Vibrations June 2012

Rotordynamics of PumpsPart II: Between-Bearing PumpsBY MALCOLM LEADER, P.E.

VibrationsJune 2012 | Volume 29, Number 2

For the Vibration Analyst Community

www.vi-institute.org

147451 Vibrations r6.indd 1 6/11/12 12:00 PM

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June 2012Volume 29, Number 2ISSN 1066-8268

l etter from the executive directorMy tenure with the Vibration Institute began August 2010, and the last two years have been the most rewarding of my professional association management career. Though our organization’s charter and mission have remained steadfast, several changes during that timeframe now provide a better experience for certified vibration analysts and members—and ultimately put our mission into action.

cust o MeR-al Igned ad MInIst Rat IVe su PPo RtAs an organization with over 2,300 certified vibration analysts and members worldwide, we wanted to be sure that our administrative support was aligned to effectively respond to the needs of all our stakeholders. Improvements include:

• Upgrading our administrative resources, including office technology, thecomputer network, financial software, and the phone system to increase the efficiency and effectiveness of daily business operations—and better serve members.

• Reorganizing staff functions to better align roles, responsibilities, andaccountabilities for certification, training membership, finance, and administration.

• Working closely with board officers and the board of directors to increasetransparency through ongoing communication, quarterly conference calls, and two annual face-to-face meetings. The board has worked diligently and effectively to review and develop new programs that are of value to you and will support the next generation of vibration analysts (see page 23)

ReVIta l IZIng ou R BRandSince 1973, the Vibration Institute’s mission has been the cornerstone for our growth and expansion. As a result, we have updated our look and interface with you to ensure that we remain vital to the profession we serve. Changes include launching the Institute’s new website, www.vi-institute.org, in January 2012. It provides information in an intuitive and easy-to-use format in six verticals:

• AbouttheInstitute• Membership• ProfessionalDevelopment• Certification• ProductsandServices• ChaptersandPartners

The website also prominently features the annual Vibration Institute Training Conference and Online Store, two of the most widely used content areas of the site. The Members Only section, which will be available soon, will include a wealth of informationandresources.Pleasestaytuned!

Karen a . Bresson, caeExecutive Director

4 | JUNE 2012 Vibrations

Vibrations is published quarterly in March, June, September and December by the Vibration Institute. Statements of fact and opinion are the responsibility of the authors alone and do not imply an opinion on the part of the officers or members of the Vibration Institute. Acceptance of advertising does not imply an endorsement by the Vibration Institute.

© Copyright 2012 by the Vibration Institute.All rights reserved. Materials may not be reproduced or translated without the express written permission of the Vibration Institute.

editorKaren E. Bresson, [email protected]

t echnical editorRobert Sayer, [email protected]

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l ist of advertisersCommtestConnection Technology Center, Inc.Data PhysicsElectro Static TechnologyIMI SensorsLudecaMeggitt Sensing SystemsRBTS, Inc.

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Please send any correspondence regarding change of address or advertising to the Vibration Institute.


More changes to increase the value of your Institute membership:

• In March 2012, we redesigned our flagship publication,Vibrations. The purpose of the redesign was to bring the look and feel of the publication into alignment with the Institute’s new branding and website. Additionally, the publishing of Vibrations was brought in-house in January 2012 and every 2012 issue will be available online. We will continue toinclude the same outstanding technical content that you have cometoexpectovertheyearsundertheguidinghandofDr.Ronald Eshleman, but we are providing new features likethese:

• Lettersfromthepresidentandexecutivedirectorthroughoutthe year

• Sectionsaboutcertification,training,andacademicprograms• From the Archives—timeless papers relevant to the

profession no matter how much time has passed since they were written (beginning with the September 2012 issue)

• New advertisers—to gain the attention of the vibrationcommunity, contact the Institute at (630) 654-2254

Wewill also be researchingour options to publishVibrations in an optional electronic format in 2013, to better serve our members and the vibration analyst community, so stay tuned.

add Ing Value fo R ou R MeMBeRsAs a nearly 40-year-old organization, we feel there is an opportunity to examine how we can further strengthen the Institute and provide added value to all our stakeholders. Ideas we’re implementing include these:

• RevisingtheCorporateSponsorshipprogramtoincludethreelevels—Platinum,Gold,andSilver—andincreasebenefitsandvisibility through the new website. The number of corporate sponsors has increased from 40 in 2010 to 52 in 2012.

• Furtherextendingourreachglobally:We enhanced communications andnow provide regular updates and information to our international representatives. Since 2010, we have increased the number of international representatives to 27, representing a 26 percent increase, with new representatives in China, India, Indonesia, Italy, and Mexico.

• Reducing turnaround time for certification examinationresults by 10 days, to

ensure

that certification examination information is available quickly to candidates.

co MIng soonThe demonstrated success of these changes further deepens our commitment and drive to continue to align with our mission and nurture the next generation of professionals. In the coming months, you will hear more about:

• A membership database that will allow us to capture andstore information more efficiently and provide up-to-the-date information on certification, training, members, products, and services, plus a new online membership directory.

• An enhanced strategic plan, developed by the board ofdirectors, that will position the Institute for growth and opportunities, and will seek like-minded organizations to partner on projects that will further enhance the profession.

Of course, none of this would be possible without the commitment and hard work of so many, including our dedicated board of directors, committees, volunteers, and hardworking staff, all of whose candid and supportive feedback helped guide us. Noneof the changes throughout the past two years would have been possible without the hard work, dedication and involvement of many—and this is just the beginning. The best is yet to come.

| 5 JUNE 2012 Vibrations

contents4 l etter from the executive

director By Karen A. Bresson, CAE

6 f eature a rticle Rotordynamics of Pumps Part II: Between-Bearing Pumps By Malcolm Leader, P.E.

11 t echnical a rticle The Effect of Structural Asymmetry on the Vibration of Small Diameter Fan Rotors By Robert J. Sayer, PE 19 c ase histories Mechanical Looseness in a Fan System By Robert Jonas

21 Vibration of a Polyester Chip Crystallizer from an Electrical Source By Clyde Bridges

23 a cademic c orner Establishing a Blueprint for the Future By Nancy L. Denton, P.E.

25 a nnual l ist of c �� Individuals



By Malcolm Leader, P.E.

P art I of this article, published in the March 2012 issue of Vibrations, concentrated on the rotordynamics of single-stageoverhungpumps.PartIIconcentrateson

the rotordynamics of between-bearing pumps.

Between-Bea RIng Pu MPsSome applications place a single impeller between bearings, usually employing a double-suction single-discharge arrangement. These designs will deliver more volume this way. With the impeller between bearings, the gyroscopicmoment of the impeller cannot increase the critical speed of the rotor as with overhung machines (see reference 4). Typical applications are cooling tower pumps and boiler feed pumps. Such was the case with several problematic high speed (4,900 rpm) boiler feed pumps in a power plant. These pumps had a large pressure differential and two large eye “wear” rings, one on each side of the impeller. A portion of the complete trainmodelisshowninFigure1.Thisfiniteelementmodelfeatured a complete case model with measured support characteristics. The orange bars represent two bushings with a 375 psi pressure differential and two eye seals with an 850 psi pressure differential. This pump experienced high vibration and bearing failures.

The calculations showed that each impeller eye seal was almost 500,000 lb/in while the plain journal bearings were only 350,000 lb/in each. The seals were supporting the rotor

and did not have sufficient damping to control vibration. The bushings outboard of each eye seal were also unloading the bearings. Since modifying the seals was not an option that this user wanted to explore, highly preloaded tilting pad bearings were retrofitted. These bearings were designed with offset pivots so that significant stiffness and damping would be applied to the rotor even if the bearings did not have a significant gravity load. Although these pumps continued to have unexplained vibration excursions, believed to be caused by thermal effects, they run very well now that the bearings are supporting the rotor as well as the seals.

f eature a rticle

Rotordynamics of Pumps

Part II: Between-Bearing Pumps

Malcolm l eader, P.e.Owner of Applied Machinery Dynamics CompanyDurango, CO

f igure 1. double-suction Between-Bearing Boiler f eed Pump



Mul t I-st age Pu MPsTake the previous example and add more stages and you get something like Figure 2. This is another boiler feed pumpwith a double-suction first stage and three additional single stage impellers. The water comes in, flows through the first and second stages, then crosses over to come back in the other side for the last two stages. This is done for hydraulic thrust balance.

This 1,800 hp pump has two plain bearings, two bushings, five eye seals and three hub seals. The seal pressure differential ranged from 40 psi to 160 psi and the speed was 3,585 rpm. Asthiswasanauditofanewpump,afullAPI610analysiswasconducted.ThisincludedanANSYSmodelofthepumpfoundationconductedbyKelmEngineering.Thebearingspanis70.562 inches. Withall attachmentsexcept thecoupling,the total wet rotor weight is calculated to be 617 pounds (7.9 pounds of water) and the coupling half-weight is 82 pounds.

Becauseof thecriticalnatureof theservice,a fullAPI610,10thEdition,AnnexIanalysiswasrequired.Thefirstrequiredcalculation is the first three “dry” critical speeds. In this case the first dry critical speed is below operating speed at 2,935 rpmandFigure3showsthemodeshape.

Next, the plain journal bearing coefficients supporting therotor were calculated. This can be a challenge due to the hydraulic loads mentioned above. However, the specification designates that the static loading only be used. As it turns out, it makes virtually no difference in the end because the seals dominate the rotordynamic response in normal operation. Figures4and5areplotsofthestiffnessanddampingvaluesof the bearings versus rotor speed.

AnANSYSfiniteelementmodelofthecasewasconstructedfrom very detailed case and support base drawings by Kelm Engineering.Oncethenaturalfrequenciesweredetermined,the dynamic stiffness in each direction (see Figure 6) was

f igure 2. t ypical Multi-stage Pump

f igure 4. Multi-stage Pump Bearing stiffnesses

f igure 5. Multi-stage Pump Bearing dampings

f igure 6. Multi-stage Pump c ase dynamic stiffnessesf igure 3. f irst c ritical speed Mode shape of Multi-stage Pump



calculated at the centerline of each bearing by applying an alternating force at the center of the bearing and then viewing the dynamic response at the bearing where the load is applied. The applied force and the calculated response were then used to determine the dynamic stiffness as shown in this equation:

This method of calculating the dynamic stiffness is similar to the method used to measure dynamic stiffness using a field test where a point compliance method is employed by applying a force and measuring the response at the same location.

Finally,thesealcoefficientsatall10locationswerecalculated.Instead of endless plots let it be said that the principal stiffness of these seals ranged from 20,000 to 50,000 lb/in at each location. The cross-coupled stiffness at each seal was about 200 to 1500 lb/in and the damping ranged from 3 to 30 lb-s/in. Seal coefficients were determined at design clearance and twice design clearance to account for wear.

Ratherthanatraditionalstabilityanalysis,theAPIrequirementis to calculate damping factors for all potential eigenvalues up to twiceoperatingspeed. APIpublishesanacceptabilityrange for these factors depending upon how close they are to operating speed. All calculated values must be in the acceptanceareaasshowninFigure7.

