As conventional centrifugal pumps are equipped with mechanical shaft seals liable to wear out, it is very difficult to run them safely incurring in particular a lot of technical efforts and high expenses when delivering highly aggressive fluids or fluids tending to crystallize. Apart from that, the maintenance work required at regular intervals considerably reduces their availability for operation [1].

Magnetically coupled pumps without shaft seal, however, have the advantage to be hermetically sealed and maintenance-free [1].

The driving magnet rotating on the outside transmits the motor power contact-free to the inner magnet and the impeller (see figure below). So there is no need of a continuous shaft nor a wearing-out seal between shaft and motor. Instead, a rear casing hermetically seals the pump chamber from the driving motor. As a result, any leakage is impossible and the pumps do not require any maintenance [1].

This repository contains characteristic curves, extracted for some magnetically coupled pumps produced by Sondermann.

References

[1] https://www.sondermann-pumpen.de/files/media/PDF/Kataloge/englisch/Magson_catalogue_EN_2020_03.pdf