Particle contamination in bearing grease, also known as lubrication contamination, is a common problem encountered by manufacturers and their lube techs around the world. A study done by the National Research Council of Canada found that 82% of bearing wear is caused by particle contamination. This makes lubrication contamination the leading cause of premature failures.
Lubrication contamination occurs regardless of industry, geographic location, facility size, standard operating procedures, and the training and experience of the maintenance staff and lubrication techs on-site. And this is because there isn’t always that much that can be done to completely avoid lubrication contamination. All it takes is one particle of dust, dirt, or other debris to get entangled within your bearing lubricant, for its effects to deteriorate the asset’s reliability. This makes the margin of error for preventing lubrication contamination very small. However, there are steps that can be put in place to minimize the disastrous effects of bearing lubrication contamination. But first, let’s learn a little more about contamination.
What is Lubrication Contamination?
The definition of contamination: The presence of a constituent, impurity, or some other undesirable element that spoils, corrupts, infects, or makes unfit, a material, physical body, natural environment, workplace, etc.
In the case of bearing lubrication, these contaminants vary depending on industry. But they can mean dirt, dust, saw dust, metal shavings, chemicals, and even mixed grease types. When your lubricant becomes contaminated, it is no longer suitable for its purpose and it needs to be taken out of service to prevent severe damage to the asset and production is forced to shut down.
- Lubrication contamination can reduce the amount of time an asset is able to operate without maintenance from years to months… and in some cases weeks or days.
- Lubrication contamination can cause machinery bearings to seize up as the grease thickens and eventually hardens.
- Lubrication contamination can degrade lubrication pumps and metering systems.
- Lubrication contamination can scratch, wear and shave off pieces on metal bearings leading to faster and more unpredictable failures.
The bottom line is that lubrication contamination is bad… very bad. It costs manufacturers unplanned downtime, otherwise unnecessary repairs, and plenty of man hours. It creates headaches for lubrication technicians and maintenance staff in addition to the nuisance of cleaning contaminated bearing grease from bearings.
So, Who’s to Blame for Lubrication Contamination?
Well, to be frank, it is us… all of us! The lubrication technicians greasing bearings, the transport truck drivers delivering the lubricants from one facility to the next, the factory workers moving lubricants from shipping and receiving to the lubrication storage room, the facility policy makers not enforcing more stringent rules regarding facility cleanliness, the condition monitoring team for not detecting tell-tale signs of contaminated lubricant, the factory for not having the necessary condition monitoring program in place to discover a deteriorating asset before it reaches a critical stage, and the list goes on.
Lubrication contamination is caused by the operational environment in which the grease is transported, stored, and injected into bearings. Bearing lubrication can collect contaminants from airborne dust and dirt particles if its storage container isn’t sealed correctly. It can become contaminated from the leftover soap residue in and on the bearing housing, zerk fittings, and lubrication storage containers. And a major source of contaminated lubrication is the mixture of incompatible lubricants.
The Design, Installation, Potential for Failure, and Failure Curve (DIPF Curve) overviews the lifetime of an asset. One of the harsh truths that the DIPF curve reveals is that no amount of maintenance can save a poorly designed, and poorly installed asset from failing. This should also apply to bearing lubrication. But in many cases, a drum of grease isn’t considered an asset to maintenance and reliability professionals. And the job of lubrication technician isn’t regarded as a noble and prestigious title. It is typically given to the young, inexperienced, new person on the job.
To attain the maximum lubrication effectiveness, while minimizing the damage caused by contamination, maintenance professionals must first hold their inventory of grease to the same regard as other assets. Precision bearing lubrication is essential to maximising uptime and prolonging the life all assets. If contamination control is not part of your lubrication strategy, then you simply have not achieved a world-class lubrication program yet.
Filtering out Lubrication Contamination
By reading the above-mentioned ways your lubrication can become contaminated, you can draw your own conclusions as to how this risk can be mitigated. The first step is to consider lubricants as an asset.
After this, consider the design of your lubrication storeroom. Is it dirty, cluttered, unorganized, improperly labeled? Are the lubrication storage containers left open? Are the funnels used to fill the grease reservoirs cleaned after each use? Is it adequately climate controlled? These are all signs of a lubrication program lacking precision.
After realizing what is necessary, goals must be set accordingly, and a system put in place to measure these goals. And facility cleanliness should be at the top of this list. While in many industries such as pulp & paper and steel production, facility cleanliness isn’t always an option. Having a clean, dedicated lubrication storage room, and strict cleaning routines for tools used in the bearing grease replenishment process should be.
The next step should include the installation of sampling ports and an on-site particle counter, so that bearing lubrication samples can be taken very fast and easily and contaminated lubricants can be identified and disposed of.
Finally, every world-class lubrication program needs well trained lube techs. The job performed by lubrication technicians is vital to the reliability of a factory. A well-trained lube team will be better organized and have a better understanding about the necessity of eliminating lubrication contamination by doing the little things.
What You’ll Notice on the way to Achieving a World Class Lubrication Program
On your journey to achieving a world class lubrication program you will notice these tell-tale signs that you’re on the right track.
- A reduction in the amount of grease consumed
- Less unplanned, unwarranted bearing failures leading to costly downtime
- Less bearing purchases to keep storerooms stocked
- Less waste from contamination
To cap this off, we at SDT want to remind you to not be surprised if you don’t see immediate results. Transforming your lubrication program and eliminating bearing lubrication contamination doesn’t happen overnight. It requires patience and most of all, dedication and diligence. But the results will certainly be worth it.
If you wish to discuss this article with me please reach out to me at: Tristan.Rienstra@sdtultrasound.com
Source: Paul Llewellyn, Ultrasound… Beyond the Essentials, Lubrication Best Practices: It’s Not the Destination… It’s the Journey.