The unbalance response of this typical multistage pump is relatively uninteresting because all the seals won’t allow a traditional critical speed to show up. The biggest concern is the operating speed amplitude at the tightest seal clearance location. This is done for design seal clearance and twice design clearance. Figure 8 is the predicted center-of-rotorrelative shaft to stationary part vibration as a function of speedwith16W/Nimbalanceattherotorcenter.

Since the nominal radial clearance is 5 mils and the predicted peak-to-peak vibration at operating speed is 0.46 mils, there should be no danger of rubs even with this high level of

imbalance. With twice design seal clearance the predictedvibration increased by about ten percent.

The overall conclusion is that the seals control the rotordynamics of most centrifugal pumps and that dry operation would be a very bad thing. If the seals become excessively worn, problems could also occur. In one particular case, the author looked at a 10-stage deep well injection pump thatwasperiodicallyusedtoflushasandfilter.Largeamountsof abrasive sand would erode all the seals and bushings each flush, the critical speed would eventually drop into operating speed and the vibration would become high enough to trip the turbine driver. In these cases the clearances would typically be 10 to 20 times normal clearance. This problem was solved by designing and building a clean water injection system. The case was drilled and tapped at each seal and bushing location and high pressure clean water was injected whenever the sand filter flush was activated.

Refe Rence lI st1. Nicholas, J.C., and Barrett, L.E., “The Effects of Bearing SupportFlexibility onCriticalSpeedPrediction,”ASLETransactions, 29 (3), July1986

2.Leader,M.E.,“PracticalRotorDynamics,”ProceedingsoftheVibrationInstitute 26th Annual Meeting, June 2002

3.Leader,M.E.,“RotorDynamicsasaToolforSolvingVibrationProblems,”Proceedingsofthe27thVibrationInstituteAnnualMeeting,July2003

4.Leader,M.E.,“RotordynamicsofSemi-RigidandOverhungTurbomachinery”,Proceedingsofthe28thVibrationInstituteAnnualMeeting, July, 2004

5. Kirk, R.G. and Gunter, E.J., “The Effect of Support Flexibility andDampingon theSynchronousResponseofaSingleMassFlexibleRotor,”ASMEJournalofEngineeringforIndustry,94(1),February1972

6. Nicholas, J.C., Whalen, J.K., and Franklin, S.D., “Improving CriticalSpeed Calculations Using Flexible Bearing Support FRF ComplianceData,” Proceedings of the 15thTurbomachinerySymposium,TexasA&MUniversity,pp.69-80,1986

f igure 7. Multi-stage Pump a cceptance c hart

f igure 8. Predicted Maximum Vibration in Multi-stage Pump



7. Leader,M.E., “ASolution forVariableSpeedVerticalPumpVibrationProblems,”“Proceedingsofthe2ndInternationalPumpSymposium,TexasA&MUniversity,1985

8. “RotordynamicsTutorial:LateralCriticalSpeeds,UnbalanceResponse,Stability, Train Torsionals, and Rotor Balancing,”API RP684, AmericanPetroleumInstitute,August2005

9.Chen,W.J.,andGunter,E.J.,“IntroductiontoDynamicsofRotorBearingSystems,” TraffordPublishing,2005

10. Lomakin,A.A.,Calculationof thecriticalspeedandtheconditionstoensure dynamic stability of the rotors in high pressure hydraulic machines, takingaccountoftheforcesintheseals(inRussian).Energomashinostroenie, 14,No.4,pp1-5,1958

11.Black,H.F.andJenssen,D.N.,“DynamicHybridBearingCharacteristicsofAnnularControlledLeakageSeals,”ProcInstnMechEngrs,Vol.184,pp.92-100, 1970

12.Childs,D.W.,“DynamicAnalysisofTurbulentAnnularSealsBasedOnHirs’Lubrication.Equation,”ASMEJournalofLubricationTechnology,Vol.105, pp.429-436, 1983

13.Corbo,M.A.,Malanoski,S.B.,“PumpRotordynamicsMadeSimple,”Proceedings of the 15th International Pump Symposium, Texas A&MUniversity,1998

14.Leader,M.E.,“IntroductiontoRotordynamicsofPumpswithoutFluidForces,”Proceedingsofthe1stInternationalPumpSymposium,TexasA&MUniversity,1984

Malcolm Leader, P.E. owner of Applied Machinery Dynamics Company in Durango, CO, has been a turbomachinery consultant for 25 years. Focusing on providing practical solutions, he specializes in lateral rotordynamics including bearing and seal optimizations and

steady-state and transient torsional analyses.

Leader holds BSME and MSME degrees from the University of Virginia. He is a Certified Vibration Analyst Category IV by the Vibration Institute and is a member of the Institute’s board of directors. He has more than 28 publications in the machinery and rotordynamics fields and holds one patent. He is an ASME Fellow and a registered Professional Engineer in Texas. He can be reached at [email protected]

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The Effect of Structural Asymmetry on the Vibration of Small Diameter Fan Rotors

The amplified response of the rotor will usually result in noticeable vibration levels at 2X fan speed measured at the bearings.AlthoughnotcommoninSWSIfans,theeffectsofstructural asymmetry can occur (see Case History 3 at the end of this article).

Robert J. sayer, PeApplied Structural Dynamics

t echnical a rticle

Impellers for many small to medium-sized commercial fan rotors are installed on the shaft using keys and set screws. Because of the lower service requirements of the these fans,

the diameter of the shaft is relatively small. The proportion of material removed from the shaft when machining the key-way canbesignificant.Inthecaseofadouble-wide,double-inlet(DWDI)fan,theimpellerislocatednearmid-spanoftheshaft,whichisalsothelocationofmaximumflexuraldeformation.Thekey-wayreducestheflexuralstiffnessoftheshaft. Thedegree of stiffness depends on the orientation of the key.

Figure 1 shows a cross section of a fan shaftwith the key-way oriented at the top center position. The flexural stiffness is directly related to the moment-of-inertia, which is larger aboutthex-axisthanthey-axis.Whentheshaftisrotated90degrees,asshowninFigure2,theflexuralstiffnessincreasesabout the x-axis and decreases about the y-axis. Duringoperation, the fan is continually rotating about its centerline, resulting in an excursion in flexural stiffness twice per revolution. Since the key-way is concentrated at the impeller and does not extend the length of the shaft, this change in flexural stiffness is small.

Gravity, a force that is constantly and statically applied toall objects on the Earth, is not a dynamic force. However,when gravity is applied to the fan rotor that has a rotating flexural stiffness, the magnitude of rotor deformation changes twice per revolution. Normally, the amount of this changein flexural deformation is extremely small since the change in stiffness is small. For most fans, it does not present aproblem. It becomes an issue only when the natural frequency associated with the flexural mode of the fan rotor is close to twice the operating speed.

Most small commercial DWDI fan rotors are designed tohave the natural frequency of the flexural mode greater than the operating speed. If the natural frequency of the rotor coincides with twice operating speed, resonance will occur.

f igure 1. shaft c ross section with Key at 12 o ’clock Position

f igure 2. shaft c ross section with Key at 3 o ’clock Position



The magnitude of the 2X vibration component varies depending upon the stiffness of the bearing support. It can be significantly larger than the vibration at rotating speed, especially for typically very flexible bearing support structures of many commercial fan units. The high 2X response in the frequency spectrum of vibration, without any other harmonics, is often misdiagnosed as misalignment.

Disk-skew also presents many of the same symptoms asstructural asymmetry. If the center plate of a fan is not perpendicular to the centerline of the shaft, the disk-skew can produce dynamic forces at twice the rotational speed of the shaft without any other significant harmonic multiples. One distinguishing indication of structural asymmetry instead is that the vibrations in the direction of gravity (vertical) are usually significantly larger than in the horizontal direction. An exception to this would be fans mounted on structural supporting conditions with strong cross-coupling of horizontal and vertical stiffness.

One method of diagnosing structural asymmetry is to perform two impact tests of the fan shaft, one with the key-way in the top-center (12 o’clock) location and another with the key-way in the horizontal (3 o’clock) location. The natural frequency in one direction should be slightly different from the natural frequency in the other direction. Also, forDWDI fans, thenatural frequency should be very close to twice rotational speed.

Since problems associated with structural asymmetry involve resonant excitation of the rotor, corrective actions include removing the dynamic force or changing the natural frequency. The following case histories illustrate the diagnosis and correction of the problem. All of these fans were mounted onavibrationisolationbasesimilartothesketchinFigure3.

case hIsto Ry 1A sterile air handling unit at a pharmaceutical plant incorporated a small belt-driven commercial DWDI fan.Sterile air handlers must operate continuously; mechanical

failures result in total loss of product. The shaft and bearings of this unit failed. The bearing race that was fixed to the shaft loosened allowing it to rotate independent of the shaft. The relative motion between the race and shaft machined the outer diameter of the shaft almost as if it were done in a lathe.

The fan wheel had a diameter of 48 inches and weighed 470 pounds. It was mounted on a shaft with a diameter of 3 15/16 inches. The fan was belt-driven by a 100 hp motor. The operating speed of the fan was 1620 rpm (27 Hz).

Figure4shows the resultsofan impact testperformedwiththe key-way in the bottom-center (six o’clock) position. The naturalfrequencyof therotorwas53.8Hz. Figure5showsthe results of an impact test performed with the shaft rotated 90 degrees so that the key-way is in the horizontal position. The natural frequency of the rotor increased to 54.5 Hz. Both natural frequencies are almost coincident with twice the operating speed of the fan. The bearing vibration at twice operating speed of the fan was 0.03 ips in the horizontal direction and 0.22 ips in the vertical direction. This vertical-to-horizontal vibration ratio of nearly 3:1, together with the natural frequency results, supported a diagnosis of structural asymmetry as the probable root cause of the failure.

f igure 3. t ypical f an a rrangement on an Isolator Base

f igure 4. Impact t est Result-Key at 6 o ’clock Position (f an Rotor – c ase 1)

f igure 5. Impact t est Result-Key at 3 o ’clock Position (f an Rotor – c ase 1)

53.8 Hz

54.5 Hz



The Effect of Structural Asymmetry on the Vibration of Small Diameter Fan Rotors

The corrective procedure used for this case was to remove the dynamic force. A new rotor was supplied that had a shaft without a key-way. The fan wheel was installed on the shaft using taper-lock hubs. Since the key-way was removed, so was the source of the dynamic force that excited the rotor resonance.

case hIsto Ry 2Anewairhandlingunit thatusedaDWDIfanwasinstalledfor several paint booths at an automotive plant. Excessivevibration during commissioning led the end user to reject the unit. The fan wheel had a diameter of 80 inches and weighed nearly 850 pounds. It was mounted on a shaft with a diameter of 4 15/16 inches. The fan was belt-driven by a 200 hp motor.

The fan operated with a variable frequency drive (VFD).Figure 6 shows the frequency spectrum of vibration datameasuredatthebearingintheverticaldirectionwithaVFDsetting of 80 percent. Vibration levels exceeded 1.2 ips!Although the fan speed was 409 rpm (6.8 Hz), almost the entire vibration was concentrated at twice fan speed (13.6 Hz). At full speed, the bearing vibration reduced to 0.40 ips, which was still considered unacceptable. Blanking out the operating rangeoftheVFDfrombelow80percenttofullspeedwasnotconsidered a viable solution to the problem.

