In technical process plants centrifugal pumps are considered as being the most used machines.

The operational safety and reliable functioning of these pumps play an important role. Looking at the troubles and, in particular, at the costs which may occur in connection with the maintenance of mechanic seals, hermetically sealed pumps have become the preferred choice for system planning engineers and operators. The praxis shows that seal-less pumps generally have less repairs than in comparison with conventional chemical pumps with mechanical seal and consequently, they feature a longer service life.

This experience from the chemical industry corresponds to the experience made in the field of the heating system technology, where canned motor pumps have been used for decades with great success and where a service life of 10 and more years is not unusual.

The medium to be conveyed such as ethylene oxide, phosgene, chlorine, vinyl chloride, just to state only a few, bears a high or a very high potential risk and constitutes a danger for humans and for the environment. An absolute tightness of the pumps must be guaranteed.

Moreover, it is to ensure that fluids which have a very low viscosity and, at the same time, a high vapor pressure, are being conveyed without any troubles and in a safe way.