flowserve gaseous noise control - ibasa.com.mx

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Flowserve Gaseous Noise Control

Experience In Motion

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IndexSection Page

� IntroductiontoNoise.......................................... 3�.� PressureProfilesThroughControlValves........ 3�.� GaseousSevereService................................... 3�.3 FactorsImpactingNoise.................................. 3�.4 PredictionTechniques...................................... 7�.5 AdditionalSelectionFactors............................. 7� ProductComparison........................................... 83 Stealth................................................................. �04 TigerTooth........................................................... ��5 MegaStream........................................................ �36 TypeIII................................................................ �47 TypeII................................................................. �48 TypeI.................................................................. �59 RLS-System........................................................ �6�0 XStream.............................................................. �6�� Multi-Hole........................................................... �7�� SilentPac............................................................. �7�3 Z-Trim................................................................. �8�4 DownstreamPlates............................................. �9

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TheBernoulliprinciple:Whenthefluidpressureinthevalvedrops,thefluidvelocityrises.

1. Introduction to Noise1.1 PressureProfilesThroughControlValves As a fluid travels through a conventional single-seated

globe-stylecontrolvalve,avenacontracta(pointofnar-rowestflowrestriction)developsdirectlydownstreamofthenarrowestthrottlingpoint.Atthepointofvenacon-tractathefluidreachesaminimumpressureandmaximumvelocitywhichrapidlyrecoverstoalowerpressurethantheinletpressure(seeFigure�.�:PressureDropthroughaControlValve).DuetotheBernoulliprinciple,whenthefluidpressure inthevalvedrops,thefluidvelocityrises(see Figures �.�: Velocity through a Control Valve). Asthevelocityofthefluidincreases,thenoisegeneratedbyturbulenceinthefluidalsoincreases.Asignificantriseinvelocitycanproducenoisebeyondsafelimits.

1.2 GaseousSevereService Highpressuredropsingasserviceswillgenerateturbu-

lenceinthefluidflowdownstreamofthepressuredrop.Asadirect resultof the turbulence,noise is radiated tothesurroundingareaby thedownstreampipingsystem(Figure �.3: Noise Radiating from Downstream Piping).Insituationswhereequipmentdamageorpersonalinjurycouldbecausedbyanoisesource,attenuationismanda-tory.

Testshavedemonstratedthatcontrolvalvenoiseincreas-esproportionaltothevelocitycubed(SPL~V3).Mod-eratelyhighervelocitiescanproducesignificantlyloudernoise.Substantialnoisecanbegeneratedevenwhenve-locitiesaresignificantlylessthansonic.

Mechanical vibration accompanies high acoustic noiselevels.Acousticnoiseandmechanicalvibrationlevelsaregreatlycompounded(upto50times)whenthefrequencyof the excitation matches acoustic and/or mechanicalnaturalfrequenciesofthesystem.

Noisesuppressionsolutionsshouldalwaysbeconsideredinhighpressuredrop,highflowrateor resonantnoiseapplications.

ControlValvenoiseismeasuredindecibels(dBa).Deci-belsusealogarithmicscale,doublingtheenergylevelofsoundpressurewavewillcausethenoiseleveltoincreasebyabout6dBa.ThedBascaleisstructuredtothehumanear,thelowestnoiseahumancanhearisaround0dBaandarivetgunisaround�00dBa.Earprotectionshouldbeconsideredwhennoiselevelsareabove85dBa.

Uncontrollednoiseisasignificantproblemthatcanleadto serious health problems, vibration and in the mostextremecasescancausedamagetoequipment. Noisecalculations should be performed on all control valveflowinggassestoverifythesuitabilityoftheequipment

1.3 FactorsImpactingNoise

FluidVelocity Themostfrequentlyusedsolutiontohighlevelsofcontrol

valvenoiseistoreducethepressurefromthevalveinlettooutletgradually,eliminatingpressureandvelocityspikesthroughoutthetrim(Figure�.4:PressurethroughaMulti-Stage Valve). By lowering the pressure gradually, lowervelocitiesarecreated.Thelowervelocitiesgeneratelowernoiselevels.Successfullyapplyingthistechniquerequirescontrollingthegasvelocitythroughthevalvetrimandatallpointsfromtheinlettotheoutletofthevalve.

Occasionallyfluidvelocitiesatthevalveoutletoreveninthedownstreampipecancauseexcessivenoise.Inthesecases,simpletrimsolutionswillnotprovidetheneedednoiseattenuation.

