Project Engineering a Machinery Management System

Project Engineering a Machinery Management SystemHow to make sure your next project delivers the tools you need to properly protect and manage machineryby Mark Snyder, P.E.price, size, ease of specification, and the philosophy of“we’ve always done it this way.” These criteria aren’t neces-Senior Solutions Specialist,Machinery Management Systemssarily wrong; but, if they become the overriding criteria, lessBently Nevada Corporationobvious (but nonetheless crucial) features may be compro-e-mail: mark.snyder@bently.commised or left out.Thus, the first step in a successful project is relatively sim-ple, but cannot be over-emphasized: don’t assume that othersThe opportunity – a new projectwill (or can) represent your interests.f you are an equipment user concerned about machineryTypically, Bently Nevada will share your interests, butassets, it’s likely that you are busier than ever because ofsometimes we can’t easily represent them, particularly formanpower cuts and broadened responsibilities. What“traditional” projects where our scope of supply only encom-happens when a new plant or upgrade project comes along?passes hardware and software – not applications engineering,You probably view it as a chance to install better machinerysystem design, and project management. In these cases, ourprotection and management tools – tools that will help youinput is sometimes not solicited or allowed until late in thework more efficiently and effectively. However, even if givenproject. Furthermore, by the time we are asked to participate,the opportunity, will you be able to effectively influence theour ability to influence project details is long past, and sys-details of the project to ensure systems that are truly “besttem evaluation has been reduced to price comparisons only.practice” get installed? How will your philosophies and pref-There are two ways to address this. erences be communicated to the project engineers and man-Approach #1 – fully utilize Bently Nevada’s service agers, some or all of whom may be of another discipline, inorganizationdifferent departments or companies, or in other states orThe first way to ensure your voice is heard is simply to out-countries? This article provides insight into how you can source the entire project to someone who shares yoursucceed.machinery protection and management philosophy. The challenge – ensuring your voice is heardTo support this, Bently Nevada has restructured and aug-Although others may have the responsibility for design andmented its service organization along the lines of an engi-specification of these systems, your ability to fulfill the assetneering services company. You’ve relied on us for years formanagement objectives of your organization will be greatlymany individual facets of project work, including cabinets,affected by their choices. If you don’t voice your needs dur-Factory Acceptance Testing of machines and instrument sys-ing the relatively brief period during which basic systemtems, mechanical and electrical system designs, site supervi-functional specifications are assembled, your long-term capa-sion, and field system commissioning. Our new organizationbilities will default to the lowest common denominator, asmakes it possible for us to participate as an alliance partnerdefined by others.with your project design team. Bently Nevada can “fill theProject engineers and managers – even your corporategaps” and provide knowledgeable and cost-effective projectmachinery consultant or operations representative – oftenengineering and management services. More importantly, weevaluate machinery protection and management equipmentcan eliminate losses and inefficiencies related to circuitousfrom a different perspective than you do. They often focus onrouting of product and field installation documentation. We24ORBIT Fourth Quarter 1999can also manage software updates and hardware upgradesmay be relegated to a line item for the purchase of a portableduring the extended project cycle and can ensure that thedata collector. That is an easy choice for a project manager tooften-neglected commissioning and training services are opti-make; it is usually an insignificant expenditure relative tomally coordinated. It is only proper that the company thattotal project cost, and is a stand-alone item that has no designdesigns and builds these sophisticated engineered systemsor integration requirements. However, how effective ashould actively participate in their application and installation. machinery management tool will it be?In an ideal world, this is our preferred solution for virtuallyLet’s review the definition of a machinery management system:all customers. The likelihood that your system will meet your“Products that provide data and information that is inter-needs (and will deliver a faster return on investment) ispreted and applied by people to correctly operate, maintain,increased when your macro objectives are communicated andand monitor the condition of their machinery.” The definitionthe numerous details of system implementation are left to us. infers that machinery decisions are made, based on data andinformation. More and better data and information logicallyThis approach is being adopted by a number of our cus-translates into better machinery decisions. A walk-aroundtomers. However, we understand that we have to provide themachinery management program relies heavily on people andlevels of service that meet your individual approaches andtime for the quantity and content of data. Consequently, thestrategies. Our services are scalable to support this; they canlogical way to provide better decisions is to throw more man-range from providing only hardware and software to behours at portable data collection. The problem with this isinstalled by others, to the full “turnkey” approach describedthat additional manpower is not available. Quite the contrary,above, to various levels in between.the only viable solution to today’s manpower shortages is toApproach #2 – “selling” your