Analysis of oil in use – Part 4


Lubes em Foco Magazine – issue 91

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In previous articles, the importance of lubricant monitoring as a predictive and preventive maintenance tool (Lubes em Foco nº88), good practices in sample collection (Lubes em Foco nº89), and selection of analyses for monitoring (kinematic viscosity, AI, and IB – Lubes em Foco nº90 . In this article, the tests water content and element content will be discussed.

Water content

Water is an unwanted contaminant for the good performance of lubricants, especially mineral-based ones. It can affect the ability to form the appropriate protective film on the metal surface, in addition to accelerating the processes of oxidation and corrosion and being a vehicle for the entry of other contaminants such as dust, dissolved chemicals and microorganisms.

There are several ways to identify the presence of water in lubricants:

  • Visual
  • Water by distillation
  • Water by Karl Fischer

When the presence of water in a sample is visually perceived through turbidity or even free water in the collection bottle, it is recommended to immediately confirm that it is contamination of the lubricant filler and not the sample collection process. If the contamination of the cargo is confirmed, this problem must be corrected as soon as possible by removing the water from the load or by changing the load. It is important to identify the source of the contamination so that it does not occur again.