PdM Power: Looking at the big picture with infrared
Predictive maintenance (PdM) changed irreversibly upon the introduction of infrared, or thermal imaging, technology. If your job is to assess the condition of plant assets through equipment condition monitoring, you know that infrared cameras have migrated from being a "nice-to-have" technology to a "must have."
PdM industry thought-leaders now count infrared among other proven components of an effective, scalable PdM practice (i.e. acoustic and sound level tests, vibration analysis, corona detection and oil analysis). So, what is the distinctive feature of infrared (IR) for plant PdM? IR inspections aren’t system-specific, spanning a much wider range of applications than most condition-monitoring methods making it more versatile across the plant.
Essentially, infrared PdM reveals equipment that is hotter or colder than a "normal status" reference temperature range. Infrared cameras illustrate those temperature differences with pictures or videos that depict temperature using colour ranges or palettes. IR can be considered for any component or system that heats up or fails to heat up indicating less-than-optimal operation: electrical, mechanical, steam, hydraulic, gas, material handling, furnaces, boilers, buildings and more.
More importantly for PdM, the extent of temperature variation can also quantify the severity of a problem. In some cases, an inspector is alerted to an imminent failure that warrants an emergency shutdown to avoid worker injury or equipment damage. Infrared also permits plant managers to expand the scope of inspections to compromised building envelope issues that affect interior controlled environments, roof water damage/leakage, or concrete moisture issues.
Depending on your plant’s configuration, there are a variety of applications for infrared thermal imaging. Infrared can be used to analyze mechanical systems for abnormalities. Pumps are monitored for overheated connections, fuse problems, or overloaded electrical cables. Process valves are checked for leakage or stuck open/closed position. Sludge levels can be easily measured in storage tanks. Pipelines are monitored for anomalies, such as scale build-up.
Motors are looked at for signs of overheated bearings, shaft misalignment, or overheated windings. Over- or under-lubrication can be diagnosed. Catching overheated bearings on conveyor belts can minimize downtime and prevent a costly stoppage. Infrared cameras specially optimized with high temperature ranges are used for furnace inspections, permitting the technician to see through flames for high temperature industrial furnaces, heaters and boilers.
On the electrical side, infrared cameras can examine issues related to a primary power source, such as an outdoor high voltage switchyard or transformers. Components that help control and direct electricity also often harbour electrical issues, such as loose or corroded connections revealed by an infrared camera: primary switchboards, distribution boards, control panels, fuse panels, electrical cabinets and motor control centres (MCC). Plus, emergency power systems are essential to uninterrupted production. Finding issues here ensure that the back-up system itself doesn’t cause cascading failures.
Technicians that use infrared cameras often utilize them in conjunction with test equipment to monitor power quality and electrical factors, such as current loads. Combining the temperature data from an infrared camera with electrical readings from a clamp-on meter, for example, can provide even more insightful monitoring. With technologies, such as FLIR’s new MeterLink system, infrared cameras can actually receive electrical readings transmitted via Bluetooth from MeterLink-enabled Extech clamp meters, imprinting the current or voltage readings right on the IR image. Not only does this offer a time saving, it ensures accurate documentation for PdM inspection reports.
The capabilities of infrared cameras aren’t system-specific, enabling technicians to think "outside the PdM box" when monitoring plant-wide systems. For example, infrared cameras can be used to audit the energy efficiency of your plant environment, including roofing, heating and cooling systems, and building structures. Versatility like this quickly drives up an IR camera’s return on investment (ROI).
If we take a step back to look at the big picture goal of PdM, cost-effective practices are imperative. Infrared cameras are most effective in an uptime environment, evaluating equipment when they are operating under normal conditions versus scheduled downtimes, saving companies dollars.
Infrared significantly speeds up inspections without compromising the quality of the diagnostic work. If performed by in-house trained thermographers, cost savings can also be attributed to reduced inspection labour costs. Depending on how your staffing, budgets and costs are structured, third-party thermographers may instead be more attractive.
From a toolbox investment perspective, infrared cameras are more cost effective than ever. Infrared cameras were once considered a pricey, "rent-only" tool, and in fact, they only broke the sub-$10,000 price barrier in recent years. As advancements in IR camera design and technology accelerate, prices on infrared cameras continue to fall with general-purpose models now starting for less than $2,200 in Canada. With a ROI potential, plant managers are finding it easier to justify purchasing multiple infrared cameras for cost-effective, in-house PdM use.
Business-side benefits of infrared thermography are worth discussing with your plant and executive management. From a business manager’s perspective, it’s important to consider the shift towards infrared cameras as also a shift towards employee safety. Putting infrared cameras in the hands of plant maintenance personnel and making infrared thermography a key non-destructive and non-contact test method in your plant—sends a clear signal that investments are being made not just to save dollars on plant asset—but also to provide safer, non-contact inspection methods that themselves will reduce employee hazards that might result from catastrophic failures.
Formal infrared thermography certification training is also available to internal PdM staff from organizations, such as the Infrared Training Center (www.infraredtraining.com). Not only is training and certification important for better inspections, it also represents an employer’s commitment to professional development for their staff. In the mid- and long-term, the ROI is apparent not only in increased employee retention rates, but also in better-defined advancement opportunities at your plant.
If your organization is delaying an IR camera investment, it’s ultimately a costly mistake. Infrared cameras offer PdM professionals accelerated detection of problems while keeping systems operational. Their diagnostic capabilities can significantly prevent premature equipment failure while extending equipment life. During scheduled PdM monitoring, IR cameras can also identify potentially hazardous equipment. Keep in mind that in some industries, infrared thermography can also reduce your insurance premiums.
The cost-effective advantage of an infrared camera can be boiled down to this question: "What would downtime cost due to a failure that could have been prevented?" Unfortunately, for some companies, it takes a million-dollar, "I told you so" failure event before infrared is seen as a reasonable and sensible investment. Infrared diagnostics can improve uptime by focusing resources on repairing or maintaining equipment to prevent failure. Adoption of infrared can result in substantial cost savings, higher system reliability and improved production and product quality.
This is an edited article provided by Extech Instruments. André Rebelo is global communications manager, Extech Instruments, a FLIR Company. You can contact him by email: firstname.lastname@example.org. For more information, visit www.extech.com.