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From the Editors of Pumps & Systems

strategies for improvedEfficiency and Reliabilityfansturbinesmotorscompressors

strategies for improvedEfficiency and Reliabilityfansturbinesmotorscompressors

From the Editors of Pumps & Systems

September 2004September 2004

Induced draft fans at a Southern U.S. power plant

undergoing performance and efficiency testing.(Photo courtesy of FLOWCARE Engineering, Inc.)

Induced draft fans at a Southern U.S. power plant

undergoing performance and efficiency testing.(Photo courtesy of FLOWCARE Engineering, Inc.)


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Scope of WorkEMEs GE 7E and 6B gas turbines are proven

performers, and the DLN units (Dry Low NOx)can achieve very low nitrogen oxide emissions,which help keep the environment clean. Ensuringthat these turbines and other operating compo-nents stay at peak efficiency demands high-qualityprocedures and personnel.

From the outset of the contract, Thomasonswork has been marked by careful attention to thecustomers outage schedules and timeframes, in-cluding review of the units operation and mainte-nance documents. Major inspections cover the tur-bines to be disassembled, to determine necessaryrepairs or component replacements, if any.Thomason also has performed refurbishments ateach facilitys site with OEM components. Allmaintenance and repairs are done to OEM specifi-cations. Depending on the condition of each GEturbine, Thomason work crews and Wood Group

project engineers have refurbished them (with gen-erator refurbishment conducted, in one case, by aresponsible third party).

In addition, Thomason has been conductingall combustion, hot gas path, and major inspec-tions, and has helped insure that State of Californiaand OSHA requirements for process safety andmechanical integrity are met.

The Payoff Is the PeopleEMEs facilities extend from Bakersfield to San

Ardo, CA, which makes Thomasons Los Angelesoffice a customer-responsive, central location.Field engineers and crews are on-site with EME

managers continually, 24-hours per day, dependingon which part of the refurbishment and inspectioncycle is being accomplished.

Rather than a flying team of engineers orcontractors that come onto a project and hire workcrews haphazardly, Thomason utilizes union mill-wrights to help assure that individual workers arehighly qualified and very experienced. The team ishand-tailored for the program. The lead WoodGroup field engineer is available full-time for allprojects. Team integrity and productivity are main-tained for the life of the program.

Even though program outages started inJanuary 2004, and will not be complete until

November, the contractors combined professional-ism and expertise are dedicated to the EME job asplanned. Personnel, encompassing both WoodGroup field engineers and Thomason craft workers,have been available in the EME facilities from out-age to outage, eliminating scheduling problems andbreakdowns in communication.

Thomason uses an ongoing checklist for follow-up and feedback, asking customer managers to scorecontract execution on items such as supervision and

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crew expertise, response times, tooling, documentation,efficiency, cost-effectiveness, safety and accounting.

Teamwork DeliversTo date, all Thomason projects for EME have

been completed on time, on budget. The gas tur-

bines that have been refurbished, inspected andreturned to service are running at optimum levels.For EME, whose mission for these cogen plants isto maintain 99.7% uptime and produce the power,Thomason and Wood Group clearly have deliv-eredand continue to deliver.

By combining its craft labor and managementcapabilities with technical direction from WoodGroup Field Services, Thomason is providing com-plete breadth of service for this EME contract. It is acrucial customer benefit, especially in a segment likeIPP, where cost control is so important. But the pro-gram has equally important implications for operatorsin all segments of the process industriesnot just

IPPs. Operations such as chemical and petrochemicalplants, refineries, pharmaceutical manufacturing, util-ities, municipal water/wastewater, pulp and paper,mining, etc., that generate their own power could alsobenefit from this type of field service.

As the EME program has demonstrated, work-ing with a non-OEM for field engineering, mainte-nance and inspection can be a low-risk, high-gainopportunity. Using an OEM may provide reassur-ance, but it doesnt necessarily always deliver the fouradditional benefits that operators desire: the same orbetter reliability, the same or better quality of work,higher contractor productivity, and very competitivecosts. RE

Company ProfileThomason Mechanical Corporation has offices in Los

Angeles, Chino, and Martinez, CA; Pasadena, TX; andPhiladelphia, PA. It serves the petrochemical, pulp andpaper, industrial gases, marine, natural gas and liquidpipeline, and other industries. The company provides bothfield and shop services for turbines (gas, steam and hydro-electric), compressors (reciprocating, centrifugal, axial, andscrew), pumps (reciprocating and centrifugal), and otherrelated process machinery including fans, gearboxes andfluid drives.

In addition to Thomason, the Wood Group FieldServices organization also includes Bender Machine, in LosAngeles, San Francisco, Houston and Philadelphia;Lovegreen Turbine Services Inc., in Minneapolis, MN; MVPTurbine Repair, in St. Louis, MO; Technical Services, inOrlando, FL; HIT Services LP in Houston; and Wood GroupField Services of Alberta, Canada.

For more information about the technical services andcapabilities in this article, log onto www.thomason-mech.com or contact [email protected]

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PUMPS & SYSTEMS Special Supplement: Rotating Equipment SEPTEMBER 2004 37


4/19

In the face of skyrocketingenergy costs, more and morecompanies are looking care-fully at specifying and maintain-ing energy-efficient equipment.They realize that the cost of ener-gy is not just a part of doing busi-ness, but rather an expense thatneeds to be identified so it can becontrolled.

