Does oil analysis prevent machines from wearing or failing? Of course not! Knowing a machine is wearing or that conditions exist leading to machine wear and failure are not factors of prevention. The reason I am making such an obvious point is that I constantly witness plants that go to great lengths to monitor the condition of their equipment, but do nothing to address the problems or else don't understand the presented information. While this problem may occur with many condition monitoring technologies, the focus of this discussion is limited to oil analysis, or more specifically, solid particle contamination.
The Appearance of Particle Contamination … Now What?
As modern lubrication has advanced, many users have become aware of the effects of particle contamination on lubricated machinery. A multi-industry study published by the National Research Council of Canada showed that particle contamination was the root cause of 82 percent of wear-related failures. Based on this type of information, it stands to reason that controlling and monitoring particle contamination should be a primary goal of the lubrication program. However, simply identifying contamination control as a goal and monitoring the levels of contamination in machines will not extend their lifespan. Strangely enough, contamination control is commonly approached by ignoring the fact that action must be taken to control contaminants; simply assessing its presence is not enough.
Effective Methods for Effective Goals
To maximize the value of oil analysis, once again focusing on particle count, several factors must be implemented. The first step is to set targets or limits. To establish the allowable particle count for a given machine, an ideal value must be determined based on what can actually be achieved by employing cost-effective measures. If the goal is not achievable, it has little value. Condition monitoring tools should be used to target problems and focus efforts where they will yield the greatest return. If all particle counts are high, there can really be no focus.
The second step is to employ the appropriate methods to achieve the identified goals. Particle contamination control has several components, but it begins with good lubricant storage, handling and application methods. New oil is a common source of particle contamination because it is typically dirty upon arrival. In the average plant, new oil is often further contaminated by being dispensed into a dirty container with unsanitary transfer equipment, and finally applied to the machine through a soiled funnel. By properly storing, filtering and applying new lubricants, along with the use of simple contamination exclusion methods such as high-quality breathers and seals, an appropriate level of cleanliness can often be maintained for even nonfiltered systems. When these exclusion methods are insufficient, methods to remove contaminants must be used. Contamination removal techniques include portable filtration, permanently mounted off-line filtration and upgrading active system filters to best possible level of performance for a given system. Of course, it is more cost-effective to practice good contamination exclusion methods, and therefore exclusion should be the first method considered.
If the Info is Inaccurate, Why Bother?
Once the appropriate contamination control measures have been identified and implemented, it is time to monitor conditions to determine the effectiveness of these tactics. Remember, it is important to ensure the information being monitored is accurate, which can be done by using proper sampling methods including sampling from the correct location with the appropriate hardware and using a consistent sampling procedure. Without proper sampling, oil analysis data is useless. This is especially true for particle counts. With proper monitoring of particle counts, fluid cleanliness goals can be achieved, unnecessary PMs or methods can be identified and cost-effectiveness can be determined.
Good oil analysis is not necessarily good lubrication. It is however, an important part of the lubrication program and is essential for ensuring the proper operating conditions exist to yield the highest level of reliability and machine life. This is the essence of proactive maintenance.