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Like most of the Noria technical consulting team, I spend a considerable amount of time in plants. As a result, I see a host of different lubrication problems, but perhaps one of the most pervasive is oil leakage. In fact, in some plants, it's often harder to find a machine that is not leaking than one that is!
While most plants are aware of leaking equipment, few have a structured plan to address these leaks. All too often, leaks are considered "normal" - but should leaks really be considered a part of everyday business, or are they avoidable?
Specific machines that need to be addressed are the larger hydraulic and circulating oil systems. With hundreds and sometimes thousands of gallons of fluid under pressure, a small leak can cause serious operational, mechanical or safety issues. Even if the leak does not cause any obvious problems and appears innocuous, the cost of leakage can be significant. In fact, just one drop of leakage per second can amount to as much as losing one 55-gallon drum of oil each week. I remember one extreme example where as much as two barrels of oil were being added to a hydraulic press each week just to overcome a serious leakage problem, with 25 percent of the plant's annual lubricant purchases being spent on this one machine alone.
Recognize, Analyze and Control
So what can be done about leaks? Best practice, of course, is to recognize the presence of a leak, and analyze and control the root cause. In some cases this can be based on a simple visual observation, but in other cases it might require more detailed inspections including partial machine teardowns or the use of dyes to identify the source of the leak. Once identified, a plan needs to be developed to fix the leak when the machine becomes available for intrusive maintenance. In some cases however, the time, effort or expense to control a leak - particularly where a major machine redesign is required - cannot be easily justified in light of production demands and maintenance budgets. Under these circumstances, what can be done to mitigate the financial impact of leakage?
Reclamation: When and Why?
Increasingly, I see companies endeavor to capture leaking fluid - sometimes in elaborate guttering systems - to reclaim and recondition before returning the oil to service, rather than fixing the problem. But is this really a sound strategy? If the economic benefit of fixing the underlying root cause cannot be justified, then there's no reason why fluid reclamation can't work. However, this is a case where extreme caution and due diligence must be exercised to avoid potential problems that exceed the initial costs of leakage and fluid replenishment.
The nature of the reclamation process, the type of the contaminants that may or may not be present and the degree to which the base oil and/or additive content may have been compromised are the factoring issues. Oftentimes, the problems are caused by a hidden contamination that is not obvious: removing solid particles and moisture is relatively straightforward and can be verified using oil analysis. It's the hidden effects on an oil's demulsibility, air release, foaming tendency, varnish potential and corrosion control that are often overlooked. More often than not, these problems are caused by chemical contaminants that are not easily removed through filtration, dehydration or other reclamation processes. And without adequate quality assurance testing after the reclamation process is completed, the user would be unaware if the fluid is indeed fit for continued service.
Utilizing Oil Analysis
Assuming oil leakage cannot be cost-effectively prevented; the best practice for reclamation is to process fluids in a batch process. For each batch, oil analysis should be conducted before reclamation is undertaken to determine the nature of the contaminants and/or fluid before a decision is made concerning whether the fluid can be successfully reclaimed. If proceeding with this process, careful analysis should be performed on each reclaimed batch to ensure the oil is not only clean (free of particles and moisture), but that important physical and chemical properties such as viscosity, acid number, varnish potential, de-aeration, foaming tendency/stability and demulsibility have not been compromised. In addition, the health of additives such as antioxidant, rust and corrosion inhibitors should be evaluated, along with any wear-preventing additives such as AW or EP additives. While such tests may seem extensive, and indeed expensive, without due diligence there is no guarantee that any reclaimed fluid will perform as it should once introduced back into the machine.
Jump Right In … Or Not
As environmental regulations continue to become more stringent, leakage will become more of an issue. But make sure to stop and think before jumping on the reclamation bandwagon. While there is no doubt reclamation can and does work, consider eliminating leaks first. If reclamation appears to be the most economical option, make sure a proper quality assurance process is in place to ensure the reclaimed fluid will not cause other problems down the road.