Figure7showstheresultsofanimpacttestthatidentifiedthenatural frequency of the fan rotor at 13.75 Hz. At 80 percent of full speed, the natural frequency of the rotor matched the frequency of the dynamic forces developed as a result of asymmetry. The solution was to replace the rotor with one that had a shaft large enough not only to remove the natural frequency at 80 percent of full speed, but also to increase it beyond the excitation range of the 2X dynamic force at full speed.

case hIsto Ry 3A roof-top air-handling unit at a food processing plant used a single-wide,single-inlet(SWSI)plenumfan.Thefanwheelhad a diameter of 54 inches and weighed 500 pounds. The diameter of the shaft was only 2 7/16 inches. The fan was belt-driven by a 25 hp motor and operated at 700 rpm (11.7 Hz). Frequencyspectraofbearingvibrationcontainedanelevatedcomponent at 2X operating speed in the vertical direction.

Figure8shows the resultsofan impact testof the fan rotorthat identified the natural frequency of the flexural mode at 19.5 Hz. In this case, the natural frequency did not equal thesecondharmonicmultipleoffanspeed.UnlikeaDWDIfan rotor, the natural frequency of a SWSI fan rotor willincrease during operation [1][2] because of centrifugal stress and gyroscopic effects. In this case, the natural frequency increased from the at-rest value of 19.5 Hz to almost 23.5 Hz, making it very sensitive to the dynamic force developed as a result of structural asymmetry.

t echnical a rticle

f igure 6. f requency spectrum of Bearing Vibration (Vertical direction)

f igure 7. Impact t est Result (f an Rotor – c ase 2)

f igure 8. Impact t est Result (f an Rotor – c ase 3)

1.26 ips @ 13.6 Hz

13.75 Hz



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The cyclic change in flexural stress, combined with the local stress concentration at the key-way, initiated a fatigue crack. The fatigue crack propagated until the shaft experienced a catastrophic failure, splitting into two pieces. The failed rotor penetrated the sidewalls of the air-handling unit and damaged the roofing that protected the food processing operation from the elements. The failure of the fan caused the shutdown of the process.

The corrective action taken for this fan was to increase the natural frequency of the rotor by decreasing the mass of the fan wheel. The original fan wheel was constructed from carbon steel. The replacement fan wheel was constructed from aluminum.

Refe Rence l Ist1. Sayer, R. J., “Modal Characteristics of Single-Wide Fan Wheels,”EngineeringPaper5207-03,AMCAInternationalEngineeringConference,Schaumburg,IL,December2003.

2. Sayer, R. J., “Flexural Critical Speed of Single-Wide Fan Rotors,”ProceedingsoftheNationalTechnicalTrainingSymposiumoftheVibrationInstitute,NewOrleans,LA2003.

Robert Sayer, P.E., owner of Applied Structural Dynamics in Medina, OH, has over 35 years’ experience with condition-based maintenance technologies, specializing in modal analysis, finite element analysis and structural dynamic studies. Sayer holds a BSCE degree from Ohio

University, a MSCE degree from Purdue University and a MSIE degree from Cleveland State University. He is Chairman of the Central Indiana Chapter of the Vibration Institute, a member of the Board of Directors of the Vibration Institute, and a registered Professional Engineer in the State of Ohio. He can be reached at [email protected].

c ertification surveillanceIn order to protect the Institute members who have justly earned certification as a Vibration Analyst, the Vibration Institute wants to pursue individuals who falsify Institute certification in any manner.

If you are aware of any instance in which you believe an individual is falsifying his/her certification status, please call or contact the Vibration Institute immediately.

If you are aware of any individual who you believe is violating basic ethics, please contact the Institute as soon as possible. Failure to do so degrades the reputation of your certification and the Vibration Institute.

(630) [email protected]



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SGRBEARING PROTECTION RING

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f igure 1. f an a rrangementd uring a routine monthly vibration survey of a fan for a dust collection system in the food processing industry, a large increase in overall energy was noted to be coming

fromthefan’sbearings.Figure1isasketchoftheequipmentarrangement, with data acquisition positions identified asnumbers1 through4. Positions1and2were locatedon themotor.Positions3and4werelocatedatthedrive-sideandfan-sideendsof the fan, respectively.Newbearingshad recentlybeen installed at positions 3 and 4.

The fan system consisted of an overhung single-wide, single-inlet fan, belt-driven by a 50 hp, 1770 rpm motor. The fan speedwasaround1109 rpm. Figure2shows fivespectraofdataacquiredbetweenDecember2008andJanuary2010.Thespectrum for data acquired in January 2010 showed multiple harmonics of the fan’s running speed that were not evident in the previous spectra.

A slight knocking could be heard coming from the fan’s drive-side bearing area (position 3). The bearing support frame and shroud were inspected for any indications of mechanical looseness.Norelativemotionwasfoundbetweenthematingsurfaces.Next,thebearingsandshaftwerevisuallyinspectedwith a strobe light. The strobe light revealed indications that

the drive-side bearing’s inner race was slightly loose and slowly rotating on the shaft.

A time waveform analysis was conducted to help identify the problemanditsseverity.Figure3isthetimewaveformofthedrive-side fan bearing vibration showing a once-per-revolution

Mechanical Looseness in a Fan System

case study

By Robert JonasIntegrated Maintenance Technologies, Inc.

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impact occurring every 0.0541 seconds, with a strong modulation at the drive-side bearing. Once-per-revolution impacting with a modulated signal is a very good indicator of mechanical looseness. Since the energy was the greatest at the fan’s drive-side bearing, it was then confirmed that the drive-side bearing was loose on the shaft.

The fan was shut down to avoid damage of the new bearings. A new shaft was installed because the old one was found to be undersized at the drive-side bearing. Vibration readings were takenfollowingtheshaftreplacement.Figure4showsspectraof vibration data acquired before and after the installation of the new shaft. A comparison of the spectra showed that the vibration at harmonic multiples of fan speed had improved significantly. The mechanical looseness problem had been corrected.

In conclusion, an increase in the operating speed harmonics of the fan indicated possible mechanical looseness. The time waveform and a strobe light were the key tools in determining where the looseness was located. The modulation helped to support the diagnosis of looseness.

Allowing this fan to run to failure would have resulted in a costly unscheduled shutdown.

Robert Jonas, a Certified Vibration Analyst II, has worked for Integrated Maintenance Technologies, Inc., in Kalamazoo, MI, for the past 16 years. In his 20-plus years in the vibration field, he has served in several industries, including paper, plastics, and the food industry. Jonas is an active member of the Vibration Institute and a Vibrations

journal contributor who has published numerous local and national peer-reviewed articles. Send questions to him at [email protected].

f igure 2. f requency spectra of f an Bearing Vibration (december 2008 - January 2010)

f igure 4. f requency spectra of f an Bearing Vibration (Before and after shaft replacement)

f igure 3. t ime waveform of f an Bearing Vibration



f igure 1. f requency spectrum of Motor Vibrationt his case study involves the drive motor for a chip crystallizer that is proprietary process equipment used in themaking of polyester film and chips. The drive

train of the crystallizer consists of a 200 hp motor, gearbox, and rotor. An unusual noise was reported, as well as a noticeable vibration. High motor current was also indicated on the operator control panel.

The panel meter indicated current on only one leg of the three-phase power going to the motor. The vibration was present ontheentiredrive train.Whenvibrationdatawerecollected,amplitudes obviously were higher than normal, and they were higher on the motor than anywhere else on the drive train.

Figure1showsafrequencyspectrumofvibrationdataacquiredfrom the motor. The spectrum was dominated by vibration at exactly 120 Hz (2X electrical line frequency). The vibration data did not indicate any change from the trend other than a 700 percent increase in amplitude at 120 Hz.

Vibration at 2X line frequency often indicates an uneven air gap between the rotor and stator. However, since noise was present and the increase in amplitude was so sudden and dramatic, it was decided to perform a thorough electrical check.

The motor current on all three legs could not be safely checked without first shutting the motor down and restarting. As an alternative to the motor current test, the motor was shut down, the power supply was locked out, and a phase-to-phase resistance check of the motor windings was done from the motor starter. The resistance check indicated an open leg in the motor.Plansweremadetoreplacethemotor.

Vibration of a Polyester Chip Crystallizer from an Electrical Source

case study

By c lyde BridgesMitsubishi Polyester Film



Before calling in a crane to lift out the motor, one of the technicians decided to double check the wiring from the motor starter to themotor. Further investigation revealed the opencircuit was in a local 3-pole switch (lock-out device) located near the motor. Evidently the switch had failed while themotor was running and allowed the motor to continue running single-phase. The switch was replaced and the motor was restarted.

Figure2showsmultiplespectraofmotorvibrationacquiredbefore and during the electrical problem and after replacement of the local 3-pole switch. Vibration levels returned to normal. It is important to note that not all vibration is caused from mechanical problems, and the motor is not always the culprit when there is a so-called “motor problem.”

Clyde Bridges, a licensed master electrician with 40 years of experience, has level 4 Vibration Institute certification and is also certified by the Municipal Association of South Carolina. Since 1994, he has worked as a machinery vibration analyst in the predictive maintenance department at Mitsubishi Polyester Film in Greer, S.C. He

can be reached at [email protected].

f igure 2. f requency spectra of Motor Vibration

Recertification Requirements

Certification as a Vibration Analyst is valid for five years from the date of current certification level. After five years, and in compliance with ISO 18436: Part I, certified Vibration Analysts are required to recertify. Re-certification at the current level of certification can be achieved in one of two ways:

Renewal. You may provide evidence of continuing education experience, training and/or technical activity. Points for renewal can be earned for vibration-related activities including work experience, professional development, attending industry, association or chapter meetings, and vibration-related presentations and published articles.

Re-examination. You may take the certification exam at the level you are currently certified. This requires scheduling an examination and securing a proctor per established Vibration Institute protocol.

Vibration Analysts are certified on the basis of ability to function at a specified level. The motivation for re-certification is to ensure that the Vibration Analyst maintains the capability to function at the level certified.

Points toward recertification can be earned in various ways. The Vibration Institute Certification Committee has approved renewal requirements as follows:

Category I: 24 points (beginning January 2011)Category II: 28 points (beginning January 2011)Category III: 32 points (beginning January 2013)Category IV: 36 points (beginning January 2014)

Visit www.vi-institute.org and click on Certification to learn more about earning points for re-certification!



Academic Corner

By nancy l . denton, P.e.

The Vibration Institute’s mission—to disseminate information on the evaluation of machine behavior and condition—is only as strong as the knowledge and expertise that our members consistently contribute to our profession. And our mission is sustainable only if we continually attract new members.

Recognizing our need to develop ties to our potential futurecolleagues, in October 2011 the Vibration Institute’s board of directors approved funding for a national effort to encourage students to consider entering the condition monitoring and predictive maintenance industry. The generous support enables the Institute to further cultivate our relationship with the next generation of condition monitoring and vibration professionals.

new acade MIc effo RtsInitially, we’ve taken a two-phase approach to develop programs that bring college students and academics to the 2012 Vibration Institute Training Conference on June 19–22, 2012, in Williamsburg,VA:

• Phase 1—Establishing academic track conferencesessions dedicated to university research, student projects, and instructional practices, while meeting the academic requirements for refereed publications.

