Machine Reliability and Protection in Plants with Hazardous Areas

Nov. 4, 2009
A recent study identified the growing need for integrated predictive health solutions to complement the core protection functionality required for high-end equipment. 
The process manufacturing industries have used dedicated machinery protection systems for high-end equipment for quite a while. These systems consist of many components, including sensors that require a large nest of wires that connect to a bank of rack-mounted electronic control equipment. These racks are often located in environmentally protected rooms or the plant control room. In plants with hazardous (explosive) areas, this can be particularly problematic, because special work permits are often required to perform repairs, upgrades or even routine maintenance on the equipment. Most legacy machinery-protection systems installed in existing plants have point-to-point connections that require as many as eight or more separate wiring runs between hazardous and safe areas of the plant. As plants increase in size, every inch of free space for new components has long since been filled with overloaded cable trays. This makes upgrading to new equipment of any kind increasingly difficult; there simply is no extra space. Even replacing older equipment with newer units is a chore, due to the increasing probability of damaging equipment and connections adjacent to or close to the slot being worked on.In the past, machinery protection systems have not taken advantage of intrinsically safe (IS) communications networks, despite the widespread acceptance of these for process-control networks in Europe and, increasingly, also in North America. And unlike the plant asset management (PAM) systems for other classes of process assets, legacy machinery protection systems rarely include much, if any, predictive asset management functionality, which could alert operators well before a costly protection system shutdown is required.These and other reasons prompted San Diego-based SKF Reliability Systems, (, a world leader in machine reliability, to introduce a compact, locally mounted, intrinsically safe integrated protection and predictive asset health solution for plant machinery. SKF collaborated with IS interface equipment leader, Pepperl+Fuchs Inc. (, Twinsburg, Ohio., to develop a field-mounted IS protection and predictive condition monitoring solution called DMx that is suitable for installation close to the equipment it protects, even in plants with hazardous environments. Low installed costSuccessful applications include critical and non-critical turbo machinery and pumps in pipelines, refineries, chemical, and water and wastewater plants. End-users value the low installed cost and its ability to quickly migrate legacy systems to DMx’s distributed architecture close to the machinery, without disrupting plant operation. The intrinsically safe design allows installation without special authorization. Current agency approvals include ATEX, CE, and UL. This validates its applicability for both hazardous and conventional environments. Additionally, the ability to use the RS-485 signal to connect operators in the control room to the intelligence embedded in the DMx system provides needed insight into equipment health.The configuration and data display software provides intuitive management of transducers, equipment health data and alarms. The interface can access scalar value, time-waveform, Fast Fourier transform (FFT) and orbit data from a multitude of DMx monitor channels. Users can also deploy SKF’s @ptitude Monitoring Suite for additional data analysis, as needed.This innovative solution provides refineries, petrochemical plants, oil and gas pipelines, mineral process plants, water and wastewater plants, and other process plants with both heavy machinery (pumps, turbines, compressors) and hazardous areas with a practical option to replace aging, legacy, hard-wired machinery protection systems with the latest digital technology.Wil Chin, [email protected], is a Research Director at ARC Advisory Group Inc., in Dedham, Mass.SKF Reliability Systemswww.skf.comPepperl+Fuchs

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