technical handbook o-rings 4. basic elastomers handbook/06 - eriks nv - o-ring technical... ·...

Sealing Elements

9

All the information in this documentation has been compiled with the greatest of care. Despite this we can bear no responsibility whatsoever for any errors present in the documentation. The recommendations are intended as guidelines.

www.eriks.info

Technical Handbook O-rings

4.1. Select the elastomerThough“elastomer”issynonymouswith“rubber”,itismoreformallyapolymerthatcanbemodifiedtoastateexhibitinglittleplasticflowandquickornearlycompleterecoveryfromanextendingforce,anduponimmediatereleaseofthestress,willreturntoapproximatelyitsownshape.AccordingtothedefinitionoftheAmericanSocietyforTestingandMaterials(ASTM)fortheterm“elastomer”itisessentialthat:*Anelastomerpartmustnotbreakwhenstretchedapproxi-mately100%.*Afterbeingstretched100%,heldfor5minutesandthenreleased,itmustretracttowithin10%ofitsoriginallengthwithin5minutesafterrelease.

Resistance to the mediaAsusedthroughoutthismanual,theterm“media”denotesthesubstanceretainedbytheo-ring.Itmaybealiquid,agas,oramixtureofboth.Itcanevenincludepowdersorsolidsaswell.ThechemicaleffectofthemediaontheO-ringisofprimeimpor-tance. It must not alter the operational characteristics or reduce thelifeexpectancyoftheo-ring.ExcessivedeteriorationoftheO-ringmustbeavoided.Itiseasy,however,tobemisledonthispoint.AsignificantamountofvolumeshrinkageusuallyresultsinprematureleakageofanyO-ringseal,whetherstaticordynamic.Ontheotherhand,acompoundthatswellsexcessively,ordevel-opsalargeincreaseordecreaseinhardness,tensilestrength,orelongation,willoftencontinuetoservewellforalongtimeasastaticseal,inspiteofundesirabletestresultsonelastomercom-pounds.Thefirststepinselectingthecorrectmaterialistoselectanelastomerthatiscompatiblewiththechemicalenvironment.

Relationship of Cross-link Denisity and Physical Properties

4. Basic Elastomers

Cross-linkDensity

Phy

sica

lPro

pert

y

High

Low High

CompoundAcompoundisamixtureofbasepolymer(s)andotherchemi-calswhichformafinishedrubbermaterial.Moreprecisely,theterm‘compound’referstoaspecificblendofingredientstailoredforparticularcharacteristicsrequiredtooptimizeperformanceinsomespecificservice.Thebasisofcompounddesignisselectionofthepolymertype.Totheelastomer,thecompoundermayaddreinforcingagents,suchascarbonblack,coloredpigments,curingorvulcanizingagents,activators,plasticizers,accelerators,anti-oxidantsoranti-radiationaddiditives.Theremaybehundredsofsuchcombina-tions.

The physics of RubberRubberiscomposedoflongchainsofrandomlyorientedmol-ecules.Theselongchainsaresubjecttoentanglementandcross-linking.Theentanglementhasasignificantimpactontheviscoelasticpropertiessuchasstressrelaxation.Whenarubberisexposedtostressorstrainenergy,internalrearrangementssuchasrotationandextensionofthepolymerchainsoccur.Thesechangesoccurasafunctionoftheenergyapplied,thedurationandrateofapplication,aswellasthetemperatureatwhichtheenergyisapplied.ISO1629identifiesapproximately25elastomerictypes.Thischaptercoversthevariousmaterialtypesusedin o-ringmanufacture.

Sealing Elements

10


www.eriks.info


Acrylonitrile butadiene, Nitrile or Buna N (NBR)Nitrile,chemically,isacopolymerofbutadieneandacrylonitrile.Acrylonitrilecontentvariesincommercialproductsfrom18%to50%.Asthenitrilecontentincreases,resis-tancetopetroleumbaseoilsandhydrocarbonfuelsincreases,butlowtemperatureflex-ibilitydecreases.Duetoitsexcellentresistancetopetroleumproducts,anditsabilitytobecompoundedforserviceoveratemperaturerangeof-30°Fto+250°F(-35°Cto+120°C),nitrileisthemostwidelyusedelastomerinthesealindustrytoday.Alsomanymilitaryrubberspeci-ficationsforfuelandoilresistantO-ringsrequirenitrilebasedcompounds.Itshouldbementionedthattoobtaingoodresistancetolowtemperature,itisoftennecessarytosacrificesomehightemperatureresistance.Nitrilecompoundsaresuperiortomostelastomerswithregardtocompressionset,tear,andabrasionresistance.Nitrilecompoundsdonotpossessgoodresistancetoozone,sunlight,orweather.Theyshouldnotbestorednearelectricmotorsorotherozonegeneratingequipment.Theyshouldbekeptfromdirectsunlight.However,thiscanbeimprovedthroughcompounding.NBRisthestandardmaterialforhydraulicsandpneumatics.NBRresistsoil-basedhydraulicfluids,fats,animalandvegetableoils,flameretardantliquids(HFA,HFB,HFC),grease,water,andair.Speciallow-temperaturecompoundsareavailableformineraloil-basedfluids.Byhydrogenation,carboxylicacidaddition,orPVCblending,thenitrilepolymercanmeetamorespecifiedrangeofphysicalorchemicalrequirements.

