Predictive maintenance, also known as condition-based maintenance, tries to prevent failures based on an equipment’s overall state. That means early detection of any problems that might lead to breakdown and, consequently, downtime. The challenge here is detecting the problems themselves, which aren’t always apparent to the everyday user or to the naked eye in their initial states. After all, where’s the merit in spotting the iceberg when you cannot turn around?
That’s why non-destructive tests (NDT) are so important to diagnose failures within the infrastructure. NDTs do not compromise nor do they cause damage to the equipment, just like the routine check-ups for humans. Blood tests, ultrasound scans, or eye exams: we do them every year, and none of them hurt us.
Thermographic Analysis and Infrared
In fact, our check-ups are not that different from several predictive maintenance techniques. Imagiology can also be applied to several types of equipment to detect wear, rusting, delaminations and disconnections that might go unnoticed to the naked eye. Another advantage is that infrareds allow us to make surface temperature maps that we can use, for example, in the maintenance of heating systems.
Oil analysis is another non-destructive and non-invasive technique that you can try. The purpose here is to measure the number and size of the particles in a given oil sample to determine equipment wear. Let’s take into consideration a hydraulic system that consists of two essential components – the rotating parts and their lubricant. As equipment ages, the sample will show byproducts of overheating and erosion. Different particles reveal many problems before you can guess a breakdown is coming.
This analysis is perfect for rotating equipment and machines, such as compressors, water pumps and engines. What we do is connect them to a sensor that can detect movement or acceleration, depending on what’s appropriate. The sensor works by detecting sound waves created by movement, which generate electrical impulses and make the equipment vibrate. Therefore, this predictive maintenance technique is ideal for infrastructures with a complex water supply system, such as hotels, spas or water parks.
We’ve already established that sound waves are our allies. Acoustic analysis is a technique used to detect problems in the material’s technical performance, pinpoint the source of the problem and do “check-ups” on the equipment’s overall health. How? By detecting changes in sound frequencies. Every working machine makes some sort of noise, but its frequency and range change whenever there are leaks or pressure changes, for example. This predictive maintenance technique is especially useful for pipelines carrying liquids or gas.
Online temperature monitoring
“The right maintenance at the right time” is the best sentence to describe predictive maintenance. But nothing is as good a weapon to spot the right time as continuous monitoring 24/7. Every temperature change might lead us to detect failures early, thus avoiding downtime. The future of predictive maintenance will certainly enlist the help of sensors to measure temperature, flow, and several other KPIs, which is already being done in some aircrafts.