" 22539-600|-RO-00 t SPACESHUTTLESEALMATERIAL AND DESIGN DEVELOPMENT FOR __ EARTHSTORABLEPROPELLANTSYSTEMS ] 97400508] -002 ; "'""'" D .,_-_., ReportNo. 22539-6001-R0-00 :..v.,.- ContractNo. NAS 9-12729 "'-'- DRL No. 8 :_:_C" DRD No. SE-411T ; ,X,. F I N A L R E P 0 R T e i4 SPACE SHUTTLESEAL MATERIALAND DESIGN -. _.,_,. DEVELOPMENTFOR EARTHSTORABLEPROPELLANTSYSTEMS _ Preparedfor ._ _. , NASA JOHNSONHouston,SPACECRAFTTexas CENTER }_ OCTOBER1973 IIN; H. MACKLIS,AssistanMtanager ChemicalPropulsionDepartment i TRW ONI I_A(:I _AIIIK • NIOONOO IIACH • CALIFORNIA _ IiIm 1974005081-003 :_ ' _- FOREWORD _ This programwas conductedby TRW SystemsGroup,RedondoBeach, _'_ California,undercontractto the NASA JohnsonSpacecraftCenter,Houston, •_- Texas The contractnumberwas NAS 9-12729 ..,_:. The NASA programmanagerwas Mr. J. W. Griffin. _:_ Numerousgovernmentand industrysourcesprovidedsupportthrough- ;_.':_ out the program,but particularlyduringthe state-of-the-artinvesti- -._ gation. Acknowledgmentof thesemany sourcesis providedin the _ Appendices. _i" The Air F_rceMaterialsLaboratory,WrightPattersonAir ForceBase, Dayton,Chio, providedapprovaland supporti_tthe use of the AF-E-411 _. and AF-E-124DmaterialsthroughMr. J. K. Sieron. " _ Personnelat TRW Systemsresponsiblefor the conductof the program _ include: Mr. J. W. M_rtinand Mr. J. R. Denson,AppliedChemistry _ Department;of the ChemicalMr. R.PropN.ulPosionrter,Depar_Mr. .F._nt.L. AdministrativeMerrittand Mr.andH. M.technicalElmendorf I._ Desuppartment;portwas Mr.providedH. Macklis,by Dr. AssistantE. A. Burns,Manager,Manager,ChemicalAppliedPropulsionChemistry Department;and Mr. D, F. Reeves,Head,PropulsionAuxiliariesSection. The programmanagerwas Mr. R. G. Gilroy. i I | =+ i i i • J m 1974005081-004 "It ;_ ABST.RACT .al, This reportprovidesthe resultsof a programto investigateand characterizeseal materialssuitablefor Space_huttleStorablePropel- j lant Systems. Two new elaston_ricmaterialswere identifiedas being potentially superiorto existingstate-of-theart naterialsfor specificsealing applications.Thesematerialswere.AF-E-I24D. and AF-E-411. AF-E-124D is a curedperfluorinatedpolymersuitablefor use with dinitrogen tetroxideoxidizer,and hydrazinebase fuels. AF-E-411_s an ethylene propyleneterpolymermaterialfor hydrazinebase fuel service. Data are presentedrelativeto low and i,ightemperaturecharacter- "zticsas well as propellantexposureeffects. Types of data includedare: mechanicalproperties,stressstraincurves,frictionand wear character- istics,compressionset and permeability.Sealingtestswith a flat poppet-sealvalvewere conductedfor verificationof sealingcapability. A Seal DesignProcedureis providedwhich containsa step-by-step procedurefor designingseals. The informationleededfor seal design is primarilysummarizedand presentedas well as referencesfor more in-depthinformation. A plan for a controlledmethodof investigatingcontamination sensitivityis also presented. f PreliminarySpecificationsfor AF-E-124Dand AF-E-4ll_r_._ also provided. Limitedpropertiesdata are also providedfor the follow- ing state-of-theart seal materials: Teflon,KeI-F,Kynar,Vespel, EthylenePropyleneRubber,Carbo_ynitrosoRubberand Viton. The bibliographyincludesover 200 referencesrelatingto seal designor materialsand presentsa concisetabulationof the more useful seal designdata sources. ii p maim _ mR ] 97400508 ]-005 CONTENTS ,)._:"' " Page ;J_ 1.0 INTRODUCTION 1-1 _C:,_a_." 