own project managementautomate time-consuming, repetitive tasks. So we see that ateamportable data collector, when applied to a program involvingIf you do choose to manage the project-related details your-a large number of machines or expensive critical machinesself, it is still essential that you clearly and convincingly con-that warrant close attention, is not in step with today’s busi-vey your macro objectives to your project management team.ness environment. If your plant really aspires to long-termThus, the second way to achieve project success is to be fullyprofitability, the obvious choice is to add an online machin-prepared to articulate your perspective on the need forery management system to the infrastructure of your newmachinery protection and management systems, and basicconstruction or control system upgrade project.system capabilities and architecture. The remainder of thisNew construction and upgrades are the most cost-effectivearticle provides the supporting information you will often“window of opportunity” you have for installing onlineneed to “sell” your own project management team on themachinery management systems. The following items are allvalue of machinery management and the proper implementa-luxuries not afforded to the person retrofitting such systemstion of it. into a completed and operating facility: • Economies of scale.FAQs• Availability of labor.If you have found yourself at a loss for the right words, thefollowing answers to “Frequently Asked Questions” will help• Easy integration into network and control system designs.you eliminate misconceptions and align the thinking of your• The chance to easily locate and route the necessary com-project engineers and managers with your own perspective ofponents and cables.this equipment and its installation. The answers include howIf you are concerned that you can’t instrument all of theyour preferred vendor can have a significant impact on themachines you want to, comprehensive systems like Bentlyproject, and in a way that successfully accomplishes bothNevada’s System 1™ will allow for portable collector data toyour own and the project’s goals.be integrated into the same database and display formatsused by online monitoring systems.Isn’t Predictive Maintenance or Condition-BasedMaintenance something we can wait to worry about untilWon’t the OEM take care of specifying this?the plant is running?Most Original Equipment Manufacturers (OEMs) do a goodSome project managers do consider Predictive Maintenancejob of providing machinery protection systems. In fact,(PM) and Condition-Based Maintenance (CBM). However, itBently Nevada works closely with many OEMs to specifyORBITFourth Quarter 199925proper protection systems. However, these are not manage-ment systems, but rather products that provide shutdown of amachine or return it to a safe or nondestructive mode ofoperation without human intervention. As such, they aremachine-specific. An OEM doesn’t typically focus on theoverall Decision SupportSM infrastructure of your plant, butrather on the automatic shutdown of the machine(s) they pro-vide. Unless stipulated in their contract, OEMs are not usu-ally concerned with your overall machinery managementFigure 1. Vibration trend of a machine during startup.strategy.A project needs to coordinate the protection systems pro-speed, and you would see the trend plot shown in Figure 1. Avided by multiple OEMs. This not only ensures that propercontrol system samples the vibration level at an interval cor-hardware and connections are provided for the machineryresponding to its scan rate, as is indicated by the dots in themanagement systems, but also guards against a patchwork oftrend plot. If the level is higher than it should be, that indi-several vendors’ transducers and protection systems, eachcates an abnormality and might even trigger an alarm or awith its own architecture and hazardous area methodology.shutdown relay in the protection system. However, not muchThis is increasingly important as plants employ performancewould be known except that the vibration is high.monitoring (Bently PERFORMANCE™) and DecisionNow, consider how a machinery management system sam-SupportSM systems (Machine Condition Manager™ 2000).ples the data. Taking just one of those dots, the system sam-Operation and training issues dictate that common systemsprovide information from different machine types and manufacturers.Can’t the process control system (e.g., distributed controlsystem or programmable controller) perform machinerymanagement functions? This is a common misunderstanding. The raw data of con-trol systems is discrete status (on/off) and proportional values(temperature, pressure, flow, level, etc.). Unlike many ofthese proportional values whose information content requiresrelatively small bandwidths (often 10 Hz maximum), vibra-tion transducers provide information content requiring amuch larger bandwidth – typically 10 kHz or more – thatcannot be addressed by a process control system. Reallymeaningful machinery data and information cannot beextracted from looking only at corresponding proportionalvibration level values. Even a trend of these values onlyFigure 2. The machinery management system samples the vibration waveform, not just the overall vibration, at 128 samplesdepicts historical levels, and, by itself, little else about theper shaft rotation. This provides more information, which assurescause or nature of the vibration. Overall vibration amplitudemore effective decision making.is suitable for machinery protection. Indeed, this is one of theproportional values that a vibration monitor uses to generateples the transducer signal 128 times per revolution for eightalarms. However, a machinery management system needsshaft revolutions. There are specific reasons for choosing thisvibration characteristics (shape, frequency, phase, direction,interval and duration of sampling [1]. Note that this is aand so on) to provide meaningful data and information aboutsnapshot of the shaft’s position relative to the tip