Key Causes Of Oil Degradation

  • Particle Pal
  • Oil Sampling
  • Oil Cleanliness Levels

The Key Causes Of Oil Degradation

Oil degradation can be caused by many different reasons although, what is clear is that if you do not understand why your oil is degrading in the first place then this it is likely to lead to escalating costs.

Listed below are the most common reasons why oil degrades:

Oxidisation: this is the reaction of materials with oxygen. Often when oxidisation takes hold the viscosity of the fluid increases, particulate build up occurs, the additives in the fluid deplete, the oil breaks down and eventually components using the oil begin to rust and corrode.

Thermal Breakdown: the operating temperature of hydraulic oil is another determining factor in the degradation of oil. If the temperature is too high then the viscosity can decrease to such an extent that the oil decomposes. On the other end of the spectrum a rapid decrease in temperature can lead to an increase in viscosity.

Microdieselling: this term usually goes by another name: pressure-induced thermal degradation, this is where when an air bubble transitions from low-pressure to a high pressure zone, it results in a combustion compression. This can lead to an increase in temperature (above 1,000 °C), leading to accelerated oil degradation and a harmful build up in carbon particulate.

Electrostatic Spark Dispatch: when oil is continually flowing through tight clearances friction can occur within the oil itself leading to static electricity. This can result in sparks leading to a rise in temperature and carbon particulate forming. Certain types of filtration can cause static.

Particulate Contamination: Over 80% of hydraulic failure is due to solid or water contamination. The rate at which your oil will degrade is dependent on the volume and type of contamination. Certain metals, silicia, water and bacterial ingress can all lead to your oil degrading.

Having an understanding of the factors that can lead to oil degradation means you can take the steps to remedy the situation before it leads to catastrophic failure of equipment.

Filtertechnik provide solutions for identifying oil degradation issues from patch test kits to laser particle counters and portable field kits to give live ISO cleanliness and water content readings.

For further information on oil degradation and how Filtertechnik can help you resolve any oil related contamination or degradation issues please visit:

More information on the causes of oil degradation can also be found here: