eriks merkel technical manual

Merkel Technical Manual

Merkel Freudenberg Fluidtechnic GmbH

Merkel_TH-Schwerhydraulik_2007_E1 1 19.02.2008 14:46:03

Hydraulics

Hydraulic components 4

Use of Hydraulic Seals 6

Sealing Systems 8

Guide Elements 11

Sealing Mechanism and Influencing Quantities 16

Sealing Gap 26

Counter Surface 28

Materials 34

Installation of Hydraulic Seals 39

General Technical Data and Materials

General Technical Data 48

Materials – Basics Concepts 55

Testing and Interpretation Test Results 60

General Material Descriptions 73

Suggestion for Storage 103

Summary of the Mentioned Standards 104

Table of Contents


Technical Manual

Merkelhydrauliccomponentsaresuitableforawiderangeofapplicationsinhydraulics,forbothlight-dutyandheavy-dutyapplications.Merkeloffersacompleterangeofstandardsolu-tionsandalsospecialsolutionscustomisedforpar-ticularapplications.Therangeincludesseals,wipersandguiderings.Thelatestproductiontechnologyguaranteesthefastestpossibleavailability.Eveninlessthan24hourswithMerkelXpress.

Hydraulics

Requirements

Operationalreliabilityunderdifferentextremeloadssuchas:

HightemperaturefluctuationsIrregulardutycyclesandmaintenanceHighlateralforcesanddeflectionsVerydirtyconditionsHighsystempressuresandpressurepeaks.


Features

RodsealswithhighpressureresistanceasprimaryorsecondarysealPistonsealswithintegratedpressureactivationgroovesforhighoperationalreliabilitywithfastpressurechangesWiperswithstaticsealingedgeforreliablepro-tectionagainstingressofdirtGuideswithpatentedprofilingensureevendistri-butionofstressSealingringsforstaticsealinge.g.cylinderheadswithendpositiondampingFriction-optimisedsealingsystemswithlowstick-sliptendency

Heavy-dutysealingsystemswithhighoperationalreliabilityundershockpressures,highlateralforcesandextremetemperaturesUniversalsealingsystemsforsupportcylinderswithgoodstaticanddynamictightnessbecauseofadditionalsupportedgeandsealingedge.

Application areas

Merkelsealingcomponentscoverawiderangeinmodernhydraulicsandareinusewhereversafetyandservicerequirementsaswellascostsareimpor-tant.


Technical Manual

Use of Hydraulic Seals

Differentrequirementsandloadsinnumerousappli-cationshaveresultedinthedevelopmentofdifferentsealdesigns.Hydraulicsealscanbecategorisedbyfunctionanddesign(→Fig.1).Hydraulicsealsarealsoclassifiedintosealswithasymmetricalcross-sectionandsealswithanasym-metricalcross-section.

Asymmetricalsealsaredesignedsothepre-loadisdistributedovertheentireaxialwidthonthesup-portingmatingareatogivethemasufficientlyfixedseatinginthegroove.Thecorrectpre-loadonthemovingsideisnotderiveduntilafterfittinginthehousing(→Fig. 2and→Fig.3).

Hydraulic seals

Dynamicseals

Inner sealing(rod)

Lipseals

Lipseals

Staticseals

Outer sealing(piston)

Compact seals

Compact seals

Fig.1 Categorisationofhydraulicseals


Ø DN

Ø dN

In free state

Fitted in thehousing

Fitted in the cylinder

Fig.2 Rodseal

Ø DN

Ø dN

Fitted to the piston in thecylinder

Fitted to thepiston

In free state

Fig.3 Pistonseal

Hydraulic seals/preselecting seals

Inadditiontothemainrequirementforagoodsealingeffect,theuserexpectsthefollowingfromhydraulicseals:

FunctionalreliabilityLongservicelifeEasyfittingCompatiblewithhydraulicfluidathighandlowtemperaturesHighresistancetomechanicaldamage(e.g.gapextrusion)LowfrictionGoodshapeelasticitytoensurecorrectfunction,evenwitheccentricitybetweenrodandhousingorpistonandcylinderbarrelcausedbyoperationaswellasthebarrelwideningasaresultoftheoperatingpressure.

Theweightingoftherequirementsforthespecificapplicationincombinationwiththeoperatingcon-ditions(pressure,temperature,slidingspeedetc.)arethedecisivefactorsaffectingtheselectionoftheseal.

Withreferencetotheoperatingconditionstheus-agelimitsspecifiedtherecanbeexceededinsomecases.Inthecaseofextendeddutycycles,opera-tionsubjecttoshocksorothersevereoperatingconditionswerecommendnotexceedingallvaluessimultaneously.Ourtechnicalconsultantswillbepleasedtoprovedappropriaterecommendations.


Technical Manual

Sealing Systems

Definition

Sealingcomponentsareusedtoretainthehydraulicmediumsecurelyinsideahydraulicsystem.Ade-finedmoisteningofthecountersurfacewithlubricat-ingmediumisdesirablewhentherequiredservicelifeistakenintoaccount.Asealingcomponentisreferredtointhisregardasleakyifthehydraulicmediumisvisiblefromtheoutsideintheformofdrip-pingleakage.

Requirements

Duringoperationsealingcomponentsaresubjecttoareciprocatingorrotarymovementwhenoperatingpressureisapplied.Inadditiontootherinfluences,theselectionofasealingcomponentissignificantlyinfluencedbythematerial-dependentresistanceagainstextrusionandtheequallymaterial-depend-entfrictionandwearcharacteristics.Thevaluesofthemainpropertiesofsealingeffect,formstabilityandfrictionorwearworkagainstoneanotherandintotalcannotbeoptimallyrepresentedbyonesinglesealingcomponent.Anapproximationoftheidealsealingcomponentisreachedwithareason-ablecombinationofsinglecomponentswithappro-priatepropertiesintoonesealingsystem.

Arrangement

Sealingsystemsgenerallyconsistofanarrange-mentofsealingcomponentswithaprimaryseal,asecondaryseal,awiperandguideelements(→ Fig.4).Thepropertiesoftheindividualcom-ponentsareoptimisedwithreferencetothemainrequirement.Theoperatingpressureisappliedtotheprimaryseal.Themainrequirementisahighresistanceagainstextrusionsimultaneouslywithacceptablefrictionvaluesunderhighpressure.CompactsealingcomponentswithaslipringofPTFEcompoundareprimarilyusedinsidesealingsystems.Theremainingoilfilmiscomparativelythickandwithoutadditionalreductionbyasecondarysealingcomponent(de-pendingontheoperatingparameters)maybevis-ibleasdrippingleakageinfrontofthewiperedge.Thelowergappressure(<5MPa)isappliedtothesecondaryseal.Themainrequirementisthereforeeffectivereductionoftheresidualoilfilmleftbytheprimarysealsimultaneouslywithacceptablefrictionvaluesinthelowerpressurerange.WithsufficientmediaresistanceU-ringsofpolyurethaneorcompactsealingcomponentswithaslipringofpolyurethanearegenerallyusedinthiscase.ThesealingeffectisbetterwithsuchsealingcomponentscomparedtoPTFEsealingcomponents.

Fig.4 Componentsinasealingsystem


Standard sealing systems for rods 1TypicaloperatingconditionsPressure:<40MPa;Runningspeed:<0,8m/sTemperature:–30...+100°CMedia:hydraulicoilHLHLPLeckagebehaviour:+++Operatingreliability:++++Frictionreliability:+++

Wiper PU 5 U-ring T 20 U-ring Syprim SM Guide ring SB

Fig.5 Standardsealingsystemsforrods1

Standard sealing systems for rods 2TypicaloperatingconditionsPressure:<40MPa;Runningspeed:<1,5m/sTemperature:–30...+100°CMedia:hydraulicoilHL,HLPLeckagebehaviour:+++Operatingreliability:++++Frictionreliability:+++

Wiper PU 5 U-ring T 20 Omegat OMS-MR Guide ring SB


++ good ++++ outstanding

+++ verygood

Standard sealing systems for rods TypicaloperatingconditionsPressure:<40MPa;Runningspeed:<1,5m/sTemperature:–30...+100°CMedia:hydraulicoilHL,HLPLeckagebehaviour:++++Operatingreliability:+++Frictionreliability:+++

Doublewiper PT 1 U-ring T 20 Omegat OMS-MR Guide ring SB


Standard sealing systems for rods Ifahighchemicalresistanceisrequired.TypicaloperatingconditionsPressure:<40MPa;Runningspeed:<2,0m/sTemperature:–30...+100°CMedia:hydraulicoilHL,HLPLeckagebehaviour:+++Operatingreliability:++Frictionreliability:+++

Doublewiper PT 1 Omegat OMS-MR Guide ring SB


++ good ++++ outstanding

+++ verygood


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Technical Manual

P Compression = PressureBuilt-in seal

Analogy as per Prokop:The maximum pitch of the hilllimits the fluid transport

Fig.9 Qualitativecompressioncurve,single-actingrodseal

Dependingontherequirements,wipershavediffer-entdesigns,suchassinglewiperordoublewiperwithextrasealingedgeandaremadeofdifferentmaterials.Theoutwardalignedwipingedgekeepsdirtfromtheenvironmentoutsidethehydraulicsys-tem.Asuitabledesignofthewipingedge(radius)ensuresthattherequiredlubricatingfilmcanbecompletelytransportedonthereturnstroke.Theadditionalsealingedgeincreasestheoperatingreliabilityofthesealingsystemwhenrequired.Theuseofguideelementsenablesalow-frictionandlow-wearrelativemovementbetweenthemovingcomponentsofthehydrauliccylinder.Thetransverseloadsoccurringduringoperationareabsorbedinadefinedmannerandpreventunwantedmetalcon-tactbetweenthepistonrodorthepistonbodyandthesurroundinghousingcomponents.

Function

Toreducefrictionandwearsolidbodiesthatmoverelativetooneanothermustbeseparatedbyalu-bricatingfilm.Theoilfilmleftbeneaththesealmustbecompletelytransportedbackintothehydraulicsystemateverycycle.Insideasealingsystemallindividualsealsandthewipermustmeetthesecon-ditions.Theformationofthehydrodynamiclubricatingfilmisinfluencedbythedesignofthesealingedge(pres-suremovement),theoperatingpressureandthe

magnitudeanddirection(extendingorretracting)oftherelativemovementaswellasbythestructureofthecountersurface(wettability)andthepropertiesofthehydraulicmedium(viscosity).

Thepressurecurvebeneaththesealingedgeisingeneraloptimisedinthatahighwipingeffect(steeppressurerise)issetatthepressurespaceandagoodreturncapacity(flatpressurerise)issetfromthereturnside(→Fig.9).Independentlyofthegeometryofthesealingedgeatlowpressure,highstrokespeedandlongstrokeacomparativelygreateroilvolumeisreleasedbeneaththesealingedgethanathighpressure,lowerstrokespeedandshortstroke.Inoperationtheprimarysealreleasesathinoilfilmintothegaparea,whichisreducedevenmorebythesecondaryseal.Theexcessoiliscollectedinthespacebetweentheprimarysealandthesecondarysealandreturnedtotheoilcom-partmentduringretraction.Athinoilfilmcoatingtherodescapesoutsideunderthewiper.Normallynomediumisaccumulatedinthespacebetweenthesecondarysealandthewiperinthisprocess.Themoisteningistransportedbackintothesystemwhilethedirtremainsoutside.Thesealingeffectofacomponentisdescribedbytheratiobetweenwip-ingeffectandreturncapacity.Thisvalueisvariabledependingontheoperatingconditionsandisnotaconstantquantity.


11

Guide Elements

Tasks of the guide element

Theuseofguideelementsenablesalow-frictionandlow-wearrelativemovementbetweenthemovablecomponentsofthehydrauliccylinder.Thetransverseloadsoccurringinoperationareacceptedinade-finedmannerandunwantedmetalcontactbetweenthepistonrodorthepistonbodyandthesurround-inghousingcomponentsisprevented.

Contact conditions

Asaresultoftheguideplayandtheelasticdefor-mationofthecomponentsunderload(deflectionoftheguideelement;bendingoftheshaft),anangulardeviationdevelopsbetweenthepistonrodorthepistonbodyandthecountersurface(→Fig.10).Calculationofthetransverseforcesandtheprob-abilityofcollisiononthebasisofidealisedcontactconditionswithparallelaxesresultsinincorrectresults.Excessivetensionpeaksintheedgeareaoftheguideelement(edgebreak)arenottakenintoconsiderationherenoristhedistancebetweenthe

metalcomponents(metalcontact),whichchangeswiththeincorrectposition,andthechangedforceinitialisation.Dependingonthetypeofguide,theresultofanidealisedobservationinthisregardmustbeevaluateddifferently.

Guide elements

Particularlywhenahightransverseloadisexpectedmanyusersinstalltraditionalflatparallelmetalplainbearings.Flatparallelmetalguidesaresubjecttomarkedtensionpeaksasaresultofthephasedis-placementposition(→Fig.11).Thepermissiblevalueofthesurfacepressureisreachedatacomparativelylowtransverseloadandsimultaneousminimumdeflection.Inthepres-surezonethereisinsufficientlubrication.Atlowslidingspeedsstick-slipmaybeexperiencedsimul-taneouslywithahighloadonthecountersurface(running-in).Ifthetransverseloadinthelimitrangeissuddenlyapplied,abreakageoftheedgeintheregionoftheguideislikely.

Fig.10 Phasedisplacementposition


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Technical Manual

Thetensionincreaseintheareaofthesupportingedgeisreducedbytheuseofflatparallelguidesleevesofcompositefabricmaterials(fabric-baselaminate)(→ Fig.12).Theelasticsupportofthefab-ric-baselaminateguideincreasesthesupportlengthoftheguideringandwithitthemaximumtransverseloadcomparedtothemetalguide.Thecollisiontestbecomesveryimportantasaresultoftheelasticsupportoftheguidesleeve.Guidesleevesarecom-parativelymoreeconomical.

Fig.11 Metalguidering

Fig.12 Guideringoffabric-baselaminate

Fig.13 Guideringwithconvexprofiling

ThepatentedGuivexgeometryforfabric-baselaminateguideringshasbeendevelopedforreduc-tionofthetensionincreaseintheedgeregion.Thezonewiththehighestcompression,evenwhenthephasedisplacementpositionistakenintoaccount,isdefinedbytheprofilingapproximatelyinthecentreofthebush(→ Fig.13).Thecompressionisreducedonbothsidesandmakestheingressofthelubricatingmediumeasier.Theelasticsupportofthefabric-baselaminateguidesleeveissimultaneouslyoptimallyusedovertheentireavailablewidthoftheguidesleeve.Insufficientlubricationandedgebreakagearevirtuallyimpossible.

GuidebeltsofPTFEcompoundhaveasubordinateroleasguideelementsfortakinguptransverseloadsinhydraulics.Thevalueforthepermissiblesurfacepressureissignificantlylowerincomparisonandwithasimultaneoussignificanttemperaturedependency.Theadvantagesofguideelementsofthistypebecomeclearwhencomparingthecostsoflargeorders.

Guide width

Inadditiontothegeometricconsideration(externalforceapplication,distancebetweenmountings,an-gulardeviation,guideplay,...)mustbeconsideredwhencalculatingthetransverseloadappliedintheareaoftheguideelementandalsotheelasticdefor-mationofallcomponentsinvolved(deflectionoftheguideelement,bendingofthepistonrod,stretchingofthecylinder...).Adetailedscrutinyisoftenne-glectedbecauseitcanonlybedonewithcomplexmeanssuchasanFEcalculation.

Arealisticestimateofthetransverseloadmustpayparticularattentiontothelimitsofthemechanicalloadingofthemetalcomponents.Inthecaseiflongslendercylindersthepermissibletransverseloadislimitedbythebendingstrengthofthepistonrodandotherfactors.Theclassicalassumptionthatabout10%ofthehydraulicforceisappliedasatransverseloadwouldinrealityresultinbendingthepistonrodinmanycases.


1

Ifthemagnitudeofthenormalforceappliedintheareaoftheguideelementisdefined,themini-mumrequiredguidewidth(H)canbespecified(→ Fig.14).

F F

H

F = P x A; A = d x H; H = F / (d x P)

H=guidestripwidth[mm]

F=transverseload[N]

A=projectedarea[mm2]

P=permissiblesurfacepressure[N/mm2]

d=nominaldiameterofrodorpiston[mm]

Fig.14 Guidewidth

Thepermissiblespecificsurfacepressureinthespec-ifiedformisamanageablecalculationvaluewithreferencetotheprojectedareaanddoesnotrep-resentthematerialcharacteristics.Inthedefinitionofthepermissiblespecificsurfacepressurethenon-linearpressurecurveoverthecontactrange,thetensionincreaseintheedgeareaoftheguideringsandaphasedisplacementpositionareallconsid-ered.Whenconsideringthespecifiedvaluesofthepermissiblespecificsurfacepressure(P)oftheguidesleeveitmustbenotedincomparisonthatsomemanufacturersincludeextrasafetyfactorsinsomecases.However,thatdoesnotbringanyincreaseinsafetyintotheresultofthecalculation,becausethisfactorisreturnedtotheassociatedequation.

H1

H1 H2

H2`

y

m

Fig.15 Usableguidewidth

Metalliccontactsbetweenhousingcomponentsandthecountersurfaceareunwanted.Themaximumpermissibledeflection(y)oftheguideringislimitedbythesmallestmetalgapinsidethesealingsystem,ingeneralthemetalstepbehindtheprimaryseal.

Dependingonthephasedisplacementposition(α)ofthepistonrodandthepossibledeflection(y)withreferencetoallinfluencingquantities,theusableguidewidthisreducedcomparedtothegeometri-callytotalwidthoftheguidebelts(H).Onlytheguidewidthactuallyincontact(H’)contributestoholdingtheload.

Fig.16 Bilateralcontact

Inthecaseoflargephasedisplacementpositions,suchasoccurinrelationtothecompliancewithlong-slendercylinders,theguideringmaycontactthecountersurfaceonbothsidesofthecentreaxis.Herelowtolerancelevelsfavourcontactonbothsides.Theadditionalcontactgeneratesausablecounteractingforcebutalsostick-slipeffects(jam-ming)asaresultofdistortion.Inthiscasethecolli-sioncheckhasparticularsignificance.Toselecttheoptimumwidthoftheguidethedesiredservicelifemustalsobeconsidered.Limitvaluesaretakeninto

H = H1 + H2 H`=H1`+H2`


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Technical Manual

accountinthecalculationoftheminimumrequiredguidewidthandalsowithreferencetothepermis-siblesurfacepressureoftheguideelements.Guideelementsthatareprimarilytraversedintherangeofthemaximumpossibleloadhaveaservicelifeinthelowerpartoftherange.Whetherreducingtheloadbyselectingawiderguideisusefulinsomecasesdependsonthepreviouslyconsideredsafetyfactorsaswellasthetotalloading.

Specific compression per unit area

Thepermissiblesurfacepressure(dynamic)isspeci-fiedatavalueintherangeof17to25N/mm²forthecopper-tinandcopper-tin-leadbronzeandhigh-loadresistantcopper-zincalloysusedintheareaofthemetalplainbearings.High-tensilealloyswithvaluesover25N/mm²areonlyusedfortheedgeloadofnon-criticalapplicationsinconnectionwithhigh-tensilecountersurfaces.

Guideringsoffabric-laminatedmaterials(fabric-baselaminate)haveimprovedfunctioncomparedtostraightmetalguides.Asaresultofthelowtensionincreaseintheedgeareaandtheelasticpropertiesofthesematerialsahighersurfacepressurecanbeaccepted.Thevalueofthesurfacepressureandthecharacteristicsunderhigheroperatingtemperatures

isgreatlyinfluencedbythecompositionofthefab-ric-basedlaminatedmaterial.Polyesterandotherplasticsandalsonaturalmaterialssuchascottonareusedintheareaoffinefabrics.Polyester,vinylesterandphenolicresinandalsoawholerangeofplasticswithdifferentpropertiesareavailablefortheresinmatrix.Whilesomeofthesecompoundsshowsignificantthermoplasticcharacteristics,thefactoroftheoperatingtemperatureonthepermis-siblesurfacepressureislowforothers.

Thevaluesforthepermissiblespecificsurfacepressuredependingontheoperatingtemperaturecanbefoundinthetablesinthedescriptionofthearticle.Underloadguideelementsshowadeformationintheelasticrange(reversible).Themagnitudeofthede-formationordeflection(y)isdetermineddirectlybythematerialcharacteristics,thethicknessoftheguidesleeveandthemagnitudeoftheload.Assumingsimilarmaterialcharacteristics,thickerguidesleeveshavesofterspringingunderidenticalloading.Pressurecanonlybeappliedtotheguideelementatthemagnitudeofthepermissiblesurfacepressureiftheassociateddeflectionoftheguideelement(→ Fig.17)canbeachievedwithoutmetalcontact.

y=0,2 S=4y=0,15 S=2,5

Spec

. Sur

face

pres

sure

[N/m

m ]2

Operating temperature [°C]

Fig.17 Deflectionatmaximumsurfacepressure


1

Inasealingsystemthecollisioncheckisgenerallyconductedwithreferencetothemetalgaponthesideoftheprimarysealawayfromthepressure.Theminimumpermissiblemagnitudeofthesealinggapisdeterminedbythedeflectionoftheguideelement.Themaximumpermissiblemagnitudeofthesealinggapisdeterminedbytheformstabilityofthesealingcomponent.Generalspecificationsforthemaximumadmissiblegapwidthdependingonthetypeofseal,theselectedsealprofileandtheoperatingpressurecanbefoundinthetablesinthedescrip-

tionofthearticle.Thereisadirectgeometricalde-pendencybetweentheminimumrequiredmetalgap(x3)andthemaximumpermissibleextrusiongap(x2)(→ Fig.18).Thegapdimensionscanthereforenotbecalculatedindependentlyofeachother.Asaresultguideelementscannotbesubjectedtothemaximumpermissiblesurfacepressureateverypressurestageandwithalltypesofseals,becausetheminimumrequiredmetalgapisnotsufficientforcompletedeflection.

ØD2

Sx3

x2

Fig.18 Sealinggap


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Technical Manual

Sealing Mechanism and Influencing Quantities

Tightness, friction, wear

GeneralHydraulicdrivesareusedinmanymachinesandsystemsbecauseoftheirvariedoptionsforuse.Majorareasofapplicationare:

MachinesandsystemsengineeringConstructionmachineryAgriculturalmachineryandMiningmachinery.

Themostimportantcomponentforgeneratingthelineardrivemovementisthehydrauliccylinder.Thefunctionandreliabilityofhydraulicallydrivenma-chinesdependsgreatlyonthesealsinstalledinthehydrauliccylinder.

Static tightnessAtrestallelastichydraulicsealsaretightbecauseoftheexcessiveinitialcompressionpv.Thesealingpressurepissuperimposedontheinitialcompres-sionpv.Thecompressioninthesealingareapdisthereforealwaysgreaterthanthesealingpressure(→Fig.19).

[1] pd=pv+p

Formation of the lubrication filmUndermovementtheslidingsurfacecoatedwithfluidispulledunderthecontactareaoftheseal.Thesealactsasawiper,butisnotabletowipeawaythefluidcompletely.

Theslidingmovementcausesadelayedflowandthesealisliftedfromtheslidingsurfacebythehy-drodynamicpressurebuild-up.Athinfilmoffluidremainsontheslidingsurfacebehindtheseal.

Thethicknesshofthefollowingfluidfilmdependsonthemaximumpitchofthecompressioncurve(dp/dx)maxontheentrysideofthefluidintheseal-inggap,thedynamicviscosityηofthefluidandtherelativespeedvbetweenthesealandtheslidingsurface.

[2] h~√_______

η⋅ v______

(dp__dx)max

Ifthefluidfilmiscompletelyreturnedtothepressurespaceonthereturnstroke,thisisreferredtoasdy-namictightness.

FrictionThefrictionofhydraulicsealsisprimarilyinfluencedbythethicknessofthelubricatingfilmbetweenthesealandslidingsurface.

Threefrictionstatesmaybeencountered.

Staticfriction(drysolid-bodyfriction)Dry-fluidfriction(solid-bodyfrictionandfluidfriction)Fluidfriction(nosolid-bodycontact).

ThethreeareascanbeshownintheStribeckgraph(→Fig.20).

Thehighstaticfrictionmustbeovercomefirstdur-ingapproach.Withincreasingspeedmorefluidispulledbetweenthesealandtheslidingsurfaceandthedirectcontactareadecreases.Thenthestaticfrictioninitiallydecreasesmarkedly.

Therangeoffluidfrictionisreachedasthespeedcontinuestoincrease.Thestaticfrictionincreasesagainasthespeedincreases.Thestaticfrictioniscausedexclusivelybytheshearstressesτinthefluidintherangeofhydrodynamiclubrication.

[3] τ = η ⋅ dv___dh

WearThewearonhydraulicsealsdependsonthethick-nessofthelubricatingfilmorthefrictionstatus.Mostsealsoperateintheregionofdry-fluidfrictionandaresubjecttocontinuouswear.


1

p = 0v = 0

p > 0v = 0

p > 0v > 0

pv

pd

pdpdx

p

v

h

η

p p = pd – v

Static t ightness

Static t ightness

Hydrodynamic formation of lubricating film

Contact pressure distribution as a result of initial compression

Contact pressure distribution as a result of initial compression andpressure to be sealed

Fig.19 Compressioncurveandhydrodynamiclubricationfilmformation


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Technical Manual

Speed

Fricti

on fo

rceStatic friction (start-up friction)Mixed friction areaFluid friction area

Fig.20 Stribeckgraph

Apartfromtheoperatingconditionsofpressure,temperatureandspeedtheweardependsprimarilyonthematerialproperties,thesurfacesoftheslidingcomponentsandthelubricatingpropertiesofthehy-draulicfluid.Airinthehydraulicfluidandcontami-nationbyforeignbodiesalsoinfluencethewear.

Physical and chemical influences

Operating pressureThesystempressurewiththesizeofthecylinderdeterminesitsliftingforce.Itisthefirstfactortobeconsideredwhenselectingthesealandthehard-nessofthesealmaterial.AccordingtotheCETOPrecommendationstandardcylindersaredesignedforthetwopressurestagesof16MPa(160bar)and25MPa(250bar).Themajorityofallhydrau-liccylindersoperateswiththesepressures.Highersystempressuresupto40MPa(400bar)arenowtheruleinminingandheavy-dutymobilehydraulics.withtheavailabilityofexistingsealtypes.

Duringoperationofthehydrauliccylinderstheseal-ingcomponentsareundercontinuouslychangingpressure.Inaddition,short-termpressurepeakscausedbyexternalinfluencesarefrequentlyen-countered,particularlyinmobilehydraulics.Theseshockloadscanreachseveraltimesthemagnitudeofthesystempressureandplacehighdemandsonthesealingcomponents.Theseloadsmustbetakenintoaccountwhenselectingtheseal.

Drag pressureWhenthefittingtolerancesarerestrictedinthespacebetweentheguideandthesealtheguidegenerateshydrodynamicpressure.Thecauseofthisisthehydrodynamicdragflow,whichdependsonthedynamicviscosityofthemedium,thegapwidthhsthespeedvandthelengthIoftheguide(→Fig.21).

Thepressureincreaseintheguideiscalculatedasfollows

[4] ∆p=p1–p=6⋅η⋅v⋅l_________h2s


1

p1p

η

p

pd

p1

hs

l

v

Fig.21 Hydrodynamicdragpressure

Topreventhydrodynamicpressurebuild-up,returnductsarerequiredtocompensatepressureinmetalguides.Otherwisethesealwillbedestroyedearlyinitslifebythehighpressure(→Fig.22).Thereturnductsarepreferablydesignedasaspiralgroovewithacross-sectiongreaterthanthelargestgapringarea(→Fig.23).Axialpressurecompensationholesshouldbeavoid-ed,becausethesprayeffectofthefluidcontributestothedestructionoftheseal.

Whenusingguidebeltsandguideringsofplasticreturnductsarealreadyavailableintheformofthejointgap(→ Fig.23).

SpeedThespeedbetweenthesealandthemovingcountersurfaceforrubberandpolyurethanematerialsisnormally0,1m/sto0,5m/s.However,thedecidingfactoristheapplication.Forexample,0,8m/scanbeapprovedfortheMerkelU-RingT20assecond-

arysealandthesamefortheMerkelCompactSealSimko300atapressureof250bar.Upto5m/sispermissibleforPTFEmaterials.