Plant engineers at a major oilcompany facility understood thedrain that unnecessary energyexpenses were putting on theirplants profits and decided to actto reduce these costs. Their firststep was to call their RockwellAutomation sales engineer andinitiate a motor efficiency evalu-ation.

Utilizing Rockwells newlydeveloped Reliance MotorEfficiency Wizard tool, Rock-

well Automation Power Servicesspecialists and certified serviceproviders can help identify ener-gy losses, making it possible forusers to reduce power usage,lower power costs and increasequantifiable savings throughouttheir facilities. Based on theWizards findings, the specialistscan then recommend energy-

efficient solutions and/or im-provements that can provide dra-matic savings within a short peri-od of time.

At this particular facility, oneof the evaluations was done onan application in which a700 hp motor was driving a com-pressor. Testing with the Motor

Efficiency Wizard demonstratedthat the efficiency of this motorwas 91.2 %. With a new premi-um efficient motor, the energyefficiency could be improved to96.4%. Based on the serviceteams calculations, the savingsassociated with replacing theexisting motor with a premiumefficient model would come to$10,903.00 annually. Armedwith this new information, theplant engineers replaced themotor and were able to eliminate

thousands of dollars from theiroverall operating expenses eachyear.

The WizardUsed by Rockwell Automa-

tions service technicians, theMotor Efficiency Wizard allowsusers of induction motors toidentify inefficient motors in

their facilities by determining theefficiency during operation. Inaddition to detecting the effi-ciency of any squirrel cage induc-tion motor with currents up to1000 amps, the Wizard also candetermine the efficiency of driv-en equipment such as pumps.

By measuring the input

power, voltage, current, speed,temperature, frequency and resis-tance at two motor load points,the Wizard provides accurateefficiency data on easy-to-readoutput screens. Once the prob-lem is identified, this tool alsoquantifies a solution. Using thedetermined efficiency value, theWizard calculates and displaysthe potential savings in energycosts that would result fromreplacing the inefficient motorwith a premium efficient design.

Time-SavingThe most accurate method

of determining an electricmotors efficiency has historicallybeen to remove the motor fromservice and transport it to a lab,where detailed load testing couldbe performed. Once at a testingfacility, motor efficiency is deter-


To control profit-drainingenergy costs, you firstmust identify andquantify them.

Dr. Yehia El-Ibiary, PEManager of Systems Engineering, Rockwell Automation

New MotorEfficiency

Audit Tool


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mined by putting the unit in question on a dyno; load-ing it up; measuring the input power, output torqueand speed at six points; and then calculating the effi-

ciency.While this is a very simple procedure, it also is anextremely costly one, especially in a plant environmentwhere operation or production must be stopped forextended periods while the motor is off-site. In nearlyall cases, the expense and downtime related to this typeof testing is prohibitive. Plus, with laboratory testing,actual operating conditions of the motor in its appli-cation cannot be duplicated. Consequently, true effi-ciency at the in-service motor output horsepower,operating temperature and plant supply voltage, is dif-ficult, if not impossible, to determine.

In contrast, the Motor Efficiency Wizard providesaccurate testing in a very short timeframewithout

disconnecting the motor from the load. In fact, the motorcan remain in service at its operating temperaturewhile supplying power to its driven load.

How Does It Work?Combining Rockwell Automations proprietary

software package with a portable power monitor, theMotor Efficiency Wizard determines a motors efficien-cy using simple measurements. Its housed in an easy-to-move case (Figure 1) that also contains a power mon-itor for measuring input current, voltage, and power; a


Figure 2. Typical output

report showing motor

efficiency and annual saving

Figure 3.

Efficiency

versus

horsepower

plot

generated

by the

Wizard

Figure 4.

Motor

output

torque

versus

speed

generated

by the

Wizard


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laptop computer to record thedata captured by the power mon-itor, and a multi-meter to mea-sure the motor stator resistanceand voltage frequency. The casealso contains a strobe light speedsensor to measure motor speed,and an infrared temperature sen-sor for measuring motor tempera-ture.

With this portable device, all

electrical measurements can easi-ly be made at the motor discon-nect box, without opening themotor conduit box. The Wizardascertains the actual motor out-put horsepower and the efficien-cy at this output horsepower towithin 1% oflaboratory test results. Thus,users can benefit from an accu-rate efficiency determination

without the inconvenience andproductivity losses associatedwith a lab test. (This ease-of-useand high accuracy are importantconsiderations when conducting

plant energy audits.)Once all the data are record-ed, the Wizards software deter-mines the motor efficiency at theoperating point and calculatesthe savings associated withreplacing the motor with a pre-mium design. The software usesthe data collected to obtain anexact solution for the motorequivalent circuit. This is the firsttime that this level of precisionhas been achieved. Samples ofprintouts provided by the Wizardare shown in Figures 2, 3, and 4.

Since the output torque ofthe motor is calculated and theoutput speed is measured, it thenbecomes possible to determinethe efficiency of the drivenequipment.

In the case of a pump, theinput power to the pump is, bydefinition, the calculated outputpower of the motor. By measur-ing the output pressure and flowof the pump, the output power isdetermined, and the efficiency ofthe pump can then be calculated.

Who Needs anEnergy Audit?

There are a number of crite-ria that should serve as warningsigns of inefficiency. Based ontesting done in the field to date,it appears that older motors (15years or older), especially thosethat have been rewound two orthree times, should be at the topof the list for evaluation. Amongsimilar motors operating undersimilar conditions, if some run

hotter than others, they also areprime candidates for efficiencytesting. Additional questions toask when considering whetheryour facility would benefit fromefficiency testing include:

Is your power bill going upevery month? Is power factor an importantissue in terms of the cost of power?

Do you have rewound motors? Do you suspect that somemotors are oversized for theirapplications? Do you need a priority list forreplacing motors? Would you like to lower yourmonthly energy costs? Does your local utility offer arebate incentive for conversion toenergy-efficient motors? Would you like to know thetorque vs. speed characteristics of your motors? Would you like to know thecurrent efficiency of your pumps? Are there old pumps in theplant that you suspect are inefficient?

With a complete energyaudit, users can learn exactly howmuch energy is being consumedand just how efficient equipmentreally is. Based on this data, plantengineers and their sales and dis-tribution partners can worktogether to specify high efficien-cy upgrades that can make a dis-cernable difference to a facilitysbottom line. RE

Dr. Yehia El-Ibiary is theManager of Systems Engineeringat Rockwell Automation, inGreenville, SC. He graduated fromCairo University in 1968 with aBachelors degree in AeronauticalEngineering, and obtained hisPh.D. in 1975 from the Univer-sity of Saskatchewan. Prior to join-ing Rockwell, he held positions asAssistant Professor at the Univer-sity of Saskatchewan, Director of the Systems Engineering Group atVickers Inc., and Director of the

Electrical, Electronics, and Hy-draulics Engineering Departmentat J. I. Case. Dr. El-Ibiary is a reg-istered Professional Engineer inMichigan. This article is based onhis recent presentation at EnergySummit 04 in Kalamazoo, MI.For more information, contact himdirectly at [email protected]


Specializing in Energy-Matched Solutions

Through a broad offering of

products and services, Rockwell

Automation provides industrialautomation power, control and infor-

mation solutions that help customers

around the globe meet their manu-

facturing productivity objectives. The

company brings together leading

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Complete Automation solutions,

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and engineered services and

Rockwell Software factory man-

agement software, DODGE

mechanical power transmission

products, and Reliance Electricmotors and drivesall designed to

enable users to save on energy and

operating costs. Rockwell Auto-

mation also is a leading provider of

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with their own customers. Head-

quartered in Milwaukee, WI, the cor-

poration employs approximately

23,000 people at more than 450

locations serving customers in more

than 80 countries.


7/19

Air compressors rep-resent one of themost valuable piecesof equipment for a widerange of operations, fromindustrial plants to majortire-repair centers tomom-and-pop size auto-motive shops.

Unfortunately, since aircompressors are often placedaway from a plant floor or amechanics shop, they sometimesdont receive the full mainte-nance attention that they require.

Air compressors are often thelife-blood of industrial and com-mercial operations. As a result,air compressor operators dependon the compressor lubricant toprovide proper protection withthe least amount of maintenance.Selecting the right lubricant and

maintenance schedule for youroperation is key to maximizingcompressor uptime.

This Q & A focuses on howto pick the right lubricant forreciprocating and rotary screwcompressorstwo of the mostwidely used types on the market and how doing so can helpenhance their service life andperformance.

Q: What should users look for inan air compressor lubricant?

A: For both reciprocating androtary screw compressors, thereare four main factors you need tolook at. They are:

Correct Viscosityto assureeffective oil distribution andfilm formation on all cylin-der and bearing surfaces;

High Resistance to Oxi-dationenabling the oil toresist the formation ofdeposits. This characteristiclargely determines the dura-bility of an oil;

Adequate Film Strengthto minimize friction andwear under conditions incylinders and sometimes inbearings where only thinfilms of oil can be main-tained; and

High Anti-rust Proper-tiesto protect against rust-ing in cylinders and bearingsthat may result from con-densation of moisture duringidle periods, or in the case ofsome reciprocating compres-sors, carry-over of waterfrom the intercooler to thefinal cylinder of a two-stagecompressor

With these factors in mind, thereare some critical differencesbetween the types of lubricantsyou should use for reciprocatingand rotary screw compressors.

Q: So then, what type of lubricantshould be used for a rotary screwcompressor?

A: Ideally, you want to look for apolyalphaolefin (PAO) syntheticlubricant capable of an 8,000-hour oil drain interval.

PAO-based lubricants deliverexceptional resistance to oxida-tion and, combined with properadditives, provide good rust pro-tection, helping to enhance dura-bility.

Original equipment manu-facturers (OEMs) typically rec-ommend either an ISO 32, 46,or 68 viscosity grade lubricantfor rotary screw compressors.

However, most major OEMscommonly recommend an ISO46 viscosity grade lubricant.

In general, most PAOs arecompatible with the majority ofseal types.

Be sure to check with theOEM on seal types within yourcompressor and your lubricantsupplier for compatibility withdifferent types of seals.


