What Is The Characteristic Curve Of A Pump

Mar 11, 2025

The curve or characteristic curve that represents the relationship between the main performance parameters is usually referred to as the performance curve or characteristic curve of a centrifugal pump. In fact, the performance curve of a centrifugal pump is the external manifestation of the movement law of liquid inside the pump, which is obtained through actual measurement.
The characteristic curve includes:
Flow Head Curve (Q-H) Flow Power Curve (Q-N)
Flow efficiency curve (Q - η) and flow cavitation margin curve (Q - (NPSH) r).
The function of the performance curve is to find a set of head, power, efficiency, and cavitation margin values relative to any flow point of the pump on the curve. This set of parameters is called the working state, abbreviated as the operating condition or operating point. The centrifugal pump takes the high-efficiency point as the optimal operating condition point, which is generally the design operating condition point. The rated parameters of the centrifugal pump, that is, the design operating condition point and the optimal operating condition point, coincide or are very close to each other.
In practice, it is important to choose a high-efficiency range for operation, which not only saves energy but also ensures the normal operation of the pump. Therefore, understanding the performance parameters of the pump is crucial.