Facts
Peristaltic- and 4-piston diaphragm pumps are based on mechanical contact between moving parts such as tube compression or valve interaction. Mechanical contact between moving parts can generate shear stress, which leads to reduced product yield.
Levitronix^® pumps have no mechanical contact between moving parts.

Test conditions
A Levitronix^® PuraLev^® 200 and 600 MU pump, a peristaltic, and a 4-piston diaphragm pump were evaluated for shear stress created in an oil-water emulsion. A fixed volume was recirculated by each pump at 3.4 and 10 l/min, and at different backpressures. The Sauter diameter, which depends on the shear stress exerted by the pumps was measured.

Results
The PuraLev^® MU and SU pumps are characterized by up to 59 % larger Sauter mean diameters than the two other pump types for comparable operational conditions. This indicates that hydrodynamic stress is lower in the PuraLev^® MU and SU pumps.

Measured sauter mean diameter d32 of the multi-use and single-use centrifugal pumps and the comparison peristaltic and 4-piston diaphragm pumps