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Figure1.1:PressureDropThroughaControlValve Figure1.2:VelocityThroughaControlValve

ConceptionDevelopmentManufacture

Outletvelocitiesbelow0.33Macharedesirable.Highervelocitiesmaybeacceptable,butrequireanengineeringreviewforeachapplication.Velocitiesmustbeassessedforthemostdifficultflowingconditionsatthefollowingcriticalpoints (asshown inFigure�.5:CriticalVelocityZonesonpage6):

•Theinletpassagewaytothevalve •Theinternalflowareaoftheseatretaineratallplug

positions•Thegalleryflowareaformedbetweentheoutside

diameteroftheseatretainerandtheinsidediameterofthevalvebody

•Outletpassageflowarea

P1/P2,thePressureRatio Thedrivingforcebehindvelocityandnoiseiscontained

intheP�/P�ratio,whichrepresentstheenergyavailabletogeneratenoise.Whenthisratioislow,theenergycon-tainedinthefluidstreamwillbelowandthenoisegener-atedwilltypicallybelowaswell.Eachnoisesolutionwill

havearangeofpressureratioswherethedesignismosteffective.Noisecontroltrimismosteffectivewhenpres-sureratiooftheserviceisbelowthetrimdesignlimits.

ReducingPressurewhileControllingVelocity Themostcommonmethodtoreducenoiseistoseparate

alargepressuredropintosmallerpressurestepswhichwillproducefarlowervelocitiesateachstep.Anumberofmechanismsareavailabletoreducethepressurewith-outcreatingexcessivevelocity.Designswhichmakeef-ficient use of these mechanisms will create the lowestnoisepossible.

SuddenExpansionandContraction Afluidthatexperiencesasuddenexpansionorcontrac-

tioncreatesturbulentzonesinthefluidflow.Thesetur-bulentzonestakesenergyoutofthefluidintheformofpressure.Thisistheprimaryeffectusedbyorificeplatestocreateapressuredrop.

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Figure1.4:PressureThroughaMulti-StageValve

ConceptionDevelopmentManufacture

SmallFlowPassages Small flow passages accentuate the friction formed by

thepassagewalls.Asthepassagegrowssmaller,morepressureisrequiredtoforcethefluidtoflow.Manyvalvedesignsusesmallpassagestocreatefrictionallossestoreducethepressure.

MutualImpingement Bydirecting twoflowsto impacteachotherat�80de-

grees,ahighlyturbulentzoneiscreated.Thisturbulentzonedissipatesenergy. Withoneflowworkingagainsttheopposingflow,thepressureisreducedwithoutadd-ingvelocitytotheflow.

Turns Each sudden turn in the fluid flow path will cause the

pressureinafluidtodrop.Asmallvelocityincreaseoc-cursasthefluidmakestheturn.Theangleoftheturncanhaveadramaticeffectontheenergylossfromthefluidasitmakestheturn.Anglessharperthan90degreesaredifficult tomanufacture,buthavemoreof aneffectonreducingpressure.

PeakFrequencyEffect Mostnoise in a control valveproduces a rangeof fre-

quencies which have a bell-curve type distribution andapeakfrequency.Changesinthegeometryofthevalvedesignwillshiftthispeakfrequency.

Shifting thepeak frequencyhigher isverydesirable fortwoprimaryreasons.First,itcanshiftthefrequencyoutoftherangeofhumanhearing.Thislowerstheperceivednoiseandreducesthedamagetohumanorgans.Second,it reduces the level of noise that canpass through thepipe.Thenaturalfrequencyofpipeislow.Whenthefre-quencyofthenoisematchesthenaturalfrequencyofthepipe, thepipewill resonate insympathy,easilypassingthenoisefromtheinsidetotheoutsideofthepipe.High-er frequenciesdon’t have this resonance andwill passlessnoiseoutofapipe.Higherpeakfrequencieswillbecontainedinsidethepipebetterthanlowerfrequencies.

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Figure1.3:NoiseRadiatingfromDownstreamPiping

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InletPassageway

InternalTrimFlowArea

OutletPassage

Figure1.5:CriticalVelocityZones

GalleryFlowArea

Acommonmethodtoraisethepeakfrequencyistomakesmalleroutletholesinthenoisecontroldevice.Cuttingaholediameterinhalfcanlowertheoverallnoiselevelbyuptofivedecibels.

WaveCrackerTechnology WaveCrackerisapatentedtechnologythatreducesnoise

asflowpassesthroughpassageswithirregularlyshapedcrosssections.Testshaveshownthistechnologyeffec-tivelycanreducenoisebymorethantendecibels.

WaveCrackerworksbyforminganirregularcrosssectionshape(seeFigure�.6:WaveCrackerPassages). Soundwavesreflectingoffthewallsofthepassagehaveirregu-lar patterns. These irregularpatterns cause the soundpressure wave to lose intensity as it moves down thepassage.

MassFlow Lowerpressuredropsacrosscontrolvalveswillproduce

significantnoiseifthemassflowrateishigh.Thishap-

pensmostofteninlargevalveswhenmanysmallnoisegenerationsitescombine toproducea loudcumulativenoise level. Combating this problem is more difficultsincetakingthepressuredropinsmallstagesmaynotbeeffective.

AcousticalAttenuation Acousticalattenuationcanprovideabarrierwhichblocks

noise.Thiscanbedone inmanyways, frominsulatingthepipeto increasingthedistancetothenoisesource.Carefulengineeringofanoisesolutionincludesevaluat-inganyexistingorpotentialattenuation.

