By: Thomas Yoon

Mechanical machines need lubrication. No machines can run for long without lubrication of its moving parts. At best, the moving parts may wear out faster. At worst, entire machines can seize up and develop cracks. In severe conditions, the heat built up can even cause explosions and loss of lives.

So lubrication is no small matter in machine operation.

Lubrication oil can last for a very long time in normal machine operation. By determining the properties of lubrication oil, many machine operators will be able to know whether the oil can still be used.

Some of the important properties to watch for when buying or replacing lubrication oil is as follows:

  • Viscosity
  • Viscosity Index
  • Pour Point
  • Oxidation Resistance
  • Flash Point, Fire Point
  • Alkalinity
  • Additives

Some of the additives that are put into the lubrication oil include the following:

  • Anti Oxidant – Amines, Phenols
  • Corrosion Inhibitor
  • Detergent and Dispersant – Ca, Ba, Compounds, Soaps
  • Alkalinity – Ca, Ba Hydroxides
  • Anti Bacterial – Biocides
  • Oiliness or Wetting Agents – fatty oils, chlorinated wax
  • Extreme Pressure Agents – organic compounds of Cl, S, P (for hydraulic, gear oil)
  • Pour Point Depressant – Organic polymers (alkyl naphthalene) (for steering gear, refrigerator)
  • Anti foam – Silicones
  • Viscosity Index Improvers – organic polymers
  • Emulsifying Agent – Polar Compounds (emulsifying but do not lose lubricating property)

With large machines that use large amounts of lubrication oil the engineer has to determine when to change the oil. This is because the change can be a very expensive affair.

The correct thing to do is to determine whether the oil can still be used without changing. The engineer must know exactly when to change the oil. He will take measurements of various parameters to help him decide.

That could be a subject for another coming facworld ezine article.

The contents of this page are part of a page from my e-book “General Engineering Knowledge Notes” that will help candidates prepare for the Marine Certificate of Competency Examinations. This e-book is available forĀ FREE downloading