Selecting The ProperAir Compressor

LubricantQ & A with Mike Dionisio, Industrial Lubrication Specialist,

ExxonMobil Lubricants & Specialties


8/19

Q: What about for a reciprocatingcompressor?

A: For reciprocating air com-pressors, diester synthetics are

best. Diesters have a broad appli-cation temperature range from -20 F ambient start-up to +400 Fdischarge air. Diesters also deliv-er excellent oxidation resistanceand thermal stability, helping tominimize sludge and deposit for-mation.

Oxidation resistance of thelubricant is vital to keep com-pressors running at peak perfor-mance. Oxidation occurs whenoxygen reacts with the lubricant,resulting in degradation of the

lubricant's composition and per-formance. Heat, light, metal cat-alysts (e.g., copper) and the pres-ence of water or solid contami-nants accelerate the process.As oxidation progresses, depositformation can occur and firstaffect efficiency, lead to other

maintenance challenges, andeventually possible compressorfailure.

Compressors, as a functionof their operation, mix largeamounts of air with oil at high

temperatures, thus creating aperfect environment for excessiveoxidation. Employing the use ofsynthetic lubricants will provideadditional resistance to oxidation

over mineral lubricants.OEMs typically recommendeither an ISO 100 or 150 viscosi-ty grade lubricant for reciprocat-ing compressors. Most majorOEMs commonly recommend anISO 100 viscosity grade lubricant.

One thing to note, diestershave selective seal compatibilityrequirements. They are generallycompatible with seals made fromfluorinated hydrocarbon, sili-cone, fluorosilicone, polysulfide,Viton, Teflon, and high nitrile

Buna N NBR (above 36% acry-lonitrile) materials.

When using a diester, be sureto check with the OEM on sealtypes within your compressorand your lubricant supplier forcompatibility with differenttypes of seals.


Photo 1. Compressor second stagevalve shows oily carbon deposits onits face from the use of a mineral oil.

Photo 2. No deposits present on thecompressor valve using a syntheticdiester lubricant.

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Q: Why do you recommended synthetic oils with PAOsor diesters so much more than conventional, mineral-based lubricants?

A: Certainly, there are some high-quality conven-

tional, mineral-based oils available. Typical conven-tional lubricants for air compressors, however, willneed to be changed on average every 500 to 1,000hours. Lubricants formulated with syntheticdiesters and PAOs are capable of achieving drainintervals of up to 8,000 hours.

Also, with conventional oils in reciprocatingcompressors, there is a faster rate of hard carbondeposits forming in the valve area. Carbon depositsallow recompression, potentially leading to firesand/or explosions.

When using mineral oils, special care should begiven to routinely inspect the compressor andlubricant condition.

Just like in the automotive market, where syn-thetics offer superior performance and protectioncompared to conventional oils, the same is truewhen dealing with air compressors. Compared toconventional lubricants, synthetic oils deliver betteroxidation and thermal stability. The high resistanceof synthetic lubricants to deposit formation enablesthem to be used over extended periods in bearinglubrication systems.

Synthetics can help reduce the cost and timeneeded for maintenance items such as cleaning,replacing worn parts and changing oil. Because ofthese factors, lubricants formulated with syntheticPAOs or diesters really are the best lubricant

options for rotary screw and reciprocating air com-pressors, respectively.

Q: Besides selecting the right lubricant, what else canmaintenance professionals do to enhance the life andperformance of their air compressors?

A: One of the best things a maintenance profes-sional can do is implement a routine oil analysisprogram. The key to the success of any oil analysisprogram is to be able to trend the results. Quarterlyoil analysis is recommended for both reciprocatingand rotary screw compressors.

Trending oil samples on a quarterly basis

should provide valuable information on equipmentand lubricant conditionsand be the final verdicton oil change intervals. Recommended testing cri-teria includes, TAN (ASTM D 664), Metals byInductively Coupled Plasma (ICP) (ASTM D5185), water content by Karl Fisher (ASTM D1744), and Particle Count (ISO 4406.2). P&S

For additional information, please log on to:www.exxonmobil.com


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12/19

Q. How do you determine the primary cause(s)of mechanical seal failure?

A. A systematic method, based on failure analysis,to investigate and correct the performance ofmechanical seals provides the means to attain longerservice lives and reduced life cycle costs.

Failures occur when a product ceases to perform itsintended purposeseither prematurely or after sat-isfactory life cycles have passed. Since downtimeusually is even more expensive than maintenance

costs, the efforts we expend on failure analysis fre-quently pay for themselves many times over whencorrective actions are taken. To understand the pri-mary causes of failure, we must first understand thebasic features of a mechanical seal system.

The function of every mechanical seal is to preventthe escape of a fluid past the clearance between arotating shaft and the passageway through the wallof a housing or pressurized vessel. End face mechan-ical seals can incorporate many designs and config-urations to accomplish this. As shown in the accom-panying figure, typical mechanical seals have threebasic components: (1) primary seal elements,

(2) secondary seals; and (3) hardware for attaching,positioning, and maintaining face-to-face contact.

The primary seal is formed by two materials withlapped faces that create a very restrictive leakagepath from rubbing contact between them. In allsuch seals, one face is held stationary, and the otheris fixed to and rotates with the shaft.

