Oxidation is the leading cause of lubricant degradation when operating under normal conditions. It is the reaction of the lubricant base oil and oxygen in foam or air in the system, and the reduced performance of the lubricant caused by oxidation can also lead to increased component wear through corrosion or increased sludge formation. It is important to monitor the oxidation rate of your lubricants to ensure oil changes are scheduled before the oil degrades to a level where problems start to occur.
The base oils in synthetic lubricants are more robust than their mineral counterparts, and many lubricants contain an anti-oxidant additive package to help reduce oxidation. However, all lubricants will eventually suffer from oxidation if there is exposure to air, water or other catalysts. You also have to remember that the lubricant is not the only consideration when it comes to monitoring oxidation rates. You should look at your equipment, the environment in which it operates, and any factors which may impact on the normal running of the equipment.
Oil analysis is the simplest way to monitor the oxidation of your lubricant, and we always recommend that you have a condition monitoring program within your proactive maintenance plan. By conducting regular oil analysis and trending the results over time, you can build up a very accurate picture of oil degradation, and identify any potential problems before they cause issues with your equipment. It is also important to conduct visual inspections where possible. Some oxidation can cause a change in the smell of the lubricant, so if you have taken a small sample, it can be beneficial to see if the odour has changed. Once you have trended the results, you can use this information to schedule your oil changes, ensuring peak performance of your lubricant.
Remember that environmental and operational changes can impact on the oxidation, degradation and performance of your lubricants, so if unexpected changes occur, you may have to adjust your maintenance routine or conduct additional oil analysis.