ThequalityofNitrile-compoundsdependsonthepercentageofacrylonitrileinthebasepolymer.Thefollowingtableindicatesthechangeofpropertiesasafunctionofacrylo-nitrile content.

4. Basic Elastomers

Acr

ylon

itrile

%

50% -15°C

18% -55°C

Flex

ibili

tya

tlow

tem

pera

ture

Low

High

Volu

me

chan

gein

oil

Higher

Lower

Com

pres

sion

set

Low

High

Per

mea

bilit

y

Sealing Elements

11


www.eriks.info


Hydrogenated nitrile, or highly saturated nitrile (HNBR)HNBRhasrecentlybeendevelopedtomeethighertemperaturesthanstandardNBRwhileretainingresistancetopetroleumbasedoils.Obtainedbyhydrogenatingthenitrilecopolymer,HNBRfillsthegapleftbetweenNBR,EPDMandFKMelastomerswherehightemperatureconditionsrequirehightensilestrengthwhilemaintainingexcellentresistancetomotoroils,sourgas,amine/oilmixtures,oxidizedfuels,andlubricatingoils.HNBRisresistanttomineraloil-basedhydraulicfluids,animalandvegetablefats,dieselfuel,ozone,sourgas,diluteacidsandbases.HNBRalsoresistsnewbio-oils(biologi-caloils).HNBRissuitableforhighdynamicloadsandhasagoodabrasionresistance.HNBRissuitablefortemperaturesfrom-30°Cto+150°C(-20°Fto+302°F).

Carboxylated nitrile (XNBR)ThecarboxylgroupisaddedtosignificantlyimprovetheabrasionresistanceofNBRwhileretainingexcellentoilandsolventresistance.XNBRcompoundsprovidehighten-silestrengthandgoodphysicalpropertiesathightemperatures. XNBRissuitablefortemperaturesfrom-30°Cto+150°C(-20°Fto+302°F).

Nitrile/PVC resin blends (NBR/PVC)PVCresinsareblendedwithnitrilepolymerstoprovideincreasedresistancetoozoneandabrasion.ThePVCalsoprovidesasignificantimprovementinsolventresistance,yetmaintainssimilarchemicalandphysicalproperties,commonlynotedamongnitrile elastomers.TheadditionofthePVCresinsalsoprovideagreaterpigment-carryingcapacitywhichallowbetterretentionofpastelandbrightcolors.

Ethylene Propylene, and Ethylene Propylene Diene rubber (EPM, EPDM)Ethylenepropylenerubberisanelastomerpreparedfromethyleneandpropylenemonomers(ethylenepropylenecopolymer)andattimeswithanamountofathirdmonomer(ethylenepropyleneterpolymers).Ethylenepropylenerubberhasa temperaturerangeof-50°Cto+120°/150°C(-60°Fto+250°/300°F),dependingonthecuringsystem.Ithasagreatacceptanceinthesealingworldbecauseofitsexcellentresistancetoheat,waterandsteam,alkali,mildacidicandoxygenatedsolvents,ozone,andsunlight.ThesecompoundsalsowithstandtheaffectofbrakefluidsandSkydrol™andotherphosphateester-basedhydraulicfluids.EPDMcompoundsarenotrecommendedforgasoline,petroleumoilandgrease,andhydrocarbonenvironments.SpecialEPDMcom-poundshavegoodresistancetosteam.

• EPDMSulphurcured:inexpensivematerialfornormaluse,maximumtemperatureof+120°C(+250°F).

• EPDMPeroxidecured:forhotwater,vapor,alcohols,ketones,enginecoolants,organicandinorganicacidsandbases.Notresistanttomineraloils.Formaximumtemperaturesof+150°C(+300°F).

4. Basic Elastomers

Sealing Elements

12


www.eriks.info


4. Basic Elastomers

Neoprene rubber Polychloroprene (CR)Neoprenerubbersarehomopolymersofchloroprene(chlorobutadiene)andwereamongtheearliestsyntheticrubbersusedtoproduceseals.CRhasgoodagingcharacteristicsinozoneandweatherenvironments,alongwithabrasionandflexcrackingresistance.CRisnoteffectiveinaromaticandoxygenatedsolventenvironments.Neoprenecanbecom-poundedforservicetemperaturesof-40°Cto+110°C(-40°Fto+230°F).Mostelastomersareeitherresistanttodeteriorationfromexposuretopetroleumbasedlubricantsoroxygen.Neopreneisunusualinhavinglimitedresistancetoboth.This,combinedwithabroadtemperaturerangeandmoderatecost,accountsforitsdesirabil-ityinmanysealapplicationsforrefrigerantslikeFreon® and ammonia. CR is resistant to refrigerants,ammonia,Freon®(R12,R13,R21,R22,R113,R114,R115,R134A),sili-coneoils,water,ozone,vegetableoils,alcohols,andlow-pressureoxygen.CRhasaverylow resistance to mineral oils.

