Although a lubricant starts degrading the moment it is made, it starts significantly degrading when applied to your lubricating systems and machines. This degradation continues until the lubricant fails or is no longer effective in its intended purpose of protecting your machine. The concept of degradation occurrence factor or DOF helps you understand the factors that lead to lubricant failure. The DOF is also essential in determining the total health and longevity of a lubricant or its overall lubricant criticality (OLC).
What is Degradation Occurrence Factor?
The degradation occurrence factor (DOF) refers to the probability of lubricant failure. This probability is affected by lubricant quality or condition, operating temperatures, lubrication process, exposure to or presence of contamination, lubricant volume, oil replenishment or reapplication, etc.
The lower the DOF, the lower the chance of lubricant failure and the lower the OLC. High DOF values mean there is a high chance of premature lubricant failure.
To determine the DOF of your machines and equipment, you must identify and evaluate all the possible sources of lubricant degradation. These steps require you to have a deeper understanding of your lubricants, machines, operations, and maintenance processes.
Factors Affecting Degradation Occurrence Factor
The following are the essential factors of lubricant degradation and how they affect the DOF:
The quality of the lubricants and their suitability for your machines may be the most important factor when evaluating the probability of failure. Different lubricants have varying types and levels of additives that prevent degradation. Choosing the highest quality lubricants that best fit your lubricating system and machines is an excellent way to prevent degradation and have a low DOF.
Oil components undergo normal oxidation that leads to degradation over time. Exposure to high operating temperatures, however, accelerates the oxidation process causing faster degradation. In addition, high temperatures also cause thermal degradation, which is the cracking of lubricant components at temperatures above 200 ℃ (392 ℉). Machines that operate at high temperatures or have hot spots during operations result in higher DOF values.
High pressures can also cause a rise in temperatures, thus leading to oxidation and thermal degradation. Additionally, high pressures can cause microdieseling, also called compressive heating. This promotes the reaction of oil components to form contaminants that ultimately result in degradation. Microdieseling forms insoluble deposits in the lubrication systems such as tars, resins, and sludge. Machines that operate in high-pressure conditions have high DOF values.
The exposure to contamination and the presence of contaminants also significantly increase the probability of lubricant failure. Contaminants serve as catalysts that promote oxidation, mechanical surface abrasion, and cavitation. High DOF values are given to machines that operate in conditions of high contamination such as dirt or dust-heavy areas or processes that involve water exposure.
Ideal lubricant volumes are critical to preventing degradation. Too high lubricant levels can result in spillage and an increase in contamination, indirectly promoting degradation. Too low volumes, on the other hand, result in a low amount of additives that prevent degradation. Low volumes also mean inadequate protection against friction and heat, thus promoting faster degradation. The closer your lubricant volumes are to the recommendation for your machines, the lower the DOF values.
Related to lubricant volume, the effectiveness of the lubricant replenishing or application process affects the DOF. Constant and effective lubricant replenishment maintains the volume and the adequate amount of anti-degradation additives. Lubricant replenishment most often neglects the fact that the addition of lubricant can dilute the amount of additives that fight degradation. Lubricant replenishment can lower DOF values if there is a high volume of lubricant but a low amount of additives.
DOF in Maintenance and Lubrication Programs
Understanding the factors that affect the degradation of lubricants is essential in estimating the DOF values. The DOF values, in turn, help you estimate the OLC, which is part of the foundation of any effective and efficient maintenance and lubrication program. To eliminate the guesswork in estimating DOF values, you can rely on a computerized tool like the Lubrication Management Software from Redlist. With Redlist, you get accurate and real-time monitoring results that let you gain better insight into the factors that degrade your lubricants. Furthermore, it can help you monitor and identify the conditions causing lubricant degradation. To learn more, schedule a demo with a member of our team today!