Fig.22 U-ringdestroyedbyhydrodynamicpressurebuild-up


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Technical Manual

Spiral groove on metal guides

Gap at the joint on guides made of plastic

Fig.23 Designmeasuresforpreventingdragpressure

Theformationofalubricantfilmandfrictiondependonthespeedtoalargedegree.Thefrictionforcedecreasesgreatlyintherangeof0,05m/sandlower.Particularlyathightemperaturesstickslipmayoccur.Thisjudderingmotionisacontinuousrepetitionofstickandslipbetweensealandcountersurface.Materialswithlowercoefficientsoffrictionareusedtopreventthis(e.g.PTFE).

TemperatureThetemperatureofthehydraulicmediumandtheambienttemperatureinfluencethematerialconfigu-ration.Theoptimumtemperatureforthefunctionofthesealsandthestabilityoftheoilis+40°Cto+50°C.Thetemperatureatthesealinglipissignifi-cantlyhigherthantheoiltemperaturebecauseofthefriction.Theusualtemperatureduringoperationofthehy-drauliccylinderis+80°C,inextremecasesitmaybeupto110°C.

Withincreasingtemperaturethesealmaterialbe-comesmoreelasticandlosesformstability.Forthisreasonwerecommendrunning-insealsatlowertemperatures(80°C)ifthetemperaturelimitof110°Cwillbecommonforourpolyurethanemate-rials.Iftemperaturesover110°Careexpected,itwillbenecessarytousespecialmaterials(e.g.FKM,PTFE/FKM).Atlowertemperaturesthehardnessofthesealmaterialswillbeincreased.Thesealwillloseelasticity.However,thesimultaneousincreaseinoilviscositywillleavethefunctionalreliabilityofthesealsvirtuallyuninfluenced.Inthetemperaturerangedownto–40°Ccold-resistantmaterialsbasedonNBRhaveprovenreliable.Aspreviouslynoted,thetemperaturehasagreatinfluenceonthephysicalpropertiesofelasticrubbermaterials.The"torsionvibrationtest"graph(→Fig.24)showshowthedynamicthrustmoduleGdependsonthetemperature(thrustmodulemeasuredinthetorsionvibrationtestaccordingtoDIN53520).Theelastic


21

rubberrangewithavirtuallyconstantmodulecanberecognisedfromrighttoleft,thenasteeprisetothetransitionrangeandfinallytheglassstatere-gion,inwhichtherubberishardandbrittle,withavirtuallyconstantmodule.Whenthetemperaturerisesagainthecoldbrittle-nessdisappearsagain.Thismeansthatthefreezingprocessisreversible.Thetransitionfromelasticrub-bertotheglassstateregionisparticularlyimportantisparticularlyimportantbecauseinmanycasesitrepresentsthelimitofoperationatlowtempera-tures.Thistransitionisnotsuddenbutextendsoveraspecificregion,asshowninthe"torsionvibrationtest"graph.

TheregionoftransitionfromtheelasticrubberregiontotheglassstateischaracterisedbytheglasstransitiontemperatureTü(temperatureofthemaximumofthelogarithmicdampingdecrementΛ).However,thisvaluecanonlyrepresentageneraldimensionforthelow-temperatureoperationlimitofthematerial,becauseinpracticalapplicationofanelastomercomponentitdependscompletelyonthetypeofloadinvolved.

Thesamematerialwillreachitsloadlimitatahigh-ertemperatureundershockloadthan,forexample,withslowelongation.Thetorsionvibrationtestcanbeusedtodistinguishamongdifferentmaterials,butinpracticethetemperaturelimitmustbetestedinoperationwiththevariouscomponents.

Example:Frictionresultingfrommovementsgeneratesheatinthecaseofcontactseals.Attemperaturesatwhichthereisadangerofhardeningbyfreezingthefric-tionalheatmaybesufficienttomaintaintheelastic-ityofthesealortoplaceitinafunctionalconditionsufficientlyquicklyafterthemovementhasstarted.Thebehaviourundercoldconditionsisthereforeonlyeverworthtestingintheformofamaterialcomparisoninconnectionwithexperienceofthetechnicalapplication.

Hydraulic mediaInhydraulicsvarioushydraulicfluidsareusedtotransmittheenergyfromthepumptothecylinder.ThemostimportantandmostfrequentlyusedDiehydraulicfluidismineraloil.

Thelubricatingcapacityoftheoilisdecisiveforthewearofthemovingparts.Thelubricatingcapacityisinfluencedbytheviscosityandadditivesthatim-provethelubrication.

HydraulicoilsareclassifiedinviscosityclassesinaccordancewithDINISO51519toidentifytheviscosity.Thecriterionforthecategorisationisthenominalviscosityatthereferencetemperatureof+40°C.

Theviscosityofhydraulicoilsdependsonthepres-sureandthetemperature.Theviscosityincreasessignificantlyfromapressureofabout20MPa(200bar).Theviscositydoublesatapproximately40MPa(400bar)dependingonthenominalviscosityandthetemperature.Underanincreas-ingtemperaturetheviscosityofoilsdecreasesveryrapidly.Thecharacteristicvalueforthisviscosity-temperaturebehaviouristheviscosityindex(VI).Thehighertheviscosityindexofahydraulicoilthelesstheviscositydependsonthetemperature(→Fig.25).


22

Technical Manual

-1 20 -80 -40 0 40 80 120 160

1 0

1

2

3

4

5

101

5

10 2

5

103

5

104

G

Cold behaviour

°Celsius

Log.

damp

ing d

ecre

ment

L

Shea

r mod

ulus G

dN mm

2

Fig.24 Graph:torsionvibrationtestinaccordancewithDIN53445;dynamicshearmodulusGandlogarithmicdecrementΛofaMerkelmaterialbasedonCR


2

10 0005 000

1 000

500

250

1008050

20

10

5-20 -10 0 10 20 30 40 50 60 70 80 90 100 120

Kine

matic

visc

osity

mm2 /s

Temperature °C

Oil with lowviscosity index

Oil with highviscosity index

ISO Vg68, VI 100

ISO Vg32, VI 150

Fig.25 Viscosity-temperaturebehaviourofvarioushydraulicoils

Hydraulicoilsareclassifiedintodifferentgroups:

Hydraulicfluidsbasedonmineraloils(→Tbl.1)Biologicallydegradablehydraulicfluids(→Tbl.2).

Apartfromthemineraloils,inrecenttimesso-calledenvironmentallycompatiblehydraulicfluidshavecomeintouse.Inthisregardadistinctionismadebetweenhydraulicfluidsbasedonvegetableoils(HETG),polyglycolfluids(HEPG)andsyntheticesterfluids(HEES).Thestandardmaterialsarenotguaranteedtobecompatiblewiththesehydraulicfluidsinallapplications.SpecialmaterialssuchasthepolyurethanematerialSimritan94AU955havebeenspeciallydevelopedforuseinthesefluids.Insomecasesengineoil/HD)isusedintravellinghy-draulicoilsystems,withtheadvantagethatonlyonetypeofoilisrequiredfortheentirevehicle.

Forspecificpurposes,suchasinaircraftandinmin-ing,fluidsbasedonmineraloilscannotbeusedbe-causeofthedangeroffire.Fire-retardantfluidsareusedfortheseapplications(→Tbl.3).

VDMADirective24317liststhepropertiesandidentificationofthesefluids.DIN24320specifiesthepropertiesofHFAfluids.Ofthefire-retardantfluidsitisprimarilytheHFAfluidsthathavebecomeestablishedinmining.HFBandHFDfluidsareonlyusedinexceptionalcases.

Contamination in oil circulationHydraulicoilscanbecontaminatedbyforeignbod-iessuchassand,metalabrasion,metalshavingsandoxidationproducts(ageingoftheoilbytheactionofhightemperaturesandoxygen).Iftheoilisinsufficientlyfilteredthesealtheothercomponentsinthehydraulicsystemmaynotoperatecorrectly.Metalshavingsandabrasivegrainsofsandwillcausefailureofthesealassoonastheseparticlesentertheareabeneaththesealingedge.


2

Technical Manual

Categorisation in accordance with DIN

Categorisation of hydraulic oils in accordance with the

ISO proposal

Identification/ properties

Application

H HH Mineraloilwithoutactiveadditives isvirtuallyneverusedtoday

H-L HLcorrosion-preventionadditivesandadditivesforincreasingageingresistance

forlightlyloadedsystems

H-LP HMlikeH-L,aswellaswear-reducingadditivesandadditivesforincreasingloading

forheavilyloadedsystems

H-LPD –likeH-LP,aswellasdetergentanddispersiveadditives

forheavilyloadedsystemswhenthereisdangerofwateringressduringoilfilling

H-V HVlikeH-LP,aswellasimprovedviscosity-temperaturebehaviour

systemsthatareusedatloworveryvariabletemperatures

Tbl.1 Hydraulicfluidsbasedinmineraloil

Classification in accordance with DIN proposal Base fluid

HEPG Polyglycol

HETG Vegetableoil

HEEG Fullysyntheticester

Tbl.2 Biologicallydegradablehydraulicfluids

Group Composition/water contentApplication temperature

rangeKinematic viscosity at +40 °C Application

Hydraulic fluids containing water

HFAEEmulsionsofmineraloilinwater,watercontent>80%(generally95%)

–+5…+60°C 0,5…2mm2/s

mining,hydraulicpresses,hydrostaticdriveswithlowoperatingpressures

HFASSyntheticoilinaqueoussolution,watercontent>80%(generally95%)

HFBEmulsionsofwaterinmineraloil,watercontent>40%

–+5…+60°C non-NewtonianfluidnotinuseinGermany

HFCaqueouspolymersolutions,watercontent>35%

–30…+60°C 20…70mm2/sHydrostaticdriveswithlowoperatingpressures

Non-aqueous hydraulic fluids

HFDR basedonphosphoricacidester

–30…+150°C 10…50mm2/snotapprovedforuseinGermancoalmines

HFDSBasedonchlorinatedhydrocarbonshydrodynamiccouplingsupto150°C

HFDT MixturesofHFDRandHFDS

HFDUSyntheticfluidsofothercompositionapproved

Tbl.3 Fire-retardantfluids

Becauseofthelargeandsomewhatconfusingselectionofmediawithdifferentandvaryingadditives,theaboveusagelimitscanonlybeconsideredrecommendedvalues.Werecommendtestingforindividualcases


2

Air in oilTherearedissolvedairmoleculesinallclassesofhydraulicfluids.Thisairdissolvedintheoildoesnotaffectthefunctionoftheseal.Hydraulicoilcanformamolecularbondtomoreasthepressureincreases.Thenwhenthepressureisreducedthedissolvedaircomesoutofsolution.Airbubblesform,whichfrequentlycollectinthegroovespacesnotfilledbytheseals.

Ifthepressureissuddenlyincreased,theair-oilmix-tureisheatedsostronglythatcompressionignitionmayoccur.Thisphenomenon,referredtoasdieseleffect,maydestroythesealifitoccursfrequently.Thesealmayalsobedamagedbyundissolvedairduringthemovement.

Theairbubblesdraggedinwiththeoilbetweenthesealandthecountersurfaceexpandmoretheclosertheycometothenon-pressurisedsideoftheseal.Thisair-bubbleerosioncauseslongitudinalscoresinthesurfaceoftheseal.Thisresultsinfurtherdestructionofthesealbywashingoutandremovalofsurfaceareasbytheflowingfluid(flowerosion).

Thedamagecausedbyairintheoilcanbegreatlyreducedifthecompletehydraulicsystemiscarefullybledbeforeoperation.

Geometrical influences

StrokeThestrokeoftheworkingcylinderismostlybetween0,1mand1,0m.Whenthestrokesareveryshort,onlyafewcentimetres,andtheloadfrequencyishigh,therequiredlubricatingfilmwillnotbeformedandsealsofrubbermaterialsmaybesubjecttoincreasedwear.

InsuchcasessealingcomponentsofPTFEarepref-erablyused.Ifthestrokesarelong,intherangeofseveralmetres,thereisadangerthatthesealingcomponentwillbeexcessivelyheated.Distortionsoftheshapeoftherod,differentsurfaceroughnessandeccentricityoccurmorefrequentlywithlongstrokes.

HousingsThefollowingcriteriaareusedtospecifythehous-ingsandthusthedimensionsoftheseal:

UseandloadtypeofcylinderStandardsealorspecialsealStandardisedhousings.

Thegreatertheloadonthesealthestrongertheprofile.Withequivalentsealdiametersealsofsmall-erradialthicknessaremorelikelytobedamagedandtowear.Thesamepercentageradialoversizetheabsoluteoversize(inmillimetres)ofasealwithasmallerradialthicknessislessthanasealwithlargerradialthickness.Asealwithastrongerprofileisbetterabletobridgelargeeccentricitiesresultingfromtheguideplay.

Thedimensionslistedinthecatalogueareavail-ableimmediatelyfromstocksorarearticlesthatcanbedeliveredatshortnotice,whichhavebeenusedsuccessfullyforyearsforsealingpistonsandpistonrods.Thedimensionsaremarkedaccordinglywhentheymatchthedimensionsspecifiedbythestandard.

ThehousingsforrodandpistonsealsarespecifiedinDINISO5597.DINISO6547containsthehousingsforpistonsealswithintegratedguideelements.DINISO6195governsthehousingforwipers.ISOStandard7425specifiescompactseals,consistingofoneslipringofPTFEandanelasticcompressionring.


2

Technical Manual

Sealing Gap

Definition

Thesealinggapisdefinedasthegapborderedbythecountersurfaceandthehousingonthepres-surisedsideoftheseal.Becauseofthedifferent

Ød ØDFØD2

Sx3

x2 xf

Fig.26 Limitvaluesofsealinggapofrodsealingsystem

Limit values

Whenconsideringthelimitvalueswithreferencetothesealinggapthemaximumadjustablesealinggap(x2)andtheminimumsealinggap(x3)with

one-sidedmountofthepistonrodorthepistonbodyaretakenintoaccount(→ Fig.26andFig.27).

ØdF ØDØd2

x2xf

x3

S

Fig.27 Limitvaluesofsealinggapofpistonsealingsystem

x2 = (D2max – dmin) / 2 + xfmax / 2

x3 = (D2– [DFmax – (2* Smin)]) /2

xfmax = [DFmax – (2* Smin)] – dmin

D2max = dmin + 2 x 2 - xfmax

d=shaft[mm]

DF=groovebaseofguide[mm]

D2=non-pressurisedside[mm]

S=thicknessguidesleeves[mm]

x2=maximumsealinggap[mm]

x3=minimumsealinggap[mm]

xf=guideplay[mm]

x2 = (D2max – d2min) / 2 + xfmax / 2

x3 = ([dFmin + (2* Smin)] – d2max) /2

xfmax = Dmax – [dFmin+(2*Smin)]

d2min = D2max + xfmax- 2 x 2max

d=bore[mm]

DF=groovebaseofguide[mm]

D2=non-pressurisedside[mm]

S=thicknessguidesleeves[mm]

x2=maximumsealinggap[mm]

x3=minimumsealinggap[mm]

xf=guideplay[mm]

generalconditionstheprimaryandsecondarysealsofasealingsystemconsideredseparatelywithrefer-encetothesealinggap.


2

Themaximumsealinggap(x2)shouldbeassmallaspossible(gapextrusion),theminimumsealinggap(x3)shouldbeaslargeaspossible(metalcon-tact).Becausethereisadirectgeometricaldepend-encybetweentheminimumrequiredmetalgap(x3)andthemaximumpermissibleextrusiongap(x2),thegapdimensionscannotbesetindependentlyofeachother.

Gap extrusion

Sealmaterialsactlikeaviscousfluidundertheinflu-enceoftheoperatingpressure.Whenthepressureisappliedthesealingcomponentispressedclosertothemetalhousingandtothesealinggap.Theingressofthesealmaterialintothesealinggapisreferredtoasthegapextrusion.Thesealingcom-ponentisdamagedintheareaofthemetaledgeoftheinstallationspacebytheingressofthesealmaterialintothesealinggap.Therepeateddamageeventuallycausesfailureofthesealingcomponent.

Whenspecifyingthemaximumgapdimension(x2)thetemperature,materialandgeometry-dependentformstabilityofthesealingcomponentandtheop-eratingandgeneralconditionsmustbeconsidered.Inadditiontotheclearconnectionbetweentheformstabilityofasealingcomponentandtheoperatingpressureortheoperatingtemperature,thelimitval-uesforthesealinggaparedeterminedbythetotalloading,aswellasotherthings.Thepressureappliedwithsimultaneousrelativestrokemovementinthedirectionoftheextrusiongapismoredemandingthanastaticorquasi-staticsealwithreferencetothepowerconsumedbyfric-tionandshearingforcesinthecontactzone.Ashortpressurepulseisuncriticalwithreferencetothegapextrusion,butanextendedapplicationofpressureplacesincreaseddemandsonthelong-termformstabilityofthesealingcomponent(flow).

Therelevantenlargementofthesealinggapasaresultofthecylinderstretching(cylinderbarrel)orcylinderbuckling(hollowrods)mustbeconsidered,particularlywithhigheroperatingpressuresorlightdesign.Thedeflectionoftheguideelementmustalsobeconsideredborderlinedesignswithhightransverseloads.Generalfiguresforthemaximumadmissiblegapwidth(x2)arelistedinthetableswiththearticlede-scriptiondependingonthetypeofseal,theselectedsealprofileandtheoperatingpressure.

Metal contact

Whenspecifyingtheminimumgapdimension(x3),thecollisioncontrolisparticularlyimportant.Thenarrowestsealinggapinasealingsystemisnormallybehindtheprimaryseal.Collisioncontrolisthereforerunprimarilyforthisarea.Wherethedesignrequireslargegapsbetweenthesealingcomponentsandalsolargeangulardeviationsthecollisioncontrolshouldbeextendedappropriately.

Marginaldesignswithhightransverseloadsandlongslendercylindersmustalsobeprotectedwithreferencetobendingofthepistonrodandthede-flectionoftheguideelement.Cylinderswithshortsupportlengtharetestedfortherequiredangularerror.

Metalcontactsbetweenthecountersurfaceandtheinstallationspacecomponentscausecomparativelyhighcostswhenserviceisrequired.Withintheper-missiblelimitsandwithreferencetotheoperatingandgeneralconditionsthedimensionsandtoleranc-esareselectedtoyieldaslargeavalueaspossibleforthesealinggapx3andthusthegreatestpos-siblesecurityagainstmetalcontacts.Theminimumrequiredvalueforx3isdeterminedprimarilybythedeflectionoftheguideelementunderload.


28

Technical Manual

Definition

Both sides are subject to wear at the contact and during simultaneous relative movement between the sealing components and the counter surface. To establish a stable sealing effect over the long term, the changes caused by the contact must be minor. After a short running period during which the seal-ing edge must not be damaged by abrasive wear, stable running characteristics must established. The system consisting of sealing components, counter surface and lubricating film must be optimised for sealing effect, friction behaviour and wear. The ge-ometry, the material of the sealing components, the topography, the material of counter surface and the properties of the hydraulic medium all influence the operation of the system.The factor of individual parameters on the overall system is strongly dependent on the operating con-ditions. While the solid-body friction is the primary factor with a low stroke speed and high operating pressure, with a high stroke speed and low operat-ing pressure a hydrodynamic lubricating film may be built up. The influence quantities are always mutually interdependent. In an optimally set up system a thin lubricating film is released outside be-neath the sealing components. The oil film must be transported completely back to the hydraulic system at every cycle. Inside sealing systems all individual seals and the wiper must meet this condition.

Fig. 28 Non-wettable surface

An absolutely sealing component that does not re-lease a lubricating film outside is as unsuitable as an

absolutely smooth counter surface (→ Fig. 28) in which there are no abrasive components and also no lubricant pockets when considering the de-pendencies described above. In both cases a very unfavourable friction and wear behaviour will be established.

Surface structure

The structure of the counter surface is primarily influenced by the machining process used for finish-ing. With reference to retaining the lubricating film it is better to generate chaotic surface structures. Dynamic effects are generated on aligned structures and in relation to the stroke movement in the area around the sealing edge. The applied lubricating film can be enlarged here and is visible as leakage. A surface generated by turning and grinding or honing cannot be accurately described geometri-cally. In turning the material is not sheared at the theoretical contour line, because during processing material particles are also pulled out from a depth. Geometrically undetermined cutters indentations and heights are also formed by grinding and honing (→ Fig. 29). A surface with formation of fine burrs is generated.

Fig. 29 Ground surface

Counter Surface


2

WhethersuchasurfaceissuitableforuseincontactwiththesealingcomponentscannotbesufficientlyderivedfromthecurrentlyusedsurfaceparametersRa,RmaxandMr.Dependingonthegeneralmanu-facturingconditionsbothabrasiveandnon-abrasivecountersurfacesarecreatedwithinthelimitvalues.Processesthatremovematerialforfinalmachiningareonlysuitableiftheprocesscanbemanaged.Thisrequiresameasuredvaluefortheabrasiveness.

Whenmanufacturingprocessesforfinalmachiningareusedinwhichmaterialisnotremoved(e.g.roll-ing)comparativelysmoothsurfacesaregenerated,whichdonotnormallyhaveanyabrasivecompo-nents.Becauseitisdifficulttowetasmoothsurface,itismoredifficulttoformalubricatingfilm.Howev-er,suchsurfacesaregenerallysuitableforacountersurfaceincontactwithsealingcomponents.

Hardness/coating

Thecountersurfaceandthesealingandguideelementsareincontactasaresultofrelativemove-ment(friction)andcompression(transverseload;operatingpressure).Therequiredhardnessofthecountersurfacedependsontheheightandtypeofloading.Slowmovementswithhighsurfaceload(deformationofthecountersurface)androtarymovements(running-inasaresultofwear)arethemostdemanding.

Thehardnessofthesurfacegeneratessufficientlywear-resistantandstableedgecoatings.However,thethicknessoftheedgecoatingandthequalityofthebasematerialareveryimportant.Ifitistoosoft,acomparativelythinedgecoatingwillbedeformedorbrokenwithdeflectionofthebasematerial.Thiseffectcanbeobservedparticularlywithhardchromecoatingsonsoftsubstratema-terial.Thehighestcompressiondependsonthetransverseloadandtheoperatingpressureintheregionoftheguideelementortheprimarysealingcomponent.WithcompletedeflectionofanHGWguideringandacorrespondinglyhightransverseloadmaximumcompressionsofpmax~110N/mm²arereached.Inthecaseofthesealingcomponents

thepressuredistributiondependsonthegeometryofthesealingedge (→ Fig.30).Anoperatingpressureof30MPaamaximumcompressionofpmax~50N/mm²canbeexpectedfortheMerkelOmegatOMS-MRRodSeal.

PCompression = Pressure

Fig.30Qualitativecompressioncurve,single-actingrodseal

Intheareaofrodsealingsystemsbasesteelofqual-ityCk45Nwithasurfacehardnessof55-60HRCisusedforcylindersunderhighloading.Ingen-eralhigh-alloy,stainlesssteelsbasedonCrMoorCrMoNihaveprovenreliable.

Pistonsealingsystemsareunderlessloadcom-paredtorodsealingsystemswithreferencetothecompressioncurve(nopronouncedsealingedge)andthelubrication.Thecountersurfaceincylinderboresarenotnormallyhardened.Underhighload-inghigh-alloy,stainlesssteelsbasedonCrMoorCrMoNi(e.g.42CrMo4+QTor42CrMo4Vand36NiCrMoT+TQ)haveprovenreliable.

Nitrated counter surfacesNitrationsaturatestheedgecoatingofthework-piecewithnitrogenbydiffusion.Theresultisahard,wear-resistantandcorrosion-resistantcompoundlayer(thickness10-20µm).Thehardnessdiminisheswithincreasingdepth(diffusioncoat).Dependingontheprocessandthebasicmaterialatotalpen-etrationdepthofupto1mmisreached.Insalt-bathnitration(inaweakerformalsowithgasnitration)alargenumberofdeepporesisformedintheoutercompoundlayer.Evenunderaminorload(abrasive)particlestendtobreakoutoftheporouscompoundlayer.


0

Technical Manual

Fig.31 Salt-bath-nitratedsurface

Asurfaceofthistypecannotbeusedincontactwiththesealingcomponentswithoutadditionalmechani-calprocessing.Nitratedcountersurfacescanbeusedinsealingtechnologywithoutproblemswhentheyhavebeenappropriatelyprocessed.

Chromed counter surfacesPolishedhardchromelayers(thickness30-50µm)donotgenerallyhaveanyabrasivecomponentand,assumingasufficientlyhardsubstrate,aresuitableforuseasacountersurfaceincontactwiththesealingcomponents.Mattchromingformsmi-croscopicallysmallsharptips,whichcauseheavywear.Suchsurfacesmustbemechanicallyproc-essedbeforeuseineverycase.

Fig.32 Chrome-nitratedsurface

Ceramic and partially ceramic counter surfacesWhenusingceramicandpartiallyceramicsur-face(totalthickness300µm)corrosionprotection(saltwaterresistance)andwearresistancearetheprimarypurpose.Ceramiccountersurfacesarenotsmoothedincon-tactwiththesealingcomponents.Thecontactwiththepermanentlysharp-edgedcrystalstructurecaus-eshighwearonthesealingcomponents.Sealingsystemsforceramiccountersurfacesaredesignedwithadaptedsealmaterialsandspecialseallayoutsandassuchhaveaspecialposition.

Fig.33 Ceramicsurface

Ingeneralbrittlecoatingswouldbreakwiththeelongationofthecylinderboreswhenpressureisapplied.Therefore,inhydrauliccylindersonlypis-tonrodsarecoated.


1

Description of counter surface measurable in the laboratory

Toevaluatethecountersurfaceasuitablerough-nessgaugeisusedtomeasurethesurfaceparam-etersRa(averageroughness),Rmax(maximumsurfaceroughness)andMr(materialcontent)andcomparedtothespecifiedlimitvalues(→ Tbl.4).

Surface quality

Surface roughness Rmax Ra

Slidingsurface ≤2,5µm0,05…0,3µm

(optimumRa=0,2µm)

Groovebase ≤6,3µm ≤1,6µm

Grooveflanks ≤15,0µm ≤3,0µm

MaterialcontentMr>50%tomax90%atcuttingdepthc=Rz/2andreferencelineCref=0%.(optimumMr=80%)

Tbl.4 Surfaceparameters

ThematerialcontentcurveorAbbottcurve(→ Fig.34)isthegraphicviewofthematerial-filledproportionofthecalculatedprofilewithreferencetothecuttingdepth.ThematerialcontentisderivedfromtheAbbottcurve.Thesealmanufacturerusesdifferentbasicdata.

0%

39%

79%

100%

0 %39 79 100

Fig.34 Abbottgraph


2

Technical Manual

InthecaseofMerkeltheentiresurfaceincludingthe

fullpeakheightrelevanttotheabrasivityandpos-sibledamageatfirstcontactisconsideredstartingfromareferencelineatCref=0%(→ Fig.35).Itre-mainsunconsideredwithareferencelineCref=5%(→ Fig.36).

10 20 30 40 50 60 70 80 90 100C ref = 0 % Mr = 48 %

Rz/2

0

[mm]

Mr [%]

Abbott curve

Fig.35 Merkelmaterialcomponentdefinition

0 10 20 30 40 50 60 70 80 90 100C ref = 5 % Mr = 61 %

Rz/4

[mm]

Mr [%]

Unconsidered for C ref = 5 %

Abbott curve

Fig.36 Competitionmaterialcomponentdefinition

ParameterssuchasRa,Rmax,RzandthematerialcontentMrhavebecomeestablished.Thebehav-iourofthecountersurfacecomparedtothesealingcomponentscannotyetbedescribedwithsufficientaccuracywithreferencetotheabrasivity.

Extended laboratory description of the counter surface

Theservicelifeofthesealingcomponentinaseal-ingsystemisdeterminedbythecontactbetweenthecountersurfaceandthesealingcomponent.Thecontactinfluencesbythecomparativelysoftsealingcomponent(wear)andthehardcountersurface(smoothing).Ifthesealingedgeisdamagedasaresultofabrasivewearonthefirststrokesofthehydrauliccylinder,thesealingeffectandtheservicelifewillbereducedaccordingly.Anextendedlabo-ratoryexaminationofthecountersurfaceisurgentlyrequiredtomeasureabrasivitytoensurestablerun-ningcharacteristicsoverthelongterm.