Silicone rubber (VMQ)Siliconesareagroupofelastomericmaterialsmadefromsilicone,oxygen,hydrogen,andcarbon.Extremetemperaturerangeandlowtemperatureflexibilityarecharacteristicsofsiliconecompounds.Asagroup,siliconeshavepoortensilestrength,tearresistance,andabrasionresistance.Specialcompoundshavebeendevelopedwithexceptionalheatandcompressionsetresistance.Highstrengthcompoundshavealsobeenmade,buttheirstrengthdoesnotcomparetoconventionalrubber.Siliconespossessexcellentresistancetoextremetemperatures-50°Cto+232°C (-58°Fto+450°F).Somespecialcompoundsresistevenhighertemperatures.Retentionofpropertiesofsiliconeathightemperatureissuperiortomostotherelasticmaterials.Siliconecompoundsareverycleanandareusedinmanyfoodandmedicalapplicationsbecausetheydonotimpartodorortaste.SiliconecompoundsarenotrecommendedfordynamicO-ringsealingapplicationsduetorelativelylowtearstrengthandhighcoef-ficientoffriction.Siliconeisresistanttohotair,ozone,UVradiation,engineandtransmissionoils,animalandvegetablefatsandoils,andbrakefluids.VMQalsohaslowresistancetomineraloils.Siliconecanbecompoundedtobeelectricallyresistant,conductive,orflameretardant.Manysiliconecompoundshaveahigherthannormalmoldshrinkage.Thereforeproduc-tionmoldsforsiliconeproductsareoftendifferentthanmoldsfornitrile.

Fluorosilicone (FVMQ)Fluorosiliconecombinesthegoodhigh-andlow-temperaturepropertiesofsiliconewithlimitedfuelandoilresistance.Fluorosiliconesprovideamuchwideroperationaltempera-turerangethanFluorocarbonrubbers.PrimaryusesoffluorosiliconeO-ringsareinfuelsystemsattemperaturesupto+177°C(+350°F)andinapplicationswherethedry-heatresistanceofsiliconeO-ringsarerequired.FluorosiliconeO-ringsmayalsobeexposedtopetroleumbasedoilsand/orhydro-carbonfuels.Insomefuelsandoils;however,thehightemperaturelimitinthefluidlistismoreconservativebecausefluidtemperaturesapproaching200°C(390°F)maydegradethefluid,producingacidswhichattackfluorosiliconeO-rings.Forlow temperatureapplications,fluorosiliconeO-ringssealattemperaturesaslowas-73°C(-100°F).Duetorelativelylowtearstrength,highfrictionandlimitedabrasionresistanceofthesematerials,theyaregenerallyrecommendedforstaticapplicationsonly.Fluorosiliconeswithhightearstrengtharealsoavailable.Someofthesecompoundsexhibitimprovedresistancetocompressionset.Manyfluorosiliconecompoundshaveahigherthannormalshrinkageratesoproductionmoldsforfluorosiliconeproductsareoftendifferentfrommoldsfornitrile.

Sealing Elements

13


www.eriks.info


4. Basic Elastomers

Polyurethane rubber (AU, EU)Polyurethanes(Polyester-urethaneAU),(Polyether-urethaneEU)exhibitoutstandingmechanicalandphysicalpropertiesincomparisonwithotherelastomers.Urethanesprovideoutstandingresistancetoabrasionandtearandhavethehighestavailabletensilestrengthamongallelastomerswhileprovidinggoodelongationcharacteristics.Etherbasedurethanes(EU)aredirectedtowardlowtemperatureflexibilityapplications.Theesterbasedurethanes(AU)provideimprovedabrasion,heat,andoilswellresis-tance. Overatemperaturerangeof-40°Cto+82°C(-40°Fto+180°F),resistancetopetroleumbasedoils,hydrocarbonfuels,oxygen,ozoneandweatheringisgood.However,polyurethanesquicklydeterioratewhenexposedtoacids,ketonesandchlo-rinatedhydrocarbons.Certaintypesofpolyester-urethanes(AU)arealsosensitivetowaterandhumidity.Polyether-urethanes(EU)offerbetterresistancetowaterandhumidity.Theinherenttoughnessandabrasionresistanceofpolyurethane(EU)sealsisparticu-larlydesirableinhydraulicsystemswherehighpressures,shockloads,widemetaltoler-ances,orabrasivecontaminationisanticipated.

Fluorocarbon rubber (FKM)Fluorocarbonelastomershavegrowntomajorimportanceinthesealindustry.Duetoitswiderangeofchemicalcompatibility,temperaturerange,lowcompressionset,andexcellentagingcharacteristics,fluorocarbonrubberisthemostsignificantsingleelasto-merdevelopedinrecenthistory.Fluorocarbonelastomersarehighlyfluorinatedcarbon-basedpolymersusedinappli-cationstoresistharshchemicalandozoneattack.Theworkingtemperaturerangeisconsideredtobe-26°Cto+205°/230°C(-15°Fto+400°/440°F).Butforshortworkingperiodsitwilltakeevenhighertemperatures.Specialcompoundshavingimprovedchemicalresistancearealsoavailablewithnewtypesalwaysbeingdeveloped.Generallyspeaking,withincreasingfluorinecontent,resistancetochemicalattackisimprovedwhilelowtemperaturecharacteristicsarediminished.Thereare,however,specialtygradefluorocarbonsthatcanprovidehighfluorinecontentwithlowtemperatureproperties.

Sealing Elements

14


www.eriks.info


FluorocarbonO-ringsshouldbeconsideredforuseinaircraft,automobileandothermechanicaldevicesrequiringmaximumresistancetoelevatedtemperaturesandtomanyfluids.FKM(FPM,Viton®,Fluorel®)resistmineraloilsandgreases,aliphatic,aromaticandalsospecialchlorinatedhydrocarbons,petrol,dieselfuels,siliconeoilsandgreases.Itissuitableforhighvacuumapplications.Manyfluorocarboncompoundshaveahigherthannormalmoldshrinkagerate,moldsforfluorocarbonproductsareoftendifferentfrommoldsforNitrile.

Perfluorocarbons (FFKM)Therelativeinertnessoffluorocarbonrubbersisprovidedbyfluorine-carbonbondsontheelastomerbackbone.Generallyspeaking,withincreasingfluorinecontent,resistancetochemicalattackisimproved.Wherefluorocarbonrubbershaveafluorinecontentof63-68%,theperfluorocarbonshaveafluorinecontentof73%.Perfluorelastomerspossessexcellentresistancetoextremetemperatures-26°Cto+260°C(-15°Fto+500°F).FFKMperfuoroelastomers:(Kalrez®)offersthebestchemicalresistanceofallelastomers.Sometypesareparticularlysuitableforhotwater,steamandhotamines.Someresisttemperaturesupto+326°C(+620°F).Manyperfluorocarboncompoundshaveunusualmoldshrinkage,productionmoldsforperfluorocarbonproductsaredifferentfrommoldsfornitrile.

Teflon®-FEP/PFATeflon®FEP/PFAisacopolymeroftetrafluorethyleneandhexafluorpropylene.Teflon® FEP/PFAhasalowermeltingpointthanPTFEmakingitsuitableforinjectionmoulding.Teflon®FEP/PFAisusedforencapsulationwithTeflexO-rings.Teflon®FEP/PFAhasawidespectrumofchemicalcompatibilityandtemperaturerangeandexcellentagingcharacteristics.MaximumoperatingtemperatureforTeflon®FEP/PFAis+205°C(+400°F).ATeflon®FEP/PFAencapsulationisavailableforhighertemperatures(260°C).

TFE/P (Aflas®) (FEPM)TFE/Pisacopolymeroftetrafluoroethyleneandpropylenewithafluorinecontentofapp.54%.Thismaterialisuniqueduetoitsresistancetopetroleumproducts,steam,andphosphate-esters.Insomerespectsitexhibitsmediacompatibilitypropertiessimilartoethylenepropyleneandfluorocarbon.Thecompressionsetresistanceathightemperaturesisinferiortostandardfluorocarbons.Servicetemperaturesare-5°C(25°F)to+204°C(+400°F).TFE/Pprovidesimprovedchemicalresistancetoawidespectrumofautomotivefluidsandadditives.Itisresistanttoengineoilsofalltypes,enginecoolantswithhighlevelofrustinhibitors,extremepressure(EP)gear lubricants,transmissionandpowersteeringfluids,andalltypesofbrakefluidsincludingDOT3,mineraloil,andsiliconeoil.TFE/Pisidealforheattransfermedia,amines,acidsandbases,aswellashotwaterandsteamupto+170°C(+340°F).

4. Basic Elastomers

Sealing Elements

15


www.eriks.info


Polyacrylate rubber (ACM)Polyacrylate-AcrylicAcidEster.Thesecompoundsaredesignedtowithstandheatwhileretainingoilresistance.Speciallydesignedforsulfurbearingoilapplications,ACMsaresubjectedtoheatandbearingenvironments.Theyhavegoodresistancetodryheat,oxy-gen,sunlight,andozonebuttheirlowtemperaturepropertiesarerelativelypoorandtheyhavelowswellinmineraloils.Servicetemperaturesare-20°C (-5°F)to150°C(300°F).ACMismainlyusedforO-ringsandshaftsealstosealheavyoilsathightemperaturesandintheautomotiveindustryfortransmissionandpower steering applications.

Epichlorohydrin (CO, ECO)Epichlorohydrinrubbercompoundsarenotedfortheirsuperiorgasimpermeabilityandphysicalpropertiesoverawidetemperaturerangewhilemaintainingexcellentresistancetopetroleumoils.Ithasastablecyclingcapabilityfromlowtohigh temperature.Resistancetoozone,oxidation,weathering,andsunlightareothertypicalECOqualities.Servicetemperaturesare-51°Cto150°C(-60°Fto+300°F).Compoundsfromthispolymercanexhibitacorrosivenatureandcanbedifficulttopro-cessinmanufacturing.

Vamac® EthyleneAcrylate.Thismaterialexhibitspropertiessimilartopolyacrylatebutcanbefor-mulatedtoexhibitlowertemperaturecapabilities.Ithasexcellentresistanceto oxidation,automatictransmission,andpowersteeringfluids.Thetemperatureservicerangeis-40°Cto+150°C(-40°Fto+300°F).

Styrene Butadiene (SBR, Buna S)Thismaterialissimilartonaturalrubber.O-ringusagehasbeenondeclinesincetheintro-ductionofethylenepropylene.SBRstillfindsserviceinbrakefluidapplications,althoughthehightemperaturerangeisinferiortothatofethylenepropylene compounds.Servicerangeforthismaterialis-50°Cto+110°C(-65°Fto+225°F).

Butyl (IIR)ButylhasexcellentresistancetophosphateesterfluidssuchasSkydrol™,buthasaninfe-riorhightemperaturelimitwhencomparedtoethylenepropylene.Butylexhibitsthebestresistancetogaspermeabilityandsomerocketpropellents.ForO-ringapplications,butylhasbeenallbutreplacedbyethylenepropylene.Thetemperatureservicerangeforthismaterialis-55°Cto+105°C(-65°Fto+225°F).

Special materialsERIKSoffersmanypossibilitiesinspecialO-ringscompoundstoimprovecertainproper-tieslike:SiliconefreeandLabsfreeCoatings-EncapsulatedFEPandPFA-PTFEO-rings-InternalLubrication-HighPurity-MicroO-rings-Vulc-O-rings.

HomologationsERIKSoffersmanycompoundswithhomologations,like:KTW–FDA–WRC–NSF–DVGWandmanymore.

4. Basic Elastomers

®

Sealing Elements

16


www.eriks.info


Table 3A-1

Elastomer NBR EPDM CR VMQ FVMQ EU FKM FFKM FEP/PFA ASTM Nitrile Neoprene Silicone Fluoro Urethane Fluoro Perfluoro encapsu- silicone carbon carbon latedGENERAL

Hardness(Shore"A") 20/90 30/90 15/95 20/90 35/80 60/95 50/95 65/90 -

Temp.range°F/°Cmax. 230/110 266/130 248/120 446/230 446/230 176/80 410/210 620/326 400/205

Temp.range°F/°Cmin. -30/-35 -67/-55 -49/-45 -67/-55 -76/-60 -22/-30 5/-15 -58/504 -76/-605

NOTE:Thetemperaturerangeisstronglydependentbythespecificcompound

Compression Set B C C A B E C B E

WearResistance C C C E E A C C E

GasPermeability C C C E E B C C E

NOTE:ThecompressionsetvalueforKalrez®isrelativetotemperature.Inlowtemperatureapplicationsthisvalueisreasonable,inhightemperaturesthis

valueisgoodtoverygood.

Air E B C A B C B A +

Alcohol B A B B B U E A +

Aldehydes U B U C U U U Bfi +

AliphaticHydrocarbons C U E E A C A A +

Alkalis B A C B B B C A +

Amines B1 B1 B1 E1 B1 U U Bfi +

AnimalFats B U C C A C B A +

AromaticHydrocarbons D U D U B D A A +

Esters,AlkylPhosphate U B U C U U U A +

(Skydrol)

Esters,ArylPhosphate U A U C B U A A +

Esters,Silicate C U E U B U A A +

Ethers U E U U E E U A +

Halogenatedhydrocarbons U U U U B E A A +

InorganicAcids E C B B B U A A +

Ketones U A A C A U U B +

MineralOil,highanalinefats B U C C B A A A +

MineralOil,lowanalinefats B U U E B B A A +

OrganicAcids C C C B B U C A +

SiliconeOils A A2 A E E A A A +

VegetableOils A U C B B E A A +

Water/Steam C A E E E U B⁄ C4 +

A Good 1 Seethelist"compoundselectionforchemicalsandfluids" B Satisfactory 2 EPDMmayshrink C Fair 3 DependingonFKMtype D Doubtful 4 Dependingoncompound E Poor 5 Depending on elastomer core U Unsatisfactory + ingeneral"A"becausetheencapsulationisFEP/PFA

Thisinformationisintendedonlyasaguideline.Chemicalcompatibilitylistsshouldbeconsulted.ERIKSwillprovidethisonrequest.

WheneverpossiblethefluidcompatibilityoftheO-ringcompoundshouldberated"A".Forastaticsealapplicationarating"B"isusuallyacceptable,

but it should be tested.

Wherea"B"ratedcompoundmustbeused,donotexpecttore-useitafterdisassembly.Itmayhaveswollenenoughthatitcannotbereassembled.

Whenacompoundrated"C"istobetried,besureitisfirsttestedunderthefullrangeofoperatingconditions.

Itisalsoparticularlyimportanttotestsealcompoundsunderserviceconditionswhenastrongacidistobesealedatelevatedtemperaturesbecause

therateofdegradationofrubberatelevatedtemperaturesismanytimesgreaterthantherateofdegradationatroomtemperature.

