The doctor is in
Peter A. Oglevie | TLT Shop Floor April 2011
Your patient might be a machine, but a physical exam is still needed to diagnose the problem.
A physical examination had kept a bad lubrication problem from becoming a catastrophe.
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We have had a lot of snow this year, and moving it has brought on stiffness in my foot and a backache to boot. A trip to the doctor may be in order. First comes the physical exam, second comes the follow-up blood tests. Both procedures are necessary to diagnose and treat the aches and pains.
The shop floor is a lot like going to the doctor. In order to be effective, I need to be there to conduct a physical exam. When I look at a machine, much like a doctor looks at me, I check for the obvious signs of problems first. Things like temperature, oil levels and noise. Does the machine have proper grease on the moving parts?
An experience I had pulling oil samples for analysis is a good example of this diagnostic principle in action. It prevented a bad problem from becoming catastrophic.
I was in an injection-molding plant for a scheduled oil analysis sampling. I needed to pull samples from 35 machines and was about halfway through when I ran into a machine with cloudy oil. Experience told me there was probably water in the oil. I took the sample to the maintenance department, and we filled a teaspoon with oil and put a torch to the bottom. The heat rose until the oil started popping and then cleared up, a strong indication of water present. The maintenance department immediately went to work on correcting the problem.
The next machine sample had the same problem. Even though we didn’t know the why yet, we knew we were in trouble by the time I found water-contaminated oil in the fifth machine. We had lost oil in five machines at 300 gallons per machine. Just like the doctor, a physical examination had spotted the problem.
Maintenance personnel took an unusual step, shutting down all of the machines. By this time they had removed the heat exchanger from the first machine, discovering that it was eaten away from the inside. They found the reason in the cooling tower. A defective pH meter in the system caused an acid buildup in the water.
We were lucky to lose just five machines. If the maintenance department had not shut down when they did, this problem would have spread to all 35 machines.
Much like a doctor will not prescribe a medication without giving you an exam, I could have lost all 35 machines if I hadn’t been there to perform the sampling myself. If this plant had pulled the samples and sent them to the laboratory, the 1- to 2-week delay would have resulted in the loss of the rest of the machines. That’s a problem turned into a catastrophe.
Oil analysis should be performed in conjunction with a physical examination of the machine. Much like a doctor checks your temperature, blood pressure and listens to your lungs, we should, at a minimum, check the temperature, oil level and noise levels of a machine.
I put a rush order on the laboratory analysis for the samples pulled on this day and confirmed the presence of water in the oil. However, our physical examination had already solved the problem long before it became catastrophic.
To solve my aches and pains, I am going to take a piece of traditional doctor’s advice and soak in a hot tub. You can bet that as part of that treatment I will monitor the pH level in the water. Otherwise I could be back to see the physician with a new complaint.
Pete Oglevie is president of International Production Technologies in Port Washington, Wis. You can reach him at poglevie@wi.rr.com.