Mechanical pumps are the second most common machine in the world (after the electric motor), so here are some of the most commonly used pumping terms and symbols.
|
TERMS |
SYMBOL |
UNIT |
| Flowrate |
Q |
L/s |
| Head |
H |
m |
| Pressure |
P |
kPa |
| NPSH Available |
NPSHA |
m |
| NPSH Required |
NPSHR |
m |
| Velocity |
V |
m/s |
| Density |
ρ |
kg/m³ |
| Gravitational Acceleration |
g |
m/s² |
| Efficiency |
η |
– |
| Rotational Speed |
N |
r/min |
| Area |
A |
m² |
| Absolute Viscosity |
μ |
mPa.s |
| Kinematic Viscosity |
v |
mm²/s |
| Specific Gravity |
S.G. |
– |
| Total Dynamic Head |
HZ |
m |
| Friction Head |
Hf |
m |
| Static Suction Head |
Hs |
m |
| Static Discharge Head |
Hd |
m |
| Atmosphere Pressure Head |
Ha |
m |
| Velocity Head |
Hv |
m |
| Total Static Head |
Hst |
m |
| Vapour Pressure Head |
Hvap |
m |
| Reynolds Number |
R |
– |
| Friction Factor |
f |
– |
| Length of Pipe |
L |
m |
| Internal Pipe Diameter |
d |
mm |
| Absolute Roughness |
e |
mm |
| Resistance Coefficient |
K |
– |
| Total Suction Head |
Hss |
m |
| Total Discharge Head |
Hds |
m |
Article courtesy of Brown Brothers Engineers Australia Pty Ltd
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