Machinery Lubrication

Reliable Plant | www . reliableplant.com Machinery Lubrication | www . machinerylubrication.com 2025 Annual 39 ML As a new lubrication tech, I assumed that maybe I had overfilled the gearbox that first time. After pulling five monthly samples of 5 ounces (four for the sample and a 1-ounce purge amount), I became curious about how I still had the proper oil level in the gearbox and decided to investigate further. During the investigation, the sight glass was pulled. e gearbox's oil level was about half what it should have been, but the sight glass still showed that it had the same amount of oil even after it was pulled from the gearbox. OS! (Not Good) I discovered that due to capillary action, there was no flow back into the gearbox from the 12mm sight glass. e oil level was immediately taken back up to the proper level. After this, I decided to do away with all the 12mm bullseyes and install column sight glasses with headspace returns in the piping underneath my desiccant breather. at gearbox is still running to this day, so I would call that a win. I installed all the 6-inch column sight glasses using a 12mm to ¼-inch adapter and all stainless-steel fittings. It is a little more expensive to do it this way, but using malleable iron or galvanized fittings can and will throw off the numbers in an oil analysis report. e oil from the gearbox flowed into the column sight glass, and all the other gearboxes were filled to the correct amount. All these gearboxes are sampled monthly, which is good because of my next learning moment. Second OS! Lesson All the machines in my facility have a preventive maintenance (PM) schedule to ensure they are inspected once a week. is inspection covers: • Oil level and condition • Desiccant breather condition • Gearbox and drive motor heat, leaks, and abnormal noise. Although samples are taken monthly, it's good practice to perform your regular inspection while you're standing there. In my case, the oil was clean, clear, and bright in the column sight glass when I took the oil sample with my vacuum sample pump. But when it came out into the sample bottle, the oil was dark red. OS! (Not Good) How could this be? e oil in the column sight glass was in just as perfect condition as the day I filled the gearbox. e reason was because that was the same oil from the day I filled it. Column sight glasses are excellent at giving an exact level of the oil in the gearbox, but there is no recirculation of the oil in and out of the glass. e only circulation is if makeup oil is added to the reservoir, pushing a small amount into the glass. Otherwise, there is no indicator of the condi - tion of the oil inside the actual machinery. In my case, this oil condition finding was bad but, thankfully, not catastrophic. Because the reservoir was sampled monthly, at most, I could have had contamination in the oil for 29 days. Had the machine been sampled every other month or, even worse, quarterly, there would have been a longer period of unresolved contamination and more serious consequences for the machine's health. Third OS! Lesson e sample was sent to the lab, but I didn't wait for the results; that day, I performed a complete drain, flush, and fill. I also began contemplating how to push the oil from the sight glass back into the reservoir to get an immediate look at the oil's condition. Air pressure is the best option, but it must be "clean and dry" air filtered through the desiccant breather. Using my own money, I purchased an air pump that pulls air in from a hose on one end of the pump and pushes it out through a hose on the other. I cut my headspace return line, attached the inflow side of the closed pump to the breather side, and attached the outflow to the section of the hose on top of the column. roughout this process, I had no idea whether this would work. If it didn't, I would take the air pump home and use it on bike tires or inflatable toys for the grandkids so my money wouldn't be wasted. I pulled out the pump's plunger, filled it with air from my desiccant breather, and pushed it in. All the oil from the glass was pushed back into the gearbox. It worked perfectly! OS! (Good) I installed a push-to-connect coupling fitting on both ends of the cut headspace return line to close the loop on my breather. Now, I could perform a visual check on my weekly PM route with an extra 30 seconds and a $7.49 air pump that I got from a local national discount tool store. Fourth OS! Lesson In another instance, I received word that a bearing had gone bad. Everyone has had a bearing fail at one point or another in their career; it happens to the best of us. No matter how much time and effort you put into the care and feeding of a bearing, sometimes they go bad, right? When the maintenance tech told me a particular bearing had gone out, I knew it wasn't a human error on my part because it was a sealed bearing – meaning it was behind a "guard" that made it part of the machine's body and nearly impossible to remove. You would hope no Original Equipment Manufacturer (OEM) would put a serviceable bearing in a difficult-to-reach place, right? Unfortunately, that was my exact situation, and once removed, I found the bearing was completely dry. OS! (Bad, very bad) I run a tight ship and pride myself on that fact; how could I have overlooked this? Truth is, it is easy to do, and I just assumed that this bearing was sealed because of the location. I never checked. A fter explaining what happened to my supervisors and admitting what I had overlooked for several years, I

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