If the operating point lies too far to the left or the right on the pump curve (see system curve B in the figure), the pump is operating outside of its range of application.

The pump has a Q-H pump curve (4) having a head H0 (28) at zero flow and a head Href (30) corresponding to the highest hydraulic power and that Href (30) is greater than H0 (28).

Plot of the characteristic curve of a centrifugal pump

The pump will operate at the intersection of the system curve and the performance curve.

The operating point of the system will occur at the intersection of the system and pump performance curves.

The power absorbed by the pump can be located on the graph as point where the power curve intersects the pump curve at the operating point.

The PULSAR 1300 pump curve goes though this point.

Treatment: Correct the curved pump shaft or adjust the relative position of the pump to the motor.

The curve for power requirement as a function of the intake pressure has the same general form as the curve for a vacuum pump.

The curve for power requirement as a function of the inlet pressure has the same general form as the curve for a vacuum pump.

The characteristic curve of a pump is the interaction of two variables that describe its performance:

If the operating point lies too far to the left or the right on the pump curve (see system curve B in the figure), the pump is operating outside of its range of application.

The pump operates with two pressure stages, depending on the characteristic map.

In some pump types with integrated motor and perhaps also an integrated frequency converter, e.g., canned motor pumps, the power consumption curve and the η-curve cover both the motor and the pump.

The figure also indicates that that the operating point will always be where the windpump rotor curve for the windspeed prevailing at a given moment coincides with the pump load line.