4. Basic Elastomers

Sealing Elements

17


www.eriks.info


Chemical and Physical Tables

NBR 6.9- 2.0-15 20-100 100-650 Good -70to0 -57to 210to 99to Good Fair- Poor Poor Poor Poor 27.6 Exc. -18 250 121 Good HNBR 31.0- 1.7- 30-95 90-450 Good- -50to0 -46to 250to 121to Exc. Fair- Poor Good- Good- Good- 10.0 20.7 Exc. -18 300 149 Good Exc. Exc. Exc.FKM 3.4- 1.4- 50-95 100- Good- -50to0 -46to 400to 200to Exc. Poor- Good- Exc. Good- Exc. 20.7 13.8 500 Exc. -18 500 260 Good Exc. Exc.EPDM 2.1- 0.7- 30-90 100- Poor- -75to -46to 220to 104to Good- Exc. Poor Exc. Exc. Good- 24.1 20.7 700 Exc. -40 -18 300 149 Exc. Exc.SBR 3.4- 2.1- 30-100 450- Good- -75to -59to 210to 99to Good Fair- Poor Fair Poor Poor 24.1 10.3 600 Exc. -55 -48 250 121 Good CR 3.4- 0.7- 15-95 100- Poor- -70to -57to 200to 93to Good- Fair Good- Fair- Good- Good- 27.6 20.7 800 Good -30 -34 250 121 Exc. Good Exc. Good Exc. Exc.IIR 13.8- 0.3- 30-80 300- Poor- -70to -57to 250to 121to Good- Good- Poor Exc. Exc. Exc. 20.7 3.4 850 Good -400 -40 300 149 Exc. Exc. VMQ,Si, 1.4- 6.2 20-90 100- Good- -178to -117to 400to 204to Exc. Fair- Fair- Exc. Exc. Exc. PMQ, 10.3 900 Good -90 -68 500 260 Good Exc. PVMQFVMQ 3.4- 3.1- 35-80 100- Fair- -112to -80to 400to 204to Exc. Fair Exc. Exc. Exc. Exc. 9.7 3.4 480 Good -90 -68 450 232ACM 8.6- 0.7- 40-90 100- Poor- -30to0 -34to 250to 121to Exc. Poor Poor Exc. Good- Good- 17.2 10.3 450 Good -18 350 177 Exc. Exc.EA 6.9- 0.7- 35-95 200- Poor- -35to -48to 250to 121to Exc. Poor- Poor Exc. Exc. Exc. 20.7 10.3 650 Good -30 -34 350 177 Fair CSM 3-15 0.2-10 40-100 100- Poor- -60to -51to 225to 107to Good- Poor- Good- Exc. Exc. Exc. 700 Fair -40 -40 270 132 Exc. Good Exc.ECO 10-15 1-10 30-95 200- Good- -60to -51to 225to 107to Good- Fair- Poor- Good Good Good- 800 Fair -15 -26 275 135 Exc. Good Good Exc.NR;IR 3.4- 0.5-0.8 20-10 300- Exc. -70to -57to 180to 82to Fair- Fair- Poor Poor- Poor Poor 34.5 900 -40 -40 220 104 Good Good FairAU,EU 6.9- 0.2- 10-100 250- Poor- -65to -54to 180to 82to Fair- Poor Poor- Exc. Good- Exc. 69.0 34.5 900 Good -40 -40 220 104 Good Good Exc.

Pol

ymer

Enl

onga

tion

(%

)

Tens

ile

Str

engt

h (M

Pa)

Tens

ile M

odul

us

at 1

00

% (

MP

a)

Har

dnes

s D

uro-

met

er (

Sho

re A

)

Com

pres

sion

Set

R

atin

g

Low

Tem

pR

ange

°F

Low

Tem

pR

ange

°C

Hig

h Te

mp

Ran

ge °

F

Hig

h Te

mp

Ran

ge °

C

Hea

t A

ging

at

21

2°F

(1

00

°C)

Ste

am

Res

ista

nce

Flam

e R

esis

tanc

e

Wea

ther

R

esis

tanc

e

Sun

light

R

esis

tanc

e

Ozo

ne

Res

ista

nce

4. Basic Elastomers

Sealing Elements

18


www.eriks.info



NBR Fair- Good Good- Fair- Good Fair- Exc. Exc. Back Good Fair- Good Good Good- Good Good Exc. Exc. Good Good Exc. Exc.HNBR Fair- Exc. Exc. Fair- Good Fair- Exc. Exc. - Good Good- Good Good Good- Good Good Exc. Good Exc. Exc. Exc.FKM Fair- Exc. Exc. Good- Good Fair- Good- Good- Brown Fair- Fair- Good Fair- Good Exc. Good Exc. Good Exc. Exc. Exc. Good GoodEPDM Good- Exc. Exc. Fair- Good Good- Good- Good- Purple Fair- Fair- Good Fair- Good Exc. Exc. Good Exc. Exc. Exc. Good Good GoodSBR Poor- Fair- Good- Fair Good Fair- Exc. Good - Fair- Fair- Good- Fair- Good- Poor Good Exc. Exc. Good Exc. Good Exc. Exc. Exc.CR Fair- Good- Fair- Fair- Fair- Fair- Exc. Fair Red Fair- Good- Good Good- Good- Fair Good Exc. Good Good Good Good Good Exc. Exc. Exc. IIR Poor- Exc. Good- Good Good Fair- Good Good - Poor- Exc. Good- Good Fair- Exc. Good Exc. Good Good Exc. GoodVMQ,Si, Poor- Exc. Exc. Poor- Good Good- Good- Exc. Rust Good- Fair Poor- Poor- Poor- Exc. PMQ, Good Fair Exc. Exc. Exc. Good Good Good Good PVMQFVMQ Fair- Exc. Exc. Poor- Good Good Good- Good- Blue Exc. Good Poor- Poor- Poor Exc. Exc. Good Exc. Exc. Good Exc.ACM Poor- Exc. Poor- Good- Fair- Fair- Good Good - Fair- Good- Fair- Poor- Fair- Good Good Fair Exc. Good Good Good Exc. Good Good GoodEA Good Exc. Good- Exc. Good Fair- Good Good - Poor- Good Good Good- Good- Fair- Exc. Good Fair Exc. Exc. GoodCSM Poor- Exc. Good Good- Good Fair- Exc. Exc. - Fair- Fair- Fair- Fair- Good- Fair Good Exc. Good Good Good Good Good Exc.ECO Poor Good- Good Exc. Good Good Fair- Good - Good Good Good Fair- Fair- Good Exc. Good Exc. GoodNR,IR Fair- Good Exc. Fair- Good- Fair- Exc. Poor - Exc. Good- Exc. Good- Good- Poor Good Good Exc. Good Exc. Exc. Exc.AU,EU Good- Good- Poor- Good- Exc. Fair- Exc. Good- - Poor- Fair- Good- Exc. Exc. Good Exc. Exc. Good Exc. Good Exc. Good Good Exc.