The phrase restrictive leakage path is used becauseall mechanical seals leak through these faces, eventhough one does not see leakage from most of themor any leakage is controlled to environmentally

acceptable levels via ancillary systems. The leakagerates, however, are normally small; and environ-mentally acceptable, non-hazardous or nontoxic flu-ids may be allowed to evaporate or dissipate to theatmosphere in a short time period. For controlled,hazardous and toxic fluids, other means are requiredfor containment.

Secondary seals made from various fluoroelastomersusually close leakage paths around the stationary faceand the rotating face. For pusher-type seals, the sec-ondary seal must move forward along the shaft tocompensate for wear and vibration at the seal faces.For non-pusher-types, such as metal bellows units,

SEPTEMBER 2004 www.pump-zone.com PUMPS & SYSTEMS46

SEALING SENSEFrom the voice of the fluid sealing industry


13/19

vibration and wear are taken up internally in the bel-lows, and here the secondary seals are truly static.The mechanical hardware supplied with and inte-gral to the seal is used to:

1. Adapt seals to various pieces of equipment. Thishardware may consist of a sleeve or housing forease and precision of seal setting.

2. Provide mechanical preloads to the seal facesuntil hydraulic pressures take over. This nor-mally is accomplished by a large single-coilspring, or by a set of small coil springs.

3. Transmit torque to both stationary and rotatingfaces. This normally is accomplished by a seriesof drive pins, dents, notches or screws integralwith the seal design.

No matter how complicated a design might appearthe first step in seal failure analysis is to identifywhich of the basic seal components show damagethat might indicate the cause of leakage. A mechan-ical seal has failed when leakage becomes excessive.Common causes include:

Allowing the seals components to becomechipped, scratched or damaged prior to or dur-ing assembly.

Incorrect seal assembly, including the incorrectsetting or misplacing of seal components in theseal cavity.

Selecting the wrong materials of construction oran incorrect design for the combination of pres-sures, temperatures, speeds and fluid propertiesrequired for a given application.

Improper startup and operating procedures,including failing to pressurize a double sealbefore starting a pump or inadvertently runninga seal dry.

Fluid contamination, which might be the pres-ence of harmful solid particles in the seal cavityfluid.

Poor equipment conditions, such as excessiveshaft runout, deflection or vibration.

Worn-out seals that may have completed a sat-isfactory life cycle.

The objective of failure analysis, naturally, is to learnfrom failures. We should carefully look at worn anddamaged seal parts, the condition of the equipment,and the operating conditions, to establish a list ofways to improve seal life. For worn parts, this con-sists of identifying damage as chemical, mechanical,or thermal and taking steps to ensure it does notrecur. Skills in mechanical seal failure analysis can beimproved by looking at the basic forms of damage

that occur to determine:1. What the damage looks like.

2. How the damage affects seal performance.

3. What the types of damage indicate about a sealspast history.

4. What corrective steps can be taken to eliminatevarious types of damage from recurring underthe same operating conditions.

Next Month:A discussion of the symptoms, examina-tion of the causes, and review of the corrective actionsfor failures of mechanical seals by chemical action.

PUMPS & SYSTEMS www.pump-zone.com SEPTEMBER 2004 47

Sealing Sense is produced by the Fluid SealingAssociation (FSA) as part of our commitment toindustry-consensus technical education for pumpusers, contractors, distributors and manufacturers. Asa source of technical information on sealing systemsand devices, and in cooperation with the EuropeanSealing Association (ESA), the FSA also supportsdevelopment of harmonized standards in all areas offluid sealing technology. The education is provided inthe public interest to enable a balanced assessment of

the most effective solutions to pump technology issueson rational Total Life Cycle Cost principles.

TheMechanical Seal Division of the FSA is oneof six divisions with a specific product technologyfocus. As part of its mission, it develops fundamentaltechnology publications such as theMechanical SealHandbook, to complement more detailed manufac-turers documents produced by its member companies.

The following Mechanical Seal Division memberssponsor this initial series:

Advanced Sealing International (ASI)A.W. ChestertonDuPont DowEagle BurgmannFlowserve FSDGarlock Sealing TechnologiesGreene TweedIndustrias Vago de Mexico

John CranePPC Mechanical SealsRobcoSealing Equipment Products Co.Simrit Div., Freudenberg-NOK

For additional information on FSA and the pub-lications and services it offers to industry, log on to

www.fluidsealing.com


14/19

Conclusions Recommendations Supporting documentation

4. Feasibility StudyIn the context of a fan or pump system, a feasi-

bility study is a documented analysis that establish-es the business case for modifications that improvesome aspect of the equipments operation. It is sup-ported by test data and in-depth technical and eco-nomic analyses. Although potential systemimprovements are sometimes driven by the need toreduce energy costs, more frequently other objec-tives must first satisfy criteria for the operation. Inmeeting those primary objectives, energy optimiza-tion should be thoroughly considered because of thelong-term operating cost implications. On the otherhand, options that reduce energy costs sometimescarry some aspect that is detrimental to the opera-tion. These also need to be addressed as necessary inthe study. The focus of the feasibility study has threemain components.

Evaluation of existing operation

Review background and overall design of thesystem.

