What is Vibration Analysis?
Vibration analysis involves measuring and interpreting the vibration amplitudes and frequencies generated by machinery during operation. This allows an Analyst to assess the condition of various parts and anticipate maintenance or replacement needs. This is because all machinery generates vibration energy; from everyday appliances like ceiling fans and washing machines, to more industry specialized machines such as pumps, motors, chillers, industrial fans, gearboxes, turbines, generators and highly specialized industry ‘one-offs’.
Each machine generates unique frequencies and amplitudes, much like the human voice. These machine frequencies and amplitudes provide valuable data that can qualify and quantify a machine’s health. Vibration data can be used to identify issues like imbalance, bent shafts, defective bearings, misalignment, gear wear, and pump cavitation. Furthermore, since this data is collected on the machine while it is in operation, there’s no need to stop or reduce plant operations, disassemble the machine or perform internal inspections.
How Does Vibration Analysis Work?
Using special software and test equipment, such as test meters, accelerometers and lasers, Analysts can trend vibration data emitted by plant equipment. The data provides Analysts with vital indicators to predict when potential breakdowns might occur, and as long as the levels are stable, the machine will “last forever”. However we all know that machines don’t last forever and the data let’s us know when it starts to approach the end of it’s reliable operating life.
The data collection and analysis processes are straightforward; a sensor is attached to the equipment at various points (as close to the bearings as safely possible) long enough to collect and store the data. The data is then uploaded into dedicated software which is then used to generate graphs in different formats. The Vibration Analyst then interprets the data based on their training and experience. The end product is a detailed report on the condition of the machine, including what if any defects are developing, and how severe the defects are at the time the data was collected.
An Example:
Consider a simple machine such as a ceiling fan. Initially, it operates smoothly and quietly but as time progresses, subtle changes start to occur. A faint clicking noise with each rotation, followed by a slight wobble in the fan’s movement. Gradually, the noise intensifies and is accompanied by a noticeable thumping sound as the fan wobbles more pronounced. Eventually a failure occurs (one of the blades which was never securely fastened during assembly) comes loose and falls to the ground. The remaining blades gouge the ceiling as the fan continues rotating … for a short while.
Every sound emitted by the fan creates a corresponding a vibration signal and offers insight into what is causing it’s failure. More importantly, even BEFORE the audible clicks are heard, the vibrations due to the loose mounting screws can be detected and identified, warning of an impending failure mode if not corrected. Had attention been paid to the early signs of failure (the subtle vibrations) the fan could have been scheduled for repair long before the failure occurred, reducing the costly damage to both the home and the fan, and the downtime of the fan itself.
Why do you need to Analyze Vibrations?
You don’t. Like changing the oil in your car, you don’t HAVE to change it; just keep on driving and you can change the engine later. Vibration analysis gives use the ability to continue using ‘the oil’ until we really need to change it. Just like predicting the failure of a ceiling fan by monitoring its vibrations, you can do the same with heavy industrial machinery. You could simply adhere to routine maintenance schedules to estimate the lifespan of your machines, but just because you can doesn’t mean you should.
Routine maintenance undoubtedly holds some benefit. For instance, running a car without changing the oil is unthinkable because oil deteriorates over time. For that reason, we change the oil every 3,000 miles to safeguard the engine’s health. Yet, imagine if you possessed real-time insights into the oil’s condition in your engine—its effectiveness moment by moment – you could postpone routine maintenance until you’ve extracted every possible mile from the oil, without increasing the risk of an engine failure. This action translates to fewer oil and filter changes without any reduction in a machine’s reliability.
For example, consider you’ve got 2,900 miles on your oil, and are planning a 600-mile round-trip to visit family. Do you opt for an early oil change or risk potential engine issues during the journey? If you REALLY knew the condition of your oil and that a breakdown mid-trip would not occur, you could avoid the additional expenses to change the oil. Of course, you can always run your car until the oil completely fails and the engine seizes, but who does this? The same applies to performing maintenance on industrial machines based on their vibration data.
From Cars to Industrial Equipment
The same principle holds true for heavy industrial machinery. Having insight into a machine’s condition enables factory owners to schedule maintenance but only as often as is needed, rather than following an overly cautious and frequent schedule. Moreover, maintenance can be coordinated to align with the factory’s financial interests. Instead of being compelled to conduct maintenance prematurely (to meet outage deadlines or risking failure by postponing it) predictive-based-scheduling optimizes maintenance activities for maximum efficiency and minimal disruption.
Vibration Analysts, like those at Vibration Analysts Inc., play a pivotal role in saving equipment owners time and money by providing vital machine information in a timely manner. Whether it’s wind turbines, Ferris wheels, nuclear power plants, DOD machinery, the range of machinery that benefits from vibration analysis is extensive.