HarmonicVibration Harmonicvibrationoccurswhenthenaturalfrequencyof

thepipeandvalveapproachacommonfrequency.Thiscausesanoisewithasinglefrequencyandacharacteris-ticsoundthatisoftencalledscreech.Sincescreechoc-curswhenthefrequencyofthevalveandpipematch,itisnoteasilypredicted.However,simplechangesinthevalvegeometrycanusuallysolvetheproblem.

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Figure1.6:WaveCrackerPassages

• Howmuchnoiseattenuationisactuallyrequired?• Whatarethelow-costalternativestonoiseattenuation?• Ifnoiseattenuationdevicesarenecessary,whatlower-

costequipmentcanbespecified?Ifthepredictedsoundpressurelevel(SPL)exceeds85or90dBA,noisesup-pressiondevicesshouldbeconsidered.However,highernoiselevelsmaybeacceptableifthenoiseisnotassoci-atedwithequip-mentdamageandislocatedinaremotelocationawayfrompeople.Otherpossiblelow-costal-ternativestonoisesuppressionequipmentare:

•Pipinginsulation •Dischargingthevalvedirectlyintoavessel(allow-

ingthenoisetobeabsorbedbythevessel) •Relocatingthenoisesource(suchasthedown-

streampiping)outsideanenclosedarea •Reversingtheflowdirectionthroughthevalve •Reducingthepressuredropacrossthevalve.

ReflectiveSurfaces Noisecomingfromapipecanbeamplifiedbyreflective

surfaces. Noise predictions assume a free field, whichisdefinedasnoreflectivesurfaces.Asingleflatsurfacenearthecontrolvalve,likeaconcretefloor,canaddthreedecibelstothenoise.Eachflathardsurfacecanaddan-otherthreedecibels.Twohardflatsurfacesthatareparalleltoeachotherwilladdsubstantiallymorethansixdecibels.Adding walls, a ceiling and a floor can add thirty to fortydecibels.

1.4 PredictionTechniques Anumberof prediction techniques existwith varying lev-

els of accuracy for different applications. Using differentpredictiontechniquestopredictthenoiseofanapplicationwilloftenresultiswidelyvaryingresults.Unfortunately,nostandardexistswhichisthemostaccurateforallpossibleconditions.Therefore,whennoiseisacriticalfactorastudyoftheflowconditions,valvedesign,andtheavailablenoisepredictionmethodsshouldbeundertaken.

ValveManufacturerStandards Mostmanufacturerhaveproprietarytechniqueswhichwill

produce acceptable predictions under a certain range ofconditionsandwithequipmentthemanufacturerisfamiliarwith. Whenusedoutsideof theacceptable rangeorwithotherequipment,predictednoisecalculationscanbesignifi-cantlydifferentthanactualnoiseproduced.

IEC60543-8-2 Inanefforttoprovideanaccuratestandardthatcanbeused

to compare different manufacturers, the IEC committeehasdevelopedtheIECstandard60543-8-�.Althoughthispredictionmethodisnotperfectforallconditionsorvalvestyles,thismethoddoescreateaclearbaselinetocomparedifferentvalvemodels

1.5 AdditionalSelectionFactors Thefollowingfactorsshouldbeconsideredbeforeapplying

expensivenoisesuppressionequipment:

WaveCrackerPassage

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2. Product ComparisonDesign Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Design

Type Stealth TigerTooth MegaStream TypeIII TypeII TypeI TypeBaseValve MarkSeries MarkSeries MarkSeries KämmerSeries KämmerSeries KämmerSeries BaseValveSizeRange 3˝to36˝ �½˝to36˝ �˝to36˝ ½˝to4˝ ½˝to4˝ ½˝to4˝ SizeRange

CvRange to4000 4to4000 5to�0�00 �.8to��8 �.8to466 CvRangeFlowDirection Flowundertheplug Flowundertheplug Flowundertheplug Flowundertheplug Flowundertheplug Flowundertheplug FlowDirection

PressureStages 6to�0 �to8 �to7 � � � PressureStagesFeatures •Attenuationofupto40dBa

•WaveCracker•Stealthisthemostefficienthighpres-

suredropnoiseattenuationtrimeverdeveloped

•Stealthuseslaser-cutdiscstocreatestackeddiscseatretainers.Thecutsinthediscsformchannelsforthefluidtopassthrough.

