Pipe 1: KQty. Total K
Pipe: K1 = 0.519 1 0.519 Energy loss hL1 = 0.43 ft
Entrance: K2 = 0.500 1 0.500 Energy loss hL2 = 0.41 ft
Gate Valve: K3 = 0.136 1 0.136 Energy loss hL3 = 0.11 ft
Energy losses-Pipe 2: KQty. Total K
Pipe: K1 = 34.488 1 34.488 Energy loss hL1 = 121.53 ft
Check Valve: K2 = 1.800 1 1.800 Energy loss hL2 = 6.34 ft
Butterfly Valve: K 3 = 0.810 1 0.810 Energy loss hL3 = 2.85 ft
Standard Elbow: K4 = 0.540 2 1.080 Energy loss hL4 = 3.81 ft
Figure 13.34 Total head on the pump at the desired operating point for Example Problem 13.1
SYSTEM CURVE PUMP CURVE: 2X3-10 PUMP WITH 9-IN IMPELLER
Q (gpm) Q (cfs) ha (ft) Q (gpm) Total head (ft)
0 0 160.8 0 370
25 0.056 162.9 25 369
75 0.167 177.6 75 366
125 0.278 205.4 125 360
175 0.390 246.1 175 349