Wow, there is so much I didn’t know about lubrication!” This is the typical response after someone attends a Machinery Lubrication course: a several-day learning journey through all sorts of topics. This includes learning about the functions of a lubricant, how to select the right lubricant for each application, how to manage them in storage and properly apply them to machines, and of course, all about monitoring lubricant and machine conditions through inspections and oil analysis.
But there are two specific areas of lubrication that must be communicated to nearly everyone working with and around plant equipment: Contamination Control and Inspections. In this article, I will review a few of the benefits of contamination control training as it drives culture change and long-term sustainable growth with plant reliability.
Consider first that contamination is defined as “any foreign or unwanted substance that can have a negative effect on system operation, life or reliability.” This is much more than just solid particulates from the environment; rather, it includes water, air, glycol, soot, fuel, etc. Even the wrong lubricant mixed into the current lubricant is a form of contamination referred to as cross-contamination.
Contamination control in the context of lubrication includes the “planning, organizing, managing, and implementing all activities required to determine, achieve and maintain a specified contamination level.” Notice that neither the word “eliminate” nor “remove” is used in this definition; more on that later.
A lot of what is important with contamination control is not intuitive, meaning that, until someone has training, they simply don’t know what they don’t know. Take, for example, the physical size of solid contaminants that could damage a rolling or sliding contacting component. Oil films are usually 5-20 microns for sliding contact (turbine bearings, gears, pistons, etc.), all the way down to less than one micron for rolling contact (rolling element bearing, gears, cams, etc.). Typical airborne particulates that ingress into machines are usually much smaller than 40 microns, which is the visibility limit of the unaided eye. This makes it common for there to be a misperception of the degree of cleanliness needed in and around lubricated machines. It is not intuitive for us to understand the importance of these virtually invisible contaminants with everyday practices. This is just one example of what must be learned through careful training - providing a discussion and explanation on why contamination control is important, rather than just telling them what to do and what not to do.
It is often assumed that contamination control is just about filtration; this is far from the truth. While it is a big part of contamination control, filtration is only necessary because contamination is allowed to get into the oil (and the machine) in the first place. The actions that must be taken to control contamination include both exclusion (seals, breathers, clean new oil, etc.) and removal (mostly filtration). In fact, it will always be much cheaper (at least one-tenth the cost) to exclude a gram of dirt from getting into a machine than it is to remove it through filtration.
Nevertheless, neither exclusion nor removal is perfect - they must be considered together as a contamination control solution for critical machines. It must be learned through training that contamination control requires a balance of this two-part approach, just like our bodily caloric control, where we strive to burn more calories than we consume. For machines, we can monitor contamination levels, such as with oil analysis, to verify that this is staying in balance. If more contaminants are accumulating in the oil than are being removed, a contamination-induced failure can develop. It is important that those who make decisions about breathers, seals, filtration and other everyday oil sump management have learned about contamination control to ensure enough is being done to keep this in balance.
For decades, countless industry studies by OEMs and end-user groups have identified that contamination is the number one cause of wear on rolling element bearings, gears and the majority of lubricated components. Additionally, it is well established that the cost of controlling contamination through optimized best practices will be considerably less than the cost savings from mechanical wear-related failures decreasing over that period.
Then why is this not often realized? This is where training is needed. As mechanical wear occurs from moderate levels of contamination, it propagates a gradual Failure Development Period that appears largely uneventful to the untrained person. As the wear gets worse, eventually predictive maintenance (PdM) may trigger a corrective action through vibration analysis, inspections or other means. If this becomes a common occurrence, then a preventative maintenance (PM) task may get scheduled to replace these components on a fixed interval that is significantly less than the intended design life. And unfortunately, this is very common.
These PdM catches and scheduled PMs are rewarded, but these habits actually form a maintenance culture focused on reacting to failure rather than establishing proactive measures to recognize the root cause (contamination) and improve proactive maintenance (contamination control).
If a root cause analysis were done, it would be difficult to pinpoint one single cause. Rather, the root cause is usually a collection of bad decisions and practices that impact contamination levels. Good practices include everyday activities or decisions such as:
The actions and decisions that influence contamination control are part of a collective effort involving nearly everyone working around the machines, including maintenance, operators, lube techs, reliability engineers, supervisors, etc. Similarly, when these teams go through contamination control trainings together, everyone builds a collective awareness and a better understanding of what each of their roles entails. The benefit of contamination control training multiplies as the importance is bought-in together, especially when the training takes place in-person as one group.
Ultimately, contamination control is everyone’s responsibility. When training is provided for those responsible, it sets the tone from the top down that lubrication is not a trivial part of maintenance but instead requires carefully made decisions, quality daily actions, and, most importantly, it impacts the bottom line. It all requires a highly trained professional.