In the last few decades, we have heard many companies perform “PMs” (Preventive Maintenance tasks) on their assets or buy tools to help perform “PdM” (Predictive Maintenance), often hoping to solve all their problems without a real strategy in place. This can be a costly mistake as it risks inducing functional failures in your assets during their infant mortality period as a result of performing unnecessary intrusive work. There are many different maintenance strategies, which are essential for ensuring the reliability and availability of equipment and assets. However, companies should not just arbitrarily choose one for their maintenance department to follow. Instead, the maintenance strategy should fit what is best for a given asset. The most common strategies are Preventive, Predictive, and Run-to-Failure, although it may initially sound strange. Now,…
Because of my many years of experience in the field of installation and maintenance of rotating equipment, I can say that installation is a fundamental thing. But why is this phase so important? Well, because the installation has a direct impact on the machinery, and will determine operating conditions, performance, and life cycle cost. Basically, the way you install your rotating equipment is the way it will perform. And personally, I always ask myself why companies buy million-dollar pieces of equipment and let inexperienced installers do the installation. Then, they spend another million dollars on condition monitoring watching them fail. Don’t get me wrong; condition monitoring is extremely important to understand what is happening to the machines and detect an early failure. But the fact is that most of the…
Frequency can be defined as how often an event occurs per unit of time. A vibration spectrum is displayed as a horizontal and vertical plot (X and Y). The horizontal (X) axis is the frequency axis and shows a representation of how often an event occurs. Typically, the vibration analyst may use multiple units of reference for the frequency axis when doing vibration analysis. The most common units used for the spectrum (FFT) are cycles per minute (CPM) and Hertz. The least known unit for the spectrum frequency axis is “Orders” or multiples of shaft turning speed. It is critical to understand the differences in the frequency units (Hz, CPM, and Orders). It can be advantageous to view data in different units depending upon the machine and the problem being…
Traditional induction heaters only offer one temperature probe, to monitor the temperature of the inner diameter (ID) of the bearing being heated, assuming that both the inner diameter (ID) and outer diameter (OD) will heat evenly. However, the ID heats faster than the OD, potentially causing stresses between the ID, OD, and the rolling elements. This stress can lead to cracks, fractures, pitting, and deformation of the rolling elements, which can reduce the lifespan of the item being heated. These issues can go undetected, especially in high-precision bearings, where tolerances between the rolling elements and the ID/OD are tight. Even with sprockets and gears, the stress between the ID and OD can produce cracks and fractures in the membrane between them. Figure 1 – illustrates how the ID heats faster…
All rotating equipment shall be designed and constructed so that its first critical speed is at least 125 percent of the maximum design speed for the equipment (i.e. rotating equipment shall operate at speeds less than 80 percent of their true critical speed). Unless otherwise required, equipment shall be balanced according to the recommendations given in this section.Equipment components such as motors, pump rotors, fan wheels, etc. shall be factory balanced both statically and dynamically, to meet the field balance requirements described below.All balance reports shall be referenced in inches per second (ips or in/sec), zero to peak. A balance report shall be provided for each piece of equipment tested.Balance of Critical Equipment:All equipment located in areas that may be sensitive to process vibration shall be classified as “critical” equipment…