range pumps are so called because of the variable displacement hydraulic
The hydraulic motor is controlled to optimise the performance for
the required output condition of the centrifugal pump. These pumps
can make best use of the available hydraulic input power over a
wide range of flow conditions.
The pump can provide a higher pressure at low flow and a higher
flow at low pressure than could be achieved with a simple fixed
displacement hydraulic motor.
The pumps are suitable for operations where flow conditions can
change substantially throughout an operation.