Pol

ymer

Gas

Per

mea

bilit

y R

atin

g

Rad

iati

onR

esis

tanc

e

Oxi

diza

tion

Res

ista

nce

(AIR

)

Wat

erR

esis

tanc

e

Odo

r

Tast

eR

ente

ntio

n

Adh

esio

n to

Met

als

Col

orab

ility

RM

A C

olor

Cod

e

Res

ilien

ce o

rR

ebou

nd R

atin

g

Vibr

atio

n D

ampe

ning

Flex

Cra

ckin

gR

esis

tanc

e

Tear

Res

ista

nce

Abr

asio

nR

esis

tanc

e

Vacu

um W

eigh

tLo

ss

4. Basic Elastomers

Sealing Elements

19


www.eriks.info



NBR Good Poor- Good Poor Fair- Poor- Good Poor- Poor Good- Poor Fair- Poor Fair Good Fair Good Exc. GoodHNBR Good Fair- Good Fair- Good- Fair- Good Poor- Good Good- Fair Good Poor Good Good Exc. Good Good Exc. FKM Good- Good- Fair- Poor- Fair- Poor Fair- Poor Poor Exc. Poor- Good- Poor Exc. Exc. Good Good Exc. Good Fair Exc.EPDM Exc. Exc. Exc. Fair- Good- Good- Exc. Exc. Fair- Good Good- Poor Exc. Good Exc. Exc. Good Exc.SBR Fair- Poor- Good Poor- Good Poor- Fair- Fair- Poor- Poor- Poor- Poor Poor Good Fair Good Fair Good Good Good Good GoodCR Exc. Poor Good- Poor- Exc. Poor- Good Poor Poor- Good Fair Poor Poor Exc. Good Fair GoodIIR Good- Fair- Good Fair- Good- Good Good Good Good Good- Good Poor- Good- Exc. Exc. Good Exc. Exc. Exc. Exc. GoodVMQ,Si, Fair- Poor- Good Fair Fair- Good Poor- Poor- Good Good Good Poor- Good PMQ, Good Fair Good Fair Exc. Fair PVMQFVMQ Exc. Good Good Fair Fair- Poor Exc. Good Poor Exc. Poor Good- Poor- Exc. Exc. FairACM Fair Poor- Poor Poor Poor Poor Fair Fair Poor Good Poor Good Poor FairEA Good Poor- Good- Poor- Good Fair- Good- Poor Good Good Poor Poor Poor Fair Exc. Exc. Exc. Good Exc. CSM Exc. Good- Exc. Good Exc. Poor- Good- Good- Poor Good Fair Poor Poor Exc. Fair Exc. Exc.ECO Good Poor- Fair Poor Fair- Poor Fair- Poor- Poor- Exc. Poor Poor- Poor Fair Good Good Fair Good GoodNR;IR Fair- Poor- Good Fair- Good- Good Fair- Fair- Poor- Poor- Good Poor Poor Exc. Good Good Exc. Exc. Good Fair GoodAU,EU Fair- Poor Fair Poor Good Poor Poor- Poor Poor- Fair- Poor Poor- Poor Good Exc. Fair Exc. Good

Pol

ymer

Aci

ds (

dilu

te)

Aci

ds

(con

cent

rate

d)

Aci

d, o

rgan

ic

(dilu

te)

Aci

d, o

rgan

ic

(con

cent

rate

d)

Alc

ohol

s (C

1 t

hru

C4

)

Ald

ehyd

es

(C1

thr

u C

6)

Alk

alie

s(c

once

ntra

ted)

Ani

mal

&Ve

geta

ble

oils

Bra

ke F

luid

;D

ot 3

, 4

& 5

Est

ers,

Alk

ylP

hosp

hate

Alk

alie

s (d

ilute

)