2.0 SUMMARY 2-I "=...." 3.0 PROGRAMDESCRIPTION 3-I •_ 3.1 Task l - Analysis 3-I 7_." 3.2 Task 2 - BasicScreening 3-4 3.4 Task 4 - MaterialCharacterization 3-9 3.4.1 Testsand Test Techniques 3-10 4,0 SEAL MATERIALPROPERTIES 4-I 3.3 Task 3 - Definitionand Development 3-6 :_,;_ 4.1 Descriptionsof MaterialsTested 4-2 4.1.1 AF-E-124D 4-2 :_' 4.1.2 At-E-411 4-6 •._ "-_ 4.1.3 AF,E-41IA 4-8 _" !I_ 4.2 Propertiesand Characteristicsof Tested!,iaterials 4-8 4.2,1 AF-E-124D 4-8 4.2.2 AF-E-411 4-38 4.2.3 AF-E-411A 4-62 4.3 Propertiesof Other Seal Materialsin CommonUse 4-81 4,3.1 TeflonTFE, FEP and Filled 4-85 4.3.24.3.3 KEL-FKynar /p 4-1134-I20 , 4-121 4.3.4 Viton ,_ 4.3.5 Vespel _ 4-135 4.3,6 CarboxynitrosoRubber(CNR) 4-146 4.3.7 EthylenePropyleneTerpolymer 4-151 4.3.8 ButylRubber 4-153 5.0 MATERIALCOMPARISON 5-I 5,1 Seal Materialsfo_ OxidizerService 5-I 5,1.1 Teflonand AF-E-124D 5-2 e ' t 1974005081-006 r4. CONTENTS(Continued) :" Page 5.2 Seal Materialsfor Fuel Service 5-11 5.2.1 AF-E-411,AF-E-124Dand Teflon 5-14 / 5.3 Fabricationand Availabilityof AF-E-124Dand AF-E-41I 5-15 5.3.1 AF-E-411 5-15 5.3.2 AF-E-124D 5-17 6.0 SEALDESIGNPROCEDURE 6-1 6.1 PolymericMaterialPropertiesand Behavior 6-I 6.2 Seal DesignProcedure _-23 6.2.1 Procedure 6-23 6.2.2 LeakageModel 6-27 6.2.3 Choiceof Configuration 6-30 6.2.4 DesignProcedure,Steps1 throughIg 6-42 to 6-110 7.0 CONCLUSIONSAND RECOMMENDATIONS 7-I • 7,1 Conclusions 7-I 7.2 Recommendations 7-2 APPENDICES A. ACKNOWLEDGMENTS A_I B. EXCERPTSFROM ANALYSISREPORT B-l # C. CONTAMINAIIONSENSITIVITYTEST PLAN C-l D. REFERENCESAND BIBLIOGRAPHY D-l E. MATERIALSPECIFICATIONS E-I ; E-I AF-E-411 E-I-I E-2 AF-E-124D E-2-1 ! iv 1974005081-007 i_ _ FIGURES Page ,,_" 3.] CharacterizationTask Natrix 3-7 , 3.2 Test ValveSeal PoppetConfiguration 3-14 _' 3.3 Seal VerificationTest Setup 3-15 /_-7"- 4.2.1 AF-E-l_4D Compression-DeflectionCharacteristics 4-24 ,_, at +70_Fand +300_F •i_ 4.2.2 AF-E-I24DCompression-DeflectionCharacteristics 4-25 _,_ at -lO0°F ' " 4,2.4 AF-E-124DO-RingsAfter Exposureto Propellants 4-27 i 4.2.3 AF-E-124DLoad-CycleCharacte_'istic_at 70°F 4-26 Compressionat 200°Ffor 22 Hoursin Propellants i 4.2.5 AF-E-124DCompressionSet RecoveryRatesAfter 30% 4-28 _: 4.2.6 N204 PermeabilityThroughAF-E-124D 4-29 •_ 4.2.7 Dow CorningWear Tester 4-30 4.2.8 Wear Ring end Rider 4-30 4,- 4,2.9 AF-E-124DCoefficientsof Frictionin Air 4-31 4,2.10 AF-E-124DCoefficientof Frictio_in 50/50 4-32 4.2,11 AF-E-124DCoefficientsof Frictionin N204 4-32 4.2.12 Wear Comparisonof Teflonand AF-E-411,AF-E-411A, 4-33 AF-E-124D 4.2.13 AF-E-124DBall ValveSeal 4-34 4.2.14 Seat Stressto ObtainZero Leakageas a Function 4-35 of Temperature 4.2.15 Seat Stressto ObtainZero Leakageas a Functionof 4-36 Numberof Cycles 4.2.16 Seat Stressto ObtainZero Laakageas a Functionof 4-37 Propellant ExposureTime " 4.2.17 AF-E-4]ICompression-Deflection,Room Temperature, 4-48 VariedLoa_ Rate 4.2.18 AF-E-411Compression-Deflecti+o3n00°F 4-49 -_ v 