Establish relationship be-tween process, systemand fan or pump requirements.

Investigate the current control strategy.

Review maintenance history to gain under-standing of past problems and remedial actions

taken. Conduct sufficient performance tests so that

capacity/efficiency, process requirements andsystem curve(s) are accurately established forthe complete range of operating points. Testsshould be conducted to a recognized field teststandard, i.e. Air Movement and ControlAssociation (AMCA) Stan-dard 203 or 803 forfans and Hydraulic Institute test standards forpumps.

Obtain sufficient electrical trend data to devel-op an annual load-duty cycle.

Conduct internal and external inspections aspossible.

Development of technical options

Review objectives for the retrofit.

Prepare list of possible options that addressoptimization objectives in the context of thecurrent operation.

Analyze options on basis of technical suitability,

i.e. different aerodynamic or hydraulic design,reduced or increased impeller diameter, changein material, change in mechanical design, vari-able speed, etc.

Completion of cost benefit analysis

Accurately determine energy savings, produc-tion benefits or maintenance improvements forthe technical options analyzed.

Establish cost estimates for the modifications,payback (overall cost vs. anticipated savings) orother economic considerations.

Upon issuing the draft and final documentationof the audit and feasibility reports, the consultantmeets with appropriate company and site personnelto present the findings.

The Case for UpgradesEnergy-efficient alterations to a fan or pump

system can provide benefits to the process, as well asreduce operating costs.

Reduced system requirementsDue to a downturn in production or reduced

system resistance, the equipment may currently beoversized for its application. This generally impliesthat the fan or pump is operating against a heavilythrottled damper or valve, or, conversely, simplyproducing excess volume. Thus, it may be ineffi-cient or difficult to control. Possible retrofitsinclude reduced speed operation or a smaller

impeller diameter.

Maintenance and reliability improvementsExisting equipment may have a history of prob-

lems. Typically the Ten/Ninety rule applies10% of the equipment causes 90% of the problems.The primary problems plaguing industrial fan andpump equipment are:

Excessive vibration levels

Bearing and seal failures

High erosion and corrosion rates

Formation of cracksProperly running equipment reduces maintenancecosts and the risk of unscheduled outages.

Increased capacity requirementsAs systems are upgraded to obtain more pro-

duction, the fans and pumps may become a bottle-neck to reaching desired levels. More flow and pres-sure may be all thats needed. Sometimes added



15/19

system components have in-creased resistance so that flow isreduced to an unacceptable level(i.e. the addition of pollution-control equipment). In theseinstances, an upgrade may beneeded to overcome pressure loss-es that werent factored in at theoriginal design stage. Possiblesolutions may be bigger or fasterimpellers, a change in design or completely newequipment.

Efficiency-focused upgradesSometimes, the efficiency of an existing system

is so poor and electrical rates so high that anupgrade may be viable on these grounds alone. Theexisting equipment may be of inefficient because ofits design, selection for the application or the man-ner of its control. At any rate, an upgrade may be

justified simply on the basis of reduced energy oper-ating costs.

Control refinementsSystems calling for precise fluid control and the

flexibility to meet various product requirementsmay benefit from an upgrade. This could involve achange in damper/valve design, modifications thatimprove the stability of the operating point(s), sys-tem changes or conversion to variable speed.

Noise reductionFor fans, there are numerous techniques that

reduce noise levels. These include insulation/cladding, low-noise impellers and silencers. Theaddition of silencers frequently necessitates animpeller upgrade to handle higher system pressurelosses. A valid alternative to retrofitting a fan is sim-ply to replace it with a new one. There, however,may be many reasons why retrofitting is better, i.e:

Existing casing, foundation, ductwork, motoror other components may be in good conditionand can be reused. Therefore, a retrofit is prob-ably more economical.

Less disruption and downtime

Resolving known problems may be less risky

than taking on the uncertainty of wholesalechanges.

What to Look for in EnergyAssessment Consultants

To make sure you capture all of the energy sav-ings possible from your system, there are a numberof things to look for in an energy assessment con-sultant:

Good communication skillsand assistance to ensure thatparties understand each otheron both technical and commercial details of the system.

Expertise and experience with

the targeted equipment. Inparticular, it is very helpful if

the consultants have a good work-ing relationship with the original equipmentmanufacturer and are able to communicatewith them effectively. Engaging consultantswith a strong background in the type of equip-ment being studied will save much time andmoney, in that they can quickly eliminateimpractical/unfeasible upgrade options.

Expertise and experience in the scope of supplyfor other parties that eventually may beinvolved, should the targeted equipment proveto be suitable for an upgrade. Typically, thisinvolves project engineering/management com-panies, upgrade equipment suppliers, specialistsin monitoring and verification procedures, andcompanies providing project specificationpreparation, experience in enforcing perfor-mance guarantees and risk assessment/reduc-tion (if this is not in the purview of the compa-ny conducting the feasibility study), etc.