•Attenuationofupto30dBa•Canbetakenapartforcleaningor

repair•TigerToothusesstackeddiscswith

grooves,orteeth,totakemultiplestagedpressuredrops

•Self-cleaningdesignwithlargepas-sages

•Attenuationofupto�0dBa•MegaStreamusesnestedcylindersin

placeoftheseatretainer.Eachdrilledcylinderrepresentsastageofpres-surereduction

•Attenuationofupto�6dBa•Bothplugcharacterizedorcagechar-

acterizeddesignsavailable•Customengineeredtomatchthe

serviceconditions•Astheplugopensintheseat,itsimul-

taneouslyopensthecageforeffectivenoisecontrolovertheentirestrokelength

•Attenuationofupto��dBa•Customizabletrimcharacteristics

available•CombinationwithTypeIpossible(up

to�9dBA)

•Attenuationofupto�3dBa•3designs(singlecage,doublecage,

doublecagewithsilencer)•Easyretrofit•StandardPlug

Features

Design Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl BallValve,Multi-StageNoiseControl DownstreamOrificePlate,Multi-StageNoiseControl Design

Type RLS-System XStream Multi-holeplug SilentPack Z-Trim DownStreamPlates TypeBaseValve FlowTop,FlowPro FlowTop,FlowPro FlowTop,FlowPro FlowTop,FlowPro Setball,Duball,ShearStreamSB Downstreamofanyvalve BaseValveSizeRange �˝to��˝ ½˝to��˝ ½˝to��˝ ½˝to��˝ �˝to�0˝ �½˝to�4˝ SizeRange

CvRange Engineeredupto8�0 4.6to�040 �.9to�040 0.73to9�5 90to�5950 6to3340 CvRange

FlowDirection BidirectionalFlow,LiquidflowtocloseGasflowtoopen Flowundertheplug BidirectionalFlow Flowundertheplug Duball;BidirectionalFlow

Setball;ShaftDownstream Downstreamofcontrolvalve FlowDirection

PressureStages �to6 �to4 � � �to5 �to3 PressureStagesFeatures •Attenuationofupto30dBadepend-

ingontheoperatingconditions•Efficient,modulardesign•Everystageiscontrolled,which

resultsinahighefficiencyevenatpartialload

•Forgas,steamandliquidservicetoreducenoise

•Attenuationofupto�0dBadepend-ingontheoperatingconditions

•Efficient,modulardesign•Easyupgradefromstandard,notrim

setchanges•Forgas,steamandliquidserviceto

reducenoise


•Efficient,modulardesign•Forgas,steamandliquidserviceto

reducenoise

•Attenuationofupto�8dBadependingontheoperatingconditions


setchanges•Forgasandsteamservicetoreduce

noise

•Attenuationofupto�7dBa•Pressuredropsuptothevalvelimits•TightShutoff•TheuniquepatentedZ-trimdesignre-

ducesnoisebytakingpressuredropsinuptofivesteps

•Thedesignmakesitpossibletoman-agehighpressuredropsatlowflowsandsmallopeninganglesandstillhavehighcapacities(Cv)atlargeropeningangles

•TheZ-Trimisselfcleaningforapplica-tionswithentrainedmedia

•Attenuationofupto�5dBa•Downstreamplatesareinstalled

downstreamofavalveproviding backpressureandnoiseattenuation•Noisecontrolplateshavemultiple

drilledholestoattenuatenoisewhiletakingthepressureloadoffthecon-trolvalve

Features

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Design Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Design

Type Stealth TigerTooth MegaStream TypeIII TypeII TypeI TypeBaseValve MarkSeries MarkSeries MarkSeries KämmerSeries KämmerSeries KämmerSeries BaseValveSizeRange 3˝to36˝ �½˝to36˝ �˝to36˝ ½˝to4˝ ½˝to4˝ ½˝to4˝ SizeRange

CvRange to4000 4to4000 5to�0�00 �.8to��8 �.8to466 CvRangeFlowDirection Flowundertheplug Flowundertheplug Flowundertheplug Flowundertheplug Flowundertheplug Flowundertheplug FlowDirection

PressureStages 6to�0 �to8 �to7 � � � PressureStagesFeatures •Attenuationofupto40dBa

•WaveCracker•Stealthisthemostefficienthighpres-

suredropnoiseattenuationtrimeverdeveloped

•Stealthuseslaser-cutdiscstocreatestackeddiscseatretainers.Thecutsinthediscsformchannelsforthefluidtopassthrough.

•Attenuationofupto30dBa•Canbetakenapartforcleaningor

repair•TigerToothusesstackeddiscswith

grooves,orteeth,totakemultiplestagedpressuredrops

•Self-cleaningdesignwithlargepas-sages

•Attenuationofupto�0dBa•MegaStreamusesnestedcylindersin

placeoftheseatretainer.Eachdrilledcylinderrepresentsastageofpres-surereduction

•Attenuationofupto�6dBa•Bothplugcharacterizedorcagechar-

acterizeddesignsavailable•Customengineeredtomatchthe

serviceconditions•Astheplugopensintheseat,itsimul-

taneouslyopensthecageforeffectivenoisecontrolovertheentirestrokelength

•Attenuationofupto��dBa•Customizabletrimcharacteristics

available•CombinationwithTypeIpossible(up

to�9dBA)

•Attenuationofupto�3dBa•3designs(singlecage,doublecage,

doublecagewithsilencer)•Easyretrofit•StandardPlug

Features

Design Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl Globe,Multi-StageNoiseControl BallValve,Multi-StageNoiseControl DownstreamOrificePlate,Multi-StageNoiseControl Design