Thedescriptionofthecountersurfacecanbere-finedbyevaluationofadditionalparametersoftheAbbottcurve(→ Fig.37):

10 20 30 40 50 60 70 80 90 100

Rpkx

0

[mm]

Mr 1

Rk

Rpk

Mr 2

RvkRvkx

Mr [%]

Abbott curve

Rpkx,fullpeakheight;abrasivecomponent.

Rpk,reducedpeakheight;profilepeaks.

Rk,coresurfaceroughness;supportingcore;themainfunctionarea

Rvk,reducedgroovedepth;profilegrooves;lubricantdepot.

Rvkx,fullgroovedepth;onlyminorinfluenceonthesealingsystem.

Rpk, Rk, Rvk, Mr1andMr2cannotbeinfluencedanymorewithoutsimultaneouslyinfluencingshape,positionanddimensions.

Fig.37 Additionalparameters


Merkelhassetanewdirectionwiththedefinitionofnewsurfaceparametersfordetaileddescriptionofthecountersurfaceforsealingcomponents.There-sultsarecurrentlybeingappliedtoawiderbaseincollaborationwithmajormanufacturersofinjectionmouldingmachines,pressesandgeneralcylindermanufacturing.InthecurrentstateofknowledgeatMerkelthesur-faceparameterslistedinTable5withthestatedlimitvaluesaresuitableforacompletedescriptionofthecountersurfaceforsealingcomponents.

Comparedtothecurrentlyconsideredsurfacepa-rametersweexpectsignificantlyimprovedpredict-abilityofabrasivityandlong-termbehaviour.Ourinsightsdonotyetincludeceramicorpartialceramiccountersurfaces.Becausesuchsurfacesincontactwithsealingcomponentshaveaspecialposition,wewouldliketoexcludethesesurfacesfromtheaboveinformation.

Ideal flat Unsuitable too fine Suitable Unsuitable too rough

1 2 3 4

Ra >0,05µm <0,30µm

Rmax – <2,50µm

Rpkx – <0,50µm

Rpk – <0,50µm

Rk >0,25µm <0,70µm

Rvk >0,20µm <0,65µm

Rvkx >0,20µm <2,00µm

Tbl.5 Limitpositionsoftheadditionalparameters


Technical Manual

Selection

Thefunctionofasealingcomponentisinfluencedbythegeometryandprimarilybythesealmaterial.Theinfluenceofthespecificmaterialpropertiesonthefunctionofthesealinthisregarddependsamongotherfactorsonthenatureoftherelativemovementbetweenthesealingcomponentandthecountersur-face(stroke,rotation,static).

Aswellasthechemicalresistancetheformstability,frictionbehaviourandelasticbehaviouraresignifi-cantinfluencefactors.Unwantedmaterialinfluencesareinpartcompensatedbyadditionalcomponentssuchasback-uprings(extrusionresistance)orpre-loadcomponents(initialsealingeffect).Afunction-orienteddesignofthesealalwaysconsidersthesealingmaterialinuse.Noteverygeometrycanbemanufacturedeasilywitheverymaterial.

Materials

Inhydraulicapplicationsmulti-componentsealingcomponentswithaslidingringofPTFEcompoundandanelastomerpre-loadcomponentaswellassingleandmulti-componentsealingcomponentsofelastomer(NBR,FKM)orpolyurethaneareprimari-lyused.Fortheguideelementsfabric-baselaminatecompoundsaremostlyused.

Back-upringsaremanufacturedofPTFE(poly-tetrafluoroethylene),PA(polyamide)orPOM(polyoxymethylene)dependingontherequirements.Aswellasthesematerialsinsomecasesspecialma-terialssuchasPE(polyethylene),TPE(thermoplasticpolyester-elastomer)andPEEK(polyetheretherke-tone)areused.

PTFE compound

Pure(virgin)PTFEhasacomparativelylowstruc-tureandfrictionstrength.Evenunderalowloadthematerialisdeformedandbeginstoflow(coldflow).Theadditionoffillers(compounding)suchasbronze,glassfibreandcarbonfibrecansignifi-cantlyimproveformstabilityandfrictionstrength.Dependingontherequirementsotherfillerssuchascarbonorgraphiteandalsocolouradditivesarealsoused.

PTFEisahorny,non-elasticmaterial.Theinitialcon-tactpressureofthePTFEsealingcomponenttothecountersurfacerequiredforthesealingfunctioncanonlybeappliedbyanadditionalcontactpressureelement(elastomerorspring)becauseofthemissingelasticity.PTFEsealingcomponentsthereforealwayshavemultiplecomponents.

Metal

Metal

PTFE compound

Polyurethane

Metal

Elastomer

Fig.38 Sealingedgeincontactwithcountersurface

Materials


PTFEcompoundsarenotedforhighpressureresist-anceandfavourablefrictionbehaviour.Africtionvalue(oiled)betweenµ=0,02andµ=0,1canbeexpecteddependingonthecontactconditions.

ThestructureofthePTFEmaterialcausesthesealingcomponenttoslideonthehighercomponentsofthesurfaces(microstructure).Thesealingedgedoesnotentertheroughnessvalleys(→ Fig.38).AsaresultofthisbehaviourPTFEsealingcomponentsallowacomparativelythickerlubricatingfilmbeneaththesealingedge.

PTFEsealingcomponentsarepreferablyusedasaprimarysealinsealingsystemsorasapistonsealwithbilateralpressureapplication.

DirtadheringtothepistonrodcanbekeptfromenteringthehydraulicsystemwithsuitabledesignofthewipingedgewhenusingwipersofPTFEcom-pound.

WhenselectingthePTFEcompoundamongstothersthefollowingpropertiesareassessedwithreferencetotheactualapplication:

TheinfluenceofthehydraulicmediumThebehaviourincontactwiththecountersurfaceTheformstabilitydependingontheoperatingtemperature.

PTFEbronze(PTFEB602)isthestandardcompoundforgeneralapplications.Inadditiontoitsverysmoothslidingpropertiesthehighformstability,evenathightemperatures,aswellashighwearre-sistanceareparticularlyimportant.

Themetalbronzeanditscomponentsarenotchemi-callyneutral.Incontactwithwaterorwateremul-sionandinsomecasesalsowithadditivesinthehy-draulicmediumchemicalreactionsmaybestarted.

Thechemicalreactionandalsogenerallytheresultsofinsufficientlubricationcancauseatypicaldam-agepattern(finestrips)onthecountersurfaceincontactwiththeslidingringofasealingcomponentofPTFEbronze.

TherestrictiondescribedisgenerallyapplicableforallPTFEbronzecompoundsavailableonthemar-ket.However,becauseofthecompounding,whichvariesindetail,theresultsmustbeevaluatedverydifferently.

Ifthelubricationisinsufficient(poorlylubricatinghydraulicmedium,shortstroke,strokeathighloadandlowstrokespeed),theuseofPTFEglassfibreMoS2(PTFEGM201)hasproventobesuitable.In-fluencebystandardhydraulicmediaisnotafactorbecausetheglassfibresarechemicallyneutral.

T = 80°CT =120°C

PTFE GM201(PTFE/Glass fibre MoS2)

PTFE B602(PTFE/Bronze)

PTFE C104(PTFE/Carbon fibre)

Competition(PTFE/carbon fibre)

Defor

matio

n

Fig.39 FormstabilityofPTFEcompoundsincomparison


Technical Manual

ThepressureresistanceofPTFEglassfibreislowerthanthatofPTFEbronze.Inthetemperaturerangeabove100°CtherearesignificantdifferencesintheformstabilityincomparisonwithPTFEbronze(→ Fig.39).

ThepositivepropertiesofPTFEbronzeandPTFEglassfibrearecombinedinthePTFEcarbonfibrecompound(PTFEC104).Thecompoundhasfavour-ablebehaviourwithinsufficientlubricationandcom-parativelyhighformstability.

ThematrixofmodifiedPTFEisthedifferenceincom-poundPTFEC104comparedtootherPTFEcarbonfibrecompounds.ThecostofthebasematerialandtheprocessingarehigherthanforPTFEbronze,PTFEglassfibreandsimplePTFEcarbonfibrecom-pounds.Therefore,thiscompoundisgenerallyusedforapplicationswhereneitherPTFEbronzenorPTFEglassfibreMoS2appearsuitable.

Themaximumpermissibleoperatingpressureisprimarilydeterminedbytheextrusiongapandthetemperature-dependentformstabilityofthesealmaterial.Becausethesizeoftheextrusiongapcan-notbeselectedasverysmallwithreferencetometalcontacts,thepressureapplicationrangeoftheseal-ingcomponentmustbelimiteddependingonthetemperature.

Anoperatingpressureofupto40MPaisgener-allypermissibleintheaveragetemperaturerange,dependingontheextrusiongap.Atanoperatingtemperatureabove100°Ctheoperatingpressureshouldremainlimitedto26MPawiththeuseofPTFEglassfibreandthesimplePTFEcarbonfibres.

ThePTFEprofileringofaPTFEsealismachine-man-ufactureduptoanominaldiameterof2000mm.Itcannotbemanufacturedbyinjectionmoulding.

Polyurethane

Polyurethanehasahighwearresistanceandacomparativelyhighformstability.Withtheelasticbehaviourofthematerialsealingcomponentscan

bedesignedassingle-piececomponents,i.e.withoutanextrapre-loadcomponent.Polyurethaneunderpressurebehavesasaviscousfluid.Atanoperat-ingpressureabove10MPasealingcomponentsofpolyurethanearecompletelyformed.Thefullcontacttothecountersurfacemakesingressofthelubricatingmediuminthecontactareadifficultandasaconsequenceincreasesthefrictionwear.Theuseofasealingsystemshouldbepreferredtotheindividualsealwithreferencetotheachievableservicelife.

Code Colour

95AUV142 dark-blue

94AU925 light-blue

93AUV167 light-red

93AUV168 light-red

95AUV149 dark-blue

AUV206 dark-yellow

AUV204 light-yellow

92AU21100 white

Tbl.6 Overviewofpolyurethane

Sealingcomponentsofpolyurethanewipeawaythehydraulicmediumreliablywithsuitabledesignofthesealingedge.Assumingadequatemediaresist-ance,sealsofpolyurethaneareusedasprimaryandsecondaryseals(gappressureupto5 MPa)insidesealingsystems.Theiruseasindividualsealsincombinationwithadoublewiperisalsowide-spread.Withitshighwearresistancepolyurethaneisalsoverysuitableasamaterialforwipers.Seal-ingcomponentsofpolyurethanecanbemanufac-turedbyinjectionmouldingorrotaryprocessestoanominaldiameterofapproximately2000mm.Thequalitiesofpolyurethaneused(→Tbl.6)canbeprocessedmoreorlesseasilydependingonthenominaldiameterandthemanufacturingprocess.Ontheotherhandsomequalitiesarenotedforexcellentpropertiessuchasincreasedresistancetohydrolysis(hydrolysis=lossofstructureasaresultofcontactwithwater)orimprovedpropertiesinthelow-temperaturerange.


Elastomers

Sealing,wipingandpre-loadcomponentsofNBR(acrylonitrile-butadienerubber)orFKM(fluoroelas-tomer)areprimarilyusedintheareaofhydraulicapplications.DependingonthegeneralconditionsHNBR(hydrogenatedacrylonitrile-butadienerub-ber)andEPDM(ethylene-propylene-dienerubber)arealsoused.

Sealingcomponentsofelastomerwipeawaythehydraulicmediumandalsofinedirtreliablywithsuitabledesignofthesealingedge.InthisrespecttheyaresuperiortoPTFEandpolyurethane.Ontheotherhandthehighsealingeffectcausestheelas-tomertopenetratethemicrostructureofthecountersurface(→ Fig.38)andthusformsaveryclosecon-tactbetweenthesealingcomponentandthecountersurface.ThefrictionandthewearareincreasedparticularlywhenpressureisappliedcomparedtoPUandPTFE(→ Fig.40).

Sealingcomponentsofelastomertendtoadheretothecountersurfaceafterextendeddowntimebe-causeofthisproperty.Becauseofthelowresistancetogapextrusion(formstability)sealsofelastomerwithoutadditionalrein-forcementsuchasfabricinserts(Chevronsealsets)orback-upringscanonlybeusedatlowpressuresupto10MPa.

Elastomersealswithfabricreinforcementarerobustandwithpressureappliedhavesufficientformstabil-ity.However,suchsealingcomponentsareoftennotsufficienttomeettheincreaseddemandsrelatedtostrokespeedandservicelife,primarilybecauseoftheunsuitableFrictionbehaviour.ElastomersaremainlyusedaswipersandintheformofO-ringsasstaticsealsorpre-loadcompo-nents.Elastomersareonlyusedassecondarysealsinsealingsystemsifpolyurethanecannotbeusedbecauseofthemediaresistanceortheoperatingtemperature.

0

10

20

30

40

50

60

70

80

90

100

110

NBR HNBR EPDM FKM PU

Abra

sion

Fig.40 Wearbehaviourincomparison


Technical Manual

60 °C 80 °C 100 °C 120 °C

Radia

l load

HG650Competition 1Competition 1Competition 1

Fig.41 Loadingdependingontheoperatingtemperature

Fabric-base laminate

Fabric-baselaminatesconsistofafinefabricbond-edwithresin.Relevantpropertiessuchasthefrictionstrength,thepermissiblesurfaceload(acceptanceoftransverseloading)andthetemperaturedepend-encyofthematerialbehaviouraresetdependingonthepropertiesofthecomponents.Polyesterandotherplasticsandalsonaturalmaterialssuchascot-tonareusedforthefinefabric.Inadditiontopoly-ester,vinylesterandphenolresinawholerangeofplasticswithvariouspropertiesareavailablefortheresinmatrix.Whilethefrictionresistanceoftheestablishedcompoundsisgenerallyatacompara-tivelyhighlevel,therearesignificantdifferencesinthepermissiblesurfaceloadandthedependenceontheoperatingtemperature(→ Fig.41).

Thermoplasticbasematerials,suchaspolyester,haveasignificantnaturaltemperature-dependentmaterialbehaviour.Athighertemperaturesguide

elementsofthesematerialscanonlyacceptlowtransverseloads.Forothercompoundstheinfluenceoftheoperatingtemperatureonthepermissiblesur-facepressureisonlyminor.

Inthediameterrangeupto300mmHG517andHG650arecurrentlyusedbythemetrecuttolengthandabove300mmtheHG650qualityisusedbythemetrecuttolength.MaterialqualityHG650representsthestandardofthefutureoverthecom-pletedimensionrange.TheadvantageofHG650inadditiontotheoutstandingpressureresistancecomparedtocompetitiveproductsistheimprovedhandling(fitting)forsmalldiameters(<60mm).

Code Colour

HG517 darkgrey

HG650 Red

Tbl.7 Overviewoffabric-baselaminates


Beforeinstallingthesealingcomponentsthecom-petesystemmustbecleanedtoremovemachiningresidues,chips,dirtandotherparticles.Sealsmustnotbepulledoversharpedges,threads,featherkeygroovesorsimilarwhenmounting.Thesepartsmustbecoveredduringfitting(→Fig.42).Sharpedgesmustbede-burredorchamferedorradiused.Neverusesharp-edgedtools.Seal,pistonrodandcylinderboremustbeoiledorgreasedbeforefitting.Heatingthesealsbeforeinstallationin+80°Cto+100°Chotoilwillmakethesealmaterialmoreelasticanditwillbeeasiertoinstalltheseal.

Insertion chamfers on rods and pipesTopreventdamagetosealingcomponentswhenmounting,cylinderboresandpistonrodsmustbechamfered.ForthesurfacequalityofthechamferRt≤4µmisapplicable.Theedgeatthetransitionfromthechamfertotheslidingsurfacemustberoundedandpolished.Prod-uct-specificinformationcanbefoundintheshapedescriptions.

Installation of Hydraulic Seals

Fig.42 Coveringthreadswhenmountingseals


0

Technical Manual

Fitting of rod seals

Whenmountingrodsealstwotypesofinstallationmustbedistinguished(→Fig.43):

Ins ta l la t ion recommendat ion I

Ins ta l la t ion recommendat ion I I

Fig.43 Installationtypesofrodseals

Snap-infittinginanundividedinstallationspace(installationrecommendationI).Sealsthataresuitableforthistypeofinstallationaremarkedwithhandwinthetablesofdimen-sions.Fittinginadividedinstallationspace(installationrecommendationII).Sealsthatrequiredadividedinstallationspacearenotmarkedinthetablesofdimensions.

Assembly tools for rod sealsSnap-infittinginundividedhousings(recom-mendedinstallation)canbemademusteasierwithsuitableassemblytools.ThefittingtoolI(orderno.00375753)canbeusedtosnapinU-ringsfrom35mmdiameter(profilesize5mm)uptoa

nominaldiameterof80(profilesize10mm)inun-dividedgrooves.Theringispressedintoakidneyshapeandpushedintotherodguide.Thefittingtooliswithdrawnafterthesealhassnappedintothegroove.

Anotheroptionforsnap-infittingofrodsealsistouseasuitablestopperandarod(→Fig.46).

Herethesealisinitiallyplacedmanuallyinthegrooveandthenpushedwitharoduntilitsnapsintothegroove.Stopperandrodshouldbemanu-facturedfromasuitableplastic.


1

Fitting of groove and compact seals with back-up ringTheMerkelSMU-Ring(primaryseal)withlocked-inback-upringcanbesnappedintoaplunge-cutgroove.Thesealingringisfirstinsertedintothegroove.Thentheback-upringisinstalled.Compactsealswithalocked-inback-upringcanbesnappedintoaplunge-cutgroove,dependingonthediameterandprofile.

Fitting of multi-part compact seals for the rod: Merkel Omegat OMS-MRForroddiameters≤15mmanaxiallyaccessiblehousingisrequired.Uptoroddiameter28mmanaxiallyaccessiblehousingisrecommended.Ifthisisnotpossiblefordesignreasons,thesealmustbeselectedinaccordancewiththesmallerinstallationsizeL.Fordiameterrange38to50mmwealsorec-ommendusingthesealinaccordancewiththesmallerfittingsizeLbecauseoftheeasierfitting(→Fig.46).Themax.permissiblegapwidthsofthetypemustbeobserved.

Fig.44 FittingtoolIforrodseals

Fig.45 FittingtoolIIforrodseals

Fitting in divided housingsFromaspecificnominaldiameter,dependingontheprofilesize,rodsealsmustbeinstalledindividedhousings.Thelimitsizesarelistedind(→Tbl.8).

Rodsealsindividedhousings(fittingrecommenda-tionII)canbeinstalledwithoutspecialtools.Forseriesinstallationwerecommendusingmountingsleevesandpilotshafts(→Fig.47).

U-rings and single-piece compact seals

Profilesize

P=DN–dN

_________

2 4 5 6 7,5 10 12,5 15

Limitnominaldiametersforsnap-infitting

25 30 40 50 80 100 105

Sealsthataresuitableforsnap-infittingareidentifiedwithh(hand)inthedescriptionsinthedimensionlists.

Tbl.8 Limitdimensionsforsnap-infitting(requiredvalues)


2

Technical Manual

Rod

Plug

Fig.46 Installationaidforrodseals

Fig.47 Fittingofrodsealsindividedhousings

Fitting of piston seals

Similartofittingofrodsealstherearealsotwotypesofinstallationofpistonseals:

Snap-infittinginundividedhousings.Sealsthataresuitableforthistypeofinstallationareidentifiedwithhorwinthedimensiontables.Fittingindividedhousings.Whenassembledthemetalpartsmustadheretoprecludeextrusionwearonthestaticside.

Multi-part compact seals for pistonsSimkoPistonSealscangenerallybesnappedinwithouttools.Thefollowingillustrationsshowthesnap-infittingwithouttoolsfortheMerkelCompactSealSimko300CompactSeal.Firsttheelasticrub-bercontactpressureelementissnappedin.ThenthePURsealingringisplacedononesideinthegrooveandpushedoverthepreviouslyoiledpistonbodyuntilitsnapscompletelyintothegroove.

Fig.48 Snappinginthepolyurethanerunningring

Fig.49 Snappinginthepolyurethanerunningring


Assembly tools for piston sealsThesnap-infittingismademucheasierwithsuitableassemblytools.

Fig.50 Fullymountedseal

Fig.51 Insertingsealingring

SimkoPistonSealsaswellasU-Ringsthatinsomecasesareusedassingle-actingpistonsealscanbeeasilyinstalledwiththeaidofsimpleinstallationtoolSeethefollowingillustrations:

Fig.52 Insertingmountingpin

Fig.53 Turningmountinglever


Technical Manual

Fig.54 Snappingintheguideback-upring

Fitting of compact seals of the Omegat series for pistons and rodsTheMerkelOmegatCompactPistonSeals(OMK-MR,OMK-S,OMK-E,OMK-ES)andtheMerkelOmegatCompactRodSeals(OMS-MR,OMS-S)aresuitableforundividedhousingsinvirtu-allyalldimensions.Fittingrequiresspecialcare.

Topreventdamagetothesealingedge,whichmayresultinleakagebeforecommissioning,itisimpor-tanttoobserveourinstallationinstructions.

Fitting for installationOmegatSealsconsistofahigh-qualitypressureandwear-resistantprofileringandanO-ringasthepre-loadcomponent.Carefulfittingisessentialforcorrectfunction.

Beforestartinginstallation,makesurethat:

Therequiredinsertionchamfersonthepistonrodandcylinderborehavebeende-burredandrounded,Threadpeaksandsharpedgesarecovered,Dust,dirt,chipsandotherexternalobjectsmustbethoroughlyremoved,TheOmegatsealingcomponentsandthecom-ponentsareoiledorgreased(useonlygreaseswithoutsolidadditives.Inthisregardmakesurethattheyarecompatiblewiththemedium.),Theassemblytoolsmustbeofsoftmaterialandhavenosharpedges.

Heatingtheminoiluptoabout80°CmakesitmucheasiertostretchanddeformtheOmegatProfileRing.

Omegat Rod Seal

FittingofOmegatRodSealsinundividedhousingsisveryeasy(d≤Ø15axiallyaccessiblehousingrequired):

InsertO-ringintothegroovewithouttwistingit.

PressOmegatProfileRingintoakidneyshape(attention:donotkink!).


Omegat Rod Seal

Afittingtoolispreferredforseriesfitting. P

Direction of pressure

PlacecompressedOmegatProfileRingontheO-ringsothesealingedgeisonthepressureside.

InsertOmegatProfileRinginoriginalshapeinthegroove.

Thencalibratewithamandrel.ThemandrelcanbemanufacturedfromPA,POMorsimilarmaterial.Chamfersof15°andminimum30mmlong.

Tbl.9 Deformationoftheprofilering

Ø d L Ø d mandrel

<50 15 Ød–0,10

≥50...<120 20 Ød–0,18

≥120...<200 30 Ød–0,25

≥200...<650 40 Ød–0,35

≥650...<900 50 Ød–0,50

Tbl.10 Recommendeddiameterofmountingequipment

Recommendation:PleaseuseanassemblytoolwhendØ>15mmandforlargerseries.Thisdeformstheprofileringless.Themajordesignprinciplesareshowninthedrawing.

15°R 1,5

L

Ø

Rounded

dmandrel

Fig.55 Calibratingmandrel

Preferredmaterials: pressuremandrel–plastic taperedsleeve–plasticWecansupplycompleteassemblytoolsonenquiry.

XX

Expanding mandrel

Conical sleeve Cylinder

O-ringOmegat profile ring

Seal housing

Fig.56 Finishedassemblytools(onenquiry)


Technical Manual

Omegat Piston Seal

OmegatPistonSealsmustalwaysbefittedinsingle-piecepistonswithafittingtool.

InsertO-Ringintothegroovewithouttwistingit. Expanding sleeve

Expanding mandrel approx. 5°chamfer

O-ring

PTFE profile ring

StretchOmegatProfileRingwithspreadersleeveoverataperedmountingsleeveandspringintothegroove,forlargerdimensionsusemountingbelt(orderno.24346745)(nosharp-edgedtools).

CalibrateOmegatProfileRingonthepistondiameterwithaslipring.WhenusingprofileringswithanL-dimension≥6,3mmwerecommendusingaplastictensionbelt.

Tbl.11 Mountingequipmentforpistonseal

1.Back-upring

2.Sealingcomponent

3.Back-upring

4.Angledbush

4. 1. 2. 3. 4.

Fitting instructions for Merkel Compact Seal L FittingoftheMerkelCompactSealL43isuncom-plicatedandgenerallycorrespondstotheconven-tionalcompactpistonseal.Theassemblyshouldbecarriedoutinthesequencebelow.

Fitting of Merkel Compact Seal T 1Werecommendusinginstallationtoolsforalldimen-sionsofthesizeseriesT19;handinstallationispos-sibleforservicing.Thesequencewhenmountingtheindividualpartsisasfollows:

FirstangledbushSealingcomponentSecondangledbush

Fig.57 FittingofMerkelCompactSealL43


Installation instructions for Merkel double wiper PT 2DoublewipersofthePT2seriescanbeinstalledinhousingsthatarenotaxiallyaccessiblewithouttoolsfromØ150mm.ForinstallationfirstinsertthelargeO-ringintothegroove,insertthesmallO-ringintothegrooveofthePTFEprofilering,thentheprofileringisplacedinakidneyshapeandsnappedin.Makesurethattheprofileringisnotkinkedandthatthesealingedgeiscorrectlyalignedtothepressuredirection.Forsmallerdimensionspleaseuseanin-stallationtool.Dimensions<Ø100mmcannotbeinstalledinaplunge-cutgroove.

Installation instructions for Merkel double wiper PT 1DoublewipersofthePT1serieswithinsidediam-eter≥30mmcanbeinstalledinnon-axiallyaccessi-blehousingswithoutfittingtools.Forsmallerdimen-sionsafittingtoolisrecommended.

PT 1

Pressure

Fig.58 Functionaldirectionofwiper

ForinstallationtheO-ringsareinsertedintothegroove,thentheprofileringisplacedinakidneyshapeandsnappedin.Makesurethattheprofileringisnotkinkedandthesealingedgeiscorrectlyalignedtothepressuredirection.

Fitting of Chevron Seal Sets

Instructions for Chevron Seal Set housingsAdjustablehousingshavetheadvantageofanop-timaladjustmentoption.Afteralengthyperiodofrunningandincipientwearonthesealtighteningtheglandcanextendtheservicelifeandsignificantlydelayasystemstandstill.Foradjustablehousingsanextensionof2,5%andanadjustabilityof7,5%ofdimensionLisrecommended.Non-adjustablehous-ingshavetheadvantageofmorecost-effectiveman-ufacture,becausewashersarenotrequired.SealSetTypeBisparticularlyrecommendedforthesehousings.Therubber-sprungback-upringshandlethefunctionofinitialcompressionandcontinuousre-adjustmentduringoperation.Maintenanceofthesealcontactareaisnotrequired.

FittingBeforeinstallationallindividualpartsofthesealsetmustbeevenlygreased.Mineral-oil-basedgreasescanbeused.Therodmustbeinthecylinder’sinstal-lationspaceduringfitting.Theindividualpartsofthesetmustbeinstalledseparatelyinthechamber.Inthisregardmakesurethatthesealsarenotre-versed.Openchevronsealsetsareusedforrepairs,e.g.inlargesystems,ifendlesssealscannotbeinstalled.

Please noteOpenchevronsealshaveanoversizeinthecircum-ferencelengthtoallowsufficientcompressionandagoodsealingeffectatthejointsections.Anendlessdeliveredsealsetshouldthereforenotbecut.Openchevronsealsarealwayssuppliedwithinstalledprofilecords.

