Pump Head Calculator
Work out the total head your sewage pump needs, from the static height, pipe length, pipe size and fittings, with a system curve for your pipeline.
Recommended pump head (incl. 10% margin)
10.7 m
Calculated total dynamic head: 9.72 m at 40 m³/h
- Static height
- 8 m
- Pipe friction loss
- 1.03 m
- Fittings and exit loss
- 0.69 m
- Velocity in pipe
- 1.41 m/s
The pump runs where its own curve crosses this line. Choose a pump whose curve passes through or just above the orange point.
Find pumps for 40 m³/h at 10.7 m with the pump selector.
Find a pumpHow the pump head is calculated
The total dynamic head (TDH) the pump has to deliver is the sum of four parts:
- Static height: the vertical distance from the lowest liquid level to the highest point of the discharge pipe.
- Pipe friction loss: from the Darcy–Weisbach equation
hf = f · (L/D) · v² / 2g, with the friction factor f from the Swamee–Jain equation for your pipe material. - Fitting losses:
hm = ΣK · v² / 2g, using standard K values for elbows, valves and tees, plus 1.0 for the exit loss at a free outlet. - Outlet pressure: any pressure required at the end of the pipe, converted to metres (1 bar ≈ 10.2 m of water).
The calculation assumes water at about 20 °C, which is also a good approximation for dilute sewage. For thick sludge or viscous liquids, ask our engineers for a detailed calculation.
The system curve
The chart shows the head your pipeline needs at every flow. Static height and outlet pressure stay constant, while friction and fitting losses grow with the square of the flow. The pump will run at the point where its own curve crosses this line.
Once you have the head, the pump selector shows which Haquan pumps suit your duty point.
Frequently Asked Questions
Total dynamic head is the total height a pump must lift the liquid at the design flow. It is the static height from the lowest liquid level to the discharge point, plus friction loss in the pipe, plus losses in fittings and valves, plus any pressure required at the outlet.