When performing condition monitoring tasks, don’t just rely on expensive condition monitoring tools. You would be surprised at the unusual and simple tools that can be used.
Here’s a preventive maintenance example (on a bearing) from my early days in maintenance management consulting to demonstrate that.
Arusha, Tanzania, 1978. I was in Tanzania for four weeks to set up maintenance centers and train the teams. I was quickly alerted to a problem with a piece of equipment in the board mill.
The bearing was not hot, but the sound coming from the equipment had gotten worse over the last month. The mill maintenance manager was worried. This bearing was used in a slow-moving press roll, and if it failed, the entire plant would shut down. It was the 70s, so was going to take some time for the maintenance manager to go through the avenues for approval to import a new bearing. On top of that, it had to be paid in USD instead of Tanzanian schillings. The typical delivery time for a new bearing was six months, best case three months¾we needed it yesterday.
“I can’t prove to top management that something is wrong with the bearing. Any way you can help?” the maintenance manager asked me.
I could have suggested methods such as Shock Pulse Measurement (SPM), wear particle analyses in oil samples, and more.
These methods were, for this plant, too expensive and unavailable. I always travelled with an SPM instrument, but back then this instrument wasn’t reliable enough to prove something was wrong with very slow-moving bearings like it can today.
By necessity, a big part of the training focused on basic and affordable inspection methods. For example, how to check misalignment and wear of a coupling using a stroboscope, checking the position of a bypass valve to find out if a heat exchanger needed to be cleaned before overheating a system, visual inspection of a V-Belt drive to see if pulley and/or belts were worn out, discovering and documenting the level of pitting in gears, using lead wire to measure clearances, alignment and roundness of rollers in cement kilns, and many more.
Simple and Unusual Condition Monitoring Tools
When you go to the dentist, they will use a hook to gently scratch the surface of your teeth. That way, small uneven areas and cavities can be discovered. Believe it or not, a dental hook is one of the condition monitoring tools I still bring with me when visiting plants.
Did you know? You can use a dental hook to check for unevenness.
Both the upper and the lower bearing elements were accessible from the side by removing a cover plate. I suggested that we use a dental hook as a condition monitoring tool to examine the inner and outer ring surfaces for any unevenness during the next short scheduled shutdown.
When we did the inspection, we discovered a damaged area in the load zone of the outer ring. We took polaroid pictures of the damaged area and then rotated the out ring 180° to get the damaged area out of the load zone.
Using this very simple and inexpensive method for condition monitoring, the maintenance manager could convince decision makers to order a new bearing. The delivery time was four months, and the bearing lasted until the new one arrived.
Conclusion
In this era of rapidly advancing technology, it’s easy to overlook the value of simple, time-tested techniques. Younger generations have much to gain by learning the old dogs’ tricks. Most experienced craftspeople probably keep a dental hook in their toolbox. These kinds of practical, low-tech approaches are wisdom worth passing down.
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Christer Idhammar
Christer Idhammar started his career in operations and maintenance 1961. Shortly after, in 1985, he founded IDCON INC in Raleigh North Carolina, USA. IDCON INC is now a TRM company. Today he is a frequent key note and presenter at conferences around the world. Several hundred successful companies around the world have engaged Mr. Idhammar in their reliability improvement initiatives.
Awards:
He received the coveted EUROMAINTENANCE Incentive 2002 award during the biannual EUROMAINTENANCE 2002 conference in Helsinki in June 2002. Among 19 member European countries he was nominated and received the award from EFNMS – European Federation of National Maintenance Societies – for outstanding achievement and worldwide accomplishments in the field of reliability and maintenance.
In 2008 he received the Salvetti Foundation Best Speaker all categories award among 154 speakers at Euromaintenance 2008 in Brussels, Belgium
In 2013 he received the “Best presentation award” among 120 speakers at Reliability 2.0 conference in Las Vegas.
A common approach to looking at vibration spectra is to display the graphs and then ask “What is wrong with this machine?” Another common approach to analyzing vibration spectra is to display the graphs and then ask “What is this peak?” and “what is that peak” A better approach to analyzing data is to first ask “What faults can this machine have?”, “Which of these are most common for this machine?” and finally...
A common approach to looking at vibration spectra is to display the graphs and then ask “What is wrong with this machine?” Another common approach to analyzing vibration spectra is to display the graphs and then ask “What is this peak?” and “what is that peak” A better approach to analyzing data is to first ask “What faults can this machine have?”, “Which of these are most common for this machine?” and finally...
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Continuous monitoring of the filter elements in a hydraulic system can provide valuable clues to the performance of the filter and the condition of the system. Before I discuss this, let's consider some of the advantages and disadvantages of common filter locations in a hydraulic system.
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Vibration and wear debris analyses are two key components of any successful condition-monitoring program and can be used as both predictive and proactive tools to identify active machine wear and diagnose faults occurring inside machinery. Integrating these two techniques in a machine condition-monitoring program provides greater and more reliable information, bringing significant cost benefits to industry.
The question I posed is: Are the harmonics real? In other words, although the mass is still only bouncing up and down 30 times per second, is there actually real vibration occurring at 60, 90 and 120 Hz, etc.? OR are these just artifacts of the FFT?
The question I posed is: Are the harmonics real? In other words, although the mass is still only bouncing up and down 30 times per second, is there actually real vibration occurring at 60, 90 and 120 Hz, etc.? OR are these just artifacts of the FFT?
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For a program to be effective it must be accepted by management as well as other maintenance personnel. Getting other maintenance people involved in Infrared Thermography is a good way of gaining acceptance not to mention the fact that, more people scanning equipment will find more problems, more quickly, resulting in payback more quickly for the plant. This paper discusses the approach which I am implementing with varying degrees of success at my client's plant sites and which could be implemented in plants with existing IR imagers.
Enter dynamic AI-powered mapping technology: an AI-powered application that integrates Internet of Things (IoT) sensors, real-time monitoring, and artificial intelligence (AI) to revolutionize maintenance practices.
Enter dynamic AI-powered mapping technology: an AI-powered application that integrates Internet of Things (IoT) sensors, real-time monitoring, and artificial intelligence (AI) to revolutionize maintenance practices.
There are four primary components to precision grease lubrication for bearings: lubricant selection, application method, the volume of lubricant to be delivered, and the frequency with which it is applied. There are, of course, many different methods for specifying these values, and opinions can vary significantly as to which approach is best. Due to the variability of operating conditions and machine design, it can be very difficult to be truly precise without introducing the "condition-based" component to the formula.
There are four primary components to precision grease lubrication for bearings: lubricant selection, application method, the volume of lubricant to be delivered, and the frequency with which it is applied. There are, of course, many different methods for specifying these values, and opinions can vary significantly as to which approach is best. Due to the variability of operating conditions and machine design, it can be very difficult to be truly precise without introducing the "condition-based" component to the formula.