• Phase 2—Sponsoring the conference attendance of aselect group of students who have expressed an interest in our profession.

acade MIc t Rac K launchThe academic track program will invite future industry professionals and the faculty who prepare them to present their vibration-related papers at the conference and their papers will be published in the Conference Proceedings. The program funding will heavily subsidize conference registration for the presenters.

My academic committee colleague, Bob Sayer, and I quickly reached out to various universities with a Call for Papers,requesting abstracts by November 18. Interested candidatessubmitted draft papers by January 27 and final papers by April 13. Eachmanuscriptsubmissionwasreviewedbyat least twopeer reviewers.

The response we received to the launch of this new program was outstanding. The 2012 program has been very successful, with eight papers, representing eight universities, accepted for presentation at the 2012 Conference and subsequent publication.

acade MIc t Rac K PReVIewAcademic authors, the majority of whom are students, will give their 20-minute presentations on Thursday, June 21, during the Training Conference inWilliamsburg. The eight selectedpresentations for the academic track program are thought-provoking and represent a variety of areas within the industry:

Vibration Data Acquisition and Analysis for a Small Residential Wind TurbineShannonSweeney,PennStateErie,TheBehrendCollegeRobertMichael,PennStateErie,TheBehrendCollege

Design and Analysis of Non-Linear Spring Based Passive Suspension Using B-Spline Collocation Method RahulAJhaveri,RochesterInstituteofTechnologyHanyGhoneim,RochesterInstituteofTechnology

Design and Implementation of Passive and Multi-channel Active Noise Treatment of a 2kw Diesel GeneratorCory M. Papenfuss, Virginia Polytechnic Institute andStateUniversityTom-Davy W. Saux, Virginia Polytechnic Institute andStateUniversityChris R. Fuller, Virginia Polytechnic Institute and StateUniversity

A Study on Effect of Foam on the Vibration Quality of Aluminum Structure Under Combined LoadingMasudNawaz,GeorgiaSouthernUniversityAniruddhaMitra,GeorgiaSouthernUniversity

An Experimental Study of the Curve-Veering Phenomenon PhillipD.Rodenbeck,Rose-HulmanInstituteofTechnologyStephenS.Sakai,UniversityofWisconsin-Madison

Compensation for Boundary Condition Effects of a Helicopter Blade Droop Stop Using Frequency Domain Impedance ModelingDouglasAdams,Ph.D.,PurdueUniversityBlakeHylton,PurdueUniversityAndrewCrandall,PurdueUniversity

Establishing a Blueprintfor the Future



The Effect of the Contact Model on Impact-Vibration ResponseMatthewR.Brake,SandiaNationalLaboratories

Static and Dynamic Behavior of Open Cell Metallic Foam StructuresSwaminadhamMidturi, Ph.D.,University ofArkansas atLittleRock

These eight papers will be published in the Conference Proceedings and will be available online from the VibrationInstitute: www.vi-institute.org.

sPonso Rsh IP PRog Ra MSome of us show up for our first conference when we are presenting our work, but for most of us, participation is the starting point on our professional growth journey. To that end, we set up our student sponsorships to benefit both authors and non-authors. With the help of key vibration and monitoringfaculty, we identified eight students from four institutions. Their transportation, hotel, and conference registration costs are provided by the academic sponsorship program. By attending the conference, students will obtain valuable experience networking with other professionals, exchanging technical knowledge, and beginning their lifelong professional journey of sharing information and findings within the industry.

Mo VIng fo Rwa RdThe Vibration Institute’s Board is committed to supporting the future generation of our profession. The success of the 2012 academic Track and academic sponsorship program will most certainly result in offering the track and program again at the Vibration InstituteTrainingConference inJacksonville,FL,onJune18–21,2013,attheWyndhamJacksonvilleRiverwalk.

InformationabouttheCallforPaperswillbeavailableinthefallon the Vibration Institute’s website: www.vi-institute.org.

A number of our chapters already offer educational scholarships. The Board is grateful to them for their efforts to ensure that we have a next generation of vibration professionals. Beginning with discussions at the June conference, we will be gathering suggestions for ways to collaborate locally and nationally to strengthen our efforts to encourage our future colleagues.

Nancy L. Denton, P.E., is professor and associate department head for mechanical engineering technology at Purdue University, where her primary teaching and research interests are machinery health-monitoring and data acquisition. Her industrial experience includes design engineering for the Naval Avionics Center and acoustical

engineering for Digital Equipment Corporation. A member of the Vibration Institute’s board of directors, she chairs the academic committee and serves on the certification committee. She is also a member of ASME and an ASEE fellow. She can be reached at [email protected].



Certified Institute Members Vibration Analyst ca tego Ry I*

Curtis J. AfflickPablo Dario AguileraNitbelle A. Aizprua B.Mohammed A. Al-

AbdulqaderAhmed Zaki Al-AlawiAbdullah Saad Al-ArjiAbdulrahman M. Al-BeshrMohammad Owied Al

EneziKhaled Saad Al-GhamdiMohammed A.A. Al-

GhamdiAbdullah Mohsin Al-HarthiFaisal I. Al-JamhoorJafar M. Al-MaiyoufOmar Abdulaziz Al ManaMajdi Mohammad Al-

ObaidSaad Mehdi Al-OsaimiMeshal Saud Al-QahtaniAhmad Abdullah Al-

SalaminAbdullah K.M. Al-SogairMuhammad A. Al-SubhiAhmad Musaad AlanaziJuan C. Albavera

HernandezNorman R. Allen, Jr.Juan Manuel Almeida

LugoMusfer Abdullah AlqahtaniJulio Mario Anaya EguisFrank Araya FernandezAlbara Bassim

AskandaraniBrian A. AtkinsonJose De Jesus Avina

CuetoJ. Jesus Ayala MedinaColin Jude BabinGabriel BallesterosChidokiso B. BandaJose G. Banda MartinezGerardo Jose BanosGurkaran Singh BansalStephen M. BarryCorey James BattamsCaleb J. BellNoel Belmonte GonzalezSergio Guadalupe Bio

FelixTony J. BlaneyMark BoettcherVenkata N.K. BoggarapuJustine D. BoggsJeremy M. BoyerKaren BressonMark P. BrocherieBrad A. BroussardDarryl D. BrownDonald Troy CalfeeSergio G. Calvillo

RodriguezJorge Calzada GomezKeith Andres Camara

LoriaLuis A. Camarena Dela

FuenteEric S. CampbellDavid Campos VillagomezBradley G. CarfootDelfino Carmona RamirezJose M.A. Carreto

FernandezRicardo E. Carrillo

NapolesRobert J. CasonGustavo Castro CastroAlejandro Cerda LopezKarol N. Cerdas MoralesEric Cervantes CruzJuan Efrain Chable

JimenezTimothy M.M. ChamaounJove Hsiao Koon ChanAngel E. Chavez ValdesPierce CheekDave ChelirasWai Kong ChongTze Keong Roy ChuaMauricio Cisneros GarciaFrank CiufiaErick Paul Contreras

RiveraGary C. CorbellRolando Coronado TorresIvan Cortes PelaezJustin CoxJorge Armando Cruz

SayagoJean Carlos CuevaNaveen Avil Oswald

D’SouzaIsmael Damian CalderilloJorge Jesus Damian

LoyolaRicardo Delgado ArellanoGildardo Delgado

CardenasDaynzu D. Delgado

CepedaMichael H. DempseyJohn R. DeVriesAndrew DiNataleWilberto D. Dominguez

HernandezJose L. Dominguez

MendezJonathan M. DonlonMarcel E. DoucetteBenjamin C. DuncanBrian DunkSimon B. DunlopChristian Dupon TafollaHector Javier Duran

NoveloPaul R. DziennikJustin EavesShannon EikelboomRabih El-EterAli M. Elsalaymeh

Ivar Alexander Erazo Munoz

Marion C. Eslao Hernandez

Ricardo Elias Espino Osuna

David Miguel Euan CouohRuben A. FabbroniKeith FalcaoDavid L. Fancher, Jr.David FergusonFederico FestaBrian D. FletcherRafael G. Flores RevoredaEloy Alejandro Flores RuizSalvador M. Flores

VelazquezDeon FoonkJulian Andres Franco

ReyesJonathon James FuryJohn R. FuschinoDaniel R. GarciaAlberto Garcia VillanuevaEloy GasperinGonzalo Jose Enrique

GattiGuillermo Arturo GayaKenneth W. GeramiMatthew Tyler GilbertRodney J. GilmoreJune GohRene W. Gomez HuarachiMiguel A. Gonzalez BonillaOdin N. Gonzalez GomezJulio C. Gonzalez ZorillaSteven GortRobert L. GrundyKurt S. GrunwaldJose Rafael Guerrero

FerrerIsidro Guerrero GarciaSadot Guevara AyalaDavid N. GuidryJoe GunnJuan C. Gutierrez BautistaEgil GuttormsenJustin M. GuyRhonda R. GuyNorhisham Bin HabdinRick E. HammondMuhammad Manazirul

HaqGreg W. HendersonDiego Alberto HerreraJorge A. Herrera CauichPaul E. HoeksmaRobert W. HoffmanTim N. HollettHeath HolodnakDavid Sebastian

HorisbergerJohn HornCasey Wade HowardWinston HowseMuhammad F. Bin Idrus

Hairul Izham B. IshakDale Alan JacksonGreg T. JansenJesus M. Jauregui

GallegosChip W. JerkinsCarlos J. Jimenez MoralesAlan C. JohnsonChris JohnsonJoaquin Juarez CabreraDavid KapelaSalim Yusuf KhanLeonard H. KirbyJames W. KleinNicholas J. KuffelTracy Su Lyn KwokPablo Andres LagosEugene Weng Hong LaiCharles Keith LaneRoberto C. Lara RoldanClaudio H. LauxmannCharles W. LavinKlaus Michael LendewigMervin R.J. LetchmanPek Yin LimEivar Dirceuo Lopez

CuevasAlfonso A. Lopez

GonzalezFrancisco J. Lopez MatiasAlejandro Lopez RamirezRobert A. MacDonaldGeoffrey A. MaherKeith F. MankaHemanath ManoharJan Etienne MaraisKen R. MariottJesus A. Mariscal GarciaMichael S. MarrelloLuis A. Martinez OrtunoVictor Hugo Mata IbarraMasiye Erick MathetaPaul MatthewsMichael P. McElligottRay M. McElroyBill McGuckinJeff McGuckinDale Gordon McKissackIan John McLarenKenneth R. McPheetersRichard Jose MedinaArmando Mendoza NavaMoni Late Meser AliBenjamin MeyeringMichael D. MichaudJorge Armando Michel

DiazThomas MiddlebrookJuan M. Monroy ViolanteNelson O. Montenegro

MeloShane MoodleyWilliam A. MooreClaudio R. Morales

RodriguezJose Oscar Moreno Cortes

Solly MotloutsiTroy MuellerMark MundineRoberto I. Murphy SullivanClaud Edward Murray, Jr.Rose Karim MussaJuan E. NasserIjaz NaushadDennis Herbert NavaJuan Pablo Navarro

