JUNE-JULY 2018 Digital copy | Page 10

ARTICLE E. Internally Generated contaminations during operation are due to following types of wears:  Abrasive Wear – Hard particles bridging two moving surfaces, scraping one or bothsurfaces.  Aeration Wear – Air bubbles in the fluid implode breaking away surface material.  Adhesive Wear – Loss of oil film allows metal to metal contact between moving surfaces.  Cavitation Wear – Restricted inlet flow to pump causes fluid voids that implode causing shocks that breakaway critical surface material.  Corrosive Wear – Water contamination in the oil causes rust that degrades the surfaces.  Erosive Wear – Fine particles in a high- speed stream of fluid eat away metering edgesand the critical surfaces.  Fatigue Wear – Particles bridging a clearance cause a surface stress riser or micro-crack that expands into a spall due to repeated stressing of the damaged area. Proper Treatment of Contaminated Oils and Lubricants The Oils and Lubricants that may have been contaminated due to ignorance or unforeseen conditions and may have lost some of their properties and may have become unfit for use, should be properly identified and recorded for the suitable action, including proper testing, cleaning and purification. The oils and lubricants might have lost the additives and their properties due to Oxidation, as the contaminations act as catalyst for the oxidation which damages the important properties of the specific Oils and lubricants. It has also to be ensured that any oil should never be mixed with the different grade and brand of oil or the degrad