How dirty is your grease?

For many years, those in industry have understood that dirty oil is a real problem. Moisture and dirt in oil are a leading cause of wear and premature bearing failure, causing fatigue, abrasion and erosion. By addressing the cleanliness of new oils, filtering oil before putting it into the machine, and protecting the machine from further contamination has demonstrated huge savings and return on investment.

But what about grease? We place grease into the same types of machines, lubricate the same bearings with grease that we lubricate with oil, yet little thought is given to the contaminants present in the grease and what that is doing to the life of our machines. Perhaps this is due to two reasons: one, its hard to do anything about dirty grease other than throwing it away or purging it out (you can't easily filter it); and secondly, there has been no easy way to quantify the presence of contaminants in greases. That is about to change, as ASTM will be shortly publishing a revision to ASTM D7918 that will include the first Standard Method for quantifying particulate and moisture levels in greases.

In the video above, a Grease Thief Analyzer being operated in accordance with D7918 was used to evaluate five different new greases right from the packaging. And the results are stunning. Some greases were found to be nearly pristine, with little to no particulate content, while others (as you can see) are downright filthy. And there was no way to differentiate these greases by looking at them. Only the high-resolution camera in the Grease Thief Particle Counter (GT-PC) was able to make this distinction, and assign a quantitative value to the cleanliness of the grease. On the moisture side, using the Arizona Instruments VaporPro on a grease substrate prepared by ASTM D7918, these greases were found with new moisture levels ranging from just under 100 ppm to several thousand ppm. With SKF stating that damage to bearings can be significant with as little as 400 ppm moisture, without knowledge of the condition of the new grease being pumped into your machines, there is no way to know how much money you are wasting on bearing replacements.

But rather than just raise the alarm, we are going to do something about it. We are going to perform a study of new greases to characterize their cleanliness and share the results on LinkedIn. The first 30 customers that contact us will be sent a free Grease Thief Sampling Sleeve to be returned with the new grease of their choice. Pick something that is used in your most critical equipment to find out whether you are lubricating with grease, dirt, water, or all three. We will analyze your sample and share the results with you, and then show you where your grease stands when graphed against the other samples that were submitted. If you are interested, comment here and we will reach out with an InMail message with instructions to participate. And we will update the results here as well. Our goal is to change the way folks treat their grease lubricated equipment by providing the data that can lead to better maintenance decisions.