OrozcoBrent L. NealLonnie B. NelsonAntonio E. Neria MerinoJohn C. NicolosiJohn David NixJames P. O’ConnellJeffery D. OgleJuan Manuel Olvera

OlveraMarco Antonio OrozcoAlfredo Ortiz OviedoJuan Osorio OntanonJoe William OutramRicardo Ovalle AlvaradoDaniel P. OwensHarold E. Pacheco

MendozaGregory P. PeaseRuben Pecero SobrevillaVidal Peralta AbrahamJoseph V.R. Peter BennyJazz Keith PetersAlvah C. PhillipsRuben Mario PizaAaron S. PosnerHector Efrain Prado

SanchezRimple P. RajanAnival Levi RamirezAntonio Ramirez GamboaWilliam Todd RauschMatthew W. ReavesAllen RectorRamon John RehmeierRichard A. RenyBlair A. RichardsonAlfredo Rivera FeregrinoElmer L. RocacurvaJesus E. Rodriguez

CamposCarlos R. Rodriguez

CardenasJose F. Rodriguez

GonzalezJavier A. Rodriguez GoveaThomas A. RoeAnthony Leonard RucciAnilkumar SabapathyAngel Antonio Salas PerezFernando Samaniego

HernandezEleuterio Santiago

RamirezEugene L. SchlegelBrian Schnitzer

Matt SchweinbergDwayne L. SefcikDarrel G. SelmanBarry C. SeniorSiboniso W. ShangeMuhammad ShehzadLewis E. Shull, IVMichael Steven SkvarkaCory SlaterTony (James) A. SmithOscar Solar CampaAntonio Solis LiraChristopher L. SpoorRobert E. StocktonThomas M. SwanBrian J. TafollaSze Chiae TanYvonne TanBrian K. TaylorTatt Huong ThamObakeng Eric ThekisoKeith A. ThomasDennis P. ThompsonGary E. ThorntonLarry W. ThreattWee Teck TohNelson Luis ToroJason D. TournierKevin Lee TrippRobert M. TuffleyGustavo A. Valenzuela

CuevaJason Dennis VallancePieter Van Der WaltGerard M. Van EyckLouis Petrus Van StadenAbraham Velazquez MayUlises Verde EstradaAlberto Villa TlasecaChristian Henry

Villadonga GuzmanMatthew VillarrealRafael Villegas ApaezEdward R. WadeJustin T. WarburtonDavid J. WarnerJason Terence WealeBrandon K. WeberJim J. WeberArne Edgar WeisethGeorge Lawrence WhiteMark A. WilliamsDwight W. WillisJohn M. WolfeDavid W. WurfelJonathan G. YarbroughCole A. YoungPedro Zapata MenchacaJose Arturo Zea MonheraJin ZhangAbdulaziz Ibrahim

Zubailah

Certified Institute Members Vibration Analyst ca tego Ry II*Ahmed Ibrahim Abd El AtyMohamed D. Abdel

Mohsen

Mohamed A. Abdel SalamMohamed Salah

Abdelalim

Mohd Nazim Abdul RazakAbdulazim H. AbdulazimSean W. Ackerman

Rodney J. AcklinCarlos F. AcostaBradley J. Adams

Daniel R. AddingtonDarlan Manuel Aguilar B.Pedro Aguilar Higueredo

Asim Munir AhmedMichael Akin-Femi AkinuliKhalifa Ali Al-Ammari

Annual List of Certified Individuals



Certified Institute Members Vibration Analyst ca tego Ry II*

Riyadh A. Al-HarbiSami Saud Al-HazmiNasser Hamed Al-HinaiYousuf Mohammed

Al-JabriBader Khaled Al-

JughaimanNasser Sulaiman Al-

KhanjariNabil A. Al-KhashramFawaz Abdulaziz Al-

NuwaisAbdullah Faheed Al-

QahtaniNadheer Lutfi Al-QudsiTariq K. Ahmed Al-SabahiBadar M. Salim Al-SalmiSaeed Ali Al-ShahraniFawaz M. Al-ShammaryAbdul Rahman K. Al-

ShehabDonald P. AlcornJohn AlexiouLuai Ahmed AlfayezAmr. Hassan AliRobert AlmondJohn Carlos AlonsoAbdulaziz Nasser

AlqahtaniAriel A. Amaya SanabriaChinniah AmburoseTony W. AmersonBenjamin E. AndersonJimmy D. AndersonErik Kenn AndreasenLoren Lee AndresenKar Bun AngDarwin ArceneauxCarlos Enrique ArenasMatt ArndtJack ArnoldDon J. ArsenaultBrian J. AtwaterAnge AucielloZeyar AungDouglas H. AyersFazlee Bin AyobRodney BabwahJorg BachmannTom BagleyJoe BalderasDoug BaldreeBrian L. BaldwinKent BaldwinRobert BallardWilliam R. BallengerDaniel G. BamfordYaxin BaoJeff BarkoSteven David BarnettJoseph D. BaronFrank BarreraGhouse Shahinshah

BashaTimothy C. BassMichael R. BaucumJurgen BauschJoni BaxterRobert W. BaxterAndrew Brian M. BealeFrederick K. BeasleyMichel BeaudryAdam M. BeaverEarl BecnelSteven J. Beerli

Todd BelschnerShawn D. BelvealPhilip BenferRyan D. BennettSamuel G. BerensteinAugusto Abilio C.

BernardoKristopher D. BertholdGautam N. BhattacharyaJohn R. BilderbackKelly S. BinghamWilliam J. BirkRalph M. BlancoBruce W. BlankenshipMichael Jeremy BlockStephen BloughSteven C. BohmScott W. BondEdwin Ray BoneChristopher A. BookoutNg Keng BoonJason S. BooneRishitosmai BoruahFrancois A. BothmaStafano BottariJohn P. BourassaTodd W. BranchDavid A. BrayAnthony E. BreehlRoger BrelandGraham M. BrewerPaul J. BrickerMartin BriffaFabio Cesar BringaJames A. BrittKelly BroadNeil P. BrooksRonald C. BrunoJohn K. BuckleyCharles BuffolanoRuben Eduardo

BugiolacchiMatthew A.P. BullBruce E. BumpusBen BundyRobert Ian BurgerJames BurnPhillip W. BurnettRyan K. BurneyKeith M. BurnikellLawrence A. BuschRonald A. BussellWesley James ByerlyBenjamin John ByrneVictor E. Cabrera ValenciaAndres Caceres LaraSteven Lee CahoyMariano A. CaissonLenin Ramiro Calderon

RuizRobert Camargo AvilaJusto Canales FerreDiego Ivan Cantor AlvarezKenneth Lee CantrellFernando L.P. CardosoAlbert J. CarolloAdan M. Carrizales

EsparzaDavid CarrollJack CarrollBruno Miguel Lopes

CartaxoDelanza S. CarterWesley CarterSam D. Carter, III

Ralph J. Carver, Jr.Jovanny CastellanosCarolina Izquierdo CastillaRodrigo Castillo VelazquezAnthony G. CataldoJesus Alejandro CervantesCarlos D. ChacinCory P. ChafinSeksun ChaikittiAldo Champion MartinezKa Kui ChanPatrick ChanParadorn ChanchaweeBijeesh ChanelrasekhavanVictor E. Chapa SernaJack E. ChichesterJohnny D. Chirinos

AnampaDavid S. CifreoDaniel E. CittiAdrian ClaassenDavid Emil ClaireKenneth ClassBenjamin D. CluffRonald T. CoakeDavid B. CochranAndrew P. ConkeyMarc ConnellyWilliam R. CookRobert A. CoppingerMark A. CorboJorge Cordero VivancoRodolfo Cordova FelixChristopher G. CornellJames Owen CornellCruz R. Coronado LunaMiguel A. CortezMichael L. CostaBlake Edward CostonJeff CrawfordTony CrnkovichHenry Cruz HuimanJustin J. CudakTerry CullenRaul Alberto Culma PerezJace M. CurtisJeffrey D. CurtisKevin S. CutchinsDiane M. CzuprynskiRamidi DamanikLonnie P. D’AntoniAhmed Mohammad

DareibiWilbur R. Darling, IIISudipta S. DasJustin T. DaveyRobert A. DavidsonDustin DavisGuyon Jay DavisJoey S. DavisMichael DavisWilliam M. DavisWilliam Scott DavisThomas W. Day, Jr.Matthew A. DeanSteven V. DeasesGavin P. DeBeerHamed DehnadHeather L. DeJesusRafael E. Del Rio

CarrizosaMichael Sean DeMariaCecil R. DemerittSergio T. DeSimoneAlfred William Devaux

John F. DevereauxOscar A. Diaz DominguezBrandon S. DiegelMauricio V. Do FannoJohn P. DobrowskyArgen DoddsWalter E. DodsonTim DonnellAndy DortchRuben Christopher

D’SouzaVictor Manuel Lopes

DuarteRodney L. DuboseJason E. DudleyGerald W. DuffyRichard A. DykeShelby E. EakerDavid L. EcklJames EdmondsRaymond K. EdwardsNathan D. EitrheimHassan Mokhtar El

RammalSherif Atef El-BeshlawyElfy Razeef El-JauzyMohamed Fathi El-SefyAhmed Aly El-ShafeiJorgen EllekjaerJustin Thomas ElliottDylan M. EllisOsama Elbshir ElnahrawyJames M. EmmertPaul EngenArron C. EnosCelestine Ugoeze EsoSean EstesJuan Manuel Estrada

HernandezJames M. EvansRonald J. EvansStephen Wayne EvansShaomei FanJim FanningPeter Kevin FanningMohammad A.O. FarghalyKenneth M. FaustWayne FeazelTyrel J. FelpsDavid P. FeltenEric FenderKun FengMartin FiduraMark FitzpatrickKare FjellvangDana FluetAlfred FonsecaSteven M. FossumTom FranciscoSteven J. FrankLionel Franklin, JrBrent R. FreemanBrant FrenettePaul A. FreyeNick FulcinitiBeau C FulfordPaul FulghumRobert J. FultonA.J. FynanBarry J. Gallant, Jr.Robert J. GallardoEdward F. GallickRichard J. GalliganGordon GamacheJuan Jose Gamboa

Gabriel Enrique GarciaManuel A. Garcia

BurguenoLuis A. Garcia JaramilloSuryakant Vithal GawdeNathan GeigerChristopher N. GermanyGeorge M. GhareebTamer N. GhobrialRoss Dale GilesStuart GillenDavid GolieriPaulo Alejandro GomezWilliam Gomez MoralesAram Jesus Gomez

OlivaresFeliciano Gonzales, Jr.Elias GonzalezHector Alvaro Gonzalez

BetancourttNicholas D. GoodmanDavid H. GoodsellSrinivas Gopal KrishnaCharles W. Gorbett, IIIYong GouVenoth K. GovindasamyArchiebald GrahamGerhardus D. GrahamDerek A. GrantMitchell K. GraysonMichael G. GreenHugo Fabian GrioliDavid A. GripeSteve GrohoskyPaul G. GrootJose Rafael Guerrero LaraSergio Guevara RuizPedro Guillen FloresRodney GuitardKerry F. GunnAndres GutierrezRuben D. Gutierrez