L x 1,025L x 0,075

Fig.59 DMSinstallationspaceexample


Technical Manual

General Technical Data

ISO Tolerances, Selection – in µm –

Nominal dimension range [mm]

Pisto

n gu

ides

Groo

ve b

ase f

or tw

o-pie

ce

pisto

n se

als

Groo

ve b

ase f

or p

iston

seals

Simm

errin

g sh

aft

pisto

n ro

ds

Simm

errin

g (h

ousin

g),

rod

guide

s, wi

per h

ousin

g

Groo

ve b

ase f

or ro

d se

als

Simm

errin

g ho

using

, sp

ecial

case

s

Cylinder bores

over to h8 h9 h10 h11 f7 f8 e8 H8 H9 H10 H11 f8

1,6 3 0 0 0 0 –6 –6 –14 14 25 40 60 20

–14 –25 –40 –60 –16 –20 –28 0 0 0 0 6

3 6 0 0 0 0 –10 –10 –20 18 30 48 75 28

6 10 0 0 0 0 –13 –13 –25 22 36 58 90 35

–22 –36 –58 –90 –28 –35 –47 0 0 0 0 13

10 14 0 0 0 0 –16 –16 –32 27 43 70 110 43

14 18 –27 –43 –70 –110 –34 –43 –59 0 0 0 0 16

18 24 0 0 0 0 –20 –20 –40 33 52 84 130 53

24 30 –33 –52 –84 –130 –41 –53 –73 0 0 0 0 20

30 40 0 0 0 0 –25 –25 –50 39 62 100 160 64

40 50 –39 –62 –100 –160 –50 –64 –89 0 0 0 0 25

50 65 0 0 0 0 –30 –30 –60 46 74 120 190 76

65 80 –46 –74 –120 –190 –60 –76 –106 0 0 0 0 30

80 100 0 0 0 0 –36 –36 –72 54 87 140 220 90

100 120 –54 –87 –140 –220 –71 –90 –126 0 0 0 0 36

120 140 0 0 0 0 –43 –43 –85 63 100 160 250 106

140 160 –63 –100 –160 –250 –83 –106 –148 0 0 0 0 43

160 180

180 200 0 0 0 0 –50 –50 –100 72 115 185 290 122

200 225 –72 –115 –185 –290 –96 –122 –172 0 0 0 0 50

225 250

250 280 0 0 0 0 –56 –56 –110 81 130 210 320 137

280 315 –81 –130 –210 –320 –108 –137 –191 0 0 0 0 56

315 355 0 0 0 0 –62 –62 –125 89 140 230 360 151

355 400 –89 –140 –230 –360 –119 –151 –214 0 0 0 0 62

400 450 0 0 0 0 –68 –68 –135 97 155 250 400 165

450 500 –97 –155 –250 –400 –131 –165 –232 0 0 0 0 68

Tbl.12 SelectionofISOdimensions


Production tolerances

Inthefollowingchapteronmaterialswillconsiderthetechnologicalqualityofthehighlyelasticmateri-alsfromFreudenberg,elastomersandplastomersaswellastheirapplicationswithreferencetotheirphysicalandchemicalproperties.However,thedimensionalaccuraciesachievableonthefinishedpartwiththeabovementionedmaterialsarealsoimportant.Designersandusersveryfre-quentlyaimfortolerancestandardsusedformetalpartsinmechanicalengineeringwhentheyconsiderthetolerancesrequiredandtherulesgoverningtol-erances.However,narrowtolerancesaregenerallynotpossibleduringthemanufactureofsealingcom-ponentsandpartsmadeofhighlyelasticmaterials.ThetolerancesspecifiedinDIN7715aregenerallyapplicableforsealingcomponentsandpartsmadeofhighlyelasticmaterials,andassumingthattherearenospecialrequirementsforspecificproductstol-erancelevelM3isconsideredapplicable.DeviationsfromthevaluesspecifiedinDIN7715mustbeagreedinconsultationbetweenuserandmanufacturer.

Permissible deviations for soft rubber parts (extract from DIN 1 Part 2)

Dimension termsAdifferentiationistobemadebetweentwokindsofpermissibledimensionaldeviationsFandCforallmouldedpartswithinthetoleranceclasses.F: Deviationsdimensionsrelatedtothemould.

Dimensionsthatarenotinfluencedbyfactorsthataffectshapesuchascompressionandlateraloffsetbetweendifferentmouldedparts(highandlowpart,cores).Seedimensionsw,xandyin→Fig.60.

C: Deviationsindimensionsrelatedtothemouldclosing.Dimensionsthatmaybechangedbychangesinthedensityofthecompressionandthelateraloffsetbetweendifferentmouldedparts.Seedimensionss,t,uandzin→Fig.60.

x

s

z

u

y

w

tUpper part of mould

Direction of pressure

Flash

Lower part of mould

Moulded part

Fig.60 Mouldandmouldedpart


0

Technical Manual


Class M 1 Class M 2 Class M 3 Class M 4

F±

c±

F±

c±

F±

c±

F±

c±

over to Permissibledeviationsofdimensionsinmm

6,3 0,10 0,10 0,15 0,20 0,25 0,40 0,50 0,50

6,3 10,0 0,10 0,15 0,20 0,20 0,30 0,50 0,70 0,70

10,0 16,0 0,15 0,20 0,20 0,25 0,40 0,60 0,80 0,80

16,0 25,0 0,20 0,20 0,25 0,35 0,50 0,80 1,00 1,00

25,0 40,0 0,20 0,25 0,35 0,40 0,60 1,00 1,30 1,30

40,0 63,0 0,25 0,35 0,40 0,50 0,80 1,30 1,60 1,60

63,0 100,0 0,35 0,40 0,50 0,70 1,00 1,60 2,00 2,00

100,0 160,0 0,40 0,50 0,70 0,80 1,30 2,00 2,50 2,50

Permissibledeviationsin%

160 0,30 *) 0,50 *) 0,80 *) 1,50 1,50

*)Valuesonlyonagreement

Tbl.13 ExtractfromDIN7715

Regardlessofthevaluesgiveninthetables,product-relatedtolerancesareshownin:DIN3760 forrotaryshaftsealsDINISO3302-1 accuracylevelM2fordiameter

rangesofmouldeddiaphragms withoutfabricreinforcement

DINISO3302-1 accuracylevelM3fordiameter rangesofmouldeddiaphragms withfabricreinforcementand/ ormetalinsert

DIN16901,Part2 formanufacturedparts madeofinjectionmoulded thermoplastics

DIN7168 formachinedpartsmadeof PTFEorotherthermoplastics

IftolerancesmustbelessthaninDIN7168forfunc-tionalreasons,the"reducedmaterialtolerances"givenin→Tbl.14mustbemaintained.Inexception-alcasesconsultationwithusisrecommended.

Nominal dimension range [mm]Tolerance according to DIN 7168 average Reduced working tolerances range

over to

6 ±0,1 0,10

6 30 ±0,2 0,15

30 65 ±0,3 0,20

65 120 ±0,3 0,30

120 200 ±0,5 0,40

Tbl.14 ExtractfromDIN7168


1


Pres

sed,

bor

ed a

nd st

ampe

d pa

rts

Flang

e thic

knes

s of p

resse

d pa

rts

Cut-o

uts a

nd p

arts

cut w

ith a

tem

plate

Batch vulcanised parts Hoses and discs cut from hose

Diam

eter

Prof

ile in

cros

s-sec

tion

and

by th

e met

re

Outsi

de Ø

gro

und

Outsi

de Ø

not

gro

und

Insid

e diam

eter

Cut h

eight

over to

3 ±0,2a) ±0,10 ±0,3b) –0,15 ±0,3b) ±0,1 ±0,3b) –0,15 ±0,15

3 6 ±0,2a) ±0,15 ±0,4b) –0,20 ±0,4b) ±0,1 ±0,4b) –0,20 ±0,20

6 10 ±0,3a) ±0,20 ±0,5b) –0,25 ±0,5b) ±0,1 ±0,5b) –0,25 ±0,20

10 18 ±0,3a) – ±0,6b) –0,30 ±0,6b) ±0,2 ±0,6b) –0,30 ±0,30

18 30 ±0,4a) – ±0,8b) –0,40 ±0,8b) ±0,2 ±0,8b) –0,40 ±0,40

30 40 ±0,5a) – ±1,0b) –0,50 ±1,0b) ±0,2 ±1,0b) –0,50 ±0,50

40 50 ±0,5a) – ±1,0 –0,80 ±1,2b) ±0,2 ±1,0b) –0,50 –

50 80 ±0,6a) – ±1,0 –0,80 ±1,2b) ±0,3 ±1,2b) –0,80 –

80 120 ±0,8a) – ±1,0 –1,00 ±1,4b) ±0,3 ±1,4b) –1,00 –

120 180 ±1,0a) – ±1,2 –1,40 ±1,6b) ±0,4 ±1,6b) –1,40 –

180 250 ±1,3a) – ±1,2 –2,00 – – ±2,0b) –2,00 –

250 315 ±1,6a) – ±1,5 –2,80 – – ±2,5b) –2,80 –

315 400 ±2,0a) – ±1,5 –3,50 – – ±3,0b) –3,50 –

400 500 ±2,5a) – ±2,0 –4,50 – – ±3,5b) –4,50 –

500 ±0,5%a) – ±0,5% –6,00 – – ±1,0b) –6,00 –

Tbl.15 FreudenbergtolerancesderivedfromDIN7715

a)ValuescorrespondingtoDIN7715accuracylevel"fine"b)ValuescorrespondingtoDIN7715accuracylevel"average"c)ValuescorrespondingtoDIN7715accuracylevel"coarse"

Dimensional units – Selection –

Basic size Basic unit Unit character

Length metre m

Mass kilogram kg

Time second s

Electricalcurrent Ampère A

Temperature Kelvin K

Luminousintensity candela csd

Amountofsubstance mol mol

Tbl.16 Basedimensions,baseunits


2

Technical Manual

Size Unit Formula symbol Units symbol

Acceleration metresbysecondssquared b m/s2

Density kilogrambycubicmetre ρ kg/m3

Pressure Newton/m2,Pascal p N/m2,Pa

Energy,work Joule A,E Nm=Ws

Area squaremetre A m2

Speed meterbysecond V m/s

Force Newton F N

Tension Newtonbysquaremetre σ N/m2,Pa

Viscosity(dynamic) Pascalsecond η PaS

Viscosity(kinematic) squaremetrebysecond µ m2/s

Volume cubicmetre V m3

ElectricalVoltage Volt V W/A

Electricalresistance Ohm Ω V/A

Electricalconductivity Siemens S 1/Ω

Inductance Henry H Vs/A

Electriccharge Coulomb C As

Frequency Hertz Hz 1/s

Power Watt W J/s

Luminousflux lumen 1m cdsr

Illuminance lux 1x 1m/m2

Tbl.17 DerivedSIunitswiththeirownunitnames


Size UnitOther commonly used

official units

Angularmomentum N⋅ m⋅s –

Torque Nm,J –

Speed 2⋅x⋅rad/s s–1

Modulusofelasticity PA N/mm2,bar

Enthalpy J kJ

Enthalpy,specific J/kg kJ/kg

Entropy J/K kJ/K

Entropy,specific J/kg⋅K kJ/kg⋅K

Geometricalmomentofinertia m4 cm4

Force N kN,MN

Gasconstant J/kg⋅K kJ/kg⋅K

Calorificvalue J/kg,J/m3 kJ/kg,kJ/m3

Linearmomentum N⋅s –

Massmomentofinertia kg⋅m g⋅m,t⋅m2

Moment N⋅m –

Unitconductance W/m⋅ K4 –

Volume,specific m3/kg –

Coefficientofheattransfer W/m⋅ K –

Heatcapacity J/K kJ/K

Heatcapacity,specific J/kg⋅K kJ/kg⋅K

Thermalconductivity W/m⋅ K –

Sectionmodulus m3 cm3

Tbl.18 Furtherstatutory,derivedunitsofmechanics


Technical Manual

Power of ten Prefix Prefix symbol

Decimal multiples

101 deca da

102 hecto h

103 kilo K

106 mega M

109 giga G

1012 tera T

Decimal fractions

10–1 deci d

10–2 centi c

10–3 milli m

10–6 micro µ

10–9 nano n

10–12 pico p

10–15 femto f

10–18 atto a

Tbl.19 Decimalmultiplesanddecimalfractionsofunits

Therulesallowdecimalmultiplesanddecimalfractionsofunitstobeexpressedbyprefixingsyllables

Conversion tables

Force: Energy, work, amount of heat: Power:

1 Newton (N) = 1 kg m/s2 1 Nm = 1 Joule (J) = 1 Ws Watt (W) = 1 Nm/s = 1 J/s

N kp dyn Nm kWh kpm cal W kW hp

1N 1 0,102 105 1Nm 1 0,278·10–6 0,102 0,238 1W 1 10–3 1,36·10–3

1kp 9,81 1 9,81·105 1kWh 3,6·106 1 0,367·106 0,86·106 1kW 103 1 1,36

1dyn 10–5 1,02·10–6 1 1kpm 9,81 2,72·10–6 1 2,335 1hp 736 0,736 1

– 1cal 4,19 1,17·10–6 0,428 1 –

Tbl.20 Conversionfactorsforforce,energy,work,heatandpowerunits

Pressure, mechanical tension

1 Pascal (Pa) = 1 N/m2 : 1 MPa (106 Pa) = 1 N/mm2= 0,102 kp/mm2

Pa MPa bar kp/cm2 mmHg atm mWs

1Pa = 1N/m2 1 10–6 10–5 1,02⋅ 10–5 7,50⋅ 10–3 9,87⋅ 10–6 1,02⋅ 10–4

1MPa = 1N/mm2 106 1 10 10,2 7,50⋅ 103 9,87 102

1bar 105 0,1 1 1,02 750 0,987 10,2

1kp/cm2(at) 9,81⋅ 104 9,81⋅ 10–2 0,981 1 736 0,968 10

1mmHg(Torr) 133 1,33⋅ 10–4 1,33⋅ 10–3 1,36⋅ 10–3 1 1,32⋅ 10–3 1,36⋅ 10–2

1atm 1,013⋅ 105 0,1013 1,013 1,033 760 1 10,33

1mWs 9,81⋅ 103 9,81⋅ 10–3 9,81⋅ 10–2 0,1 73,6 9,68⋅ 10–2 1

Tbl.21 Conversionfactorsforpressureandmechanicaltensionunits

unitsnolongerpermittedafter31.12.1977


Materials – Basics Concepts

Freudenbergprocesseshighlyelasticmaterials,polyurethane,thermoplasticsandduroplasticstomanufacturesealsandmouldedcomponents.

Generalinformationonthesematerialsisgivenbe-low,particularlyanoverviewofthematerials,theirstructureandpossibleapplicationsaswellastheirlimitationsinuse.

Naturalandsyntheticrubbersarehighpolymers,thatcanbechangedtothehighlyelasticstatebyvulcanisation.

Rubberandvulcanisedrubbersareunspecifiedterms,whichcanbeusedtorefertobasepolymeraswellastovulcanisedrubber.Vulcanisateisthevulcanisedrubber.

Elastomersarecross-linkedpolymersthatarecapableofabsorbinglargereversibledeformations.Theyhavethesamemeaningasvulcanisedrubber.

Thermoplasticsarenotcross-linkedhighpolymersthatcanbepermanentlydeformedbytheactionofpressureandtemperature;theyhavealowdegreeofsoftelasticproperties.

Thermoplasticelastomersarenotcross-linkedhighpolymers.Theareproc-essedlikethermoplasticsandhavehighlyelasticproperties.

Duroplasticsarehighlycross-linkedpolymersthathavehardelasticpropertiesatverylowdeformation.

ThemainstructuralfeaturesofpolymermaterialsareexplainedindetailinDIN7724.


Technical Manual

Codes

Overview of codes for materials

Elastomers

Chemical name for the base polymersCode according to

ASTM D 1418 ISO 1629

Acrylonitrilebutadienerubber NBR NBR

Hydrogenatedacrylonitrile-butadienerubber HNBR HNBR

Chlorinebutadienerubber CR CR

Carboxylatednitrilerubber XNBR XNBR

Acrylaterubber ACM ACM

Ethylene-acrylaterubber AEM AEM

Siliconerubber

Methylpolysiloxane MQ MQ

Vinyl-methylpolysiloxane VMQ VMQ

Phenyl-vinyl-methylpolysiloxane PVMQ PVMQ

Phenyl-methylpolysiloxane PMQ PMQ

Fluorosiliconerubber

Fluoromethylpolysiloxane FVMQ FVMQ

Fluoroelastomer FKM FKM

Perfluoroelastomer FFKM FFKM

Polyurethanerubber

Polyester-urethanerubber AU AU

Polyether-urethanerubber EU EU

Ethyleneoxide-epichlorhydrinrubber ECO ECO

Epichlorhydrinpolymer CO CO

Chlorosulfonatedpolyethylene CSM CSM

Naturalrubber NR NR

Isoprenerubber IR IR

Polybutadienerubber BR BR

Styrene-butadienerubber SBR SBR

Ethylenepropylenedienerubber EPDM EPDM

Ethylenepropylenecopolymer EPM EPM

Butylrubber IIR IIR

Chlorobutylrubber CIIR CIIR

Bromobutylrubber BIIR BIIR

ASTM = AmericanSocietyforTestingandMaterials;ISO = InternationalOrganizationforStandardization;DIN = DeutschesInstitutfürNormunge.V.

Tbl.22 Overviewofcodesformaterials


Thermoplastics

Chemical name of the base materialsCode according to

DIN 7728, Part 1, ISO 1043.1 ASTM D 1600

Polytetrafluoroethylene PTFE PTFE

Ethylenetetrafluoroethylenecopolymer E/TFE E/TFE

Perfluoroalkoxycopolymer PFA PFA

Polyvinylchloride PVC PVC

Acrylonitrile-butadienestyrene ABS ABS

Styreneacrylonitrile SAN SAN

Polypropylene PP PP

Polyamide PA PA

Polyoxymethylene(polyacetal) POM POM

Polyphenyleneoxide PPO PPO

Polysulphone PSU PSU

Polyetherblockamide PEBA PEBA

Polyetherketone PEEK PEEK

Polyetherimide PEI PEI

Tbl.23 Codesforthermoplastics

Thermoplastic rubbers

Chemical name for the base polymersASTM code

D 1418

Blockpolymerofstyreneandbutadiene YSBR

Polyetherester YBPO

Thermoplasticpolyolefin TPO

Tbl.24 Codesforthermoplasticrubbers

Duroplastics

Chemical name for the materialsCode according to

DIN ISO 1043.1 ASTM D 1600

Unsaturatedpolyester UP UP

Phenolformaldehyde PF PF

Ureaformaldehyde UF UF

Glassfibrereinforced,unsaturatedpolyesterresin UP-GF –

Tbl.25 Codesforduroplastics


Technical Manual

Freudenberg material codes MaterialsfromFreudenbergarenamedusingcodesandprefixedorsuffixedcodenumbers,e.g.72NBR902.TheprefixnumberdescribesthehardnessofthematerialinShoreA.

ThegroupoflettersidentifiesthebasepolymerasperDIN/ISO1629.ThenumberafterthegroupoflettersisaninternalFreudenbergcompoundcodenumber.

Summary of some trade names for elastomers and plastics

Elastomers

Chemical name Trade names

Acrylonitrile-butadienerubber(NBR) Perbunan,Hycar,Chemigum,Breon,Butakon,EuropreneN,Butacril,Krynac,Paracril,Nipol,Nitriflex

Chlorinebutadienerubber(CR) Neoprene,Baypren,Butaclor,DenkaChloroprene

Acrylaterubber(ACM) Cyanacryl,EuropreneAR,NoxtitePA,NipolAR

Ethyleneacrylate(AEM) Vamac

Siliconerubber(VMQ,FVMQandPVMQ) Silopren,Silastic,Silicone,Rhodorsil

Fluoroelastomer(FKM) Viton,Fluorel,Tecnoflon,DaiEl,Noxtite

Perfluoroelastomer(FFKM) Kalrez,Simriz,Chemraz

Polyurethane(AUandEU) Vulkollan,Urepan,Desmopan,Adipren,Estane,Elastothane,Pellethane,Simputhan

Ethyleneoxide-epichlorhydrinrubber(ECO) Epichlomer,Hydrin,Gechron

Styrene-butadienerubber(SBR) BunaHüls,BunaSB,Europrene,CariflexS,Solprene,Carom

Ethylenepropylenedienerubber(EPDM) Dutral,Keltan,Vistalon,Nordel,Epsyn,BunaAP,Royalene,PolysarEPDM

Butylrubber(IIR) EnjayButyl,EssoButyl,PolysarButyl

Chlorosulfonatedpolyethylene(CSM) Hypalon

Tbl.26 Elastomers(tradenames)

Plastics for seal applications

Chemical name Trade names

Acrylonitrile-butadienestyrene(ABS) Cycolac,Novodur,Terluran

Acetalresinpolyoxymethylene(POM) Delrin,HostaformC,Ultraform

Polyamide(PA) Durethan,Dymetrol,Nylon,Rilsan,Ultramid,Vestamid

Polybutyleneterephthalate(PBTP) Crastin,Pocan,Ultradur,Vestodur

Polyethylene(PE) Alathon,Baylon,Hostalen,Lupolen

Polycarbonate(PC) Lexan,Makrolon

Polyphenyleneoxide(PPO) Noryl

Polypropylene(PP) HostalenPP,Novolen

Polystyrene(PS) Hostyren,Lustrex,Vestyron

Polytetrafluoroethylene(PTFE) Algoflon,Fluon,Halon,Hostaflon,Teflon

Ethylenetetrafluoroethylenecopolymer(ETFE) Tefzel

Polyvinylchloride(PVC) Breon,Hostalit,Plaskon

Perfluoroalkoxycopolymer(PFA) Teflon-PFA

Phenolicresinhardfabric Ferrozell,Pertinax

Tbl.27 Plasticsforsealapplications(tradenames)


Classification according to ASTM D 2000/SAE J 200

ThisclassificationsystemisintendedtoassisttheuserinselectingtherequiredmaterialsfromFreuden-berg.ItalsoenablesthematerialstobespecifiedbyusingsimplequalitativecharacteristicsforShorehardness,strengthvalues,temperatureandswellingbehaviour,etc.

Thefollowingexampleillustratestheclassificationofthematerial72NBR872usingthisclassifica-tionsystem.FordetailedinformationonthissystemseetheAnnualBookofASTMStandards"Rubber"Volume09.01and09.02.TheASTMclassificationfortheindividualFreudenbergmaterialscanbefoundinthetables.

72 NBR 872 = M2 BG 714 B14 B34 EA14 EF11 EF21 EO14 EO34 F17

Basic requirements

M 2 BG 714M = valuesinSIunits2 = qualityB = type(specifiedbyheatresistance)G = class(specifiedbyresistancetoswelling)7 = hardnessasperShoreA=70±514 = tensilestrength=14MPa

Supplementary requirements

B 14B = compressionset1 = testduration22hours,solidtestspecimens4 = testtemperature100°C

B 34B = compressionset3 = testduration22hours,laminatedtestspecimens4 = testtemperature100°C

EA 14EA1= swellingindistilledwater,testduration70hours4 = testtemperature100°C

EF 11EF1= swellinginreferencefuelA(isooctane),testduration70hours1 = testtemperature23°C

EF 21EF2= swellinginreferencefuelB(isooctane):toluene/70:30),testduration70hours1 = testtemperature23°C

EO 14EO1= swellinginASTMoilno.1,testduration70hours4 = testtemperature100°C

EO 34EO3= swellinginIRM903*,testduration70hours4 = testtemperature100°C

F 17F1 = testoflowtemperatureresistancemethodA,testduration3min.7 = testtemperature–40°C

*replacementproductforASTMoilNo.3

Tbl.28 ClassificationofamaterialfromFreudenbergbyexampleof72NBR872


0

Technical Manual

Highlyelasticmaterialsdifferfromothermaterialnotsimplybythefactthattheyare"elastic".Thepropertiesaredifferentinmanyaspects.Theusualterminologyfrommaterialstestingsuchashardnessortensilestrengthmustbeinterpreteddifferentlybytheengineer.Newtermssuchasageingresistanceordeformationspeedappear.Therearevirtuallynoconstants;mostpropertiesarehighlydependentonthetemperatureandotherexternalfactors,someareevendependentonthesizeandstructureoftherelevanttestspecimensormouldedparts.Thereisalargenumberofsyntheticrubbers.Andthesehaveayetlargernumberofvariationsinthematerialcomposition.However,therearelimitstohowmaterialpropertiescanbecombined.Asanexample,withNBRitisnotpossibletocombinehighoilresistancewithoptimumlowtemperaturebehaviour.Arangeofmaterialpropertiesisinterlinkedduetochemicalandphysicalreasons.Ifonepropertyischanged,thenotherpropertiesinevitablychangeaswell.Thismaybeanadvantageforthespecificap-plication,butitmayalsohavedisadvantages.Takingthisaspectintoconsideration,unnecessaryrequirementsshouldnotbeplacedonthematerialwhendrawingupspecifications.Thisapproachsmoothesthewaytoamaterialtosuittherequestedapplication.

Physical properties

HardnessThemostcommonparameterusedtocharacterisehighlyelasticmaterialsishardness.Testingisper-formedusingtestequipmenttoShoreAorDandIRHD.ThehighlyelasticmaterialsfromFreudenbergaregenerallytestedtoShoreA.Inthetestlaboratorythemeasurementsareperfor-medundertheconditionsspecifiedbyDIN53505.HardnessaccordingtoShorecanalsobemeasuredwithahandhelddevice.However,measurementun-certaintiescanoftennotbeexcludedhere.Inmanycases,however,usablerelativeorcompa-rablevaluescanbeobtainedifthestandardsareobserve,andthefollowingisheededduringmeas-urements:

Highermeasuredvalueswillbeobtainedifthesam-pleisnotthickenough.Thesameappliesifthecontactpressureistoohigh.Conversely,measurementstooclosetotheedge,e.g.onmouldedpartsthataretoosmall,yieldex-cessivelylowvalues.Thetestspecimensshouldbeasflataspossibleandnotliewithacavity.Alwayskeepthesampleandthemeasuringinstrumentparallelandobservethetimefortakingreadingsaccurately.Anothermeasurementmethodinthetestlaboratoryistodeterminetheinternationalrubberhardnessdegrees(IRHD;DINISO48)bymeansofthemeasurementofthepenetrationdepthofadefinedsphereunderadefinedforce.WithhighlyelasticmaterialstheIRHDvalueisapproximatelyequaltotheShoreAhardness.Measuredvaluesdeterminedbythetwomethodsmaybeverydifferentformateri-alsthattendtobesubjecttoplasticdeformation.Avariantofthismethodwithcorrespondinglyre-ducedspherediameter(0,4mm)makesitpossibletomeasuresmallandthinsamples(referredtoasmicro-hardness,DINISO48MethodM).Thismeth-odisfrequentlyusedformeasuringmanufacturedcomponents.Withthismethodthereare,inaddi-tiontotheabovementioneddifferencesduetothevariousmeasurementprocesses,effectsduetoalsoadditionalinfluencesresultingfromthedifferencesofthespecimensurfacecausedthevariousmeas-urementprocesses(unevenness,e.g.bygrinding,curvesbecauseofthegeometryofthecomponent,surfacehardening,coefficientoffriction),whichcanresultinevengreaterdifferencesinvalues.Meas-uredvaluesderivedfromfinishedcomponentsgen-erallydonotconformtothevaluesmeasuredonthestandardtestspecimens.Whenstatingthehardnessthemeasurementmethodmustalwaysbeincluded,e.g.hardness80ShoreAorhardness72IRHD.Whentestingthehardnessoffinishedcomponentsthemethodmustalwaysbepreciselydefinedbythesupplierandthecustomertopreventinaccuracy.Thetoleranceforhardnessmeasurementsandhard-nessfiguresisgenerally±5degreesofhardness.Thisapparentlyrelativelylargerangeisnecessarytotakeintoaccountdifferencesinvariousdevicesandtestersandalsotheunavoidableproductionscatter.

Testing and Interpretation Test Results


1

0 100 200 300 400 500

25

50

75

100

EPDM

NR

Mod

ulus o

f elas

ticity

dN mm

Elongation %

2

high filler content

low filler content

Graph1 Dependencyofthemodulusofelasticityondeformation(tensiletrials)fortwodifferentvulcanisationprocesses

Tensile stress and modulus of elasticityLikethehardness,tensilestressandmodulusofelasticityareparametersforthedeformabilityofelasticmaterials.Thetensilestressmeasuredinten-siletrialsinaccordancewithDIN53504at100or300%elongationisdefinedastheforcerequiredfortherelateddeformationdividedbytheoriginalcross-sectionofthetestspecimen.Thetensilestressisfrequentlyincorrectlydescribedas"modulus".Themodulusofelasticityorelongationmodulusisthetensilestressdividedbytherelativechangeinlength(elongation).Itisnotaconstantforhighlyelasticmaterials.Hooke'slawσ=E⋅ε,accordingtowhichthetensionσisproportionaltotheelonga-tionε,wherethemodulusofelasticityErepresentstheproportionalityconstant,isapplicabletorubberonlyinaverylimiteddeformationrange,whichcanbedifferentfrommaterialtomaterial.Themodulusofelasticitycanincreaseanddecreasewiththeelongation→ Graph1.