of a proxim-a machine’s operation. It is important to understand this ity probe (not the vibration amplitude or level) every 1/128thdistinction, as illustrated by the following example.of a shaft revolution (Figure 2). At a typical shaft speed of3600 rpm, this sampling is extremely rapid. These analogConsider a machine where the vibration level increases withsamples are digitized and placed in a memory buffer before26ORBIT Fourth Quarter 1999being sent, on demand, to a machinery management work-plots like those shown in Figure 3, in conjunction with trendsstation computer.and process information, enable a Machinery DiagnosticsA level measurement by a process control system (one dotEngineer or a Decision SupportSM software program to trans-in Figure 1) would be four bytes of information. The digi-late the vibration characteristics into Actionabletized waveform and supporting information associated withInformationSM. This information supports decisions regarding:this point is approximately 100,000 bytes of information. A1. What part of the machine is deterioratinggood analogy to this 25,000:1 ratio is the amount of fuel in a2. How severe the problem is, how long the machine canlarge dual-tank semi trailer truck compared to the amount itoperate under the current conditionstakes to fill your lawnmower.3. What process changes might be made to alleviate theThis is just one transducer. To correctly assess machinesituationbehavior, the same sampling must occur simultaneously on4. Whether it should be restarted after it was automaticallyeach transducer on the machine. This high speed “parallel”or manually shut down on high vibration. data collection is an essential feature of good machinery dataThis information should also be readily available, via localacquisition systems, but would quickly bog down a controland wide-area networks, to others who can assist with or con-system and is somewhat foreign to its sequential scanningfirm the decisions you make. architecture. Don’t let the system architectures designed forcontrolling the process limit the information required forAren’t such systems really optional? It seems like weproper machinery management and decisions.could do without such “frills,” or add them later.While it is true that project costs can be saved by removingIsn’t trending vibration levels in the process controlsuch systems from the project’s scope, this is almost never ansystem good enough?enlightened business decision when the ongoing needs of theContinuing with the above example, there is a marked dif-plant are considered. Nobody would seriously suggest remov-ference between the data from the control system and theing the process control system from the scope of a plant,data from the machinery management system. Diagnosticopting instead for some kind of basic “process protectionsystem” by itself. However, that is howmachinery is sometimes approached –that it is merely enough to “protect it”rather than “manage it.” Remember,there is a very real cost associated withlack of proper machinery managementcapabilities. How expensive will theinability to make informed machinerydecisions be to the plant once it isoperational? This must always be theoverriding criteria when assessing thevalue of a proper machinery manage-ment system. For many of the projectswe are involved in, just a few hours oflost production will immediatelyeclipse the cost of the machinery pro-tection and management system. Also,as addressed in a later question, thecost to retrofit a system is always sig-nificantly higher than the cost to installit concurrently with the machinery protection functions. Figure 3. Diagnostic plots from the DM2000 software program are the foundation forActionable InformationSM.ORBITFourth Quarter 199927Can’t we connect a Bently Nevada machinery manage-information. Other manufacturers’ monitoring systems can bement system to our non-Bently Nevada protection system? connected to Data Manager® 2000 using a TDXconnX™It is possible, but installation will be complicated andadapter. However, the protection system must have propor-tedious, far more expensive than connecting to a Bentlytional (4-20 mA) recorder outputs for each channel, two Nevada protection system, and the system’s functionality willlevels of alarm relay outputs for each pair of channels, abe limited. Two premises are fundamental to an understand-buffered and unfiltered transducer output for each channel,ing of why this is so.and up to four Keyphasor® signals (Figure 5). For a 24-chan-First, a protection system performs functions that are essen-nel system, this equates to over 125 color-coded wire termi-tial to the machinery management system. Vibration ampli-nations on the back of the protection system. All these inputstudes (levels) are calculated from the sensor measurements,must be isolated from the machinery shutdown signals andand eventually trended in the machinery management system.circuitry to ensure that the machine protection is not compro-Alarm levels are set to communicate when a machine ormised. If there is insufficient I/O available from the protec-machine component is in distress. Transducer integritytion system, it may or may not be possible to add it. Evenchecking, or “OK” circuitry, helps administer the transducerwith complete I/O, this system will have diminished func-system on which the protection and management systemstionality and accuracy relative to that afforded by the two-depend. Duplicating these functions in the machinery man-cable connection to the Bently Nevada racks. Consideringagement system would add unnecessary cost and duplicatethis, some customers with third-party monitoring systemshardware, result in conflicting measured levels, and requirehave resorted to the (more economical) purchase of a Bentlythe management of duplicate sets of alarms. Nevada protection system to replace or run in parallel withtheir existing protection system. Second, a good machinery management system adjusts itsdata collection, data storage, and data movement based onthe condition of the