Technical Study: Chain Reaction of Abrasive Wear
| Particles generated as a result of abrasive wear are work hardened; thus they become harder than the parent surface and, if not removed by proper filtration, will recirculate to cause additional wear. This "chain reaction of abrasive wear" will continue and result in premature system component failure unless adequate filtration is applied to break the chain.
Pall participated in a study to quantify the impact of using finer filtration, and the results of this study are displayed in the chart shown. In the study a typical hydraulic system equipped with nominal 25µm rated filtration was operated for 180 hours. Analysis of the hydraulic fluid found 20,000 particles per milliliter greater than 5µm. Further, 25% of these particles were metallic, having been worn from system components by the chain reaction of abrasive wear.
The next phase of the technical study replaced the 25µm rated filtration with 3µm rated clearance protection filtration. Analysis showed a drop in particulate contamination in the 75m size range from 20,000 particles/ml to only 200 particles/ml, with a corresponding drop in metallic composition from 25% to only 3%. Contamination levels continued to decline, and after 320 hours of operation the fluid contained only 30 particles/ml >5µm with approximately 0% metallic content. Finer filtration had significantly reduced abrasive wear. In the final phase of the test 25µm rated filtration was reintroduced in place of 5µm rated filtration. The particulate contamination increased to levels near those originally found after only 100 hours of operation.
This technical study concluded that coarser filters allow abrasive wear to take place, leading to a chain reaction effect that causes ever increasing amounts of wear and particulate contamination. Finer filtration can break the chain reaction of wear and maintain improved fluid cleanliness levels.