Themodulusofelasticitydependsonthesocalledformfactor,theratioofloadedtounloadedsurfaceonthecomponentortestspecimen.Inthisregardtheloadedsurfaceisconsideredtobeanareaun-dertensionorcompression(withoutthematingsur-face)andtheunloadedareaisthetotalofallareaswherethespecimencanfreelystretchorcompress.

Bothareasaremeasuredinunloadedstatus.ThustheformfactorFforanaxiallyloadedcylinderis

F = d/4h(d = diameter,h = height).

Additional modulesOthermodulesarealsosignificantforthedeforma-tionproperties.Shearmodulusormodulusofelastic-ityinshearanddynamicmoduliareimportantforvibrationprocesses.Theywillnotbedescribedinmoredetailhere.TestproceduresaredefinedinpublicationssuchasDIN53513,DINENISO6721andASTMD945(YERZLEYtesting).

Relationships between deformation properties and their parametersBasedonthepriorstatements,onlyanapproximaterelationshipcanbeexpectedbetweentheindividualmeasurementparameters.Thefollowingapproxima-tionisapplicableforshearmodulusGandmodulusofelasticityE,forhighlyelasticmaterials

G = 1/3E.

TheapproximaterelationshipappliesbetweenthehardnessinShoreAorIRHDandthemodulusofelasticityat5–10%compression,whichisshowngraphicallyin→Graph4.


2

Technical Manual

Stres

s

Elongation

SteelThermoplastic

Elastomer Stres

s

Elongation

HeightDeformation rate

LowDeformation rate

Pseudo staticBehaviour

Graph2 Tension-elongationgraph. Left:comparisonofsteel,thermoplastic,elastomer Right:behaviourofelastomersatdifferentdeformationspeeds.

However,thehardnessisnotgenerallyrelatedwiththemoduliforlargerdeformations,evenifingeneralamaterialwithgreaterhardnesshashighermoduliatthesametime.Thecommonfactorinalldeformationpropertiesisthattheyarehighlydependentontemperatureandtime.Time-dependencymeansthatthespeedofde-formation(e.g.withdrawlvelocityintensiletrialsorthefrequencyforthedynamicmodulus)orthetimeatwhichthemeasuredvalueisread(e.g.measure-mentofhardness)affectthemeasuredvalues.

0 0,5 1,0 1,5

100

200

300

400

45

60

70

80Shore A

Form factor

Mod

ulus o

f elas

ticity

dN mm

2

Graph3 Dependencyofthemodulusofelasticityontheformfactor(20%compression)atvarioushardness

Thereisnosuchthingas"the"modulusofelasticityofahighlyelasticmaterial,whichisoccasionallyrequested!

Tensile strength and elongation at breakThesevaluesareonlylimitedqualitativecharacter-isticsforassessingpossibleapplicationoptionsandservicelifeofelastomercomponents,becauseonlyinexceptionalcasesaretheysubjecttotensionsorelongationsthatcomeclosetothefracturevaluesofthematerial.Forexample,indiaphragmstheelongationneartheclampingflangecanreachveryhighvalues,whichcanleadtoprematurefailure.Insuchcasesthesolutionoftheproblemisnotonlytobefoundinthematerialbutalsointhedesign,asshownatthebeginningofthischapter.ThevaluesfortensilestrengthandelongationatbreakdeterminedinaccordancewithDIN53504areusedtocomparethecharacteristicsofmaterials,foridentificationandoperationinspectionaswellasfordeterminingtheresistanceagainstdestructiveinfluences(aggressivemedia,ageing).

Resistance to tear propagationAdditionalinformationisobtainedbytestingtheresistancetotearpropagationinaccordancewithDINISO34-1astheforcethatisappliedtoade-finedspecimenfortearpropagationbasedonthe


thicknessofthesample.Thevaluesfoundherearetobeusedasascaleforthesensitivityofelastomerstotearpropagationofcutsorcracksandarenotrequiredalongwiththetensilestrength.Becausetheresultsofthetearpropagationtestde-pendstronglyonthespecifictestconditionsandpar-ticularlyontheshapeofthespecimen,thesequenceusedinthelaboratoryonthelaboratoryspecimensforthevarioustestmethodsdoesnotneedtomatchthesequenceinpractice.Thetestproceduresandspecimenshapemustbegivenwiththederivedmeasuredvalues.

Elasticity and dampingTheelasticityis,likethedeformability,dependentonthetemperatureandparticularlyonthetimesequenceofthedeformationprocess.Thetestingofimpactelasticityforsealingcomponentsinac-cordancewithDIN53512doesnottelltheusermuchabouttheelasticbehaviourunderoperatingconditions.Itisfrequentlymoreusefultomeasurethespringbackorthelastingdeformationundertestconditions,whichcanbeselectedinaccordancewiththeoperatingconditions.Themechanicaldampingisthereciprocalpropertytotheelasticity.Itcanbedeterminedusingthe

methodgivenforthemeasurementofthedynamicmodulus.Abodyiselasticifitresumesitsoriginalshapeim-mediatelyafteraforceddeformation(e.g.steelspring).Abodythatretainsitsdeformationisplasticorviscous(e.g.plasticine).Aviscous-elasticcom-ponentiscomparabletoboth,wheretheelasticpredominatesinthecaseofhighlyelasticmaterials.Akeyfeatureofviscous-elasticbehaviouristhatthespringbacktotheoriginalstatusdoesnotoccurimmediatelyonrelease,butitisonlyattainedgradu-allydependingontheconditions.Thisisalsosignifi-cantforsealingcomponentsandcanbespecifiedbyappropriatelaboratorytests.Theviscoelasticityistheactualcauseforthespecificphysicalbehaviourofthehighlyelasticmaterials.Typicalviscous-elasticcharacteristicsarecompressionset,tensilerelaxa-tionandcreep(→Graph7and→Graph9).

Other physical propertiesPhysicalpropertiessuchasthermalexpansion,fric-tionbehaviour,electriccharacteristics,permeabilitytogasesorfluidsetc.maybeimportantforspecialapplications.Theseissueswillnotbecoveredinfur-therdetailhere.

2000

1000

500

200

100

10

20

50

20 30 40 50 60 70 80 90 100

Hardness in Shore A

Mod

ulus o

f elas

ticity

dN mm

2

Graph4 RelationshipbetweenhardnessinShoreAandmodulusofelasticityatapproximately10%compressionset (formfactor0,2)


Technical Manual

Temperature behaviourAspreviouslymentioned,thetemperaturehasasignificantinfluenceonthephysicalpropertiesofthehighlyelasticmaterials.→Graph5showsthedependenceofthedynamicshearmodulusGonthetemperature(shearmodulusmeasuredinthetorsionvibrationtestinaccordancewithDINENISO6721).Thehighlyelasticregioncanbeseenfromrighttoleftwithanalmostconstantmodulus,thenwithasteeprisethetransitionrangeandfinallythereistheglassstateregion,inwhichtherubberishardandbrittle,againwithanalmostconstantmodulus.Whenthetemperaturerisesthecoldbrit-tlenessdisappears.Thefreezingprocessisthereforereversible.Thetransitionfromhighlyelastictotheglassstateisparticularlyimportant,becauseinmanycasesitshowsthelowtemperaturelimit.Thistransition,asshownin→Graph4,isnotsharpbutextendsoveraspecificrange.

TherangeofthetransitionfromthehighlyelasticrangetotheglassstateischaracterisedbytheglasstransitiontemperatureTg(temperatureofmaximumoflog.dampingdecrementΛ).However,thisvaluecanonlybeageneralreferenceforthelowtemper-aturelimitofthematerial,becauseinthepracticalapplicationofanelastomercomponentitdependscompletelyonthetypeofloadinvolved.Thesamematerialwillreachitsloadlimitatahighertempera-turewhensubjectedtoasuddenloadatveryhigh

deformationspeedthan,forexample,duringaslowdeformation.Thetorsionvibrationtestcanbeusedtodifferentiatebetweendifferentmaterials,butthetemperaturelimitinpracticemustbetestedwhenus-ingthecorrespondingcomponents.

Example:Withstaticcontactsealsheatisproducedbythefrictionthatoccursduringmotion.Attemperatureswheretheriskofhardeningduetofreezingalreadyexists,thefrictionalheatcansufficetokeepthesealelastic,orquicklyplacethesealinafunctionaloper-atingstateafterstartofthemotion.Thetestingofthelowtemperaturebehaviourisonlyworthwhileintheformofamaterialcomparisoninconjunctionwithexperienceontheengineeringapplication.Thedifferencesbetweenvariousmaterialsforlowtemperatureuselimitsderivedfromthetorsionvibra-tiontestandfromuseinpracticeareverycloseinmanycases.Ifthecoldlimitforamaterialhasbeendeterminedinpracticaltrial(frequentlyverydifficulttodetermine),theTgvaluesfortheothermaterialscanbeusedtomakerelativelyreliableforecastsoftheirlowtemperaturebehaviourunderpracticaluse.


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Graph5 TorsionvibrationtestinaccordancewithDIN53445. DynamicshearmodulusGandlogarithmicdecrementΛofamaterialfromFreudenbergbasedonCR

Thesituationissimilarforthecomparisonofstand-ardcoldvaluesthatweremeasuredunderdifferentlaboratorytestmethodsasforthecomparisonbe-tweenthelow-temperaturelimitsdeterminedinprac-ticaluseandtheglasstransitionstatetemperaturemeasuredinthetorsionvibrationtest.Deviationsofonlyafewdegreesbutalsoof30to40degreescanbefoundbetweendifferenttestmethods.

Thestandardcoldvaluemustalwaysincludethemeasurementmethodusedtodetermineit.Thesamemethodsasdescribedaboveareapplicablefortransfertothecomponentbehaviourinpracti-caluse.Variousstandardlaboratorymethodsforcharacterisingthelow-temperaturebehaviouraredescribedbrieflybelow:


Technical Manual

Differential Thermo-Analysis (DTA), Differential Scanning Calorimetry (DSC)Inthismethod(DIN3761Part15)asmallrub-berspecimenandaninertreferencespecimenareheatedataconstantheatingrate.Thetemperaturedifferencebetweenthesampleandthereferencesampleisappliedtothetemperature.Aconstantofnegativetemperaturedifferenceisspecifiedbychangeofthespecificheatoftherubbermaterialwhentheglasstransitionrangeisreached.Theturn-ingpointoftheglassstageoftheDTAcurvedefinesthestandardcoldvalueTR.

Temperature retraction testInthistest(ASTMD1329-79)arod-shapedrubberspecimeninelongatedstateisfrozeninatempe-raturecontrolledbathandtemperaturesTR10,TR30,...aremeasuredatwhichtheelongationofthesamplehasbeenreducedby10,30,...percent.

Cold brittleness temperature with impact loadThecoldbrittlenesstemperatureTs(DIN53546)isthetemperatureatwhich(afteranincreaseinthetemperatureofsurroundingcoolant)alltestspecimensjustdonotbreakunderadefinedimpactloading.Inadditioninformationonthelow-temperaturebe-haviourcanbederivedfromrelativelysimpletests.ExamplesarethecoldbendingtestoveramandrelatadefinedbendingspeedortheShorehardnessmeasurementatvarioustemperatures.

Forexample,thetemperatureatwhichtheShoreAhardnessis90pointscanbedefinedasthestand-ardcoldtemperature.Thesequenceofthecompres-sionsetatlowtemperaturesalsoprovidesinforma-tiononthetemperatureflexibilityofthematerial.Forexample,thetemperatureatwhichthecompressionsetisat50%canbedefinedasthestandardcoldtemperature.

Media resistanceThechangestothehighlyelasticmaterialscausedbyenvironmentaland/oroperatingconditionsareoftenmuchmoresignificantthantheinitialvaluesofthetechnologicalproperties.Thebehaviourofthematerialsmustbetestedunderpracticalconditions.

Swelling and chemical corrosionThecorrectchoiceofasuitablematerialforsealsfrequentlydependsonthechemicalresistanceandtheswellingbehaviourofthematerial.Theusershouldalwaysbeawareofwhichfluidsorgaseousmediacomeintocontactwiththematerial.Thetem-peraturesofthemediaalsoplayanimportantrole.Theconsequencesofachemicaleffectaresimilartothoseofageinginhotair,i.e.softeningorharden-ing,reductionofstrength,elongationatbreakandelasticity,lossoftensionandcreep.Anotherresultisvolumetricchangebyswellingorshrinkagedepend-ingonwhetheradditionalmaterialsareabsorbedorextractablesubstancesaredissolvedout.Aminorincreaseinvolumebyswellingisnotadangertothefunctionoftheelastomersealwithsuitablede-sign.Incontrast,volumeshrinkagewilladverselyaffectthesealingfunctionintheformofleakage.Therearenoelastomersthatmeetallrequirementsforoilresistance,heatandcoldresistanceequally.Therefore,theambientmediumandthetemperatureconditionsoftheapplicationmustbeconsideredwhenselectingasuitablesealingmaterial.Thebasicchemicalprincipleapplies:"thesamesubstancedis-solvesthesamesubstance".Thismeansthatpolarelastomers(e.g.NBR)inpolarmedia(e.g.glycol)swellgreatlywhilenon-polarelastomerssuchasEPDMinnon-polarmedia(e.g.mineraloil)arenotresistant.Formoreinformationonthesuitabilityofelastomermaterialsinselectedsealingmediaseetheappendixtothischapter.


IIR

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Graph6 Heatandoilresistance(inASTMOilNo.3)ofelastomers(inaccordancewithASTMD2000)

Thetestingbehaviouragainstfluids,steamsandgasesisperformedinaccordancewithDINISO1817inthemediumusedintheapplication,orinstandardisedtestingfluids(e.g.ASTMOilNo.1,IRM902*andIRM903**,ASTMReferenceFuelA,BandC,FAMtestfuels).* ReplacementproductforASTMOilNo.2**ReplacementproductforASTMOilNo.3

Volumetric change indexTheregularityoftheswellingeffectofmineraloilsincontactwithhighlyelasticmaterialscanbetestedonstandardreferenceelastomers.SuchaNBRstand-ardreferenceelastomer(SRE)hasalreadybeenproposedastestmaterialNBR1andisalsostand-ardisedunderDIN53538.ThevolumetricchangedeterminatedonthisSREunderstandardisedcondi-tionsinamineraloilisreferredtoasthevolumetricchangeindex(VA)ofthetestedoilinaccordancewithaVDMAproposal.

Ifanelastomermaterialislefttoswelltoitssatura-tionstateinanyoils,thereisalinearrelationshipbetweentheobservedvolumetricchangeoftheelastomerintheoilsandthevolumetricchangede-terminedonthestandardreferenceelastomer(SRE)inthesameoils,i.e.theVAIoftheoils,observedundersimilarconditions.IfthemaximumvolumetricchangeofanelastomerinvariousoilsisplottedonacoordinatesystemovertheVAIvaluesofthesameoils,astraightlineisderivedthatcharacterisestheswellingbehaviour(QVH)oftheelastomer.AstraightQVHlinecanbeplottedforeveryelasto-mericmaterial.ThemaximumvolumetricchangesoftheassociatedelastomerscanbeforecastforalloilswithknownVAI.TheseQVHstraightlinesareavail-ableforallmaterialsfromFreudenberg.Usingthisdiagram,materialsbeingconsideredfortherespec-tiveapplicationscanbecombinedwiththesuitableoils.Thevolumetricchangeindex(VAI)isnotspeci-fiedbytheoilmanufacturers.


Technical Manual

VAI2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

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Graph7 SwellingbehaviourofmaterialsfromFreudenberg

Example:thefollowingvolumetricchangevaluesoccurinamineraloilwithVAI15:

MaterialsfromFreudenberg Volumetricchange83FKM575 1%94AU925 6%88NBR101 10%72NBR872 15%

Heat resistance, ageing behaviourLikeallorganicchemicalproducts,thepolymersonwhichhighlyelasticmaterialsarebasedcanbealteredbytheactionofoxygen,wearand/orothermedia.Asaresultoftheseprocesses,referredtoasageing,importantpropertiessuchashardness,flexibility,elasticitycanbeadverselychanged.Thematerialcanbecomesusceptibletocrackingandmaybreak.Heatacceleratestheageingprocesses.Exposuretolightandradiationmayalsohavedestructiveeffects.Thehigherthetemperaturetowhichthematerialissubjectedthelowertheservicelifeofacomponent.Thismeansthattherearedifferentpermissiblemaximumoperatingtemperaturesforshort-termandcontinuousloadingfortheindividualmaterials.

Therespectivelimitsdependprimarilyonthebasepolymer.Ageingcanbetestedoverareducedpe-riodbystorageinaheatingcabinet(DIN53508).However,thetesttemperatureandtheactualoper-atingtemperatureshouldbetoodifferent.Thechangesinhardness,tensilestrengthandelon-gationatbreakaswellasthecompressionsetorthetensilerelaxationareincludedintheassessmentoftheageingbehaviour.

Chemical tensile relaxationAnexactassessmentoftheageingbehaviourandanin-depthexaminationoftheageingmechanismenablesmeasurementofthechemicaltensilerelaxa-tionatvarioustemperatures.Comparativemeas-urementsarealsoconductedinnitrogenorinfluidmediatoallowabetterassessmentofthevariouschemicalageinginfluences.AnArrheniusplotoftheresultsenablesextrapolationtolongexposureperi-odsatlowertemperatures.


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Graph8 Predictedservicelifebasedonextrapolationofmeasuredvaluesofthetensilestressrelation (material:NBRwettedwithperoxide)measuredinairandnitrogenatvarioustemperatures. E=elongation,EA=activationenergyoftheageingprocess.

Inthicktestspecimensthediffusionoftheoxygenorozoneintotheelastomeristhelimitingfactorfordestructionoftheelastomermatrixandtheassoci-atedageingprocesses.Therefore,thickelastomercomponentsagemoreslowlythanthincomponentsinpractice.Theknowncrackformationonstretchedrubberpartsexposedtoweatherisprimarilycausedbytheozoneintheair.Proceduresfortestingozoneresist-ancearedescribedinDIN53509.

Elastomer,not aged

withoutozone protectant

withozone protectant

Fig.61 Damagetoelastomerbytheeffectofozone

Service life

Static continuous load and continuous deformationIfanelastomercomponentisconstantlydeformedforaperiod,acertaindegreeofdeformationre-mainsafterrelaxation.Theresidualdeformation,whichismeasuredinacompressiontestinaccord-ancewithDINISO815andisgivenasapercent-ageoftheoriginaldeformation,isreferredtoascompressionset.

Thecompressionsetdependslargelyonthetem-peratureandthedurationofdeformation.Atlowertemperaturestheinfluenceoftheviscoelasticityisstrongerandathighertemperaturestheinfluenceofageing(formoreinformationsee→ ExplanationofDINISO815).


0

Technical Manual

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Graph9 Compressivestressrelaxationofanelastomericmaterialatvarioustemperatures

Thecompressionsetcanbeconnectedwiththefunc-tionofsealingcomponentsinsamecases,e.g.forO-rings.Theflowbehaviour,thevulcanisationstatusandtheheatresistanceinfluencethetestvalue.Thismeansthatthemeasurementofthecompressivestressre-laxationismoresuitable(DIN53537),becauseitgivesadirectscaleforthereductionofthecontactpressureovertimeofaconstantlydeformedseal.Ifhighlyelasticcomponentsareunderconstantloadinsteadofconstantdeformation,thedeformationincreasesovertime.Thisisreferredtoascreep.Compressionset,tensilerelaxationandcreeparerelatedphenomenawiththesamecauses.Ifthetesttemperaturesforthebasepolymerarebelowthemaximumpermissiblecontinuousoperationtem-perature,compressivestressrelaxationandcreepfollowanapproximatelogarithmictimelaw,i.einpracticaltermstheycometoastopaftersometime.

Dynamic loading, fatigue and service lifeDestructionofrubberpartsistheresultofdynamicloadingfarmoreoftenthanexceedingthestrengthorelongationlimitsonce.Undercontinuouslyre-peateddeformation,thematerialisdamagedasaresultofinternalfriction,whereinitiallysmallcrackscanoccur,whichgrowandultimatelyleadtofrac-ture.StandardisedmethodsfortestconditionsarespecifiedinpublicationssuchasDIN53522and53533.

Resistance to wearThisimportantpropertyforfrictionloadingisalsostronglydependentontheoperatingconditions,suchasthetypeoflubrication,materialandrough-nessofthematingsurface,slidingspeed,slip,con-tactpressure,temperature.Weartestsshouldthereforeonlybeconductedwiththefinishedproductandunderconditionsascloseaspossibletotheoperatingconditions.


1

Material modelsThemeasuredmechanical,thermalanddynamicvaluesarethebasisforthedevelopmentofmaterialmodels.Otherthan,forexample,metalandceramicmaterials,thereisnolinearconnectionbetweentensionandelongationforelastomers.Asaresultitisnotsufficienttouselinear-elasticmaterialmodelsforsimulations.Specialmodels,referredtoashy-perelasticmaterialmodels,areused.Theycanbeusedtodescribethebehaviourofevenverylargeelongations.

Inadditiontothestaticnon-linearbehaviourofelas-tomersthestiffnessofthematerialdependingonthespeedofloadingmustbeconsidered.Freudenberghasdevelopedoptimisedmaterialmodelsforthispurpose,whicharestillapplicableforlargermate-rialdeformations(>150%).

Additionalinformationfromcomponentanalysesandageingtestsleadtonumericalanalysesthatgiveacomprehensiveviewoftheservicelifeofelastomerseals.SimulationswithappropriateFEMmodelsareusedforoptimisingthetopologyandshapesofmechanicallyloadedcomponentswithconsiderationofmoderatenon-linearitiesandassur-anceofcomponentfunction.FormoreinformationpleasecontactyourFreudenbergrepresentative.

Properties of seal materials

ThepropertiesofaFreudenbergmaterialarepri-marilydeterminedbythebasepolymer.However,theycanbevariedinmanywaysdependinginthemixingrationandcanbeadaptedtotherequiredapplication.

Cross-linking densityThecross-linkingsystemdeterminestheprocessingproperties,thechemicalstructureofthepolymernetworkandthephysicalpropertiesoftheelastom-ers.Thetwomostcommoncross-linkingtypesaresulphurcross-linkingandperoxidecross-linking.Sulphurcross-linkingisusedprimarilyincross-link-ingdienerubberssuchasNR,SBR,BR,NBRorCR.Peroxidecross-linkingcanbeusedtocross-linkrub-berswithoutdoublelinksinthemainchain.Italsooffersimprovedheatresistance,particularlywithNBR.Inadditiontotherubbertype,thedegreeoflinkedchemicalinksbetweenthepolymerchainsduringvulcanisationdependsprimarilyonthetypeandamountoftheselectedcross-linkingsystemandisreferredtoascross-linkingdegreeorcross-linkingdensity.Thecross-linkingdensityisveryimportantformaterialpropertiessuchashardness,tensilestrength,elongationatbreak,friction,shrinkagebehaviourandfatigue.Withincreasingcross-linkingdensitymodulusofelasticity,hardnessandelastic-ityincrease,whileelongationatbreak,damping,lastingdeformationdecrease,andresistancetotearpropagationandtensilestrengthreachandpassthroughamaximum.


2

Technical Manual

Tear strengthFatigue

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HysteresisSettlingCoefficient of frictionElongation at break

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nisati

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Graph10 Influenceofcross-linkingdensityontheelastomerproperties

Thismeansthatataspecificcross-linkingdensityanoptimumforallmaterialpropertiescannotbeachieved.Ingeneralthecross-linkingdensityisselectedtoachievetheappropriatephysicalproper-tiesfortheapplication.Thecross-linkingreactioncanbemeasuredovertimeandusedforassessmentofthecross-linkingdegreebymeasurementofthetorque,whichisapproximatelyproportionaltothecross-linkingdegree.Thevulcametercurveshowsinformationonthemixtureviscosityatthevulcanisa-tiontemperature.Threecharacteristicsectionsaredistinguished:→Graph10.1)Theflowperiodcoversthetimeintervalfromthestartofmeasurementtothestartofcross-linking,i.e.

totheincreaseoftorque.Itidentifiestherangeofviscousflow,whichisusedtofillthemould.Duringthisperiodthetorqueinitiallydecreases.2)Thecross-linkingperiodshowsinformationontherequiredtimesforthematerialtotransitiontothestableshapestatus.3)Completecross-linkingisachievedwhenallpos-siblecross-linkingpointshaveformed.ThecharacteristicpropertiesandtheresultingmainareasofapplicationofmaterialsfromFreudenbergaredescribedingeneraltermsbelow.Refertothematerialtablesformoredetaileddifferencesbe-tweenindividualmaterials.

0 1 2 3 4 5 60

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Graph11 Cross-linkingcharacteristicsofelastomersbymeasurementofthetorque


Elastomeric materials

ACM (Acrylate rubber)Itisapolymermadeofethylacrylateorbutylacrylatewithaminoradditionofthemonomersre-quiredforcross-linking.ElastomersbasedonACMaremoreheatresistantthanthosebasedonNBRorCR.Simmerrings,O-RingsandmouldedcomponentsmadeofmaterialbasedonACMareprimarilyusedathighertemperaturerangesandinoilswithaddi-tivesforwhichmaterialsfromFreudenbergofNBRarenolongersufficient,howevermaterialsbasedonfluorineelastomerandsiliconerubberarenotyetnecessary.Resistancetoageingandtoozoneareverygood.

Goodswellingresistancein:mineraloils(engine,gearbox,ATFoils),alsowithadditives.Heavyswellingin:aromaticandchlorinatedhy-dro-carbons,alcohols,brakefluidswithaglycoletherbase,flameretardanthydraulicfluids.Hotwater,steam,acids,alkalis,andamineshaveadestructiveeffectonthematerialThermalapplicationrange:approx.–25°Cto+150°C.

AEM (Ethylene-acrylate rubber)Isapolymermadeofethylenemethylacrylatewithcarboxylgroups.Ethylene-acrylaterubberismoreheatresistantthanACMandhaspropertiesbe-tweenthoseofACMandFKM.

Goodswellingresistancein:mineraloilswithadditivesandbasedonparaffin,waterandcool-ants.GoodresistancetoweatherandozoneHeavyswellingin:ATFandtransmissionoils,min-eraloilsrichinaromatics,brakefluidonaglycoletherbase,concentratedacidsandphallicacidestersThermalapplicationrange:approx.–40°Cto+150°C.

AU (Polyurethane)Polyurethaneisahighlymolecularorganicmaterial,inwhichthechemicalstructureischaracterisedbyalargenumberofurethanegroups.withinspecifictemperaturelimitspolyurethanehasthecharacter-isticelasticpropertiesofrubber.Threecomponentscharacterisethestructureofthematerial:

polyoldiisocyanatechainextender.

Dependingonthetype,amountandreactioncondi-tiontheyarethedeterminingfactorsfortheproper-tiesoftheresultingpolyurethanematerial.Polyurethaneshavethefollowingproperties:

highmechanicalstrengthgoodwearresistancemodulusofelasticityvariableoverawiderangegoodflexibilitywidehardnessrangewithgoodelasticity,(poly-urethaneclosesthegapbetweenstretchablesoft-rubbertypesandbrittleplastics)verygoodozoneandoxidationresistancegoodswellingresistanceinmineraloilsandgreases,water,water-oilmixtures,aliphatichydro-carbonsapplicationtemperaturerange–30°Cto+80°C,high-loadresistanttypesuptoabove+100°Cinmineraloils.

Notresistanttopolarsolvents,chlorinatedhydro-carbons,aromatics,brakefluidswithglycoletherbase,acidsandalkalis.