VasquezDavid A. GuyBritta E. HaalboomDale E. HafnerTaqi-Ud-Din HaiderDennis HallReed J. HammLyle L. HanelineJames D. HansonJanet Nan HapperJerry W. HarasymJohn R. HardyMark HarkooPithak HarnwiwatPhillip L. HarperClayton W. HartRichard D. HartTarek HassanMichael Morgan HastingsKenny HatfieldRune Morten HaugCharles D. HauserRick S. HavlicakDrew M. HawksKenneth E. HayesGrant Sean HealyAndrew W. HeffernanCarl HeitfeldAndrew HemetsbergerCharles Henderson, IIJoe Lee Kian HengChris Allen HentzThomas H. Herbert

Carlos M. HernandezJuan J. Hernandez

ContrerasAbraham Herrada LopezTom HessJuan C. Hidalgo BarrantesRobert L. HillardScott A. HitchingsThomas Tak Kin HoDarren HodkinJohn B. HollingshausMichael B. HoltMarcos A. HomesVincent Lim Hong ChinRon D. HooverAlan R. HornerYongqiang HouJared J. HouleMichael D. HowardKevin L. HowertonYin-Hui (Alex) HuangPatrice HuardSteven HudsonSteven Peter HudsonAlexis A. HuntMark E. HurleyMirza Sohail HussainGlen A. HuttoTan Kin Steven HwaKuddush Syed IbrahimReynaldo IcoPoongkunran IlangovanVincent In Den KleefTimothy S. IrwinAfandi Bin IsmailJack M. JacksonJobin Paduthoddu JacobDeybi Gualfre Jaimes

GelvezDinesh Bhawarlal JainBharat JanaJacek M. JaroszTony (Mahmoud) JarrahaGerard S. JeremiahMark A. JetterIshwar Kumar JhaJun JiIvan Jimenez ChavezSiqin JinAron Keith JohnsonDarren M. JohnsonPreston JohnsonRobert H. JonasDonald E. JonesGary L. JonesJason W. JonesJeffrey M. JonesDevin K. JordanJoseph E. JunionGary B. JustisTonphong KaewkongkaSultan Hassan M. KamliThanakorn KamolpattanaBalasubramaniyan KarthikSathiyaseelan

KaruppasamyBryan A. KasischkeR. Guy KeeseJames M. KempAnthony KempinskiJohn R. Kenfield, Sr.James R. KetchumAdnan Ali KhanSanatan KhamraiMaxcy S. Khoe




Denni KhusumaStephen R. KieferDavid KingKerry Herman KnappFrancis A. KnightMatthew J. KnuthChee Wee KoayDavid C. KoehlerLingjun KongJames S. KosinskiEdward N. KrinerBalasubramanian

KrishnakumarArunkumar KrishnanS. Murali KrishnanSujit KshatriMeaghan L. KubisaPasit KulkitdecharatNicholas H. KulupkaRishikesh KumarIman Parta KusumaPrakash KutagollaMaano Archibald KwindaWilliam A. LackeyThomas LagardeLuis Torres LagosErrol J. LainSteven A. LakePraveen LakshmananCraig Scott LandryJim R. LandryLouie J. LangfordMark A. LaniusGeorge LankfordAlain LaporteShanmugam LatchamanLouis P. LavalleeJohnny H. LawsonJames G. LaxsonGlyn S. LearmonthJerome R. LeBlancCherk Koon LeeDavid H. LeeFook Mun LeeJung-Chieh LeeKim Yang LeeKit LeeRamiro M. LeonFrancois LeonardWilliam R. LewisLihong LiZhen Dong LiangAri Dinata LideraSergey LikhachevJirapong LimThomas R. LippincottJing Feng LiuZheng LiuPoongkunran LlangovanJohn LombardozziGary G. LongGodofredo LopezSergio Lopez ChoraAngel Ramon Lopez

ZugastiAsle LotveitJerold LubyTom LumadueMichael F Mac Kinnon, Jr.James G. Maddrey, Jr.Marvin Madriz BarrantesCarlos R. Magana JavierDomenico MaggioMohamed S. Mahmoud

Hilal

Mark A. MalanyaPaul T. MalekLucy MaloneAmr Yousrey ManisyRobert A. MarcelManuel A. MarinJorge Arturo Marin CastilloRichard B. Marks, Jr.Charles W. MartinRodney W. MartinCosme MartinezEloy Martinez MartinezJ. Jesus Martinez

RodriguezScott E. MasonWalter Keith MatherneRoshan Elias MathewPeter R. MattesSteve MatthewsGrant D. MayersEdgar Manuel Mayo FilioMatthew A. McDonaldPhilip Glenn McDugleRobert A. McEvoyTammy McGathMark T. McGownMike McGregorRaymond F. McKinneyMichael R. McMahanRichard McMullenMichael R. McNultyKhairil Safuandy Md SallehKeith L. Mead, Jr.Alejandro Medina

GonzalezAlok MehrotraKenny A. Melendres

QuispeTed MelnykFabio A. Mendoza GomezHecner Merino BerrocalStephen F. MerkelKevin MeyermannJohn J. MeyersJohn J. MichaelRichard MiedemaYoussef Ibrahim MikhailStephen W. MirelesBrian MiskaDavid R. MitchellMichael MizellSascha MoebusTony J. MoellerDarrell W. MoerbeKhavi Fazal MohamedMeeran Mohideen M.Abel Ortega MollarPeter I. MoncrieffPablo B. MonteverdeDonald J. MontryWilliam Jeff MoranTino G. MorassutBernardo Moreno LozanoRichard A. MorrisDavid E. MorrisonJerry MorrisonScott MorrisonMark MosherBrian MroozianPhillip MunozSrinivasan MuraliJames P. MurphyBevan Scott MurrayKit Chandler (Casey)

Murray

Stephen M. MurrayMuhamad Saiin MustofaThangavelu

MuthukumaranHalvard MyrvangMohan NachiappanMuhammad Naeem AkhterRavi NaidooJuan Manuel Najera PerezVenkatesan NarayananClaude G. NasseRavi L. Natarajan Navapun

NavasearttavisootrDeepak G. NayakJoel Negreros ZamoraChristopher P. NemarichMichael P. NeroCameron NewtonTze Shen NgYen Yee NgWong Fook NgianThanh Ngo DuyRaymond R. NicholJiramit NoothongMark A. NowakowskiPeter A. OakesTimothy R. OkersonFred G. OlivaBrett C. OliverTracy O’NealRandy Paul O’RoscoThomas OrrDavid P. OsisNicholas P. OslowskiLuis F. OvalleJosue Rosemberg C.

OzunaAlex Pachas SulcaLuis Alberto Padron RojasPradeep Raghoba ParabGlen W. ParkerJacquelyn G. ParkerRobert Aaron ParkerDaniel J. ParryDarrin K.J. ParsonsPiyush PatelPratap Ramrao PatilPasakorn PatisonthiRanganayakulu PatnalaCraig D. PattersonAndrew M. PaukenDenis PauletGary M. PayneDavid PeckChristopher D. PekrulWilliam J. PelletierJoseph M. (Mike) PenkinHarish S. PeraIvan Jorge Perez GutierrezRosalio Perez MartinezMarco Antonio Perez

PerezJoseph M. PerkinsDedi PermanaRichard K. PernichRichard S. PetersonKevin PettinelliMark K. PhillipsJames J. Phillips, IIEduardo F. PiattiMike PicouSalvador A. Pineda IbanezLee Han PingWillman R. Pinto Flores

Gasper PizzolatoJohn C. PlottThomas J. PluskatGreg PoirierMichael PolkBrandon M. PolletErnest E. Polmateer, IIIBopanna P. PonnannaRoss PorterScott PorterRandell L. PowersDoug J. PrasekAlberto Prieto HernandezWidhya Putra PropatriaMichael A. PytlinskiBrian J. QuirkAlex Quispe QuispeRoss Kendrick RabunMichael D. RaffettoAlaa Eldin M. RagabDaniel RainsSudhar RajagopalanAbdoh Ahmad RajhiAlexi S. RakowChandran RamalingamJose A. Ramirez EscobarAmrit A. RamnananAmaresh RathJose Luis RattiaPalanisamy RaviDavid R. RayleImanel Kostanv RebelloPathakota Sudheer K.

ReddyJonathan ReedJeffrey L. ReevesJuan Carlos ReichSheldon ReidJon ReisnerNeva J. RhoeFranco Matias RicciCarlos Jorge RieraWilliam A. RinehartAdrian RiosAlvaro Marcelo RiveroAlen Antony RobertPhil RobinsonWilmers Cruz RodriguezJanio J. Rodriguez

MartinezArquimedes Rodriguez

MataDennis O. RogersFernando Rojas CarreonDanuta RomanowskiGustavo Romero PradillaLuis Carlos Romero RoaRuben Jose RosalesMohd Kazzlan Bin RosalieSteven A. RosenauPablo Enrique RossiDale A. RountreeMichael T. RouseRafael R. RozoAndy RuehsAbraham L. RuperMatthew RushAnthony D. RussellRick RussellMajed Hassan SaimaldahrAsif Ramzan Ali SajwaniMohamed Salahudeen

K.H.Luis A. Salcedo CabezasMohamed Ibrahim Salem

Israel SalinasLeandro SalvatorePathiri Narayanan

SampathKenneth F. SanchezMario Sandoval TolentinoWorasak SansriJoseph SantilloGhilmar J. Santos ChaucaRobert L. SardoAndri SasongkoArturo Sastre NobleJerl W. SavageChuck SaverlineMichael A. SayreJason W. SchleyKenneth W. SchoenbauerJeffrey S. SchwartzCharles R. ScottCharles S. ScottMichael R. ScottDale E. SedamLawrence V. SegerJeremy Scott SelfLe Roy M. SellMurugesan SellapillaiJoe SendejoRamasamy Senthil KumarPaul SettlesIrvin Jean Sewell, Jr.Essam Ewis ShabanRakeshkumar N. ShahAbdulrahman N.

