Success in today's highly competitive building management business depends upon high tenant occupancy, controlled expenses, and most importantly - uninterrupted and trouble free operation. That means no unexpected shutdowns, no major equipment and service failures, and no high cost emergency repairs.

     Contrasting most building management and engineering practices prior to 1990, today's successful commercial property can no longer afford to follow the "run to failure" mode of operation for its mechanical equipment. Computer centers, hospitals, financial interests, and Internet related business all demand virtually uninterrupted power, cooling and other HVAC services. Yet, industry wide reductions of maintenance manpower have reduced or greatly limited the ability to perform "preventative maintenance" anywhere other than at the most well recognized problem areas.

     With the conflicting demand to provide more reliable building services at lower cost and with limited personnel, many property managers and plant engineers have turned to "predictive maintenance" programs as the answer.

     Unlike preventative maintenance, which sets a fixed and often arbitrary interval for performing regular maintenance and corrective tasks, necessary or not - predictive maintenance, utilizing a variety of nondestructive testing techniques (NDT), can identify only those specific pieces of equipment in need of service. In most cases, NDT can provide months and even years of advance notice that a problem exists, or is developing.

     Nondestructive testing also serves as a valuable property evaluation tool for long term capitol planning and improvement, as well as for property acquisitions. Such testing becomes invaluable when applied to older properties relying upon original electrical and piping services, and especially where the prior maintenance history is unknown, or is suspected to have been deficient.

     With only a limited amount of engineering investigation typically performed prior to most purchases, it has become common for property owners and operators to learn of serious mechanical or electrical flaws only after the property has changed hands.

     By far, the most commonly recognized and employed nondestructive or predictive testing tool is the use of infrared thermography (IR) to detect hot spots at electrical panels and equipment. IR testing not only replaces the older, time consuming preventative maintenance procedure of torquing down all electrical connections and taking amperage readings, but also identifies a variety of other potential electrical problems, previously unaddressed.

     Any building operator who has performed IR testing has likely seen the direct benefits of such an annual inspection; most can cite examples of where infrared testing has prevented an imminent fire or electrical meltdown, along with the resulting repair costs and service interruption.

     The benefits of IR are so well recognized that many insurance companies now require annual inspection as part of their terms of coverage. Read more about infrared electrical testing.

     With the growing age of most established properties, often at 40 years or more, building owners and plant operators are also beginning to question the remaining service life of their main HVAC piping systems. This concern surprisingly exists at many newer buildings and renovations which, for a variety of reasons, are finding themselves faced with advanced corrosion problems and premature piping failures rarely seen decades ago.

     Unlike older properties, which were constructed typically using extra heavy or schedule 80 steel pipe, commercial properties built within the past 25 years have used much thinner materials. During this same time, hours of service have increased, the use of lower quality foreign steel pipe is widespread, and government regulations and restrictions have reduced the effectiveness of both corrosion inhibitors and microbiological controls. Read about changes in piping trends over the past few decades.

     Considered more of a general evaluation method than a predictive maintenance tool, ultrasonic testing (UT) offers the ability to accurately measure pipe wall thickness on-line and without any service disruption. Combined with thorough data analysis comparing original, current, and lowest permissible wall thickness, UT will provide the property owner or plant operator with a clear understanding of current corrosion conditions and the remaining service life of any piping system.

     For a property manager concerned about a recent leak condition, UT will show not only if it was an isolated event or the first occurrence of a system wide problem, but also provide the hard documentation to justify its repair if necessary.

     Whether a general concern about a 45 year old condenser water system, suspicions about the quality of one's water treatment program, a deficient maintenance history, or the more obvious indication of a problem shown by leaks, clogged pipes, and buckets of removed scale, properly performed ultrasonic testing will provide the answers. See Technical Bulletin P-7 for more about the level of information provided by ultrasonic testing.

     Growing concern about the aging infrastructure of older properties often points to the many tanks and vessels critical to a building's HVAC operation. Again, ultrasonic testing provides the opportunity to evaluate domestic water house tanks, expansion tanks, cooling tower pans, heat exchangers, and other metal structures for remaining service life based upon their remaining wall thickness.

     Properly applied, and given sufficient wall thickness readings, UT can actually provide a three dimensional view of the interior wall to show the general corrosion loss or a specific weakened area. The below graphs, produced after performing 400 to 500 or more ultrasonic measurements per side wall, well illustrate not only this particular problem, but the power of ultrasound to produce a virtual 3-D dimensional profile of each interior tank wall and bottom.

     At the left, ultrasonic testing along a standard X-Y grid at the side tank walls produces a clear picture showing a failure of the coating and the resulting corrosion at the water line. We see the uniform wall thickness profile below the water line, to the right, and the slightly more corroded area above the water line to the left.

     At the right side graph, based upon a separate ultrasonic investigation, we can show an extremely uniform wall thickness at the front and back sides. No corrosion exists at the exterior, and the inside coating is obviously intact - as average wall thickness exists virtually at the specification for this steel tank.

     For rotating equipment, vibration analysis offers the ability to track equipment operation under real time conditions and detect the very slightest defect. A bearing that has a small developing fault will produce a tell-tale change in the machine's vibration signature - so will a weight imbalance, shaft misalignment, or literally hundreds of other causes. Such an ability to identify mechanical problems at this early stage, and before they even reach the point of being able to be detected by infrared testing, defines vibration analysis as the ultimate predictive maintenance tool. See Technical Bulletin M-9 for more about vibration analysis.

     Overall, the benefits of nondestructive testing have been well documented in virtually every commercial and industrial setting. Whether employed as an annual prediction maintenance tool, or as a means to investigate a specific equipment failure or area of concern, nondestructive testing offers major benefits in savings and increased operations reliability to all management professionals.

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