Analyzing Industrial Lubricants to Get Informed About Failures
There’s a reason machine lubrication is a consistent chore. Lubricants have a finite life before they break down and fail to do their job. But if this failure comes earlier than expected, it’s worth investigating. Looking at tainted lubricant can yield tremendous insight into problems with machinery. Identifying distinct problems with lubricant contamination may be the key to delivering a higher standard of maintenance — one that prevents similar problems from occurring again.
Make fluid analyzation routine
When a machine breaks down, it’s often assessed as part of the repair process. There are a multitude of approaches for Failure Modes and Effects Analysis (FMEA). The purpose is to understand what caused the failure, even if it seems apparent. Fluid analysis should be a routine part of FMEA.
Heat and friction are the common denominators in most machinery failures. Lubrication mitigates both variables. Failure within normal operating capacity due to heat and friction ultimately means a failure of lubrication in some form. Components like bearings, in particular, demand further investigation of the quality and quantity of lubrication.
What’s wrong with the fluid?
Fluid analysis can be as involved or as simple as you need it to be. For example, it’s easy to see discoloration or spot debris within the lubricant. Conversely, testing for exact viscosity changes or air ratio will require special instrumentation. What matters most is analyzing fluids to the capacity available to you, to discern what you can about the most important composition variables.
- Change in viscosity. Has the lubricant retained an acceptable level of viscosity, allowing it to provide a consistent friction buffer within the specific application?
- Lubrication debris. Can you detect dirt, dust, or metal shavings suspended within the lubricant? If so, in what volume?
- Loss of additives. Have the chemical properties of a specialized lubricant been stripped away? If so, are there any detergents or foreign chemicals present?
- Presence of water. Is there water within the lubricant? If so, to what degree does it affect the viscosity of the lubricant?
- Air ratio. Are there air bubbles in the lubricant or signs of cavitation occurring within the fluid power system?
- Color. Is there discoloration or a noticeable color difference in the lubricant? If so, to what degree and what caused this shift?
Investigating changed properties can yield tremendous insight into how or why a lubricant failed to mitigate friction or heat.
Separating contamination from wear
Contamination to some degree is common in factories. The likelihood of contamination rises when lubrication processes aren’t controlled or machinery is ill-maintained. Identifying these problems should be relatively straightforward. Nevertheless, it’s important to distinguish them from signs of wear.
Lubricants break down with time and under duress — which is why lubrication is a routine procedure. Learn to identify signs of lubricant breakdown due to wear versus contamination. And, it almost goes without saying, strive to develop processes to mitigate contamination opportunities.
Your spent fluid can tell you more than you realize about the health of your machinery — especially when there’s downtime involved. Make fluid analysis part of your FMEA process or a standalone step in maintenance and start paying attention to what your lubricants are trying to tell you.