Oil Hygiene - Contamination Control Practices for Industrial Plants

Ray Garvey, Emerson Process Management

How do you know when someone doesn’t practice good oral hygiene? The individual experiences tooth decay, gingivitis and usually bad breath. In this day and age, everyone should understand how important it is to brush and floss daily to maintain healthy teeth and gums. And we know these factors can directly relate to whether or not we will keep our own teeth when we get older.

Like many children, I didn’t understand the value of brushing and flossing. Until the age of 12, I didn’t take good care of my teeth. Fortunately for me, my father’s medical benefits paid for much of my reactive maintenance. I now have a mouth full of root canals, gold caps and 35-year-old fillings. Although my oral hygiene habits did improve with the introduction of some parental discipline, the damage had been done. But at least I experienced almost no cavities after that time.

A lot of people treat oil hygiene like I treated oral hygiene as a youngster. In light of the strong benefits of good oil hygiene, it’s hard to understand how individual plants with really bad practices can be so comfortable with the way they are doing things.

Oil Hygiene

It is amazing how different the oil hygiene practices are in the industrial plants that I visit. I graphed my assessments of lubrication systems’ cleanliness against oil hygiene practices, including contamination control, filtration, particle counts with size-distribution and wear debris analysis. The result is shown in Figure 1. It is not surprising that the plants with good oil hygiene had clean systems and plants with dirty lubrication systems were doing little or nothing about it.

Figure 1. Good Oil Hygiene Leads to Clean Lubrication Systems.

In spite of this logical correlation between clean systems and the degree to which particle counts and wear debris analysis are practiced, both extremes can be found within the same industry. For example, I have found an aluminum plant and a power plant with the poorest hygiene and the dirtiest oil; but have also seen the best hygiene and the cleanest oil in other aluminum and power generation plants. While the benefits of a clean oil system are obvious, they are often not shared across the industry.

Oil hygiene is simple: keep it clean, dry, fit-for-use and monitor the wear debris. These principles closely parallel those of good oral hygiene, and likewise, failure to follow them can produce negative results. In your plant, that can include abrasion, corrosion, fatigue and adhesion, all of which degrade load-bearing surfaces and shorten machine life.

So why do some plants have exceptionally good oil hygiene and others are totally comfortable with bad practices? I think the answer to this question is the same as the answer to why I had poor oral hygiene as a child. I was undisciplined and didn’t really believe it was important, and my parents were satisfied with reactive maintenance.

Unfortunately, poor oil hygiene is rampant in industry; like so many other proactive maintenance actions, oil hygiene can be ignored for a long time and the root cause of so many ailments never understood. Take a serious and impartial look at your oil hygiene practices. Is your oil clean, dry and fit-for-use? Do you regularly analyze wear debris? Do you believe these practices are important? Are you so busy you don’t have time to consider the condition of your lubrication systems? Are you letting your supplier completely take care of the health of your oil?

The right answers to these questions are just as obvious as the right answers to “Do you brush regularly? Do you floss regularly?” Knowing the right answers doesn’t mean we will do the right thing. If your plant has good oil hygiene, great! The benefits are obvious. If you don’t have good oil hygiene, then make that change. It is the best thing you can do for your company and it pays off in the long run.

Can You Do Too Much Oil Hygiene?

Like any other hygiene factor, enough is enough. When the oil is clean, dry and fit-for-use, there is not much benefit to cleaning it again or changing it again. You will want to set target cleanliness levels (TCLs) for particulate contamination and for moisture contamination. You will want to set limits for condemning used oils. Below these limits, you can spend a lot of money and even introduce new problems. Remember that oil drains are intrusive, possibly causing problems such as leaks, incorrect lubricant, system contamination or even personal injury.

Contamination control is a balancing act. You have sources and you have removal points. By setting TCLs and measuring particle counts with size distributions, you are able to apply your continuous improvement efforts most effectively.

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