General Material Descriptions


Technical Manual

BR (Polybutadiene rubber)Itisapolymermadeofbutadiene.Itischaracter-isedbyhighelasticity,abrasionresistance,verygoodheatandcoldresistancepropertiesandlightelongationatbreak.ItisusedasblendingagentwithNRandSBRfortyres,drivebelts,conveyorbeltsetc.

Goodswellingresistancein:diluteacidsandbases,inalcoholsandwater.Heavyswellingin:hydro-carbonsThermalapplicationrange:approx.–60°Cto+100°C.

CSM (Chlorosulfonated polyethylene)Goodswellingresistancein:hotwater,steam,waterlye,oxidisingmedia,acids,bases,polarorganicmedia,ketones,flameretardanthydraulicfluidsoftheGroupHFCandsometypesoftheGroupHFD,brakefluidsonaglycoletherbaseAverageswellingresistancein:aliphatichydro-carbonsandgreases.Resistantinoxidisingme-dia,inorganicandorganicacidsandbasesHeavyswellingin:aromaticandchlorinatedhydro-carbonsandestersThermalapplicationrange:approx.–20°Cto+120°C.

CR (Chlorine butadiene rubber)Itisapolymerbasedonchlorinebutadiene.ElastomerswithcorrespondingcompositionofCompoundarecharacterisedbychemicalresist-ance,goodresistancetoageing,weathering,ozoneandflameresistance.

Goodswellingresistancein:mineraloilswithhighanilinepoint,greases,manyrefrigerantsandwa-ter(withspecialcompositionofCompound)Averageswellingresistancein:mineraloils,lowmolecularaliphatichydro-carbons(petrol,isooctane)Heavyswellingin:aromatics,e.g.benzene,toluene,chlorinatedhydro-carbons,esters,ethers,ketonesThermalapplicationrange:approx.–45°Cto+100°Cdependingoncomposition(transientupto130°C).

ECO (Ethyleneoxide-epichlorhydrin rubber) CO (Polyepichlorhydrine)Itisapolymermadeofepichlorhydrineandethyl-eneoxide.Materialsbasedonthisrubberarechar-acterisedbylowgaspermeability,goodresistancetoozoneandweathering.

Goodswellingresistancein:mineraloilsandgreases,plantandanimal-basedoilsandgreasesaswellasaliphatichydro-carbons,suchaspro-pane,butaneetc.andpetrolaswellaswaterHeavyswellingin:aromaticandchlorinatedhy-dro-carbons,flameretardanthydraulicfluidsoftheGroupHFDThermalapplicationrange:approx.–40°Cto+140°C.

EPDM (Ethylene propylene diene rubber)Itisapolymermadeofethylene,propyleneandasmallproportionofadiene.Ethylenepropylenerubber(EPM)isapolymermadeofethyleneandpropylene.MouldedpartsandsealingcomponentsmadeofEPDMarepreferredinwashingmachines,dishwashingmachinesandplumbingfittings.SealsmadeofthismaterialarealsousedinhydraulicsystemwithflameretardanthydraulicfluidsoftheGroupHFCandGroupHFDandinhydraulicbrakesystems.ElastomersmadeofEPDMhavegoodre-sistancetoozone,ageingandweatheringandarethereforeidealformanufactureofprofilestripsandsealingstripsthatareexposedtoweathering.

Goodswellingresistancein:hotwater,steam,waterlye,oxidisingmedia,acids,bases,polarorganicmedia,ketones,flameretardanthydraulicfluidsoftheGroupHFCandsometypesoftheGroupHFD,brakefluidsonaglycoletherbaseHeavyswellingin:mineraloilsandgreases,petrolandaliphaticaswellasaromaticandchlorinatedhydro-carbons.SpeciallubricantsarerequiredforextralubricationofthesealsThermalapplicationrange:approx.–50°Cto+150°C.


FFKM (Perfluoro elastomer Simriz)Specialperfluorinated(i.e.completelyfreeofhydro-gen)monomersandcorrespondingcompoundingandprocesstechnologiescanbeusedtomanufac-turematerialswithhighlyelasticpropertiesthatareveryclosetoPTFEinmediaresistanceandthermalresistance.Sealsmadeofperfluororubberareusedeverywhereextremesafetystandardsareap-plicableandhighermaintenanceandrepaircostsexceedthepriceoftheseals.Preferredareasarethechemicalindustry,oil-producingandprocessingindustry,instrumentationandpowerstationconstruc-tionandaerospaceindustry.

Thermalapplicationrange:–15°Cto+230°C.

FKM (Fluoro elastomer)Polymerisationofvinylidenefluoride(VF)andselectiveapplicationofvariableproportionsofhexafluoropropylene(HFP),tetrafluoroethylene(TFE),1-hydropentafluoropropylene(HFPE)andperfluor(methylvinylether)(FMVE)canbeusedtomanufactureco,terortetrapolymerswithvari-ousstructuresandfluorocontentof65–71%andasaresultwithdifferentmediaresistanceandcoldflexibility.Theyarecross-linkedbydiamines,bisphenolsororganicperoxides.ThespecialsignificanceofthematerialsbasedonFKMistheirhightemperatureresistanceandchemi-calstability.Thegaspermeabilityislow.InvacuumconditionselastomersmadeofFKMshowminimumweightloss.Theresistancetoozone,weatheringandlighttear-ingisverygood,asistheflameresistance.Aminesmayhaveadestructiveeffectonthemate-rialandrequireaselectionofsuitabletypesaswellasspecialcompositionofcompound.AspecialelastomergroupiscopolymersmadeofTFEandpropenewitharelativelylowfluorocontent(57%).Materialsusingtheseelastomershaveoutstandingresistancetohotwater,steamaswellasaminesormediacontainingamineswithlowswellingresist-ancetomineraloils.

Goodswellingresistancein:mineraloilsandgreases(includingwithmostadditives),fuelsaswellasaliphaticandaromatichydro-carbons,someflameretardanthydraulicfluidsandsyn-theticaeroplaneengineoils.Newlydevelopedperoxidecross-linkedmaterialsalsohavegoodresistancetomediathathavelittleornocompat-ibilitytoconventionalFKM.Forexample,theyare:alcohols,hotwater,steamandfuelscontain-ingalcohol.Heavyswellingin:polarsolventsandketones,flameretardanthydraulicfluids,type:Skydrol,brakefluidonaglycoletherbaseThermalapplicationrange:approx.–20°Cto+200°C(transientupto+230°C).Specialtypes:–35°Cto+200°C.

Withsuitableshapingandmaterialcompositionsspeciallydevelopedforsuchapplicationssealsandmouldedcomponentscanalsobeusedatlowertemperatures.

FVMQ (fluorosilicone rubber fluoromethyl polysiloxane)Itisamethylvinylsiliconerubberwithfluorine-con-taininggroups.Elastomersmadeofthissyntheticrubberaresignificantlymoreresistanttoswellinginfuels,mineralandsyntheticoilsthanthosemadeofsiliconerubber.

Thermalapplicationrange:approx.–80°Cto+175°C(transientupto+200°C).

HNBR (Hydrogenated acrylonitrile-butadiene rubber)MadeofnormalNBRpolymerbyfullorpartialhydrogenationofbutadienecomponentscontain-ingdoublebonds.Withperoxidecross-linkingthisincreasestheheatandoxidationstability.Highme-chanicalstrengthandimprovedabrasionresistancecharacterisethematerialsmanufacturedofit.MediaresistancesimilartoNBR.

Thermalapplicationrange:approx.–30°Cto+150°C.


Technical Manual

NBR (Acrylonitrile-butadiene rubber)Itisapolymermadeofbutadieneandacrylonitrile.Theacrylonitrilecontentcanbebetween18and50%anditinfluencesthefollowingpropertiesoftheNBRsealingmaterialsmanufacturedofit:

swellingresistanceinmineraloils,greasesandfuelselasticitycoldflexibilitygaspermeabilitycompressionset.

Forexample,anNBRmaterialwith18%ACNcontenthasaverygoodlow-temperatureflexibil-ityuptoapprox.–38°Cwithmoderateoilandfuelresistance,whileonewith50%ACNcontentandoptimumoilandfuelresistanceonlyhaslow-temperatureflexibilityuptoonlyapprox.–3°C.WithincreasingACNcontenttheelasticityandgaspermeabilityisreducedwhilethecompressionsetisworse.MaterialsfromFreudenbergbasedonthissyntheticrubberaresuitableforaverylargenumberofap-plicationswiththeirgoodtechnologicalproperties.Inparticular,theprovenSimmerrings,sealingcomponentsforhydraulicsandpneumaticsaswellasO-RingsaremanufacturedinlargenumbersofmaterialsbasedonNBR.Freudenberghasmoreex-periencethanallothersealmanufacturerswiththisbaseelastomer.

Goodswellingresistancein:aliphatichydro-car-bons,e.g.propane,butane,petrol,mineraloils(lubricatingoils,hydraulicoilsofgroupsH,H-LandH-LP)andmineral-oil-basedgrease,flameretardanthydraulicfluidsoftheHFA,HFBandGroupHFCs,plantandanimal-basedoilsandgreases,lightheatingoil,dieselfuel.Somemateri-alsareparticularlyresistantto:hotwateruptotemperaturesof+100°C(sanitaryvalves),inor-ganicacidsandbasesatreasonableconcentra-tionandtemperature.Averageswellingresistancein:fuelswithhigharomaticcontent(superfuels).

Heavyswellingin:aromatichydro-carbons,e.g.benzene,chlorinatedhydro-carbons,e.g.trichlo-rethylene,flameretardanthydraulicfluidsoftheGroupHFD,esters,polarsolventsaswellasinbrakefluidsonaglycoletherbase.Thermalapplicationrange:dependingonthecompositionofcompoundbetween–30°Cand+100°C,transientupto130°C;athighertem-peraturesthematerialhardens.Withspecialmix-turesthecoldflexibilityisupto–55°C.

NR (natural rubber)Itisahighpolymerisoprene.Thevulcanisatesarecharacterisedbyhighmechanicalstrengthandelas-ticityaswellasgoodlowtemperaturebehaviour.Itispreferablyusedinmanufactureoftorsionaloscil-lationdampers,enginemounts,machinebearings,rubber-metalsuspensioncomponents,diaphragms,mouldedpartsetc.

Goodswellingresistancein:acidsandbasesatlowconcentrationaswellasinalcoholsandwateratnotexcessivelyhightemperaturesandconcentration.Brakefluidsonaglycoletherbase,e.g.ATE-SLattemperaturesupto70°C.Heavyswellingin:mineraloilsandgreases,fuelsandaliphatic,aromaticandchlorinatedhydro-carbons.Thermalapplicationrange:approx.–60°Cto+80°C.Naturalrubbermaysoftenafterinitialhardeningunderextendedeffectofhighertem-peratures.


Silicone rubbers VMQ (vinyl-methyl polysiloxane) PVMQ (phenyl-vinyl-methyl polysiloxane)Theyarehighpolymerorganosiloxanesthatareparticularlynotedforhighthermalresistance,goodcoldflexibility,gooddielectricproperties,verygoodresistancetoattackbyoxygenandozone,particularlylowtemperaturedependencyoftech-nologicalproperties.Thegaspermeabilityatroomtemperatureishigherthanforotherelastomers.Thisisparticularlyimportantforthin-walleddiaphragms.Thematerialisdecomposedbydepolymerisationwhenexposedtooxygenathighertemperatures.

Averageswellingresistancein:mineraloils(com-parativetomaterialsbasedonCR)andbrakefluidsonaglycoletherbase.Itcanbeusedinwateruptoabout+100°C.Sufficientresistanceinaqueoussaltsolutions,singleandmultiplevaluealcohols.Heavyswellingin:lowmolecularestersandethers,aliphaticaswellasaromatichydro-car-bons.Concentratedacidsandalkalis,waterandsteamtemperaturesaboveapprox.100°Chaveadestructiveeffectonthematerial.Thermalapplicationrange:approx.–60°Cto+200°C(transientupto+230°C).Componentsthatonlybecomebrittlebelow–100°Ccanbemanufacturedfromspecialmixtures.

SBR (Styrene-butadiene rubber)Itisapolymermadeofbutadieneandstyrene.SBRmaterialsarepreferredformanufacturingseal-ingcomponentsforhydraulicbrakes.

Goodswellingresistancein:inorganicandor-ganicacidsandbasesaswellasinalcoholsandwater,brakefluidsonaglycoletherbase.Heavyswellingin:mineraloils,lubricatinggreas-es,petrolandaliphatic,aromaticandchlorinatedhydro-carbons.Thermalapplicationrange:approx.–50°Cto+100°C.

IIR (Butyl rubber) CIIR (Chlorine butyl rubber) BIIR (Bromine butyl rubber)Theyarepolymersmadeofisobutyleneandchlorin-atedorbrominatedisobutylsandasmallproportionofisoprene.ElastomersofIIRhaveaverygoodresistancetoweatheringandageing.Thegasandvapourpermeabilityofthesematerialsislow.Somematerialshaveaverygoodelectricalinsulatingcapacity.

Goodswellingresistancein:brakefluidsonaglycoletherbase,inorganicandorganicacidsandbases,hotwaterandsteamupto120°C,hydraulicfluidsoftheGroupHFCandsometypesintheGroupHFD.Heavyswellingin:mineraloilsandgreases,pet-rolandaliphaticaswellasaromaticandchlorin-atedhydro-carbons.Thermalapplicationrange:approx.–40°Cto+120°C.

XNBR (Carboxylated nitrile rubber)Theyareterpolymersorblendsmadeofbutadiene,acrylonitrileand(meth)acrylicacid.Themainprop-ertiescorrespondtothoseoftheNBRpolymer,buttheyarecharacterisedbyimprovedwearbehaviourindynamicsealingapplications.ThecoldflexibilityisrestrictedcomparedtothecomparableNBRtypes.

Thermalapplicationrange:approx.–25°Cto+100°C(transientupto+130°C).


TPE (Thermoplastic rubbers)

TPEshavepropertiesbetweenthoseofelastomersandthermoplastics.TPEsaremulti-phasesystemswithahardandasoftphase.Thehardsegmentsarelayeredtogethertoformacrystallinestructurethatislaminatedwithsoftsegments.Apseudo-crosslinkedstructureisformed.

CategorisationofTPEsTPE-OThermoplasticrubberbasedonolefins

e.g.(YEPDM)TPE-SThermoplasticrubberbasedonstyrene

(YSBR)TPE-EThermoplasticrubberbasedonesters

(YBBO).

YEPDM (Olefin thermoplastic rubber)PropertiesarecomparabletoEPDM,i.e.verygoodchemicalresistance,butnotresistanttooil.Theproductscannotbeusedaboveatemperaturelimitof120°C.

YBBO (Copolyester TPE)YBBOsarecharacterisedby:

hightensilestrengthhightensilemodulusgoodstretchabilityexcellentresistancetosolventsresistancetooxidisingacidsaliphatichydro-carbonsalkalinesolutions,variousgreasesandoils.

Stronglyoxidisingacidsandchlorinatedsolventscausestrongswelling.

YSBR (Thermoplastic rubber containing styrene)Thehardphaseisstyrene,thesoftbutadiene.Properties:themechanicalpropertiesarecompara-bletoSBR.Hardorsofterproductsareobtainedde-pendingontheratioofstyrene/butadiene.Above60°Ccreepandlossoftensilestrengthareencoun-tered.Thecoldresistanceextendsupto–40°C.Goodchemicalresistancetowater,diluteacidsandalkalis,alcoholsandketones.YSBRisnotresistanttonon-polarsolvents,fuelsandoils.

Thermoplastic materials

Productsmadeofthermoplasticmaterialareusedinlargequantitiestodayinallareasofengineering,includingforsealsandmouldedcomponents.

Thesoftertypes(polyethylene,softPVC,thermoplas-ticelastomers)competewithhighlyelasticmaterialsinmanyapplications,whilethemechanicallystrongplastics(polyamides,acetalresins)arebeingusedinapplicationsthatwereformerlyreservedexclu-sivelyformetals.

Sealingcomponentsandconstructionpartsmadeofthermoplasticmaterialsaredifferentdependingonthebasematerials.Inmanycasestheycanbevariedbyincludingspecificadditivesandcanbedesignedspecificallyforthepurposeofthemanu-facturedcomponent.

Somecharacteristicpropertiesandtheresultingmajorareasofapplicationaredescribedbelow.Formoreinformationseethematerialtables.

ETFE (ethylene tetrafluoroethylene copolymer)Itisaninjection-mouldablefluoroplasticwithverygoodchemicalandthermalproperties,whichhow-evertodoquitereachthevaluesofPTFE.Upperapplicationtemperatureapprox.+180°C.

PA (Polyamide)Ischaracterisedbyveryhighstrengthvalues.Thehighwearresistance,thetoughmaterialstructure,thedampingcapacityandthegooddry-runningcharacteristicsmakethismaterialparticularlysuit-ableformachineelementsofvarioustypes(gear-wheels,plainbearings,guidestrips,camsetc.).Upperapplicationtemperature+120°Cto+140°C.


PBTP (Polybutylenterephtalate)PBTPisapartiallycrystalline,thermoplasticpolyes-termaterial.Inhydraulicsunfilledorfilledtypesareuseddependingontheloadinvolved.

PBTPhasthefollowingproperties:highstiffnessandhardnessgoodslidingpropertieslowwearverylowwaterabsorption(=highdimensionalstability)temperatureapplicationrange–30°Cto+120°C(shaperesistance)

Resistanttoalllubricantsandallhydraulicfluidsusedinhydraulics,dilutealkalis,acidsandalcohols.Notresistanttostrongalkalisandacids.

PFA (Perfluoroalkoxy copolymer)Itisaninjection-mouldablefluoroplasticwithsimilarchemicalandphysicalpropertiestothoseofPTFE.Bothmaterialsareparticularlysuitableformanufac-turinghigh-qualitymouldedandinjection-mouldedparts.Upperapplicationtemperatureapprox.+260°C.

POM (Polyoxymethylene), (Polyacetal)Isoneofthemechanicallyhighlyloadablether-moplastics.Itsstiffness,hardnessandstrengthcom-binedwithoutstandingformstabilityevenathighertemperatures(uptoapprox.+80°C)makeitsuit-ableforreplacementofdie-cast,brassoraluminiumparts.Thelowwaterabsorptionisparticularlyworthnoting.Itretainsitsformbetterthanmouldedpolya-midepartsevenwhenexposedtomoisture.Acetalresinsareattackedbyacids.Temperatureapplicationrange–40°Cto+140°C.

PP (Polypropylene)Itisresistanttohotwaterandwaterlye,resistsboil-ingandcanwithstandsterilisationtemperaturesof+120°Cforshortperiods.Preferreduseinpumps,motorvehiclesanddomesticappliances.

PPO (Polyphenylene oxide)Itisatough,rigidmaterialthatisprimarilycharac-terisedbygooddimensionalstability,lowtendencytocreepandlowwaterabsorption.Ithashighpunctureresistanceandavirtuallyconstantlowlossfactor.PPOishydrolysis-resistantbutnotoil-resistant.Variouspropertiesofpolyamides,acetalresinsandPPOcanbesubstantiallyimprovedwithglassfibres.Forexample,thetensilestrengthingeneralcanbemorethantwiceashighasthatofunreinforcedma-terial.Theheatresistanceissignificantlyimprovedandnotchedimpactstrength,whichwithoutglassfibrereinforcementfallsquicklyasthetemperaturefalls,remainsvirtuallyunchanged.Thecompressionstrengthisalsoincreasedandthetendencytocoldflowisreduced.Thelinearthermalexpansionissignificantlyreduced.Itisinthegeneralrangeofdie-castmetal.Upperapplicationtemperatureshorttermapprox.+130°C,extendedperiodapprox.+90°C.

PTFE (Polytetrafluoroethylene)PTFEisathermoplasticpolymermadeoftetrafluor-oethylene.Thisnon-elasticmaterialischaracterisedbyaseriesofoutstandingproperties:Thesurfaceissmoothandrepellent.Thismakesitsuitableforuseinallapplicationsinwhichadhesionofresiduesistobeavoided.

PTFEisphysiologicallysafeatoperatingtempera-turesupto+200°C.Thecoefficientoffrictionisverylowwithmostmatingmaterials.Staticanddy-namicfrictionarevirtuallyidentical.Theelectricalinsulationpropertiesareextraordi-narilygood.Theyarevirtuallyindependentofthefrequencyaswellastemperatureandweatheringeffects.Thechemicalresistanceissuperiortoallotherelastomersandotherthermoplastics.Theswell-ingresistanceisgoodinalmostallmedia.Liquidalkalimetalsaswellassomefluorinecom-poundsattackPTFEathigherpressuresandtem-peratures.


0

Technical Manual

Thethermalapplicationrangeisbetweenapprox.–200°Cto+260°C.At–200°CPTFEstillhassomeelasticity;thematerialcanthereforebeusedforsealsanddesigncomponents,e.g.forliquidgases.

NotethefollowingwhenusingpartsofpurePTFE:thatthematerialispermanentlydeformedfromaspecificloadbycreeporcoldflow,thattheabrasionresistanceislow,thatthethermalexpansion,aswithmostplas-tics,isabout10timeshighercomparedtomet-als,thatthethermalconductivityislow,sotheheatdissipationinbearingsandmovingsealsmaybecomeaproblem,thatthematerialisnotelasticrubberbuthorn-likesimilartopolyethylene.

FortheabovereasonsdesignswithelastomericsealscannotbeconvertedtoPTFEwithoutothermodifications.Forlipsealsanadditionalcontactpressurebyspringsorothermeansisrequired.PTFEisfilledwithgraphite,glassfibres,bronzeandcarbontogiveitspecialproperties.

PVC (Polyvinyl chloride)iscurrentlyfrequentlyusedinsteadoftheformerlyusedelastomermaterialsbecauseofitsgoodtech-nologicalandchemicalproperties.ThematerialsbasedonPVChaverubber-likepropertiesincontracttotheotherthermoplasticsdescribedinthissection.PVCisusedfor:bellows,faceplates,seals,covers,sleeves,caps,bushesandmouldedair-ductcomponents.

Thermalapplicationrange:–35°Cto+70°C.

High-load resistant thermoplastic polycondensates "high-tech, engineering plastics"Theseproductsaregenerallyveryexpensivebe-causeoftheverycomplexmanufacturingtechniquesrequiredinmanycases.Theyarealwaysusedformouldedcomponentswhereotherplasticswouldcertainlyfailbutmetallicpropertieswouldcauseproblems,particularlyintheelectricalindustry.

Allmaterialshavegoodstrengthpropertiesandahightemperatureresistance(+140°Cto+200°C).

Specialfeaturesoftheindividualmaterials:

polyethersulfane(PESU)resistanttowaternotresistanttobrakefluids.

polysulfane(PPSO)notusableinboilingwaterspecificsolvents,esters,ketones,aromatics,chlorinatedhydro-carbonsdestroythematerialbyformationoftensioncracks.

polyphenylenesulphide(PPS)greaterchemicalresistancethantheotherproductsnottoughandsensitivetonotchingbecauseofcrystallinestructure.

polyetherketone(PEEK)verygoodchemicalresistanceuniversallyusablereinforcedtypescanbeusedupto+180°C.

polyetherimide(PEI)amorphousandtransparentKetonesandchlorinatedhydro-carbonsattackthismaterial.


1

Duroplastics

Materialsthatdonotsoftenormeltinheat.Theyretaintheirshapebetterwhenhardenedthanun-crosslinkedplastics.

Themostimportantproductgroupsare:Phenolformaldehydemasses(PF)Unsaturatedpolyesterresins(UP)Polyimides(PI).

PF (Phenol formaldehyde)Thereactionofphenolwithformaldehyderesultsinresin-likecondensationproducts–novolakorresolresins.DIN-classifiedmasseshavedifferentfillerandrein-forcementmaterials.Themechanicalandtechnicalpropertiesareextremelyuseful.Temperedcom-ponentscanbesubjectedtotemperaturesupto+300°Cforshortperiods.Othergeneralproperties:

temperaturerange–30°Cto+120°Chardandverystronglowtendencytocreeplowflammabilitysensitivetonotchingnotforusewithfoodresistanttoorganicsolvents,weakacidsandalkalis,saltsolutions.

PI (polyimides)Theyarederivedfrombis-maleinimide.Underpo-lymerisationduroplasticpolyimideswithdifferentmolecularstructuresareformed.Thegeneralchar-acteristicoftheseheterocyclicpolymersistheimide-ringwithinthemainchain.Polyimidecomponentsarecharacterisedbyhightemperatureresistanceuptomorethan+260°C,andevenabove+300°Cforshortperiods,whileretainedmostoftheirme-chanicalproperties.Thematerialsarealsocharac-terisedbygoodslidingandwearproperties,whichcanbeimprovedevenmorewithsuitableadditives.Theelectricalpropertiesandradiationresistanceofpolyimideareoutstanding.Thematerialsaregenerallyresistanttosolvents,greases,fuels,oilsanddiluteacids.Strongacids,alkalisandhotwaterattackpolyimides.

UP (Unsaturated polyester resins)Reactionproductsof

unsaturateddicarboxylicacidesterdioldicarboxylicacidandstyrene.

Theyareusedasinjection-mouldingmaterials,bulk-mouldingcompounds(BMC)ortrackmaterial,sheet-mouldingcompounds(SMC).Processingbypressesandinjectionmoulding.

Properties:unlikephenolresinslowershrinkagelowerwaterabsorptioneasiertocolourbetterpricesuitableforcontactwithfoodgoodnotchandimpactsensitivity.


2

Technical Manual

Seals and moulded components of Simriz

Perfluoroelastomers(FFKM)offerthewidestrangeofchemicalandthermalresistanceandcompatibilityamongtheelastomersealingmaterials.Freudenbergmanufacturessealsoftheall-roundperfluoroelas-tomerSimriz.

These sealing materialshavealmostthesameresistanceaspurePTFEsalsohavethegreatadvantageofhighelasticitytheyarealsocharacterisedcomparedtocon-ventionalelastomersbyamuchlongerservicelife.

The universal usabilityoftheseperfluoroelastomersisbasedontheirre-sistancetoaggressivemediaandtheirusabilityinunusuallywidetemperatureranges.Simrizoffersreliablesealingof:

chlorinatedandhigh-polarorganicsolvents,suchaschloroform,dichloromethane,alcohols,loweraldehydes,ketones,estersandether,N-methylpyrrolidone,cellosolve,nitratedhydro-carbons,amines,amidesaromaticssuchasbenzene,tolueneorxylene.

Simrizisalsoparticularlysuitableforsealing:stronginorganicacidsandalkalissuchassul-phuricacid,hydrochloricacid,nitricacidandtheirmixturesaswellassodiumandpotassiumhydroxideorammonia,strongorganicacidsandbases,e.g.formicacidorethylenediamine.

Simrizsealsarealsotopintheirtemperaturelimits.Theyremain

coldflexibledownto–12°Candcanbeusedupto+300°Cwithoutproblems.

Safe solutions for many applicationsSimrizsealsareexcellentlysuitedforallsealingapplicationsunderhighchemicaland/orthermalloads.Simrizistheidealsealfor:

analysistechnologysystemsandmechanicalengineeringaerospaceindustrymachinesandunitsmineraloilprocessingmedicaltechnologypharmaceuticalindustrypumpsprocessingtechnologypackagingmachines.

Tell what form your seal should be. We will supply it.SealsandmouldedcomponentsofSimrizaremanu-facturedinstandardsizesoftheISCO-RingrangebySimritorcustomisedtoyourrequirements.ISCO-Rings,ISCO-RingspecialshapesormouldedcomponentsofSimrizcanbedesignedpreciselyforyourapplicationorrequirements.

Solutions for complex requirementsHighpressure,cyclictemperatures,staticordynamicloading,chemicalandabrasiveattackbytheseal-ingfluidformamatrixofrequirementsforasealwhichcanbecomeextremelycomplex.Wewillbepleasedtoworkwithyoutodevelopcustomisedsolutionsforsafeandreliablesealinginsuchdifficultcases.HightemperatureandFDAma-terialsonenquiry.Ourtechnicianswillbepleasedtoassistyouwithyourrequirements.