Type RLS-System XStream Multi-holeplug SilentPack Z-Trim DownStreamPlates TypeBaseValve FlowTop,FlowPro FlowTop,FlowPro FlowTop,FlowPro FlowTop,FlowPro Setball,Duball,ShearStreamSB Downstreamofanyvalve BaseValveSizeRange �˝to��˝ ½˝to��˝ ½˝to��˝ ½˝to��˝ �˝to�0˝ �½˝to�4˝ SizeRange

CvRange Engineeredupto8�0 4.6to�040 �.9to�040 0.73to9�5 90to�5950 6to3340 CvRange

FlowDirection BidirectionalFlow,LiquidflowtocloseGasflowtoopen Flowundertheplug BidirectionalFlow Flowundertheplug Duball;BidirectionalFlow

Setball;ShaftDownstream Downstreamofcontrolvalve FlowDirection

PressureStages �to6 �to4 � � �to5 �to3 PressureStagesFeatures •Attenuationofupto30dBadepend-

ingontheoperatingconditions•Efficient,modulardesign•Everystageiscontrolled,which

resultsinahighefficiencyevenatpartialload

•Forgas,steamandliquidservicetoreducenoise



setchanges•Forgas,steamandliquidserviceto

reducenoise


•Efficient,modulardesign•Forgas,steamandliquidserviceto

reducenoise

•Attenuationofupto�8dBadependingontheoperatingconditions


setchanges•Forgasandsteamservicetoreduce

noise

•Attenuationofupto�7dBa•Pressuredropsuptothevalvelimits•TightShutoff•TheuniquepatentedZ-trimdesignre-

ducesnoisebytakingpressuredropsinuptofivesteps

•Thedesignmakesitpossibletoman-agehighpressuredropsatlowflowsandsmallopeninganglesandstillhavehighcapacities(Cv)atlargeropeningangles

•TheZ-Trimisselfcleaningforapplica-tionswithentrainedmedia

•Attenuationofupto�5dBa•Downstreamplatesareinstalled

downstreamofavalveproviding backpressureandnoiseattenuation•Noisecontrolplateshavemultiple

drilledholestoattenuatenoisewhiletakingthepressureloadoffthecon-trolvalve

Features

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IntroductionThemostsophisticatednoiseattenuationdesign,Stealth trimeffectivelyreducessoundpressurelevelsinthemostdemand-ingapplications (Figure3.�:ControlValvewithStealthTrim).TheadvancedStealthdesigncombinesthemosteffectivenoiseandpressurecontrolmechanismstoproducethemostefficientnoisereductiontrimevercreated.DesignStealthisproducedbylasercuttingcirculardiscstoformfluidpassageways and then braising the discs together to form aseat retainer (Figure3.�:StealthStack).Threedifferentdiscsarecutandmatched together to formaflowpathset (Figure3.3:StealthDiscs)(Figure3.4:StealthFlowPassage).Anumberofdiscsetsarethenstackedtogetherandthewholeassemblyisbraisedtogethertoformastack.

Similar to TigerTooth an important mechanism reducing thepressureinStealthtrimisthesuddenexpansionandcontrac-tionphenomenonthattakesplaceastheflowpassesovertheteeth. The Stealth trim’s ability to gradually reduce pressurewithoutgeneratinghighvelocitiesisimportantforthereductionofnoiseintheprocessline.

Inadditiontoreducingthepressuregradually,Stealthtakesad-vantage of frequency shifting by providing small outlet holeswhichraisethefrequencyandlowerthenoise.

An important feature in the noise control capabilities of theStealthisthepatentedWaveCrackertechnology,patentnumberWO�006/093956A�.WaveCrackertechnologyprovidesextranoiseattenuationwithoutcreatingextrapressuredropsinthevalve.

TrimexitflowpathsontheStealthareangledtodirecttheflowtothevalveexit.Thisfeatureincreasestheflowcapacityofthevalveandlowersthenoisebyreducingexitturbulence.

Combiningthepressurereduction,andvelocitycontrolfeatureswiththenoiseeliminationfeaturesoftheStealthproducesthemostadvancednoiseeliminationtechnologyavailable.

Figure3.1:ControlValvewithStealthTrim

3. Stealth

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Figure3.2:StealthStack

Figure3.3:StealthDiscs Figure3.4:StealthFlowPassage

BaseValveDesignBasevalvesfortheStealthincludetheMarkOneandMark�00.MechanismsatWork•PressureControl•VelocityControl•Attenuation•FrequencyShifting•NoiseCancellation•WaveCracker

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IntroductionDecadesoffieldexperiencehasproventhesophisticatedde-sign of the TigerTooth to be one of the most effective noisereductiontrimsavailable.Designedtobemosteffectiveathighpressuredrops,theTigerToothdesigneffectivelyreducesthesound pressure levels in the most demanding applications(Figure4.�:ControlValvewithTigerToothTrim).

