Page 298 -
P. 298
The Practical Pumping Handbook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.2.9 The effect of changes in pipe diameter on the flow rate in
a system
2.5
Q2
Q1
where D = Pipe Diameter
Q = Flow Rate
16.2.10 Total head in a system
Total Head (H) = Hs + Hsd + Hv + Hf
where Hs = Static Head
Hsd = System Differential Head
Hv - Increase in Velocity Head across pump
Hf = Friction Losses
16.2.11 Net positive suction head available from a system
NPSHA = Hs + Ha- Hvp - Hf
where Hs = Static Head over impeller
Ha - Surface Pressure in source
Hvp = Vapor Pressure of liquid
Hf = Friction Losses
16.2.12 Impeller specific speed
N~Q
NS -
HO.75
where Ns = Specific Speed
N Pump Rotational Speed
e Flow Rate at BEP
(50% of BEP with double suction impeller)
H = Total Head at BEP
m 270