ShamsudeenScott L. ShapiroJed Cameron ShawJainul O. Sheik MohamedGeorge SheppardElvin B. ShieldsThomas L. ShirleyAndrew J. ShoafIlya ShulkinRobert Shumate, Jr.Robert E. SiebertTheodore C. SillJohn S. Simmons, IIIRobert B. SimpsonGlenn E. SimsRajeev Rajkumar SinghaiMatthew W. SingkoferDale SkinnerJoseph L. Sklepik, IIIChristopher SlatonJames J. SlawsonPhilip C. SlifkinKevin J. SmallDan SmithMartin L. SmithMichael Nathan SmithRonald H. SmithTimothy J. SmithKjetil SolbergJose Saul Sosa BaltazarFrancisco Gerardo Sosa

De Los SantosJohn David SpannJohn M. SperrazzaKenneth E. SquiresRajendra Kumar SridharGudipudi SrinivasuluJonathan L. StanJoseph A. StilwellMark V. StokleyMartin StradeScott A. Stranford

Katie Ann StrautmanTom StrawleyE.J. Stringer, Jr.Ray StuddardBaoding SuShitiz SudTroy A. SullimanJunqiang SunAhmed Abdullah SuqaitEric SusenoVirgil E. SuttonRick Svendsen, Jr.Greg SvicarovichKedrick W. SwainKyle K. SwartleyMichael R. TallmanFernando Tapia ArteagaChristopher J. TaylorGordon K.L. TempletonTenzinSemjon TerehhovSukham ThanapaisarnkitKenneth L. TheimerCorey Scott ThoeDavid J. ThompsonVictor E. ThompsonTed A. ThullChaiyan TibdeeAndrew G. TierneyIrappa S. TikkundiBrian TjelleEdwin E. Todd, Jr.Watson TomlinsonMarcel B. Torrejon TorricoRonnie Valenzuela TorresAlejandro Torres AlemanJuan H. Torres GuevaraJose Torres MejiaHelge TorviJim TownsendRobert TrahanGustavo Trinidad VenturaVimalendu Bhushan

TripathiMark A. TrosclairMichelle Lobben TveitRichard TymWilliams E. UdofiaLarry A. UlschmidKeith UlyattAlbert Ike UmunnaJuan Carlos UstiolaSubramanian K.

VaidyanathanJavier Marcelino

Valderrama SeguraAlfonso ValdezRonald R. Van CleaveMarc Van DykJoe Van DykeEric Shawn Van LeuvenSteve VandagriffNicolas VasenaFrancis S. VassGirish Padinhare VeetilVijayakrishnan VenugopalJorge Luis Vera MechanDavid E. VerbanickOscar Beja VieiraPalani VijayaraghavanJose Noel VillamizarEdgar Villavicencio MattosGreg VokovanMukesh VyasManojkumar B. Wagh

CertificationsCertified Institute Members Vibration Analyst ca tego Ry II*



David S. WagnerRyan WaitheLarry Dale WaldenMike WalkerTrevor R WalkerMike WallerHua Xiang WangJineng WangPeng WangZhigang WangTiffany A. WardMichael D. Warren

Amr Hassan AbayazeedMohamed H. Abdel

RahmanEdgar L. AblanMohammed Hamad

Al-HajriAli Hassan Al-HanabiRiyadh Abdulbaqi Al-

JaafariAbdullah M. Saif Al-ShehhiKhalid Ragab Al-YamaniMichael G. AlexisEdward J. AllardRush E. AllenMitchell D. AndersonMichael S. AndjelicGregory P. AndreolliDouglas W. AndrusAlan D. ArmsteadGrover ArmstrongBenjamin P. AustinTimothy David AutyJim (Louis) AzzolinaH. Frederick BaatzJohn D. BagbyDavid Alan BaggsKannan BalamuruganAbdullah S. BalhaddadJoseph J. BalkovecTodd A. BarhamMichael G. BarnettRonald A. BartschMark P. BassKenneth R. BatesClayton BeallRandy E. BeasonRichard M. BechelliMarcel BelangerMichael BensemaJames E. Berry, P.E.Ashok Dadaji BhogleDr. Kenneth R. BischofKevin Ray BivensMark E. BlanchardBrandon J. BlatterJeffrey A. BoczarAndrew W. BoggsStanley R. BognatzBernard Francois BoueriMatthew K. BourneRobert K. BracherGene BradburyAdriaan BreedtSteven D. BriganceMark R. Brooker

Joseph A. WashinskiMargaret H. WatkinsDrew WatsonTimothy WatsonWayne Malcolm WatsonRusty WeaverGary J. WebbGary Alan WeberKenneth R. WebsterBryan C. WeddleVictor Lim Wee TeckJimmy D. Weeden

Brian D. BruceMark BrutcherSteven BurggraafWalter BurseySteve A. ByersAlbert B. CanadyCarl CapriottiDavid M. CarabelloAdam S. CarneyJames B. CarrelGary F. CarrollClint R. CarterKerry D. CarterDavid V. CaryJorge A. Castillo NoyolaRoy ChapmanProtim Kumar ChaudhurySiripong CheanklinChad W. ChichesterChia-Yuan ChuangChiara CiulloLoren W. ClevenJohn C. ClymerRonald L ClymerDouglas J. CoffmanMike G. CollierKeith ConleyLawrence J. ConradRobert Dennis ConroySteve CooperCarlos Alberto CoppieJames W. Corke, IIGuillermo Cortes RosasCraig CotterTod CotterShawn R. CovingtonJayden R. CowanMary M. CoxRick CroixKenneth J. CulversonJohn H. DametRiyaz A. DaveMichael D. DawsonDeiveegan R.

DeivasigmaniAnthony J. DeMatteoNancy L. DentonClarence N. DeSouzaDonald DeStasoDane A. DevanneySean D. DeVinneySalvatore J. DiFranciaJoe Paul DinaroJoe A. DominickThomas R. Dominowski

Nick J. WeinzapfelThomas M. WerkingDan WestMark D. WestAndrew J. WestmacottDaniel T. WhirleyDewey WhitakerDaniel A. WhiteDustin A. WiethoffGeorge E. WilkinsonJesse T J WilkinsonThomas D. Wilonski

Aiden DonahueRandal M. DossRobin D. DrummIgor (Bill) DunarSteve DuncanAlex DurocherScott DyarLarry A. DykgraafJesse R. EdwardsLawrence W. EidsonSantiago EscobarLuis M. Esparza RamirezKim L. EvansDavid F. FarverRonald FennellMichael J. FeuserMike L. FitchWilliam C. FoilesMurray J. FookesGary A. ForeBrent FosterJoseph A. Francz, Jr.Nathan B. FrankJoseph J. FronczekDavid A. FryGrady GageAndrew J. GaleRoy Arthur GariepyJuan Adolfo Garza OrtegaDaniel Lee GerdesAndrea GiammatteiBradley E. GittingerRobert K. GloverArthur J. GodfreyDarrell GoeddeGustavo A. Gomez DoncelErbin Gomez HernandezRaul Pedro Gonzales

QuispeGuillermo Gonzalez

ZavaletaMichael W. GoodingTimothy F. Gorman, MS,

P.EJames GovertMichael J. GradyJason GrahamJacob GreenbergSascha GuttColin Peter HaleyRandy E. HallRoger HambyTravis HammondDouglas S. HanbackJulian Hanks

Michael L. WilsonRaymond R. Wingard, Jr.Robert V. WintersStephen E. WithersJimmie R. WolfgangTimothy J. WolowiecRay WonderlyJordan W. WoodSteven Lee WoodDavid L. WoodsJo E. WorthenYanyan Wu

James R. HannonChristian Sweeney HansenRonald V. HarveyJames P. HeberleinGregory E. HensonTodd K. HillStephen B. HilscherUsui HiromiCheng Tien HockAshley James HowardJoseph E. HumphreyAhmed S. Mohamed

IsmailAlex JablonskiRamsumair JagessarGary W. JamesRonald C. JansenAdam C. JenkinsSeldon T. JenningsJohn C. JohnsonMichael S. Johnson, Jr.Roshan P. JosephSeemant S. JoshiRobert J. JudgeGary L. JudkinsPaul G. KaczmarekGerhart E. KaiserMakeshkumar

KandaswamyNick KangRobert KaplanJames A. KeckJoseph KeckeisenWalter A. KelmJeffrey KenneyWendy Diana KeraJess KingSuwatchai KlakerdpolRobert A. KonnyuSteve S. KoumaGeorge R. KredelJohn F. KuchlerDavid P. Kwolek, P.E.Brian LambertScott A. LambieLaurent H. LaPorteTom LaRocqueDavid A. LeachRandall L. LeachVernon Ledoux, Jr.Andre LegerKrissada LertprasertwechJames LiKok Hin LiemMichael H. Lind

Steven G. Wyman, IIJuncai XiaJia XuWei XuXinqiang YangEric YarbroughK.S. Mohamed Yasar AliJustin H. YatesEric YaxDerreld YostBrett A. YoungGarth A. Young

David H. LippmanRichard S. LittleNorman F. LopezRobert S. LykowskiJohn MacFarlaneGlenn M. MaclinVernon L. Maddox, Jr.Daniel J. Mahar, IIIHattan Saleh MahranPramuan MalaratStephen Malec, Jr.Daniel H. MaloyRoberto ManfrediArshad MansoorJeffrey R. MarrsDana MartinRobert L. MartinGuillermo Martinez LopezCiro A. Martinez TrinidadMichael W. MarundeTodd H. MatthewsJorge M. Mauricio

CananaoDouglas MayorMichael T. McAfeeJoe McCollumSteven M. McConnellDavid J. McFateIan Charles McKenzieJoseph E. McLaughlinMatt McPhateHeimo H. MengesKeith R. MengesMichael MertenPatrick A. MiculekPhilip W. MillerShane MohammedDouglas J. MoonWilliam H. Morgan, Jr.Christopher D. MorrisTimothy A. MorrisonGamal MoussaJohn T. MoyerSudalaimuthu MuthusamyPurushotham R.

NagireddyKrishna Ekanath NangareHector E. Navarro

NavarreteJames M. NeilsonGregory C. NelsonMarty L. NelsonNorman T. NelsonHock Swee NgCac Ngoc Nguyen

Anthony YuRuya YuJay A. ZaffinoAzrul Hairi Bin ZainalKristel K. ZamanJulio Cesar Zamora

GomezWillem Petrus ZandbergWei ZhouRoni H. ZulkarnainXu Zuo

Donald Nice, Jr.David P. O’BrienMatthew G. O’DonnellJohn M. OgrenChristopher J. OlsenJeffrey D. OlsenMichael A. OlszewskiDora Orchard-LarsenColin OstergardBryan J. OubreBrian A. PaeKarthikeyan PalaniBlake A. ParkerJames W. ParrLarry J. ParrDomenico PascazioAndrew M. PattersonDaniel A. PattersonKenneth L. PattersonRonald W. PaulCharles D. PaxtonJames H. Payne, Jr.Saravana Murugan

PerumalJay Scott PetersonStephen W. PiankaPatrick W. PickettNopparoek PimsanDonald S. PitschBradley J. PontJames R. PowersRichard Earl PrattParinya PuangpairojFrancis Sprague PughPuchong PutthawongZoran RacicDakshina Murthy Ram

SekarChristopher J. RauchSteve RaverCharles D. RayDonald G. RayBommidi Ramana ReddyAllan RedfordJames M. RennerJames F. RescheskeMark W. RespondekDonald L. RhodaRobert L. RhodesGregory Dean RichardsonStan (Bobby) RiddleDavid Waller RigdonDean RileyWilliam L. RinehartAutsadayut Rodpai


Certified Institute Members Vibration Analyst ca tego Ry III*



Gary J. RoesnerDennis H. RoinickMalla Guna SagarJusto Jesus A. Salgado

RazoArt SalterSean M. SampsonTareq Essam SaqrManish Kumar SaxenaAlberto G. SchirmerJacob SchlottmanMichael T. SchunkMichael G. SchutzeGregg SchwartzJeff Eric ScottTerry ScrogginsKarl SeguinRobert F. Seibert