DesignTheTigerToothdesignemployshighlyengineeredconcentricgrooves (or teeth)machined into the face andbacksideof aseriesofcircularstackeddiscs(calledastack),whichformtheseatretainer(Figure4.�:Cross-SectionedTigerToothSeatRe-tainer).Legsseparateonediscfromanother,providingagapbetweenindividualdiscs,formingflowpassages.

An important mechanism reducing the pressure inTigerToothtrimisthesuddenexpansionandcontractionphenomenonthattakesplace as theflowpassesover the teeth. TheTigerToothvalve’sability togradually reducepressurewithoutgeneratinghigh velocities is important for the reduction of noise in theprocessline.

Inaddition to thestandard linearandbi-lineardesigns,Tiger-Toothcanalsobedesignedwithafull-openareaatthetopofthestacktoprovideadditionalflowcapacity.Thisdesignflexibilityallows the TigerTooth to take very high pressure drops whenthrottling low and still deliver high capacities when required,whilegeneratingexceptionallylownoiselevels.

PassagesintheTigerToothdesignareselfcleaning.Passagesgrowwideras thefluidpassesfromthe insideto theoutside.Thisallowslargesolidstoeasilypassthroughthetrim.

BaseValveDesignBasevalvesfortheTigerToothincludetheMarkOne,MarkTwo,MarkEight,andMark�00.

MechanismsatWork•PressureControl•VelocityControl•Attenuation

Figure4.1:ControlValvewithTigerToothTrim

Figure4.2:Cross-SectionedTigerToothSeatRetainer

4. TigerTooth

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IntroductionTheMegaStreamdesignemploysaheavydutydrilled-holeseatretainer (cage)withup to seven stages to lowernoise levels(Figure5.�:ControlValvewithTwoStageMegaStreamTrim).With decades of proven experience, the MegaStream controlvalveistheoneofthemostcommonsolutionstocontrolvalvenoise.

DesignPressuredropsaredistributedbetween the throttlingpointoftheplugandseatringaswellasthestagesoftheretainer.Eachstage isdesigned to takeasmallpressuredrop,avoiding thehighvelocitiespresentinsingle-throttling-pointtrims.Fluidex-pansionandvelocityarecontrolledbyincreasingtheflowareasofeachsubsequentstage.

CuttingtheMegaStreamretainerholesizeinhalfwillreducethenoise levelbyup to7dBa through frequencyshiftingeffects.Holessizesareoptimizedtobalancenoiseandmanufacturabil-ity.

AstandardtwostageMegaStreamconstructedfromheavydutydrilled-hole cylinders. Standard designs eliminate special en-gineeringwhich results in lower costs andquicker deliveries.Becauseofpartsinterchangeabilitywithstandardseatretainers,oneand two-stageattenuatorscanbefitted intoconventionalMarkSeriesvalveswithoutspecialoradditionalparts.

Whenmoreattenuationisneeded,seatretainersincorporatingfrom three to sevendrilled-hole stages are available. Most ofthebasevalvepartsarestillinterchangeablewithstandardvalveconstruction.

Specialdesignsareavailablewhenprocessconditionsrequireaspecializedsolution.Forexample,guidingthepluginthecageeliminatestheseatringasathrottlingpoint,whichcanprovidemoreattenuationatlowthrottlingpoints.

BaseValveDesignBasevalvesfortheMegaStreamretainerincludetheMarkOne,MarkTwo,MarkEight,andMark�00.

MechanismsatWork•PressureControl•VelocityControl•Attenuation•FrequencyShifting

Figure5.1:ControlValvewithTwoStageMegaStreamTrim

5. MegaStream

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IntroductionUsingthesameskirtguideddrilled-holeplugastheTypeIIde-signandaheavydutydrilled-holecage, theTypeIIIdesign iscreated(Figure6.�:TypeIIITrim).TheTypeIIIsystemismosteffectiveatreducingnoisegeneratedbyhigherpressuredrops.TheTypeIIItrimoffersoneortwostagesofpressurereductioninaheavydutydesign.DesignWhenusing two stagesof pressuredrop, theType III designhas a skirt guideddrilled-holeplug, andaheavydutydrilled-holecage.Inthesinglestagestyle,theheavydutydrilled-holecageisused.Bothstylesusecageguidingtothrottleeachstageforeffectivenoisecontroloverthecompleterange.Eachstagetakespartofthepressuredroptoproducetheminimumnoisewhile still attenuating noise generated upstream. Both designworkbyattenuatingupstreamnoiseandshiftingthenoisefre-quencyhigher.

Standardized designs allow for quicker deliveries and lowercosts.

BaseValveDesignAvailableinanumberofKammerplatforms,themostcommonlyusedisthe35000seriescontrolvalve.


Figure6.1:TypeIIITrim

IntroductionByaddingaskirtguideddrilled-holeplugtotheattenuatorsusedintheTypeIdesign,theTypeIIdesigniscreated(Figure7.�:TypeIITrim).TheTypeIIsystemismosteffectiveatreducingnoisegeneratedbymoderatetohighpressuredrops.TheTypeIItrimoffersuptofourstagesofpressurereduction.

