Facts
Friction due to mechanical contact of moving parts such as check valves, bellows, or diaphragms leads to wear. Wear can result in particle shedding, which causes wafer defectivity.

Test Conditions
Ten pumps from four different manufacturers were evaluated for particle shedding in ultrapure water during operation at multiple test conditions. The test conditions were chosen such that all pumps in the group could be compared under typical operating conditions.

Results
The Levitronix^® pumps consistently shed the fewest particles of all evaluated pumps, regardless of pump operating conditions. In all tests, the particle concentrations measured downstream of the Levitronix^® pumps were very close to the concentrations measured without a test pump in the system.

Particle size distribution measured downstream of large pump systems at 5gpm and 40 psig