Standard materials for hydraulic components

Media to be sealed with information on continuous temperature (in °C)

Material ASTM

D 2

000

Perm

issibl

e low

tem

pera

ture

°C

Mineral lubricants

Synthet. lubri-cants

Mineral. hydr. fluids

Biodegrad-able hydraulic fluids as per VDMA 24568 & DIN 24569

Flame retardant hydraulic

fluids as per VDMA 24317

& DIN 24320 *

Other media

Com

men

t

Engin

e oils

Trans

miss

ion oi

ls

Hypo

id tra

nsm

ission

oils

ATF o

ils

Grea

ses

Polya

lkyle

negly

cols

(PAG

)

Polya

lphao

lefins

(PAO

)

HLP

as p

er D

IN 5

1524

Par

t 2

HLVP

as p

er D

IN 5

1524

Par

t 3

HETG

rape

seed

oil *

HEES

– sy

nthe

tic es

ter

HEPG

poly

glyco

ls**

Grou

p HF

A

Grou

p HF

B

Grou

p HF

C

Grou

p HF

D **

*

Heat

ing oi

l EL a

nd L

Brak

e flui

d DO

T 3/D

OT 4

Wate

r

Wate

r lye

air

94AU925 M7BG910 –30 + + ⊗ + 110 ⊗ + 110 110 50 80 40 50 50 40 ⊗ – – 40 – 100

98AU928 M7BG910 –25 + + ⊗ + 110 ⊗ + 110 110 50 80 40 50 50 40 ⊗ – – 40 – 100

95AUV142 – –30 + + ⊗ + 110 ⊗ ⊗ 110 110 50 80 40 50 50 40 – – – 40 – 100

95AUV149 – –30 + + ⊗ + 110 ⊗ ⊗ 110 110 50 80 40 50 50 40 – – – 40 – 100

94AU985 M7BG910 –30 + + ⊗ + 100 ⊗ + 100 100 60 80 50 60 60 50 ⊗ – – 80 – 100

93AUV167 – –30 + + ⊗ + 100 ⊗ ⊗ 100 100 60 80 50 60 60 40 – – – 60 – 80

93AUV168 – –30 + + ⊗ + 100 ⊗ ⊗ 100 100 60 80 50 60 60 40 – – – 60 – 80

70FKMK655 – –10 150 150 140 150 150 150 150 150 150 80 100 80 55 60 60 150 150 – ⊗ ⊗ 200

HGWHG517 – –50 + + + + + + + 120 120 + + + 60 60 60 80 – – 90 – 120

HGWHG600 – –40 + + + + + + + 120 120 + + + 60 60 60 80 – – 90 – 120

88NBR101 M7BG910 –30 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 + 100

90NBR109 M7BG910 –30 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 + 100

80NBR709 M6BG814 –30 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 90 100

72NBR872 M2BG714 –35 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 90 100

80NBR878 M7BG814 –30 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 + 100

80NBR99033 M7BG814 –30 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 + 90

80NBR99035 M7BG814 –30 100 100 80 100 100 80 80 100 100 80 80 80 55 60 60 – 80 – 90 + 90

85NBRB203 – –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

70NBRB209 M2BG710 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

89NBRB217 M2BG910 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

81NBRB219 M2BG810 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

79NBRB246 M2BG810 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

87NBRB247 M2BG910 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

70NBRB276 M2BG710 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

75NBRB281 M2BG821 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

90NBRB283 M2BG910 –30 100 100 80 100 100 80 80 100 100 80 80 60 55 60 60 – 80 – 100 90 100

PA4112 – –30 + + + + + + + 130 130 + + + 55 60 60 90 – – 90 – 100

PA4201 – –30 + + + + + + + 120 120 + + + 55 60 60 80 – – 90 – 100

PA6501 – –30 + + + + + + + 120 120 80 80 50 60 60 60 80 – – 60 – +


Technical Manual


Material ASTM

D 2

000

Perm

issibl

e low

tem

pera

ture

°C

Mineral lubricants




Flame retardant hydraulic

fluids as per VDMA 24317

& DIN 24320 *

Other media

Com

men

t

Engin

e oils

Trans

miss

ion oi

ls

Hypo

id tra

nsm

ission

oils

ATF o

ils

Grea

ses

Polya

lkyle

negly

cols

(PAG

)

Polya

lphao

lefins

(PAO

)

HLP

as p

er D

IN 5

1524

Par

t 2

HLVP

as p

er D

IN 5

1524

Par

t 3

HETG

rape

seed

oil *

HEES

– sy

nthe

tic es

ter

HEPG

poly

glyco

ls**

Grou

p HF

A

Grou

p HF

B

Grou

p HF

C

Grou

p HF

D **

*

Heat

ing oi

l EL a

nd L

Brak

e flui

d DO

T 3/D

OT 4

Wate

r

Wate

r lye

air

PF48 – –50 + + + + + + + 120 120 + + + 55 60 60 80 – – 90 – 120

POM20 – –40 + + + + + + + 100 100 + + + 55 60 60 80 – – 80 – 100

POMPO202 – –40 + + + + + + + 110 110 + + + 60 60 60 80 – – 80 – +

POMPO530 – –40 + + + + + + + 110 110 + + + 60 60 60 80 – – 80 – +

PTFEB502 – –40 + + + + + + + 200 200 80 100 80 – – – 200 + + – + 200

PTFEB504 – –40 + + + + + + + 200 200 80 100 80 – – – 200 + + – + 200

PTFEB602 – –30 + + + + + + + 200 200 80 100 80 – – – 200 + + – + 200

PTFEGM201 – –30 + + + + + + + 100 100 80 100 60 60 60 60 150 + + 100 + 200

PTFE/15177026 – –80 + + + + + + + 200 200 80 100 100 + + + 150 + + 150 + 200

PTFE/25177027 – –80 + + + + + + + 200 200 80 100 100 + + + 150 + + 150 + 200

PTFE/25177030 – –80 + + + + + + + 200 200 80 100 100 + + + 150 + + 150 + 200

PTFE/40177024 – –80 + + + + + + + 200 200 80 100 100 + + + 150 + + 150 + 200

PTFE/60177023 – –80 + + + + + + + 200 200 80 100 100 + + + 150 + + 150 + 200

97TPE113TP – –30 + + ⊗ + 100 ⊗ ⊗ 110 110 60 80 50 60 60 40 – – – 60 – +

* operatinglimitsdefinedbythemedium + resistant,ingeneralnotusedforthesemedia** forstaticuseonly;dynamicuse

requiresanadditionaltest⊗ oflimitedresistance– notresistant

*** resistancedependsontheHFDtype


Special materials for hydraulic components

Material ASTM

D 2

000

Perm

issibl

e low

tem

pera

ture

°C


Mineral lubricants




Flame retardant hydraulic fluids as per VDMA 24317 & DIN 24320 *

Other media

Engin

e oils

Trans

miss

ion oi

ls

Hypo

id tra

nsm

ission

oils

ATF o

ils

Grea

ses

Polya

lkyle

negly

cols

(PAG

)

Polya

lphao

lefins

(PAO

)

HLP

as p

er D

IN 5

1524

Par

t 2

HLVP

as p

er D

IN 5

1524

Par

t 3

HETG

rape

seed

oil *

HEES

– sy

nthe

tic es

ter

HEPG

poly

glyco

ls**

Grou

p HF

A

Grou

p HF

B

Grou

p HF

C

Grou

p HF

D **

*

Heat

ing oi

l EL a

nd L

Brak

e flui

d DO

T 3/D

OT 4

Wate

r

Wate

r lye

air

94AU20889 M7BG910 –25 + + ⊗ + 110 ⊗ + 110 110 60 80 50 60 60 50 ⊗ – – 80 – 110

92AU21100 - –50 + + ⊗ + 80 ⊗ + 100 100 50 70 40 50 50 40 – ⊗ – 50 – 80

80EPDML700 M2CA810 –40 – – – – – – – – – – – – – – 60 100 – + 150 130 150

85FKM580 M3HK910 –5 150 150 140 150 150 150 150 150 150 80 100 100 55 60 60 150 150 – 80 ⊗ 200

75FKM595 M2HK710 –5 150 150 140 150 150 150 150 150 150 80 100 100 55 60 60 150 150 – 80 ⊗ 200

86FKMK664 M2HK910 –10 150 150 140 150 150 150 150 150 150 80 100 80 55 60 60 150 150 – – – 200

90HNBR136428 M4DH910 –25 120 120 100 120 120 100 120 120 120 80 ⊗ 100 55 60 60 – 80 – 120 120 130

85HNBR137891 M4CH910 –25 120 100 100 100 120 100 120 120 120 80 ⊗ 100 55 60 60 – 80 – 120 120 120

80HNBR150351 –25 120 120 100 120 140 100 120 140 140 80 80 100 55 60 60 – 80 – 120 120 140

70HNBRU463 - –25 120 120 100 120 120 120 120 120 120 80 ⊗ 100 55 60 60 – 80 – 120 120 130

80HNBRU464 - –25 120 120 100 120 120 120 120 120 120 80 ⊗ 100 55 60 60 – 80 – 120 120 130

70NBRB262 M2BG710 –35 100 100 80 100 100 80 80 100 100 80 ⊗ 60 55 60 60 – 80 – 80 90 100

75NBRB280 M2BG810 –45 80 80 60 80 80 60 60 80 80 60 ⊗ 60 55 60 60 – 80 – 80 80 80

PTFEB604 - –30 + + + + + + + 200 200 80 100 80 – – – 200 + + – + 200

PTFEM202 - –30 + + + + + + + 100 100 80 100 60 60 60 60 150 + + 100 + 200

97TPE106TP - –30 + + ⊗ + 100 ⊗ ⊗ 110 110 60 80 50 60 60 40 – – – 60 – 140

* operatinglimitsdefinedbythemedium + resistant,ingeneralnotusedforthesemedia** forstaticuseonly;dynamicuse

requiresanadditionaltest⊗ oflimitedresistance– notresistant

*** resistancedependsontheHFDtype


Technical Manual

Chemical resistanceTheinformationinthefollowingtablehasbeenprocessedandcompiledfromourowntesting,rec-ommendationsoroursuppliersofbasematerialsandexperiencereportsfromourcustomers.However,thisinformationcanonlybeusedasageneralguide.Itcannotbetransferredtoalloperat-ingconditionswithoutadditionaltesting.Withthevarietyoffactorsaffectingsealsandmouldedcomponentsthechemicalresistanceisaveryimportantfactorbutstillonlypartoftheoveralloperatingconditions.Otherfactorsthatmustbecon-sideredincludetheselectionofmaterialbyFreuden-bergandtheshapeofthesealingcomponent:

rotationalspeedandstrokelengthstrokespeedforpartswithaxialmovementstaticordynamicloadingsurfacecharacteristicsofmetalcomponentstypeofmaterialofmachinecomponentstobesealed.

Iftherearenospecialinstructionsgiveninthetable,standardpurity,concentrationandroomtempera-turearespecifiedwiththemedia.Incaseofdoubt,particularlywithuntestedornewapplications,we

recommendconsultingustoallowustoconductspe-cialtestingifnecessary.TheelastomerslistedinthetablearereferredtowiththeirchemicalnamesaswellasthecodesspecifiedinASTMD1418.

Thechemicalnames,generallyusednamesortradenameshavebeenusedforthemedia.

Explanation of material codes

ACM Acrylaterubber

AU Polyurethane

CR Chlorinebutadienerubber

CSM Chlorosulfonatedpolyethylene

EPDM Ethylenepropylenedienerubber

FFKM Perfluoroelastomer

FKM Fluoroelastomer

FVMQ Fluorosiliconerubber

HNBR hydrogenatedacrylonitrile-butadienerubber

IIR butylrubber

NBR Acrylonitrilebutadienerubber

NR Naturalrubber

PTFE polytetrafluoroethylene

SBR Styrene-butadienerubber

VMQ siliconerubber

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

acetaldehydewithaceticacid,90/10% 20 D G D C C B D D D C D C B C D

acetamide 20 G G G F F B G F F F F G B G G

aceticacid,aqueous,25to60% 60 G G G B B B G G D B D D B D G

aceticacid,aqueous,85% 100 G G G F F B G G D F D D B D G

aceticanhydride 20 G G B B B B D G D B D C B B G

aceticanhydride 80 G G C F F C D G D F D D B C G

acetone 20 D D D F B B D D D B D B B B D

acetophenone 20 G G G F F B G G G F G G B G G

acetylene 60 B F B B B B B B B B B B B B B

acrylicacidethylester 20 D D G G F B D D D C D G B G D

acrylonitrile 60 G G D G F B D D D D D D B D D

B=littleornocorrosion F=nodataavailable,probablysuitable,testbeforeuse.Pleaseconsultus.

C=weaktomoderatecorrosion G=nodataavailable,probablynotsuitable.Pleaseconsultus.

D=strongcorrosiontocompletedestruction H=specialcompositionofcompoundrequired.Pleaseconsultus.

1)testtemperaturein°C


Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

adipicacid,aqueous 20 F F B B B B B F B B B B B B F

air,clean 80 B B B B B B B B B B B B B B B

air,oily 80 B B B B D B B B B D B D B C B

alaum,aqueous 60 G D D B B B B G D B D C B C G

alaum,aqueous 100 G G B B B B B F B B B D B B F

allylalcohol 80 G D C C B B D G C B C B B B G

aluminiumsulphate,aqueous 60 G D C B B B B F B B B B B B F

aluminiumsulphate,aqueous 100 G D C B B B D F B B B C B B F

ammonialiquor 40 D D C B B B D C B B B B B B C

ammonia,100% 20 G D C B B C D G C B C B B B G

ammoniumacetate,aqueous 60 G D C B B B D F B B B B B B F

ammoniumcarbonate 60 G D C B B B D F B B B B B B F

ammoniumchloride,aqueous 60 G D C B B B B F B B B B B B F

ammoniumfluoride,aqueous 20 G G C B B B B B B B B B B B B

ammoniumfluoride,aqueous 100 G G C B B B D F B B B D B B F

ammoniumfluoride,aqueous 20 G G C B B B B B B B B B B B B

ammoniumfluoride,aqueous 100 G G C B B C D F B C B D B B F

ammoniumnitrate,aqueous 60 G D C B B B B F B B B B B B F

ammoniumnitrate,aqueous 100 G G C B B B D F B B B D B B F

ammoniumphosphate,aqueous 60 G D C B B B D F B B B B B B F

ammoniumsulphate 60 G D C B B B B F B B B B B B F

ammoniumsulphate 100 G D C B B B D F B B B D B B F

ammoniumsulphide,aqueous 60 G D C B B B B F B B B B B B F

ammoniumsulphide,aqueous 100 G D C B B B D F C B C D B C F

amylacetate 20 G G G F B B D G D B D B B D G

amylalcohol 60 G D C B B B D F C B C B B B F

aniline 60 G D D G G B D D D G D D B D D

anilinechlorohydrate 20 G D C C C B B F C C C D B D C

anilinechlorohydrate 100 G D F G G B G G D G D D B D G

anisole 20 G G D G G B G G D G D D B D G

anthraquinonesulphonicacid,aqueous 30 G D G B B B G G C B C B B B G

anti-freeze(automotive) 60 G D B B B B B B B B B B B B B

antimonychloride,aqueous 20 B G B B B B B B B B B B B B B

antimonytrichloride,dehydrated 60 G G C B B B G G B B B B B B G

aquaregia 20 D D D D D B D D D D D D B D D






Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

arsenicacid,aqueous 100 G G C B B B D F B B B D B B F

arsenicacid,aqueous 60 F D C B B B B F B B B B B B F

asphalt 100 F G G G G B F G G G G G B G G

ASTMfuelA 60 C B C C D B B B B D B D B D D

ASTMfuelB 60 D D D D D B B B C D C D B D D

ASTMfuelC 60 D D D D D B B C D D D D B D D

ASTMOilNo.1 100 B C B D D B B B B D B D B D B

ASTMOilNo.2 100 B C C D D B B B B D B D B D B

ASTMOilNo.3 100 B C C D D B B B C D B D B D C

ATEbrakefluid 100 D G C G B F D B D B D B B B B

ATFoil 100 D C C D D B B B B D B D B D C

aviationfuelsJP3(MIL-J-5624) 20 C C D D D B B B C D B D B D D

aviationfuelsJP4(MIL-J-5624) 20 C C D D D B B C C D B D B D D



bariumhydroxide,aqueous 60 G D B B B B B F B B B B B B F

bariumsalts,aqueous 60 G D C B B B B B B B B B B B B

batteryacid(sulphuricacid) 60 G D D B B B B G D B D C B C G

beeftallowemulsion,sulphurated 20 G G C B D B B C B D B D B D C

beer 20 B B B B B B B B B B B B B B B

benzaldehyde,aqueous 60 G D D G C B B G D C D C B C G

benzene 20 D D D D D B C C D D D D B D D

benzoicacid,aqueous 60 G D C B B B B B B B B B B B B

benzylalcohol 60 G D G F F B G C G F G F B F C

biogas 20 F C B B G B B D B G B D B D B

bisulphitealkali 50 G D C B B C G F C B C B B B F

bitumen 60 G G D G G B B G D G D G B G G

blackliquor 100 G G C B B B B G C B C C B C G

blast-furnacegas 100 B F C C C B B B C C C D B C B

bleach 60 G D C B B B C G D C D D B C G

boneoil 60 B B D D D B B B B D B D B D C

borax,aqueous 60 G D C B B B B B B B B B B B B

boricacid,aqueous 60 G D C B B B B B B B B B B B B

brakefluids(glycolether) 80 D G C F B F G B D B D B B B B

brominevapours 20 G G D C F F G G D F D D B D G






Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

brominewater,coldsaturated 20 G G D C F F G G D F D D B D G

bromine,liquid 20 G G D C F F G G D F D D B D G

bromobenzene 20 G G G G G F F F G G G G B G G

bromochloromethane 20 G G G C C C C C G C G G B G G

bunkeroil 60 F G G G G F F F C G C G B G G

butadiene 60 G F C D D B B B F D F D B D C

butane,gaseous 20 B B C D D B B B B D B D B D F

butanediol,aqueous 20 G F C B B B C F B B B B B B F

butanediol,aqueous 60 G D B B B F F F B B B C B B F

butanol,aqueous 20 C B D B B B C B C B B B B B B

butanol,aqueous 60 G D C B B B G F D B D B B B F

butter 20 F B B G G B B B B G B G B G B

butter 80 F F C G G B B F B G B D B D F

butylacetate 20 G G D D C B D G D C D C B D G

butylalcohol 60 G D C B B B G F D B D B B B F

butylphenol 20 D D D D D B C G D D D D B D D

butyleneglycol 60 G B B B B B C B B B B B B B B

butylene,liquid 20 F B C G G B B B B G B D B D F

butynediol 20 G B C B B C C F B B B B B B F

butyraldehyde 20 G G G C C C G G G C G C B C G

butyricacid,aqueous 20 G F C F F B B F B F B D B F F

calciumbisulphite,aqueous 20 G B B B B B B F B B B B B B F

calciumchloride,aqueous 100 G D B B B B B B B B B D B B B

calciumhydroxide,aqueous 20 G D B B B B B B B B B B B B B

calciumhypochloride,aqueous 60 D D C B B B C G D B D D B D G

calciumnitrate,aqueous 40 G G B B B B B B B B B B B B B

calciumphosphate,aqueous 20 G F B B B B B B B B B B B B B

camphor 20 G G C D D B C G B D B D B D G

camphoroil 20 G G D C D B C G C D B D B D G

carbolineum 60 G G G C C B F F G C G G B G G

carbolineum 80 D B D D D B B B D D D D B D D

carbondioxide,dry 60 B F B B B B B B B B B B B B B

carbondisulphide 20 G D D C D B B G D D D D B D D

carbonmonoxide,dry 60 B B B B B B B B B B B B B B B

carbonmonoxide,wet 20 B G B B B B B B B B B B B B B






0

Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

carbontetrachloride 60 G G D D D B B G D D D D B D G

cellosolve 20 G G G C C F G G G C G G B G G

chloralhydrate,aqueous 60 G G D C C B C G D C D D B D G

chloramine,aqueous 20 F F B B B C G F B B B B B B F

chloricacid,aqueous 80 G G D C C B C G D C D D B D G

chlorinatedlime,aqueous 60 G D D B B B B G D B D D B D G

chlorinewater,saturated 20 G G D B B B B G D C D D B D G

chlorine,drygaseous 20 G C D C C C C G D C D D B D G

chlorine,liquid 20 G G D C C C C G D C D D B D G

chlorine,wetgaseous 20 G G D C C C C G D C D D B D G

chloroaceticacid 60 G D C B B C G G C B C D B D G

chlorobenzene 20 D F D D D C C D D D D D B D D

chloroform 20 G D D D D B C G D D D D B D G

chlorsulphonicacid 20 D G D D D F G D D D D D B D D

chromicacid,aqueous 60 G G D B F B B G D F D D B D G

chromicacid/sulphuricacid/water,50/15/35%

40 G G D B F B B G D F D D B D G

citricacid,aqueous 60 G G C B B B H F B B B B B B F

clophenAtypes 100 F D D G G B B B D G D D B D B

clophenT64 100 F D D G G B B F D G D D B D C

coconutoil 80 B B C D D B B B B D B D B D B

coconutoil 80 F F C G G B B F B G B D B D F

coconutoil 60 B B C D D B B B B D B D B D B

coconutoilalcohol 20 F G B C C B B F B C B C B C F

codliveroil 20 B B B C C B B B B C B C B C B

coking-ovengas 80 G G D D D B B F D D D D B D F

copperchloride,aqueous 20 B B C B B B B B B B B B B B B

copperfluoride,aqueous 50 G G C B B B B F B B B B B B F

coppernitrate,aqueous 60 G G C B B B B F B B B B B B F

coppersulphate,aqueous 60 G G C B B B B F B B B B B B F

cornoil 60 F F C G D B B F B D B D B D F

cotton-seedoil 20 F B C C C B B F B C B C B C F

cresol,aqueous 45 G B D D D B B G D D D D B D G

crotonaldehyde 20 G F G B B C D G G B G C B C G

crudeoil 20 B B C C D B B B C D B D B D C






1

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

cyclohexane 20 C B D G D B B C B D B D B D C

cyclohexanol 20 G B D D D B G C B D B D B D G

cyclohexanone 20 G G D G D B G G D D D D B D G

cyclohexanone 20 G G D D D B G G D D D D B D G

cyclohexylamine 20 G G D D D C D G D D D D B D G

decahydronaphtaline(decalin) 20 C G D D D C C G D D D D B D G

decahydronaphtaline(decalin) 60 C G D D D C C G D D D D B D G

DesmodurT 20 D C D D D C G G D D D D B D G

Desmophen2000 80 F G F F F F F F B F B F B B F

detergent,synthetic 60 D F C B B B B F B B B B B B F

detergents 100 G G C B B C C G B B B D B C G

dextrine,aqueous 60 G D B B B B B B B B B B B B B

dextrose,aqueous 80 G G B B B B B B B B B D B B B

diacetonealcohol 20 G F C B B B G F C B C B B B F

dibenzylether 20 G G D C C B D G D C D D B D G

dibuthylether 20 G G D C C B D G D C D D B D G

dibuthylphtalate 20 G B D F F B B B D F D D B D B

dibuthylphtalate 60 G F D F F B C B D F D D B D B

dibuthylsebacate 60 G F D D D C G C D D D D B D C

dichloraceticacid 60 G D D B B C D G D B D D B D G

dichlorbenzene 20 G G D D D B B C D D D D B D G

dichlorbutylene 20 G G D D D B C G D D D D B D G

dichlorethane 20 D D D G D C C F D D D D B D D

dichlorethylene 20 G G D G G C C G D G D D B D G

dichlormethane 20 D D D D D B B G D D D D B D D

dieselfuel 60 C C C D D B B B B D B D B D C

diethylether 20 G G D D D B D G D D D D B D G

diethylsebacate 20 G G D C C C C G D C D D B D G

diethylamine 20 G G D B B C D G C B C D B D G

diethyleneglycol 20 G G B B B B B B B B B B B B B

diglycolicacid,aqueous 60 G G C B B B B F C B C B B B F

dihexylphtalate 60 G G D D G C D G D G D D B D G

diisobutylketone 60 G G D F B C D G D B D C B D G

dimethylamine 20 G G D B B C D G D B D D B D G

dimethylether 20 G G D B B C D G D B D C B D G






2

Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

dimethylformamide 60 F D D C C C D F D C D C B D D

dinonylphtalate 30 G G D D G C D G D G D D B D G

dioctylphtalate 60 D G D D G B C G D G D D B D G

dioctylsebacate 60 G G D G G C D G D G D D B D G

dioxane 60 G G D C C F D G D C D C B C G

dipentene 20 F F D D D B B F C D C D B D F

diphenyl 20 G F D D D B B G D D D D B D G

diphenyloxide 100 G G G G G F G G G G G G B G G

engineoils 100 B C C D D B B B B D B D B D C

epichlorhydrine 20 G G G G C F D G G G G G B G G

essentialoils 20 G G D D D B C G D D D D B D G

ethane 20 B B C D D B B B B D B D B D C

ethanol(spirits) 20 G C C B B B H B C B C B B B C

ethanol(spirits) 80 G D D B B B H F D B D B B B F

ethanol(spirits)withaceticacid(fermentationmixture)

60 G G D B B B H G D B D B B B G

ethanol(spirits)withaceticacid(fermentationmixture)