machine. If the protection system sensesa vibration level that exceeds an alarm setpoint, you want themachinery management system to save a waveform sample atthe moment the alarm occurs. If an unanticipated shutdownoccurs, you want the machinery management system to rap-idly capture transient data at set speed intervals as themachine coasts down [2]. Figure 5. Six cables and twelve connections needed to carry datafrom only two channels in hybrid system.Vibration transmitters are an attractive option to the instru-ment engineer who considers vibration as just anotherprocess measurement. In an attempt to interface a machin-ery management system to vibration transmitters, bufferedsignal outputs may not be available, not to mention the otherinputs described above. In general, vibration transmittersaren’t the low-cost option they appear to be [3], and areFigure 4. Two cables and four connectors carry data from 24 channels in a BNC machinery protection system.very problematic from a machinery protection and manage-ment standpoint [4].The communication between a Bently Nevada machineryIf you specify Bently Nevada systems from the beginningprotection system and the Data Manager® 2000 System isfor both protection and management, you will get a systemaccomplished with two cables and mating multi-pin connec-that is better integrated, easier to maintain, and costs less.tors (Figure 4). One of the connectors carries the raw trans-The most advantageous time to do this is during a project,ducer outputs, and the other carries digital status and levelnot afterwards.28ORBIT Fourth Quarter 1999Why bring process variables into the machinery manage-be left as an afterthought of project planning. It saves moneyment system?to plan for them from the start of the project.Process conditions are often responsible for the onset ofDo project resources really need to be dedicated to coordi-machinery problems. The ability to view and correlatenating the plant-wide machinery protection and manage-process trends with vibration trends and plots is a powerfulment system?diagnostic tool for understanding your machine’s behavior.Yes. Few people would purchase a process control systemProcess variables are factored into Machine Condition(such as a large-scale DCS) as simply a box of parts andManager™ 2000 software’s rule sets for fault diagnosis and“do it themselves.” The complexity and integration detailsare used by Bently PERFORMANCE™ to provide an inte-warrant that people with dedicated skills and experiencegrated machine health and performance package. Asprovide the project-related services to make sure the systemdescribed earlier, moving the bandwidth-intensive machineryworks as intended. Machinery protection and managementdata to the control system is not practical. It makes moresystems are no different. The complexity and integrationsense to move a smaller amount of process proportional val-details in such systems rival those encountered in processues to the machinery management system, where it will becontrol systems.available for distribution with the vibration data to remoteviewers. Using today’s network technologies, it is possible toSummaryretrieve process data from the control system or plant histo-By now, I hope you have gained an appreciation for how arian with an insignificant hardware investment. Time-machinery management system should be an integral part ofstamping and time synchronization capabilities make theall facets of a facility’s design. The project disciplinesvibration/process correlation more accurate than ever before.involved in a proper machinery management installationKnowing this, is there any advantage to bring bearinginclude mechanical, electrical, instrumentation, control sys-temperatures in through the protection system (as opposedtem, information technology, and network engineering.to the control system)? Bently Nevada has the multi-disciplined ability to success-fully and cost-effectively engineer and install your machineryYes. The basic premise is that the alarms and process vari-management system project. We have offices worldwide, giv-ables will be most useful during a quickly occurring machineing us the unmatched ability to globally coordinate OEM,transient or problem. As mentioned above, the machinerydesign, and fabrication activities. Contact your local Bentlymanagement system adjusts its sampling rate during an alarmNevada sales or service professional for more information. or machine startup/shutdown, and this sampling rate is fasterthan the sampling rate of the process control system. Forproblems that occur rapidly, this disparity will introduceuncertainty into the problem analysis that channeling theReferencestemperatures through the protection system would avoid. It is1. Southwick, D., “Sampling waveforms and computing spectra,” ORBIT,also good practice to group all machinery protection parame-Bently Nevada, September 1993.ters (for instance, bearing metal temperatures) into a single,2. Thomas, R., “The importance of transient data analysis,” ORBIT, Bentlydedicated system, such as a Bently Nevada instrument rack,Nevada, September 19953. Heckman, A. T., “Vibration ‘transmitters’ cost less than monitors . . . Factrather than using the basic process control system for suchor fiction?” ORBIT, Bently Nevada, March 1997.protective functions.4. Sabin, S., “The limitations of protecting and managing machinery usingShouldn’t we wait until after we get the machines pur-vibration ‘transmitters,’” ORBIT, Bently Nevada, March 1997.chased and the control system all designed to discuss this?Machinery monitoring no longer consists only of stand-alone systems. Effective machinery monitoring has alwaysrequired knowledge of proper transducer selection andmechanical installation, and proper signal-wire shielding andgrounding. However, now it is integrated with the controlsystem, emergency shutdown system, plant information sys-tem, local area network, and computerized maintenance man-agement system (CMMS), etc. These interfaces can no longerORBITFourth Quarter 199929