A sound working knowledge of field perfor-mance measurement techniques and/or testingorganizations that can do this work. RE

Vern Martin is the Sales Manager and a partnerin FLOWCARE Engineering, Inc., of Cambridge,Ontario, Canada, a company providing fan, pumpand blower technical consulting services worldwide.His primary responsibilities with the company includeconducting energy optimization studies and trou-bleshooting large turbo machines with performance,noise, vibration, control or failure problems, as well asdeveloping energy-reduction strategies and trainingprograms for companies and utilities interested indemand-side management. Prior to joining FLOW-CARE, Martin engineered and tested fans for Sheldons

Engineering, a manufacturer of heavy-duty industrialfans. A graduate of the University of WaterlooMechanical Engineering Department and a registeredProfessional Engineer, hes the author of several hand-books on fan, pump and blower technology. For moreinformation on the services referenced in this article,e-mail Martin directly at [email protected] or visitwww.flowcare.com



16/19


Safe To Use

Non-OEMs To MaintainAnd Refurbish Crucial

Turbomachinery?Heres the answer from California.

By Jane Alexander, Editor,with Bruce Perry, Vice President Sales and Marketing, Thomason Mechanical Corporation

Having been awarded Edison Mission Energys 2004 Gas Turbine Maintenance contract for five facilities, Thomason

Mechanical Corporation is demonstrating how working with the right non-OEM contractor can save time and money.


17/19

Under mission-critical de-mands for 99%+ uptime,many operators stick

with OEMs for maintaining andrefurbishing crucial operating

systems. Today, Edison MissionEnergy (EME) is successfullyusing a non-OEM contractor,Thomason Mechanical Corpo-ration to refurbish and inspectgas turbines in five of the ninefacilities in its California cogen-eration fleet. For operations thatare responsible for generatingmore than 1,400 MW, Thom-ason is demonstrating an effec-tive, cost-conscious alternative tosupport a full 48% of EMEsCalifornia cogen capacity.

It is the first time in almost adecade that EME has used a non-OEM for its major gas turbinemaintenance efforts. The pro-grams success shows that opera-tors of complex facilities canachieve both effective results andadditional benefits from non-OEM contractors.

Starting Line-UpThomason brings wide-

ranging experience to this pro-

ject, having served the powerindustry since 1975 in rotatingand reciprocating machineryinstallation, maintenance andoverhaul. The company has beenworking on industrial frame gasturbines since the early 1990s. Asa non-OEM, Thomason focus-es on lowering customers risksduring machinery maintenanceand setting high standards oftimeliness, quality, reliability,safety and productivity.

The Thomason organization

is part of the Field Services unit ofWood Group Gas Turbine Ser-vices, which has 2,000 employees

with in-depth knowledge in sup-porting operators of gas turbines,steam turbines, generators andother high-speed rotating equip-ment. Wood Group is recognized

worldwide as a leading indepen-dent gas turbine maintenanceprovider.

Thomason has involvedadditional Wood Group FieldServices resources to provideboth qualified field engineers andwork crews for the same project

or program. Wood Groups fieldengineering expertise consider-ably expands TMCs traditionalcapability: the provision of well-qualified union millwrights,including all tools and labor.

Bundling OutagesA leading independent pow-

er producer, EME has earned areputation as a responsible oper-ator of environmentally soundprojects, and it takes its commit-ment to reliable energy produc-tion seriously.

When EME was evaluating

service contractors for the 2004gas turbine maintenance pro-grams at its California cogenfacilities, it set out some unusualrequirements. The proposal bun-dled the outages of five sites:Kern River (300 MW), Mid-Set (38 MW), Salinas River(38 MW), Sargent Canyon(38 MW), and Sycamore (300MW). EME is a 50% partner

with ChevronTexaco in thesefacilities; EME is the operationsand maintenance contractor.

The request for quote (RFQ)required the provision of com-

prehensive technical direction,craft supervision and labor andtooling to complete the combus-tion inspections and major over-hauls for the facilities GeneralElectric Frame 6B, 6B DLN, and7EA DLN heavy industrial gasturbines, all of which are naturalgas-fueled.

Additionally, EME wantedthe same third-party engineersand supe rvi sor s throughout theprojecta key factor in ensuringthe reliability and quality of all

procedures, end to end.The contract posed unique

challenges.All outages at the five facili-

ties were bid under the singleRFQ. It included the craft super-vision, labor and tooling requiredto perform this work, and alsothe provision of technical direc-tion. Experienced field engineersand full-time, fully qualified craftpeopleon one team, under onecontractmight appear to bedifficult for a contractor, whetherOEM or not.

Since Thomason is part ofWood Group, it was able torespond to the RFQ and provideall the services required. Overand above the proven labor skills,the contract and the work requirethat field engineering alwayshave the necessary expertise andexperience. Wood Group fieldengineers must be able to meetEME expectations.

The competitively bid con-

tract was awarded to Thomasonfor the 2004 program that beganin January, and will continuethrough November, when thefinal combustion inspection isconducted at Sycamores Unit 4.This is the first time that EMEhas contracted field engineersfrom a third party other than theOEM.


Working with a

non-OEM for

field engineer-

ing, maintenance

and inspection

can be a low-

risk, high-gain

opportunity.


18/19

Energy efficiency is one ofthe most pressing issuesfacing industry today.

Some of the most visible targetsof efficiency campaigns are elec-tric motors driving equipmentsuch as fans and pumps. Criticalto most plant and building oper-ations, this equipment is alsoamong the most costly to keeprunning.

