Centrifugal pump Calculations
Formulas & Calculations
How to Calculate...
- Head Calculation
- Hydraulic power calculation
- Pump Shaft Power
- Electrical Power
- Specific Speed
- Centrifugal Pump Calculations Energy loss in discharge valve throttling
- NPSHa - Net Positive Suction Head Available
- Head ↔ Pressure
- Volumetric flow ↔ Mass flow
- Break Power Calculation
Formulas
Head
Head is net work done for unit weight of water.
H = Head ; Unit - Meter
P = Water Pressure ; Unit - kPa, psi
Γ = Specific weight of Fluid ; Unit - kN/m³
V = Water Velocity ; Unit - m/s
g = Gravitional force ; Unit = m/s² Value = 9.8m/s²
Z = Elevation to be lift
Horizontal pump - Datum is a horizontal plane from center line of shaft
Vertical pump - Datum is horizontal plane of impeller eye.
See calculations
Pump Capacity ( Volume flow rate of pump)
Capacity is the amount of water pumped per unit time.
Capacity Q = A V
A = Area of pipe
V = Volume flow rate
See calculations
Hydraulic power calculation
⍴ = densityGravitional force of fluid ; Unit = kg/m³
g = Gravitional force ; Unit = m/s² Value = 9.8m/s²
H = Total Head = Hd - Hs; Unit = m
Hd = Discharge head
Hs = Suction head
Q = Discharge flow ; Unit = m³/hour
See calculations
Pump Shaft Power
ηpump = Pump efficiency
Maximum shaft power
Mmax = ɑ1 ⍴ g H Q / η0
See calculations
Electrical Power
ηmotor = Motor efficiency
See calculations