The iSave 21 Plus and iSave 40 consists of an isobaric pressure exchanger, a high-pressure positive displacement booster pump and an electric motor.

The isobaric pressure exchangers are based on the technology used in the Danfoss APP pumps, and the high-pressure booster pumps are based on the vane pump principle enabling a very light and compact design. The design of iSave 21 Plus and iSave 40 ensures lubrication of the moving parts by the fluid itself. All parts included in the iSave 21 Plus and iSave 40 are designed to provide long service life with a constant high efficiency and minimum service required.

The vane pumps are fixed displacement pumps in which the flow is proportional to the number of revolutions of the driving shaft – enabling flow control. The electric motor provides speed control of both the pressure exchanger and the highpressure booster pump on the same shaft – preventing overspin/overflushing. The iSaves need a VFD that allows the motor to apply a constant torque from low speed to maximum speed.