In many plants, premiumproducts, designs and accessoriesare being installed, yet the antic-ipated energy efficiency benefitsarent being captured. Sometimesthis becomes evident immediate-lysometimes more gradually.As there may be few observableindications of reduced equip-

ment efficiency, operators oftenare unaware that deficiencies anddegradations exist at all. To theexperienced eye, though, thereare a number of subtle tell-talesigns that provide valuable clues.

Its difficult to really knowhow efficiently fluid-handlingsystems are performing withoutconducting detailed testing. A

preliminary indication of ineffi-cient operation is frequently theexistence of maintenance prob-lems. This is similar to a sputter-ing car which has an obviousmaintenance problem and acoincidental thirst for fuel.

As highlighted here, thereare four primary phases in theidentification, qualification andstudy of a fan or pump system

for the purpose of energy reduc-tion. This is what you can expectto happen when you call onexperts to help determine theefficiency of these systemsandprovide recommendations forfeasible and cost-effective modi-fications that will lead toimprovements. Since each systemis unique, the following general-izations need to be carefully con-sidered as applied to specific situ-ations. Furthermore, at the con-clusion of each phase, evaluationof the information must be com-pleted to determine if proceedingfurther is warranted.

1. PrescreeningPrescreening is used to

describe the activities required toevaluate whether there actually isan energy-saving opportunityworth pursuing at a specific site.During prescreening, the site isnot actually visited (typically, thisis the case, but theres no reasonnot to visit the site). Therefore,this step primarily concentrateson non-technical issues. The typeof required information is usual-ly obtainable through a phonecall. Other sources are also used

depending on availability, type ofcompany, etc. Typical informa-tion gathered and issues investi-gated are:

Types of products manufac-turered and processes used

Age of plant and equipment

Sizes of motors and applica-tions


Vern Martin, P. Eng., FLOWCARE Engineering, Inc.

Analyzing Fan And Pump

Systems For Energy SavingsYouve been hearing aboutenergy assessmentsheres what its all about.

Consultant collects data for performance and efficiency testing as part of a

comprehensive energy assessment.


19/19

Operating hours Electrical rates Utility program availability Company financial viability

Future plans for plant Payback criteria Personnel technical knowledge and decision-

making positions

2. ScreeningFor facilities that show promise after prescreen-

ing, a site visit is required. Screening refers to thequalifying activities conducted during the visit tothe customers office and related inspection of theequipment. In most cases, sufficient informationcan be obtained to provide an initial approximationof the energy-saving potential. The following func-tions and data gathering are required to obtain suf-

ficient information to make a decision on whethercontinued pursuitand further investigation andstudy is warranted.

Technical information to define specific sys-tems, ie. motor, sizes, driven equipment types,other system componentry, equipment age andcondition, control, etc.

System classification, ie. fixed resistance, con-stant pressure, constant flow or fixed resistancewith constant static pressure requirement.

Operating information, ie. number of hours,number of load points (as defined by the par-ticular process parameters measured or produc-tion records), motor amperages, control param-eters/set-points, etc.

Process and instrumentation diagrams, equip-ment specification sheets, performance curves,etc.

Identification of system problems, ie. inade-quate capacity, control, vibration, noise, exces-sive maintenance requirements, premature andunscheduled equipment failures, etc.

Physical inspection of system from point wherefluid enters system to point where it is eventu-ally dispelled. Note the following:

Damper/valve positions Ductwork/piping and system design System maintenance condition Motor and driven quipment nameplate data Leakage, blow-off, recir-culation modes or

other wasted flow opportunities

General customer information not obtainedduring prescreening efforts (see Pre-screeningsection for details).

Prioritization of issues critical to the site, ie. reli-ability, payback criteria, longevity requirements(future plans), control, flexibility, process capac-ity, etc.

3. Audit

The audit is a technical review of a particularsystem to establish the existing conditions, deter-mine the energy-reduction opportunities and estab-lish the optional methods that will achieve the ener-gy savings. Typically, the audit uses all the informa-tion gathered during the Prescreening andScreening phases. Sufficient additional detail mayalso be required to compile the data into a suitablereport format. To prepare an audit report requires thefollowing:

Organization of information obtained duringPrescreening and Screening

Gathering of any additional information toround out the auditors understanding of theexisting system. At this stage, system perfor-mance testing is typically not required,although recording ammeters may be needed toobtain an approximation of motor load and sys-tem load trend.

Preparation of an estimate of existing energyusage based on the information obtained

Compilation of a list of inefficiencies notedwith the system(s), based on the informationobtained and estimate of the energy savings.Since no test data is available at this stage, anattempt should be made to establish the rangeof the estimate.

Preparation of a list of options that will addressthe inefficiencies noted. For each, an estimate ofthe energy savings and, if possible, an approxi-mate cost of the modification are provided.

Compilation of an audit report incorporatingall of the foregoing information. A comprehen-sive report would include the following:

Appropriate cover matter Executive summary Equipment and process description

Overview of current operating conditionsand modes Description of inefficiencies noted Description of energy reduction options

and electrical savings estimate for each List of additional production and opera-

tional benefits (if applicable) Scope of work for further testing and

analysis as would be conducted in a feasi-bility study


rotating eqeip maint

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