Am

ines

Dle

ster

Oils

4. Basic Elastomers

Sealing Elements

20


www.eriks.info



NBR Poor- Poor Good- Fair- Fair- Poor Poor Fair Exc. Good- Exc. Good Good Fair Exc. Good Good Exc.HNBR Poor- Poor- Exc. Fair- Good- Poor- Poor Fair Exc. Good- Exc. Good Good- Fair Fair Good Exc. Fair Exc. Exc.FKM Exc. Poor Exc. Exc. Exc. Good- Poor Poor Exc. Exc. Exc. Poor Exc. Exc.EPDM Exc. Fair Poor Poor Poor Poor Good- Poor Poor Poor Poor Good Exc. Exc.SBR Poor Poor Poor Poor Poor Poor Poor- Poor Poor Poor Poor Good Poor GoodCR Poor- poor Poor- Poor- Fair Poor Poor- Poor Good Good Good Exc. Fair- Fair Good Fair Fair Exc.IIR Exc. Poor- Poor Poor Poor Poor Poor- Fair- Poor Poor Poor Good Poor Fair Exc. GoodVMQ,Si, Good Poor Poor- Poor Poor Poor Poor Poor Fair Poor Good Exc. Poor- PMQ, Fair Fair PVMQFVMQ Good- Fair Exc; Good- Exc. Good- Poor Poor Exc. Good Good Exc. Exc. Exc. Exc. Exc.ACM Poor Poor- Exc. Poor- Fair- Poor- Poor Poor Good Fair Poor Fair Exc. Fair Good Good GoodEA Poor Poor Good Poor- Fair Poor- Poor Poor Poor Poor Poor Poor- Good- Fair Good Good Exc.CSM Fair Poor Fair- Fair Fair Poor Poor Poor Good Poor Fair Good Exc. Good ECO Poor Good Good- Good Fair Poor Fair Fair Exc. Good- Poor Poor Good- Exc. Exc. Good Exc. Exc.NR,IR Poor Poor Poor Poor Poor Poor Fair- Poor Poor Poor Poor Good Good GoodAU,EU Poor Fair Good- Poor- Fair- Poor- Poor Poor Fair- Good Good Poor Exc. Exc. Fair Good Good Good Note:thechartdataprovidesgeneralelastomerbaseproperties.Inmanydesignapplications,specialcompoundsarerequired.ERIKS,therefore,will

notberesponsiblefortheusageofthischartinanymanner.

Pol

ymer

Eth

ers

Ket

ones

Sili

cone

Oils

Fuel

, A

lipha

tic

Hyd

roca

rbon

Est

ers,

A

ryl P

hosp

hate

Fuel

, A

rom

atic

Hyd

roca

rbon

Fuel

, E

xten

ded

(Oxy

gena

ted)

Hal

ogen

ated

S

olve

nts

Lacq

uer

Sol

vent

s

L.P.

Gas

es &

Fuel

Oils

Ref

rige

rant

A

mm

onia

Pet

role

um

Aro

mat

ic -

Low

Ani

line

Pet

role

um

Alip

hati

c -

Hig

h A

nilin

e

4. Basic Elastomers

Sealing Elements

21


www.eriks.info


Chemical Terms, Abbreviations, and Trade Names

ChemicalTerm ASTMDesignated PolymerTradeNames AbbreviationAcrylonitrileButadiene NBR Chemigum®,Nipol®,Krynac®,Paracril®,PerbunanN®,Buna N®

HighlySaturatedNitrile HNBR Therban®,Zetpol®

CarboxylatedNitrile XNBR Nipol®,Krynac®,Chemigum®

Fluorocarbon FKM Viton®,Fluorel®,Technoflon®

EthylenePropylene EP,EPDM,EPT,EPR Nordel®,Royalene®Vistalon®,BunaEP®,Keltan®

StyreneButadiene SBR AmeripolSynpol®,SBR®,Plioflex®,Stereon®

Polychloroprene CR Neoprene,Baypren®,Butaclor®

IsobutyleneIsoprene IIR Butyl®

Silicone VMQ,PMQ,PVMQ Silastic®,SILPLUS®,Elastosil,Wacker®

Fluorosilicone FVMQ FSE®,Silastic®,Sylon®

Polyacrylate ACM Cyanacryl®,HyTemp®,Thiacril®

EthyleneAcrylic AEM Vamac®

ChlorosulfonatedPolyethylene CSM Hypalon®

Epichlorohydrin ECO/CO Gechron®,Hydrin®

Polyisoprene •Natural NR SMR®,PaleCrepe®,SmokedSheet® •Synthetic IR AmeripolSN®,Natsyn®

Polyurethane(PolyesterorPolyether) AUorEU Adiprene®,Millathane®,Vibrathane®,Vulkolan®,PURPerfluoroelastomer FFKM Kalrez®,Isolast®,Chemraz®,Simriz®,Parafluor®,Perlast Thefollowingareregisteredtrademarksoftheirrespectivecompanies: Cyancryl-AmericanCyanamidCo.;AmeripolCB,AmeripolSN,AmeripolSynpol-AmeripolSynpolCo.;Butaclor-distigil;Silastic-DowCorningCorp.;Hypalon,Nordel,Vamac,Viton-DuPontPerformanceElastomers;Vistalon-ExxonChemicalCo.;Stereon-FirestoneTire&RubberCo.;FSE,SILPLUS-GeneralElectricCo.;Budene,Chemigum,Natsyn,Philoflex-GoodyearRubberProductsCorp.;Herclor-HerculesInc.;Aflas,dyneon,sylon-DyneonCo.;Hydrin,HyTemp,Gechron,Nipol,Zetpol-ZeonChemicalsInc.;Krynac,Taktene,Tornac,PerbunanN,BunaEP,Baypren,Therban-BayerCorp.;Millathane-TSEIndustries,Inc.;Adiprene,Royalene,Paracril,Thiacril,Vibrathane;Uniroyal,Inc.

4. Basic Elastomers

technical handbook o-rings 4. basic elastomers handbook/06 - eriks nv - o-ring technical... ·...

Documents