DesignWhenusingallfourstagesofpressuredrop,theTypeIIdesignhas a skirt guided drilled-hole plug, an inner perforated metalstage, a metal mesh silencer and an outer perforated metalstage.Eachstagetakespartofthepressuredroptoproducetheminimumnoisewhilestillattenuatingnoisegeneratedupstream.Whenonlyasinglestageisrequired,theskirtguideddrilled-holeplugisused.Thethreestagedesignusesaskirtguideddrilled-holeplugalongwithboththeinnerandouterstagesofthecage.Adding thebafflecreates the fourstagestyle.All threedesignsworkby attenuatingupstreamnoise andshifting thenoise fre-quencyhigher.


BaseValveDesignAvailableinanumberofKammerplatforms,themostcommonlyusedisthe35000seriescontrolvalve.


Figure7.1:TypeIITrim

6. Type III 7. Type II

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IntroductionTheTypeIlownoisebafflesreducenoisegeneratedbymoderatepressuredrops(Figure8.�:TypeITrim).Byonlychangingafewofparts,thenoisereducingcagecanbeaddedtothestandardvalvewithoutspecialplugsorseatrings.Controloftheprocessisthroughthestandardcontouredplug,yieldinghighturndownandgreatcontrol.Availablewithonestage, twostagesor twostageswithbaffles,theTypeItrimoffersuptothreestagesofpressurereduction.

DesignWhen using all three stages of pressure drop, the Type I de-signhasaninnerperforatedmetalstage,ametalmeshsilencerand anouterperforatedmetal stage. Each stage takespart ofthepressuredroptoproducetheminimumnoisewhilestillat-tenuatingnoisegeneratedupstream.Whenonlyasinglestageis required, theouterperforatedmetal stage isused.The twostagedesignusesboththeouterandinnerstagestocreatetwopressuredrops.Addingthebafflecreatesthethreestagestyle.Asthenumberofstagesincrease,thenoiseattenuationalsoin-

Figure8.1:TypeITrim

creases.Allthreedesignsworkbyattenuatingupstreamnoisewhileshiftingthenoisefrequencyhigher.


BaseValveDesignAvailableinanumberofKammerplatforms,themostcommonisthe35000seriescontrolvalve.MechanismsatWork•PressureControl •FrequencyShifting• VelocityControl•Attenuation

8. Type I

Asafluidtravelsthroughaconventionalsingle-seatedglobe-stylecontrolvalve,avenacontracta(pointofnar-rowestflowrestriction)de-velopsdirectlydownstreamofthenarrowestthrottlingpoint.

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IntroductionAvailablewithfivestages,(Figure�0.�:XStreamTrim)XStreameliminatesnoiseinmoderatetohighpressuredrops.

DesignUsing four drilled hole stages (three downstream of the plugandoneupstream)andacontouredplug,theXStreamprovidesexceptionalnosereductionandexcellentturndown.Usingsmallholesineachstageforfrequencyshifting,theXStreamproduc-eslowernoiselevelswhileattenuatingupstreamnoise.

BaseValveDesignAvailableintheFlowTopandFlowPro.


Figure10.1:XStreamTrim

IntroductionAvailablewithtwoorthreeindividuallythrottledstages,(Figure9.�:RLS-SystemTrim)RLS-Systemeliminatesnoiseinmoder-atetohighpressuredrops.

DesignByindividuallythrottlingeachstage,fluidexpansionandvelocityistightlycontrolledformaximumefficiencyatallplugpositions.Availablewith twoor threestages, theRLS-System issimple,robustandeffective.Usingafourflangebody,thethreestageRLS-Systemprovidesformorepressuredropthanthetwostagesystem.Usingsmallholesineachstageforfrequencyshifting,theRLS-Systemproduceslowernoiselevelswhileattenuatingupstreamnoise.Standardizeddesignsallowforquickerdeliver-iesandlowercosts.

BaseValveDesignAvailableintheFlowTop,FlowPro.

MechanismsatWork•VelocityControl•Attenuation•FrequencyShifting

Figure9.1:RLS-SystemTrim

10. XStream9. RLS-System

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IntroductionUsingacosteffectiveskirtguidedplugheadwithdrilledholes(Figure ��.�: Multi-Hole Trim) the Multi-Hole reduces noisegeneratedbymoderatepressuredrops.Usingspecialplugsandseatrings,allothervalvepartsremainthesame.

DesignTheMulti-Holegenerateslessnoisethanconventionaldesignsbyusingsmalldrilledholesintheplugskirttoshiftthefrequen-cyandlowernoise.Smallholesprovideeffectiveattenuationofnoisegeneratedupstreamoftheplugskirt,loweringthenoisetransmitteddownstream.




Figure11.1:Multi-HoleTrim

IntroductionThe SilentPac low noise baffles (Figure ��.�: SilentPac Trim)reduce noise generated by moderate pressure drops. By onlychanging a couple of parts, the noise reducing cage can beaddedtothestandardvalvewithoutspecialplugsorseatrings.Controloftheprocessisthroughthestandardcontouredplug,yieldinghighturndownandgreatcontrol.