4.2.1g AF-E-41]Compression-Deflection-100°F 4-50 v t | 1974005081-008 FIGURES(Continued) Page 4.2.20 AF-E-411Compression-DeflectionHysteresis 4-51 4.2.21 AF-E-41]CompressionSet RecoveryRates 4-52 , 4.2.22 AF-E-411O-Ringafter200°F/22Hour Exposureto 4-53 50/50 4.2.23 Permeabilityof Helium,ThroughAF-E-411 4-54 :.2.24 AF-E-411Coefficientsof Frictionin Air 4-55 % 4.2.25 AF-E-411Coefficientof Frictionin 50/50 4-56 4.2.26 Wear Comparisonof Teflonand AF-E-411,AF-E-4IIA, 4-57 AF-E-124D 4.2.27 AF-E-411Seat Stressto ObtainZero Leakageas a 4-58 Functionof PoppetSurfaceFinish 4.2.28 Seat Stressto ObtainZero Leakageas a Function 4-59 of PropellantExposureTime • 4.2.29 Seat Stressto ObtainZero Leakageas a Function 4-60 of Numberof Cycles 4.2.30 Seat Stressto ObtainZero Leakageas a Functionof 4-61 Temperature 4.2.31 AF-E-411ACompression-Deflectionat 70°F 4-73 t 4.2.32 AF-E-411ACompression-Deflectionat -lO0°Fand +300°F 4-7_ • 4.2.33 AF-E-41IACompression-DeflectionHysteresisand 4-75 Repeatability 4.2.34 AF-E-411ACompressionSet RecoveryRates 4-76 I 4.2.35 HeliumPermeabilityThroughAF-E-411A 4-77 4.2.36 AF-E-411ACoefficientsof Frictionin Air 4-78 , 4.2.37 AF-E-411ACoefficientof Frictionin 50/50 4-79 4.2.38 Wear Comparisonof Teflonand AF-E-411,AF-E-411A, 4-80 AF-E-124D 4.3.1 TeflonTFE StressStrainin Air 4-I01 i 4.3.2 TeflonFEP StressStrainIn Air 4-102 _ vi T, t . _ , , ,q ' 'w ' "" '= w . • . _ u- 1974005081-009 -_ FIGURE3(Continued) Page 4.3.3 TeflonTFE TotalDeformationvs Time -65°F 4-103 4.3.4 TFE and FEP Deformationvs Time +73°F 4-]04 • 4.3.5 TFE and FEP Deformationvs Time +212°F 4-]05 % 4.3.6 TFEElevateand FEPdTemperatureDeformationvs Time underTensileLoad at 4-106 4.3.8 IFE and FEP DeformationUnderCompressiveLoad +212°F 4-108 I 4,3.7 TFE and FEP DeformationUnder CompressiveLoad +73°F 4-I07 4.3,10 TFE and FEP CompressiveRecoveryat +212°F 4-110 _! 4.3,9 TFE and FEP CompressiveRecoveryat +73°F 4-109 4.3.11 TFE and FEP LinearThermalExpansion 4-11l _', 4.3.12 TFE and FEP Coefficientsof Friction 4-I12 _k i_" _ 4,3.13 Coefficientof LinearThermalExpansion-Kel-F 4-118 4.3.14 StressStrainCurvesfor Kel-F 4-]19 4.3.15 KynarCold Flow Resistance 4-124 4,3,16 KynarLinearThermalExpansion 4-125 4.3.17 KynarTGA Analysis 4__._6 i 4.3.18 VitonA MechanicalPropertiesas a Functionof 4-133 Temperature 4.3.19 VitonA Elongationas 3 Functionof Temperature 4-133 4.3,20 VitonB CompressionDeflectionCharacteristics 4-134 4.3,21 Viton E-60CElevatedTemperatureCompressionSet 4-134 in Air 4.3.22 VitonA and E-60CLong Term CompressionSet 4-135 4.3.23 VespelTensiIe Strengthvs Temperature 4-I39 4,3,24 VespelModulusof Elasticityvs Temperature 4-]39 4.3.25 Vespel_._-I,SP-21Stress-StrainCurves-Tension 4-140 vii ; i 1974005081-010 1 . FIGURES(Continued) 4.3.26 VespeiSp-l, SP-21Stress-StrainCurves-Compression 4-]41 4.3.27 VespelSP-22 Stress-StrainCurves-Compression 4-142 / 4.3.28 VespelSP-I Deformationvs Time 4-143 J 4.3.29 VespelSP-21Deformationvs Time 4-143 4.3.30 VespelSP-22 Deformationvs Time 4-144 4.3.31 VespelSP-I and SP-22FatigueResistance 4-144 4.3.32 ThermalExpansionof VespelSP-I and SP-21 4-145 4.3.33 ThermalExpansionof VespelSP-22 4-145 4.3.34 Permeabilityof CNR, TeflonFEP and Butylto N204 4-154