Each centrifugal pump has its own characteristic curve, which is the graphical representation of the pump's performance.
- On the x-axis (horizontal axis) is the flow rate Q, usually in m3/h. It indicates the amount of fluid that passes through each section of the centrifugal pump over a defined period. This amount depends on the pump's dimensional characteristics, the motor's speed (i.e., the rotation speed of the impeller), and the fluid's characteristics (density and viscosity depending on temperature). The flow rate influences all the performances of the centrifugal pump and is the first technical parameter to consider.
- On the y-axis (vertical axis) is the head H, usually in meters. It is calculated from the pressure difference between the outlet and the inlet of the centrifugal pump and represents how far the fluid can be pushed if it encounters resistance along its path, such as height, curves, or valves.