DesignStainlesssteelwiremeshattenuator.Thestainlesssteelattenu-atorisweldedtogethertoformasinglerobustpart.Theproc-ess fluid diffuses through the cage silencing noise generatedupstreamwithverylittlenoisegeneration.



MechanismsatWork•PressureControl •VelocityControl•Attenuation•FrequencyShifting

Figure12.1:SilentPacTrim

11. Multi-Hole 12. SilentPac

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IntroductionZ-Trimcombinesthebenefitsofanadvancedcontrolvalvewiththesimplicityofaballvalve.Mosteffectivewithlowtomediumpressure drops, the Z-trim excels at eliminating noise in highflowservices.Using thestandardSetball (Figure�3.�:SetballControlValvewithZ-Trim)orDuball(Figure�3.�:DuballControlValveZ-Trim)asaplatform,addingtheZ-Trimrequiresonlyoneparttobechanged.

NoiseControlDesignThesimpledesignoftheZ-Trimgetsit’seffectivenoisereductionbypassingthefluidthroughasmanyasfivestagesofpressurereduction. Increasingpassageareasofeachsubsequentstageof the Z-Trim allows the gas to expand while maintaining lowvelocitiesforlowernoise.

Eachstageprovidesbothattenuationofupstreamnoiseandlim-its the velocity through the trim minimizing noise generation.

Figure13.1:SetballControlValvewithZ-Trim Figure13.2:DuballControlValvewithZ-Trim

Asthevalveopens,fewerstagesaretakenuntiltheballisopenandthevalvedevelopsfullcapacity.Thisfeaturegiveseffectivenoiseattenuationatthelowend,wherepressuredropsarehigh,andstilldeliversthehighcapacityexpectedfromaballvalve.

BaseValveDesignTheZ-TrimisavailableintheDuball,SetballandShearStreamSBcontrolvalves.


13. Z-Trim

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IntroductionInstallinganti-noiseplatesdownstreamofacontrolvalveisasimple,costeffectivewaytoreducecontrolvalvenoise,with-outmakinganychangestothevalve(seeFigure�4.�:ControlValvewithDownstreamPlates).Platesprovidelowernoisebyloweringturbulence,providingbackpressuretothevalveandprovidingattenuationonnoisegenerated inside thevalve.Toprovidesuccessfulnoiseattenuationdownstreamplatesneedtobefitfortheindividualapplication.Platesaremosteffectiveinlowtomediumpressuredropapplications.NoiseControlDesignEach plate incorporates one or more stages. Noise controlplatesaresimilar toorificeplates,buthavemanysmallpas-sagesinsteadofonelargehole.Somemayhavemetalmeshorotherdevicestoattenuatenoise.Severalplatedesignsareof-feredbyFlowserve,allincorporatingthesamebasicoperatingprinciples.Tocontroldownstreamlineturbulence,eachstageabsorbsaportionofthepressuredrop.Aseachstageabsorbs

pressure,italsoattenuatesnoiseandturbulencedevelopedup-streamoftheplate.

BaseValveDesignNoisecontrolplatesareusedwithallstylesofFlowservecon-trolvalves.


Figure14.1:ControlValvewithDownstreamPlates

14. Downstream Plates

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FCD FCENBR0067-00 – 12/07

To find your local Flowserve representative, visit www.flowserve.com or call USA 1 800 225 6989

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Flowserve Corporation has established industry leadership in the design and manufacture of its products. When properly selected, this Flowserve product is designed to perform its intended function safely during its useful life.However, the purchaser or user of Flowserve products should be aware that Flowserve products might be used in numerous applications under a wide variety of industrial service conditions. Although Flowserve can (and oftendoes) provide general guidelines, it cannot provide specific data and warnings for all possible applications. The purchaser/user must therefore assume the ultimate responsibility for the proper sizing and selection, installation,operation,andmaintenanceofFlowserveproducts.Thepurchaser/usershouldreadandunderstandtheInstallationOperationMaintenance(IOM)instructionsincludedwiththeproduct,andtrainitsemployeesandcontractorsinthesafeuseofFlowserveproductsinconnectionwiththespecificapplication.

Whiletheinformationandspecificationscontainedinthisliteraturearebelievedtobeaccurate,theyaresuppliedforinformativepurposesonlyandshouldnotbeconsideredcertifiedorasaguaranteeofsatisfactoryresultsbyreliancethereon.Nothingcontainedhereinistobeconstruedasawarrantyorguarantee,expressorimplied,regardinganymatterwithrespecttothisproduct.BecauseFlowserveiscontinuallyimprovingandupgradingitsproductdesign,thespecifications,dimensionsandinformationcontainedhereinaresubjecttochangewithoutnotice.Shouldanyquestionariseconcerningtheseprovisions,thepurchaser/usershouldcontactFlowserveCorporationatanyoneofitsworldwideoperationsoroffices.

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