Linda Antoun Al-RabadyDr. Behzad AlaviNicholas R. AndersonVictor G. ArzaniBradley B. BartonNelson L. BaxterJohn BezuglyBrian BibyWilliam J. BrancaDonald A. BrandtLyle E. BreauxClyde B. BridgesWalter P. BrostowDavid P. ButchyBarry T. CeaseChieu Q. Chau

Linda Antoun Al-RabadyDavid Alan BaggsRandy E. Beason

Jerry BartlettBen Burkin

Thomas AbrahamPaul BedfordKevin BoechlerEdward DaltonBill DowNicholas Fewer

Ramesh SeshanKenneth SharpBarry L. ShawKenneth R. ShifflettDavid W. ShookA. Keith SmithAdrian M. SmithAllen L. SmithJohn N. SmithMichael SmithMohd. Abd Elkreem SoltanTimothy SorensenSomkhuan SornpetchBroc A. SparksJohn R. SpeerKevin A. SpencerJason T. SpettelDino Spina

Sooyong ChoiMichael C. CookDavid A. CorelliJames A. CroweThomas H. Crum, P.E.George D. D’EntremontDonald S. DoanPaul T. DowdicanMarcus D. EdgeAly El-ShafeiLowell Douglas ElamBryan D. EvansCristian FilisanuJoy P. FrancisRicardo Garibay GarciaDavid A. Geswein

Todd W. BranchWalter P. BrostowCharles Buffolano

Jeff DavidsonJesse R. Edwards

Troy FordJean Luc FournierJerico GaffudBrian GauthierJonathan GibbonsAdam Greening

Gary M. StamperBruce C. StanleyKeith StantonCharles StevensTodd StevensOctavian Ion StirbuSteven E. StiversMichael S. StivesBrian K. StrampeTerry Q. SudduthJames SullivanMichael SuppleeDeren SwartzMichael A. SzurkowskiMozaid Bin TajuddinRobert TapiaPeggy TarnowieckyiIvan Lee Taylor

David GluzmanJ. Stuart GoodeMichael C. GraceScott GratonJoseph M. GurneyKevin R. GuyTimothy HartmanChuck HildebrandAngel V. HurtadoMichael IngramNicholas A. JaganOscar Jimenez YennyRay D. KelmAlexey KovalMax L’vovMalcolm E. Leader, P.E.

Jorge A. Castillo NoyolaJesse R. EdwardsBryan D. Evans

Christopher J. RauchFredy G. Sansom

Curtis HacheyPaul HoeksmaDarren HolstDarren HumTony JiKathleen Lui

James L. ThomasMark R. ThomasJames ThompsonRobert E. ThompsonMichael E. ThorntonTim ThreattScott TilleyLuther B. Tilley, Jr.Jeffrey C. TippsStephen J. ToomeyKiran K. ToramJohn TrulliMikhail TsypkinRoger W. TuckerIosefa TuimaualugaGino UlianaMario P. Urquizo CalderonMuthusamy Vaikundam

Joseph G. MadisonMammar MaghraouiMartin D. MaierSambhaji N. MaliBenoit MarcotteJ. Howard MaxwellWilliam Taft McNealDavid F. MetzgerArthur W. Miller, P.E.Andres Montemayor V.Eduardo Murphy ArteagaNestor E. Nino HerreraJames R. PassmanJanos PattantyusDustin E. PavelekJack D. Peters

Eduardo Murphy ArteagaJay Scott PetersonBradley J. Pont

Michael A. SayreMichael R. Schmidt

Andrew MacFarlaneGilles J. MartinStan MitchellGlen OldfordRyan PalmerBrent Park

William Van HeyningenBlake W. Van HoyJohn Adriaan Van ZwienenEarl Randall VaughanDennis K. VaughnOrlando L. VenegasChristopher J. VerinkLuis Fabian VillacresEugene T. VogelMark F. VowellRobby D. WallaceZhiping WangStephen L. WarehamRay WarpehoskiC. Nelson WatsonNelson Gregory WatsonBruce WeathersbyTimothy C. Wechsler

Allen PlymonWilliam T. Pryor, IIIRay W. RhoeJ. Michael RobichaudMohammad (Moe)

SaiedfarFredy G. SansomRichard M. SchochSteven M. SchultheisMichael A. SeamanJeff R. SimpsonGarrett E. SmithRichard L. SmithThomas E. SpettelThomas J. StephensRonald L. Stiemsma

David Waller RigdonFredy G. SansomJacob Schlottman

Steve SlapeRonaldo Sullivan

Dharma PokharelDale RowswellLesley RumboldtCory RyanStephen ShaddickPaul Sinyard

Marc E. WilliamsShawn A. WilliamsChristopher P. WillsDavid Ray WilsonAnthony T. WoffordStanley M. WolczykVincent F. WoodkotchRick R. WoodwardPrasada Rao YaramattiPeera YongsuwanMichael A. YucatonisDavid Zambrana FonsecaMolly A. Ziergiebel

David M. StobbeGanti Subba RaoGyorgy SzaszDavid B. SzromMark A. TarbetJeffrey D. TeterRichard A. TylerMonroe D. VoylesLarry I. WalkerThomas J. WalterJianke WangChristopher J. WhiteEd WilcoxMaryon J. Williams, Jr.Michael G. Womack

Michael T. SchunkLewis E. Shull, IVKenneth L. Theimer

Jimmie Lee Williams, III

Bradley StewartTodd StokesDoug ThomasMichel Valcourt


Certified Institute Members Vibration Analyst ca tego Ry IV*

Certified Institute Members Balancing Technician ca tego Ry I**

Certified Institute Members Shaft Alignment Specialist ca tego Ry II

Certified CMVA Members Vibration Analyst ca tego Ry I***

CertificationsCertified Institute Members Vibration Analyst ca tego Ry II*



Steve AgnewGrant AkittMohamed AliAndy AmiraultDon ArsenaultAndrew BealeMichel BeaudryDominic BeaulieuKlaus D. BeckMattieu BerlinguetteRaghav BhoplaElihu BloodsworthYves G. BourgaultLuc BrazeauGhislain BrouilletteKevin BryantonBill BulmerTom BurkeJason CalderDavid CarrollAaron ChambersMatthew ChaseCrane ChenShui ChoiMervyn ChoyDaniel Clement

Marc BelangerMichael BongaBernard Francois BoueriErik BouthillierWalter BurseyJames Chin YutRalph CoppAndrew CostainCharles DespresAiden DonahueKevin Duffy

Behzad AlaviChieu Q. Chau

Carl ClicheStewart R CooperDaniel CotéMario CoteJason CoveyKenneth C. CrawleyNathan CrealockSerge CroisetièreDumo Denni-FiberesimaSilviu DiaconuJonathan DionLes DorwartJeff DownDaniel DufourMarc DuhaimePaul DuJohnMichael EdmundsXianfeng FanKarl FortinBrant FrenetteBradley L GabrielliMichel GariépyAlexandre GauthierVito GinevraJoseph GiuntaGilmour Glencross

Alexandre DurocherRichard L. DusenerRon EnsingNorm FehrJohn FrenchBruno GirardRangarajulu GurumurthyColin HaleyJohn H. HalleyDarryl HawkinsChristopher Hugh

Cristian FilisanuJoy P. Francis

Virginia L. GoodwinDerek A. GrantDavid GreenRodney GuitardDave HaineCorey HannanJerry W. HarasymSarah HartM.G. HicksEric HlookoffJosh HodgePaul HoogendamAlain HoulePatrice HuardCorwin HusseyMahmoud JarrahaDarwin JohnsonYanick JolyWilf JopeCharles KingMatti KokkoArthur LacelleAlain LachanceFrançois LafleurChenrayan LakshmananJim Landry

Ken KeithDarren KennedyMarion KlepschMichel LaforgeAndré LégerJames LiJohn MacFarlaneDonnie MacInnisKeith McArthurCurtis McDowellJoseph McLaughlin

Nicholas JaganAlexey Koval

Jesse LapaireAlain LaporteEric LapriseLouis LavalléeJill LaytonMartin LeducDany LenquetteFrançois LéonardAlejandro LiberatoscioliAndrew LiddleMichael LordCallum MacDonaldLuke MacGregorBrent MacLeodLucy MaloneBryan MankowskeDuane MarksDon MatchettDon MathesonMartin McFarlingCharles McKyesGiovanni MieleAndrew NealIan NenerRon NewmanRobert Page

Caroline MessierEdward MewKevin MorrellDora Orchard-LarsenColin OstergardDerek J. ParsonsTed PaterDan PeriasamyAaron PierowayBernie PringleFrancis Provost

Sambhaji N. MaliBenoît Marcotte

David PaineBruno PalardyDenis PauletAlain PellegrinoSteven PerriconeSteeve PerronThomas P. PhelanSylvain PicardGarry PicheNelson PiresGreg PoirierAllan PollockRoger RadcliffeScott RaithbyChris RamosJeff RichardsonDavid RiseboroughChris RobertsMark RoweRafael RozoChander SanbhiAndré SaulnierTerry SevensonRégent SimardThomas SkiddMathieu Soares

Stephen PyePaul QuinnSimon K. Rivers-MooreJean-Marc RobertCharles ScottKarl SeguinJohn SherrardMark E. ShoupMark SifordSandy SmallwoodDino Spina

Janos PattantyusJ. Michael Robichaud

Paul St. AmourJosee St. LaurentChristopher StickneyDavid StredderAlain TardifChris J. TaylorBlaine TuckerNormand VachonFrancis S. VassStéphane VenneAlexandre VezinaWilliam WallaceRick WallachGeorge WardMichael WestBrennan WestHerbert WhiteKurtis WiselkaFelice WongAndy WoodcockChris WoodsSteve ZacharukIraj Zarieh

Ken SquiresDerek TeolisJerzy WapiennikJohn WatlingStanley WolczykChii H. Wu

Mohammed Saiedfar

Certified CMVA Members Vibration Analyst ca tego Ry II***

Certified CMVA Members Vibration Analyst ca tego Ry III***

Certified CMVA Members Vibration Analyst ca tego Ry IV***

*Current Vibration Institute certified Vibration Analysts according to ISO 18436 Vibration Analysts (certification fees paid and ISO form on file as of May 18, 2012).

**Certification current and fees paid as of May 18, 2012.***Current CMVA certified Vibration Analysts according to ISO 18436 Vibration Analysts (certification fees paid and ISO form

on file as of May 1, 2012).


visit us at www.imi-sensors.com/wireless

Toll-Free in USA 800-959-4464 � Email [email protected] � Website www.imi-sensors.com

Wireless VibrationMeasurements?

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We Do! We do it all - sensors to measurevibration, acoustics, force, pressure, load,strain, shock and torque - Sure we do!

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Certified CMVA Members Vibration Analyst ca tego Ry II***

Certified CMVA Members Vibration Analyst ca tego Ry III***

Certified CMVA Members Vibration Analyst ca tego Ry IV***

visit us at www.imi-sensors.com/wireless

Toll-Free in USA 800-959-4464 � Email [email protected] � Website www.imi-sensors.com


We Do! We do it all


We Do! We do it all - sensors to measurevibration, acoustics, force, pressure, load,strain, shock and torque - Sure we do!

TM

WirelessVi b r a t i o n M o n i t o r i n g S y s t e m


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Documents

Vibrations June 2012