20 G G C B B B H G D B D B B B G

ethylacetate 20 G G G C C C D G D F D D B D G

ethylacetate 60 G D D D D C D G D D D D B D G

ethylacrylate 20 D G G G F C D D D C D G B G D

ethylbenzene 20 D F D D D B C C D D D D B D D

ethylchloride 20 D C C F C B C G C C C C B C D

ethylenechloride 20 D C C F C B C G C C C C B C D

ethylenechlorohydrin 60 G G D C C C D G D C D D B D G

ethylenediamine 60 D D D F B C D G D B D C B C D

ethyleneglycol 100 G D C F B B B F B B B D B B C

ethylenetrichloride 20 G G G G G C F G G G G G B G G

ethylether 20 D D D D C B D D D C D C B D D

exhaustgases,containedhydrogenfluoride,traces

60 F G B B B B B F B B B B B B F

exhaustgases,containednitrousgases,traces

60 D G B B B B B C F C F D B F D

exhaustgases,containednitrousgases,traces

80 D G B B B B B C F C F D B F D

exhaustgases,containingcarbondioxide 60 B F B B B B B B B B B B B B B






Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

exhaustgases,containingcarbonmon-oxide

60 B B B B B B B B B B B B B B B

exhaustgases,containinghydrochloricacid

60 G G B B B B B F C B C B B B F

exhaustgases,containingsulphurdioxide 60 G G B B B B B F C B C C B C F

exhaustgases,containingsulphuricacid 60 G G C B B B B F C B C C B C F

exhaustgases,containingsulphuricacid 80 G G C B B B B F D B D C B C F

FAMtestfuelsDIN51604-A 20 G B D D D B B B C D C D B D D

FAMtestfuelsDIN51604-C 20 D D D D D B H C D D D D B D D

fattyacids 100 G G C C G B B G C G C G B G G

fattyalcohol 20 B G B C C B B F B C B C B C B

ferricchloride,aqueous 40 G F B B B B B F B B B B B B F

fertilisersalt,aqueous 60 G G C B B B B B B B B B B B B

firedamp 20 B F B C C B B B B C B C B C B

fishoil 20 B F B C C B B B B C B C B C B

fluorine,dry 60 G G G G G F G G D G D D B G G

fluorobenzene 20 D G D D D B C D D D D D B D D

fluorocarbonoils 100 F F F F F F F F F F F F B F B

fluorosilicicacid 100 G G F F F F F F F F F D B F F

fluorosilicicacid,aqueous 60 G G C B B B B G B B B B B B G

formaldehyde,aqueous 60 D G C B B C G F C B C B B B F

formamide 60 G G D B B B C G D B D B B F G

formicacid,aqueous 60 G D D C C B G G D C D C B C G

freonasperDIN8962R11 20 G G C G G G C F C G B G B G G

freonasperDIN8962R113 20 G C B G G G C F C G B G B G G

freonasperDIN8962R114 20 G B B B B G F F C B B B B B G

freonasperDIN8962R12 20 G B B C C G C G C C B C B C G

freonasperDIN8962R13 20 G C B B B G C G C B B G B B G

freonasperDIN8962R134a 20 G G B G B D D F C G C G B G G

freonasperDIN8962R22 20 G C B B B G D F D B D B B B G

fruitjuices 100 G D C B B B B F C B C D B B B

furan 20 G D G G G C D G G G G G B G G

furfural 20 G D G G G C G G D G D G B G G

furfurylalcohol 20 G D G G G C G G G G G G B G G

furnacegases,dry 60 G G C B B B B B D B D B B B B






Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

gasoil 80 B B C D D B B B B D B D B D C

gaswater 40 D G D D D B B D B D B D B D D

gasohol 20 D D D D D B H C D D D D B D D

gelatine,aqueous 40 C G C B B B B B B B B B B B B

glacialaceticacid 60 G D D C C C D G D C D D B D G

glucose,aqueous 80 G G C B B B B B B B B C B B B

glue 20 B B B B B B B B B B B B B B B

glycerine,aqueous 100 G G C B B B B B B B B C B B B

glycerolchlorohydrine 60 G G D C C C G G D C D C B C G

glycine,aqueous,10% 40 F G B C B B B F C B C C B C F

glycol,aqueous 100 G D C B B B C F B B B C B B C

glycolicacid,aqueous,37% 20 G G C B B B B B B B B B B B B

greases,mineral,animalorvegetable 80 B B C C D B B B B D B D B D B

heatingoil,mineral 60 B B C D D B B B B D B D B D C

HenkelP3solution 100 G G C B B B G F B B B C B B F

heptane 60 B B C D D B B B B D B D B D D

hexachlorobutadiene 20 G G G G G B B G D G D D B D G

hexachlorocyclohexane 20 G C G G G B B F G G G D B D G

hexaldehyde 20 G G D G G C G G D G D D B D G

hexane 60 B B C D D B B B B D B D B D D

hexanetriol 20 G G C B B B B B B B B F B F B

hexene 20 B B C C D B B B C D C D B D F

hydraulicfluids,oil-in-wateremulsionsHFA

55 G G C D D B H F B D B D B D F

hydraulicfluids,polyglycolwaterHFC

60 G G C B B B B B B B B B B B B

hydraulicfluids,water-oilemulsionsHFB

60 G G C D D B H F H D H D B D F

hydraulicfluids,hydraulicoilsDIN51524 80 B B C D D B B B B D B D B D C

hydraulicfluids,phosphoricacidesterHFD 80 D D D D H B H D D H D D B D D

hydrazinehydrate 20 G C C B B C G C C B C D B C G

hydrobromicacid,aqueous 60 G D C B B F G G C B C F B F G

hydrochloricacid,conc. 20 G G D B B B B G D B D C B C G

hydrochloricacid,conc. 80 G G D B B B C G D B D D B D G

hydrochloricacid,dilute 20 G D C B B B B G C B B B B B G

hydrocyanicacid 20 G G C B F B F F F B F F B F B






Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

hydrofluoricacid,conc. 20 G G G C C C G G G C G G B C G

hydrogen 20 B G B B B B B B B B B B B B B

hydrogenchloridegas 60 G G D B B B B G D B D C B C G

hydrogenperoxide,aqueous 20 G G D B B B B C D B D D B D C

hydrogenphosphide 20 G G C B B C C F D B D B B F F

hydrogensulphide,aqueous 60 G G C B B B B G C B C C B B G

hydrogensulphide,dry 60 G F C B B B B F C B C C B C F

hydroquinone,aqueous 20 C G C B B B B F B B B C B C F

hydrosulphite,aqueous 40 G G C B B C G F C B C B B B F

hydroxylaminesulphate,aqueous 35 G G C B B C G B B B B B B B B

ink 20 B B B B B B C B C B B B B B B

iodinetincture 20 G D C B B B B C B B B B B B C

iodoform 20 G G G G B B B G G B G G B G G

isobutylalcohol 20 D D B B B B B C C B C B B B B

isooctane 20 B C C D D B B B B D B D B D C

isophorone 20 F C F F B C F F F B F F B F F

isopropanol 60 D G C B B B H B C B C B B B B

isopropylacetate 80 D G D C C C D D D C D D B D D

isopropylchloride 20 D D D D D B B C D D D D B D D

isopropylether 60 D D D G G B D D D G D G B D D

kerosine 20 B B D D D B B B C D B D B D C

lactam 80 G G D D D C D G D D D D B D G

lacticacid,aqueous10% 40 G B B B B B B F B B B B B B F

lanolin 50 B B B B B B B B B B B C B B B

lanolin(woolgrease) 60 B B C C D B B B B D B C B C B

laurylalcohol 20 F F B C C B B F B C B C B C F

lavenderoil 20 C F D G G B B C C G C G B G G

leadacetate,aqueous 60 G D C B B B B F C B B B B B F

leadacetate,aqueous 100 G D C B B B D F C B B D B B F

leadnitrate,aqueous 20 F D C B B B B F B B B B B B F

lemonjuice,undiluted 20 G F C F F B H F B F B B B B B

linoleicacid 20 G F G G G B C F C G C G B G C

linseedoil 60 F C B C C B B F B C B C B C B

liqueurs 20 B B B B B B B B B B B B B B B

lithiumchloride,aqueous 20 G B C B B B B B B B B B B B B






Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

lithiumbromide,aqueous 20 G B C B B B B B B B B B B B B

machineoils,mineral 80 B B C D D B B B B D B D B D C

magnesiumchloride,aqueous 100 D G C B B B B F B B B G B B F

magnesiumsulphate,aqueous 100 D G C B B B B F B B B G B B F

maleicacidanhydride 60 G G G G G B B F G G G G B G G

maleicacid,aqueous 100 G G C B B B B F B B B D B D F

margarine 80 B B C D D B B B B D B D B D B

menthol 60 G G D D D B C G D D D D B D G

mercury 60 B B B B B B B B B B B B B B B

mercurysalts,aqueous 60 G G C B B B B B B B B B B B B

mesityloxide 20 G F G G C F F F F C F G B G G

methane 20 B F B C C B B B B C B C B C B

methanol 60 G G C B B B H B C B C B B B C

methoxybutanol 60 G F C C C B B F B C B D B D F

methylacrylate 20 D D D D D C D D D D D D B D D

methylamine,aqueous 20 G G G B B C D G D B D C B C G

methylbromide 20 D D D D D B B F D D D D B D D

methylchloride 20 D D D D D B B G D D D D B D D

methylchlorine 20 G C D D D B C G D D D D B D G

methylethylketone 20 D D D C C B D D D C D D B D D

methylisobuthylketone 20 D D D D C C D D D C D D B D D

methylmethacrylate 20 D D D D D C D D D D D D B D D

milk 20 G B B C C B B B B C B C B C B

milkoflime 80 G G C F F B B G D F D D B C G

mineraloil 100 B C D D D B B B B D B D B D C

mineralwater 60 G F C B B B B B B B B B B B B

mixedacidI(sulphuricacid/nitricacid<D%0>/water)

20 D D C B B B B D D B D D B D D

mixedacidII(sulphuricacid/phosphoricacid/water)

40 G G D B B B B G D B D C B C G

molasses 100 G G C C C B B F B C B D B D F

monobromobenzene 20 D D D D D B C D D D D D B D D

monochloraceticacidethylester 60 D D D C C B C D D C D D B D D

monochloraceticacidmethylester 60 D D D D B B C D D B D D B D D

morpholine 60 G G D C C F G F D C D D B D F

myricylalcohol 20 B F B B B B B F B B B B B B F






Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

naftolenZD 20 F G D D D B B F C D C D B D G

naphta 20 C D D G G B B C D G D G B G G

naphthalene 60 G G D D D B B G D D D D B D G

naphtoicacid 20 G G F G G B B B C G C G B G G

naturalgas 20 B B B C C B B B B C B C B C B

naturalgas 20 F C B B G B B D B G B D B D B

nickelacetate,aqueous 20 G D C B B C F F B B B B B B F

nickelchloride,aqueous 20 G G C B B B B F B B B B B B F

nickelsulphate,aqueous 60 G G C B B B B F B B B B B B F

nitricacid,conc. 80 G D D B D F D G D D D D B D G

nitricacid,dilute 80 G G C B C B C G C C C D B C C

nitricacid,fuming 60 G D D D D F D G D D D D B D G

nitrobenzene 60 D D D D D C D D D D D D B D D

nitrogen 20 B B B B B B B B B B B B B B B

nitrogentetraoxide 20 G G G G D F G G G D G G B G D

nitroglycerine 20 G G G B B B B G D B D C B C G

nitroglycol,aqueous 20 G F C B B B B F D B D F B F F

nitromethane 20 D D G C C C D D D C D C B C D

nitropropane 20 D D D C C F D D D C D C B C D

nitrousgases 20 D D D B B B B D D B D D B D D

nitrousoxide 20 B B B B B B B B B B B B B B B

n-Propanol 60 G D C B B B C B C B C B B B B

octane 20 G F G G G B B C F G F G B G G

octylalcohol 20 G G B B B B B C C B C C B C C

octylcresol 20 D G D D D C C D G D G D B D D

oleicacid 60 B G C D D B B C B D B D B D C

oleum,10% 20 D D D C C B B D D C D D B D D

oleylalcohol 20 B D B B B B B B B B B B B B B

oliveoil 60 B F B C C B B B B C B C B C B

o-nitrotoluene 60 D G D D D F D D D D D D B D D

oxalicacid,aqueous 100 G G D B B B B G D B D D B C G

ozone 20 C F C B B B B B C C D D B D B

palmkernelfattyacid 60 F F B D D B B F B D B D B D F

palmiticacid 60 F F C D D B B F C D C D B D F

paraffin 60 F F B D D B B F B D B D B D F






Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

paraffinemulsions 40 B B B D D B B B B D B D B D B

paraffinoil 60 B B B D D B B B B D B D B D B

pectin 20 B B B B B B B B B B B B B B B

pentachlorodiphenyl 60 G G D D D F G G D D D D B D G

pentane 20 F F C D D B B F B D B D B D F

peraceticacid,<1% 40 D D D D B B B D D D D D B D D

peraceticacid,<10% 40 D D D D C B H D D D D D B D D

perchloricacid 100 G G D B B B B G D B D D B D G

perchloroethylene 60 G G D D D B B G D D D D B D D

petrol 60 D D C D D B B B C D C D B D D

petrol-benzenemixture,50/50% 20 D C D D D B B C D D D D B D D

petrol-benzenemixture,60/40% 20 D C D D D B B C D D D D B D D

petrol-benzenemixture,70/30% 20 D B D D D B B B D D D D B D D

petrol-benzenemixture,80/20% 20 D B D D D B B B D D D D B D D

petrol-benzene-ethanol,50/30/20% 20 D D D D D B H C D D D D B D D

petroleum 60 B B C D D B B B B D B D B D C

petroleumether 60 B B C D D B B B C D B D B D C

phenol,aqueous,upto90% 80 G G D D D B C G D D D D B D G

phenylbenzene 20 G G D D D B C G D D D D B D G

phenylethylether 20 D D D D D C D D D D D D B D D

phenylhydrazine 60 G G D D D B C G C D C D B D G

phenylhydrazinechlorohydrate,aqueous 80 G G D C B C C G C B C D B D G

phosgene 20 G G G F F F F G G G G G B G G

phosphoricacid,aqueous 60 G G C B B B B G D B D C B B G

phosphorusoxychloride 20 G G G F F F F G D G D G B F G

phosphorustrichloride 20 G G D B B C C G D B D B B F G

photodeveloper 40 G G C B B B B F C B C B B B F

photoemulsions 20 G G B B B B B F B B B B B B F

photofixingbaths 40 G G C B B B B F C B C B B B F

phthalicacid,aqueous 60 G G C B B B B F B B B D B F F

picklingsolution(leatherpickling) 20 G G F C C C C G F C F G B G G

picricacid 20 G C B C C B B C C C C C B C G

picricacid,aqueous 20 G G C B B B B B B B B B B B B

Pineneedleoil 20 G F D G G B B F C D C D B D G

pinene 20 G C C C G B B C C G C G B G G






Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

pine-needleoil 60 B B D D D B B B C D C D B D C

piperidine 20 G G G G G F G G G G G G B G G

potash,aqueous 40 G G C B B B B B B B B B B B B

potassiumacetate,aqueous 20 G C C B B B B F C B B B B B F

potassiumbisulphate,aqueous 40 G D C B B B B F B B B B B B F

potassiumborate,aqueous 60 G D C B B B B F B B B B B B F

potassiumbromate,10% 60 G D C B B B B F B B B B B B F

potassiumbromide,aqueous 60 G D C B B B B F B B B B B B F

potassiumcarbonate,aqueous 40 G G C B B B B B B B B B B B B

potassiumchlorate,aqueous 60 G D C B B B B F D B D C B C F

potassiumchloride,aqueous 60 G D C B B B B F B B B B B B F

potassiumchromate,aqueous 20 G D C B B B B F C B C B B B F

potassiumcyanide,aqueous 40 G F C B B B B B B B B B B B B

potassiumcyanide,aqueous 80 G D C B B B B B C B C D B D B

potassiumdichromate,aqueous40% 20 G G C B B B B F C B C D B C F

potassiumhydroxide,50% 60 D D C B B C D D C B C C B C D

potassiumiodide,aqueous 60 G D C B B B B F B B B C B B F

potassiumnitrate,aqueous 60 G D C B B B B F B B B B B B F

potassiumperchlorate,aqueous 80 G G C B B B B F D B D D B D F

potassiumpermanganate,aqueous 40 G G C B B B B G D B D D B C G

potassiumpersulphate,aqueous 60 G G D B B B B G D B D D B C G

potassiumsulphate,aqueous 60 G G C B B B B F B B B B B B F

propane,liquid/gaseous 20 B B B G G B B B B G B D B D B

propargylalcohol,aqueous 60 F G B B B B B F B B B C B F F

propionicacid,aqueous 60 G G C F F B B G B F B G B F G

propyleneglycol 60 G G C B B B B F B B B B B B F

propyleneoxide 20 G G G G G C G G D G D G B G G

pyridine 20 D D D G G F D D D G D D B D D

pyrrole 20 G G G G D F F C G D G D B D C

rapeseedoil 20 C C C C C B B B C C C G B G G

refrigerantasperDIN8962R11 20 G G C G G G C F C G B G B G G

refrigerantasperDIN8962R113 20 G C B G G G C F C G B G B G G

refrigerantasperDIN8962R114 20 G B B B B G F F C B B B B B G

refrigerantasperDIN8962R12 20 G B B C C G C G C C B C B C G

refrigerantasperDIN8962R13 20 G C B B B G C G C B B G B B G






100

Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

refrigerantasperDIN8962R134a 20 G G B G B D D F C G C G B G G

refrigerantasperDIN8962R22 20 G C B B B G D F D B D B B B G

sagrotan 20 G D C B B B B B C B C B B B B

salicylicacid 20 G B B B B B B G B B B B B B G

saltwater 20 G G B B B B B B B B B B B B G

seawater 20 G C C B B B B B B B B B B B B

silicicacid,aqueous 60 G G C B B B B G B B B B B B G

siliconegrease 20 B B B B B B B B B B B C B B D

siliconeoil 20 B B B B B B B B B B B C B B D

silvernitrate,aqueous 100 G G C B B B B F C B C G B C F

silversalts,aqueous 60 G G C B B B B B C B C C B C B

skydrol 20 D D D G C C D D D F D D B D D

soapsolution,aqueous 20 G B C B B B B F B B B B B B F

soda,aqueous 60 G G C B B B B B B B B B B B B

sodiumbenzoate,aqueous 40 G F C B B B B F B B B B B B F

sodiumbicarbonate 60 G G C B B B B F B B B B B B F

sodiumbicarbonate,aqueous 60 G G C B B B B F B B B B B B F

sodiumbisulphite,aqueous 100 G G C B B B B F B B B B B B F

sodiumchlorate 20 G G D B B B B F D B D D B D F

sodiumchloride 100 G G C B B B B F B B B G B B F

sodiumhydroxide 20 D G C B B B D D C B C C B C D

sodiumhypochlorite,aqueous 20 G G C B B B B F C B C D B D F

sodiumnitrate,aqueous 60 G G C B B B B F B B B B B B F

sodiumnitrite 60 G G C B B B B F C B C B B B F

sodiumphosphate,aqueous 60 G G C B B B B F B B B B B B F

sodiumsilicate,aqueous 60 G G C B B B B F B B B B B B F

sodiumsulphate,aqueous 20 C G C B B B B F B B B B B B F

sodiumsulphate,aqueous 60 G G C B B B B F B B B B B B F

sodiumsulphide 40 G G C B B B B F B B B B B B F

sodiumsulphide 100 G G C B B B B F C C C D B C F

sodiumthiosulphate 60 F G B B B B B F D B D B B B F

spermaceti 20 F F C D D B B F B D B D B G F

spindleoil 60 B B C D D B B B B D B D B D B

starchsyrup 60 G G B B B B B F B B B B B B F

starch,aqueous 60 G G B B B B B B B B B B B B B






101

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

steam 130 G D D C B D H D D B D D B D D

steam 130 G D D C B D H D D B D D B D D

stearicacid 60 B B C B B B B B B B B D B B B

stoddardsolvent 20 B B D D G B B B B G B G B G G

styrene 20 G G D D D F C G D D D D B D D

succinicacid,aqueous 60 G D C B B B B F B B B B B B F

sugarsyrup 60 G G G B B B B F B B B B B F F

sulphur 60 G F G B B B B F G B G G B G F

sulphurchloride 20 G G D C G B B B D G D G B G G

sulphurdioxide,aqueous 60 G G D B B B B G D B D D B C G

sulphurdioxide,dry 80 G G D B B B B F D B D D B C F

sulphurdioxide,liquid 60 G G D B B B B G D B D D B G G

sulphurhexafluoride 20 F F B B B B B B B B B F B B B

sulphuricacid,conc. 50 G D D B B B C G D B D D B C D

sulphuricacid,dilute 20 G G D B B B B G C B C C B C G

sulphurylchloride 20 G G D B C B B G D C D C B C G

tallow 60 F G C D D B B F B D B D B D F

tannicacid 60 C G C B B B B B B B B B B B B

tannin 40 G B B B B B B F C B C B B B F

tanningextract 20 C G C B B B B B B B B B B B B

tar 20 G G D D D B F G D D D D B D G

taroil 20 G G D D D B F G D D D D B D G

tartaricacid,aqueous 60 G G C B B B B B B B B B B B B

tetrachlorethane 60 G G D D D B C G D D D D B D G

tetrachloroethylene 60 G G D D D B C G D D D D B D G

tetraethyllead 20 G G D D G B B C C G C G B G G

tetrahydrofuran 20 G G D D D C D G D D D D B D G

tetrahydronaphthalene(tetralin) 20 G G D D D B B F D D D D B D G

thionylchloride 20 G G D B B B B G D B D C B C G

thiophen 60 G G D D D F D G D D D D B D G

tin(II)chloride,aqueous 80 G G C B B B B F B B B B B B F

titaniumtetrachloride 20 C B C B B B C C B B B B B B C

toluene 20 D D D D D B C D D D D D B D D

towngas,benzene-free 20 B B C D D B B B B D B D B D B

transformeroil 60 B B D D D B B B C D B D B D C






102

Technical Manual

Medium °C1) ACM

AU CR CSM

EPDM

FFKM

FKM

FVMQ

HNBR

IIR NBR

NR PTFE

SBR

VMQ

transmissionFluidtypeA 20 B B C C G B B B B G B G B G C

triacetin 20 G G C C B F G G C B C C B D G

tributoxyethylphosphate 20 G G D D D B C G D D D D B D G

tributylphosphate 60 G D D D D B C G D D D D B D G

trichloroaceticacid,aqueous 60 G G D C C B D G C C C C B C G

trichloroethylphosphate 20 G G D G G C D G D G D G B G G

trichloroethylene 20 G D D D D B C G D D D D B D D

tricresylphosphate 60 G C D D C F C F D C D D B D G

triethanolamine 20 G G C C C C G G D C D D B F G

triethylaluminium 20 G G G G G C C G G G G G B G G

triethylborane 20 G G G G G B B G G G G G B G G

triglycol 20 G F B B B B B F B B B B B B F

trimethylolpropane,aqueous 100 G G C C C B B F D C D C B F F

trinitrotoluene 20 G G C C G B C C G G G G B G G

trioctylphosphate 60 G G D C C B C F D C D D B G G

trisodiumphosphate 20 G F C B B B B B B B B B B B B

turpentine 60 F D D D D B B G C D C D B D G

turpentineoil 20 F G D D D B B G C D C D B D G

urea,aqueous 60 G G C B B B B F B B B B B B F

vaseline 60 B F B C D B B B B D B D B D C

vaselineoil 60 B F B C D B B B B D B D B D C

vinylacetate 20 G G G G G C G G G G G G B G G

vinylchloride,liquid 20 G G G G G C G G G G G G B G G

water 100 D D C B B C C F B B B C B B C

waxalcohol 60 F F C D D B B F C D B D B G F

whisky 20 G B B B B B B B B B B B B B B

whitelye 100 G G C B B C D G C B C D B B G

whiteoil 20 B F C C G B B B B G B G B G B

whitespirit 60 B F C D D B B F C D B D B D F

wine 20 F B B B B B B B B B B B B B B

xylamon 20 D C D D D B C G D D D D B D G

xylene 20 D D D D D B C D D D D D B D D

yeast,aqueous 20 G F B B B B B B B B B B B B B

zeolite 20 B B B B B B B B B B B B B B B

zincacetate 20 B B C C B B B B C B C B B D B






10

Suggestion for Storage

(inconformitywiththerevisionofISO2230dated16.09.1992)

Storage conditionsThestoragetemperaturemustbebelow25°C;theitemsmustbestoredawayfromsourcesofdirectheatandmustnotbeexposedtodirectsunlight.Therelativeairhumiditymustbesuchthatnocondensa-tionoccurswhenthetemperatureinthestorageroomchanges.Theeffectofozoneandionisingradiationmustalwaysbeexcluded.

PackagingAllmaterialsforbins,forcoveringandwrappingmustbefreeofsubstancesthathaveadecomposingeffectonelastomers.Suitablepackagingmaterialsincludesodapaper,aluminiumfoiloropaquePEfoil(min.0,075mmthick).

Thepackageditemsmustbelabelledasfollows:a)part/articlenumber ISCO-Ring ofmanufacturer 20-2/335674

b)descriptionofpolymer 72NBR872

c) quarterandyearofmanufacture oftheelastomerpart 1/99

d)theclassificationofthe elastomer(group) group2

e)numberofpackages 10pieces

f) nameortrademark ofmanufacturerSimrit.

Theelastomerproductsaredividedintothreegroups:

1st storage time in years

1st extension in years

Group 1 NR,AU,EU,SBR 5 2

Group 2 NBR,HNBR,ACM,AEM,XNBR,ECO,CIIR,CR,IIR

7 3

Group 3 FKM,VMQ,EPDM,FVMQ,PVMQ,FFKM,CSM

10 5

Additionalextensionsarepossibleundercertaincircumstances,butonlyafterconsultationwiththerelevanttechnicaldepartment.Thetechnicaldepart-mentwillconductappropriatetestsandwilldecidewhethertheproductscancontinuetobeusedormustbediscarded.

Suggestions for the assessment of elas-tomer parts after the first storage time:

1)Testinaccordancewiththerespectiveproductspecifications.Ifsuchactionisnotincludedintheproductspecifications:

2)VisualinspectionEverypartoreverycomponentintherepresenta-tivesamplemustbecheckedasfollows:

lastingdeformationsuchasfoldsorflatsmechanicaldamagesuchascuts,cracks,abra-sionsordetachedlayerscrackformationonthesurface,observedundera10xmagnifyingglasschangesofstatusofthesurfacesuchashardening,softening,tackiness,discol-orationanddirt.

Theinspectedfeaturesofthestoredpartsorcompo-nentsmustberecorded.Ifthetestsyieldrecordableresults,therecordsmustincludetheacceptableconfidenceintervaloftheaveragevaluesofeverytestparameter.

Arecordmustalsocontainthefollowing:

a)thestoredquantityofeveryitemorevery component,thedateoffirstpackaging, thedateofstorage

b)thedateofeachsubsequentre-packaging

c) themanufacturer'sbatchnumber

d)thenumberofpartsorcomponents thatformarepresentativesampleofthese partsorcomponents.


10

Technical Manual

Summary of the Mentioned Standards

DIN3760 Rotaryshaftliptypeseals

DIN3761 Rotaryshaftliptypesealsforautomobiles

DIN3771 Fluidsystems–O-rings

DIN7168 Generaltolerancesforlinearandangulardimensionsandgeometricaltolerances

DIN7715 Permissibledeviationsforsoftrubberparts(extractfromDIN7715part2)

DIN7716 RubberproductsRequirementsforstorage,cleaningandmaintenance

DIN7724 Polymericmaterials;groupingofpolymericmaterialsbasedontheirmechanicalbehaviour

DIN9088 Aerospaceseries-Storagelifeofrubberproducts

DIN16901 Plasticmouldings;tolerancesandacceptanceconditionsforlineardimensions

DIN24320 Fire-resistantfluids-HydraulicfluidsofcategoriesHFAEandHFAS-Characteristicsandrequirements

DIN51524 Hydraulicfluids–Hydraulicoils–HL,HLP,HVLP

DIN51604 FAMtestingfluidforpolymermaterials,Compositionandrequirements

DIN52612 TestingofthermalinsulatingmaterialsDeterminationofthethermalconductivitywiththeguardedhotplateapparatus,Procedureandevaluation

DINENISO6721 TestingofpolymermaterialsTorsionvibrationtest

DINENISO1183 TestingofplasticsandrubberDeterminationofthedensity

DIN53504 TestingofrubberTensiletrials

DIN53505 TestingofrubberShoreAandDhardnesstest

DINISO34-1 TestingofrubberDeterminationofthetearstrengthofelastomers;Trousertestpiece

DIN53508 TestingofsoftrubberAcceleratedageing

DIN53509 TestingofrubberResistanceofrubbertoozonecracking

DIN53512 TestingofrubberDeterminationthereboundresilienceofrubber

DIN53513 TestingofrubberandelastomersDeterminationoftheviscoelasticpropertiesofelastomersonexposuretoforcedvibrationatnon-resonantfrequencies

DIN53516 TestingofrubberandelastomersDeterminationofabrasionresistance

DINISO815 TestingofrubberDeterminationofthecompressionset.ThermalTestingProcedures.

DIN53533 Testingofelastomers;Testingofheatgenerationandservicelifeduringthefatiguetest(flexometertest)

DIN53538 Testingofelastomers;StandardreferenceelastomersForcharacterisingservicefluidswithrespecttotheiractiononvulcanisednitrilerubbers

DIN53545 Testingofelastomers;Determinationoflow-temperaturebehaviourofelastomers;principlesandtestmethods

DIN53546 Testingofelastomers;Impacttestforthedeterminationofthelow-temperaturebrittlenesspoint


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DINISO1817 TestingofrubberandelastomersDeterminationofthebehaviourofrubberandelastomerswhenexposedtofluidsandvapours

DINISO48 ElastomersandthermoplasticelastomersTensilestrength.

DINISO1629 RubberandlatexDifferenceandabbreviations

VDMA24317 HydraulicfluidsFlameretardanthydraulicfluidsMinimumtechnicalrequirements

ASTMD395 TestMethodsforRubberProperty-CompressionSet

ASTMD471 Standardtestmethodforrubberproperty-effectofLiquids

ASTMD746 Testmethodforbrittlenesstemperatureofplasticsandelastomersbyimpact

ASTMD945 Testmethodsforrubberpropertiesincompressionorshear(Mechanical-Oscillograph)

ASTMD1418 Practiceforrubberandrubberlatices-Nomenclature

ASTMD1600 Abbreviationsoftermsrelatingtoplastics

ASTMD2000 Classificationsystemforrubberproductsinautomotiveapplications

DINStandardLeafletscanbeobtainedfrom:Beuth-VertriebGmbH,D-10719Berlin,Uhlandstraße175,aswellasD-50672Cologne,Friesenplatz16ASTMstandardscanalsobeobtainedfromBeuth-Vertrieb.Summaryofapplicablestandards.


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Asia Merkel Freudenberg Fluidtechnic GmbHc/oEKKEagleIndustryAsiaPacificPte.Ltd.52SerangoonNorthAvenue4#03-02,EverTechBuildingSingapore555853

Headquarter Europe Merkel Freudenberg Fluidtechnic GmbHIndustriestraße6421107HamburgPhone: ++40/75306-0Fax: ++40/75306-440E-mail: [email protected]


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