Improving Rolling Mill Lube Oil Performance and Useful Life

The more I delve into this subject, the more I discover the pronounced impact lubrication has on energy and the environment. A case in point is the impact of clean oil on fuel consumption and emission in engines. There are many ways that a lubricant could fail to deliver fuel-efficient engine performance. Many of these are due to formulation issues as opposed to transient properties of the lubricant in service.

So what is going wrong with the lubricant and bearings in our pumps? We do not get a service life any where near those numbers. It turns out that most bearings fail prematurely for only two reasons: High heat that caused the lubricant to "varnish" and then form "coke" that will introduce solids into the lubricant, and contamination of the lubricant by water, moisture, and solids.

This article provides 6 tips for lubricants concerning how they're handled, stored, and dispensed in facilities.

Rotating-element bearing manufacturers measure the reliability of their bearings using a Load-Life calculation rating, which is known as the L10 rating life. To achieve its design rating, the manufacturer assumes the bearing will be run in a clean operating environment. This takes into account providing an adequate lubricant film (adequate described as a film equal to, or greater than, the composite roughness of the two mating surfaces) of the correct viscosity for the designed maximum bearing speed and operating temperature ratings.

SES Technical takes a "hands on" approach to all disciplines of predictive maintenance. The same Field Engineer who collects the data performs vibration, infrared, and ultrasonic analysis. This allows the engineers to develop an understanding of the equipment and develop a familiarity with its maintenance history. SES has also applied this principal to oil analysis.

Air can also be temporarily entrained into oil through bearing agitation. This can occur in healthy oil, but is more common in oil containing high amounts of moisture, as well as oil having other forms of contaminants. Air entrained in oil sumps of rotating equipment tends to rise out and re-enter the headspace over time. Read to learn some of the potential effects of air entrainment.

Begin by not reading this editorial. Most "old school" lube programs like to hold to the status quo. Editorials like this one threaten their comfort zone. After all, change takes guts . . . it takes imagination . . . it takes commitment. Who's got the time (and courage) for that?