1、Designation: D 3771 03Standard Specification forRubber Seals Used in Concentrating Solar Collectors1This standard is issued under the fixed designation D 3771; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the general requirements formaterials used in rubber seals of concentrating solar collectors.Particula
3、r applications may necessitate other requirements thatwould take precedence over these requirements when speci-fied.1.2 Design requirement pertains only to permissible deflec-tions of the rubber during thermal expansion or contraction ofthe seal in use and the tolerances in dimensions of molded ande
4、xtruded seals.1.3 This specification does not include requirements per-taining to the fabrication or installation of the seals.1.4 The values stated in SI units are to be regarded as thestandard.1.5 The following safety hazards caveat pertains only to thetest methods portion, Section 9, of this spec
5、ification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenc
6、ed Documents2.1 ASTM Standards:C 661 Test Method for Indentation Hardness ofElastomeric-Type Sealants by Means of a Durometer2C 717 Terminology of Building Seals and Sealants2C 719 Test Method for Adhesion and Cohesion of Elasto-meric Joint Sealants Under Cyclic Movement (HockmanCycle)2D 395 Test Me
7、thods for Rubber PropertyCompressionSet3D 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTension3D 865 Test Method for RubberDeterioration by Heatingin Air (Test Tube Enclosure)3D 1149 Test Method for Rubber DeteriorationSurfaceOzone Cracking in a Chamber3D 1229 Test Method for
8、Rubber PropertyCompressionSet at Low Temperatures3D 1349 Practice for RubberStandard Temperatures forTesting3D 1415 Test Method for Rubber PropertyInternationalHardness3D 1566 Terminology Relating to Rubber3D 2137 Test Methods for Rubber PropertyBrittlenessPoint of Flexible Polymers and Coated Fabri
9、cs3D 2240 Test Method for Rubber PropertyDurometerHardness3D 3182 Practice for RubberMaterials, Equipment, andProcedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized Sheets3D 3183 Practice for RubberPreparation of Pieces for TestPurposes from Products3G 7 Practice for Atmospheric
10、 Environmental ExposureTesting of Nonmetallic Materials4G 151 Practice for Exposing Nonmetallic Materials in Ac-celerated Test Devices that Use Laboratory Light Sources5G 155 Practice for Operating Xenon Arc Light Apparatusfor Exposure of Nonmetallic Materials52.2 Other Standards:RMA Handbook Rubber
11、 Products: Molded, Extruded,Lathe Cut, and Cellular43. Terminology3.1 Refer to the definitions of terms in Terminology C 717and Terminology D 1566.4. Classification4.1 Types:4.1.1 Type C, intended for use in cold climates(below 10C in winter).4.1.2 Type W, intended for use in warm climates(above 10C
12、 in winter).4.2 Grades4.2.1 Grade designations represent differing degrees ofhardness in accordance with Test Methods D 1415 and D 2240as follows:1This specification is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.36 on Seals.Current edit
13、ion approved June 10, 2003. Published June 2003. Originallyapproved in 1979. Last previous edition approved in 2000 as D 3771 00.2Annual Book of ASTM Standards, Vol 04.07.3Annual Book of ASTM Standards, Vol 09.01.4Available from the Rubber Manufacturers Association (RMA), 444 MadisonAve., New York,
14、NY 10022.5Annual Book of ASTM Standards, Vol 14.04.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2.1.1 Grade 2, hardness of 20 6 5.4.2.1.2 Grade 3, hardness of 30 6 5.4.2.1.3 Grade 4, hardness of 40 6 5.4.2.1.4 Grade 5, hardness
15、of 50 6 5.4.2.1.5 Grade 6, hardness of 60 6 5.4.2.1.6 Grade 7, hardness of 70 6 5.4.2.1.7 Grade 8, hardness of 80 6 5.NOTE 1The grade to be used in a particular application depends onthe design of the seal and must be specified by the designer.4.3 Classes:4.3.1 Seals shall be classified as follows:4
16、.3.1.1 Class PS, preformed rubber seal.4.3.1.2 Class SC, sealing compound.NOTE 2Class SC material should not be used in designs where theseal is under mechanical stress.5. Materials and Manufacture5.1 Resistance to solar radiation can be determined by oneof the following:5.1.1 Desert outdoor exposur
17、e, in accordance with recom-mended Practice G 7 using the exposure rack at an angle of 45for unbacked exposure of the specimens. Desert outdoorexposure shall be for at least six months including at least onemonth preceding and following the summer solstice.5.1.2 Xenon arc laboratory exposure, in acc
18、ordance withrecommended Practice G 151 and G 155 using daylight filtersand operating conditions as described below:5.1.2.1 The irradiance level shall be maintained at 0.55 60.02 W/(m2nm) at 340 nm at the control point. For equivalentbroad band irradiance levels and tolerances at 300 to 400 nmand 300
19、 to 800 nm, consult the manufacturer of the apparatus.5.1.2.2 The default exposure cycle shall be 102 min lightonly followed by 18 min light plus either water spray on thefront surface or immersion in water. The water spray tempera-ture is typically 21 6 5C, but may be lower if ambient watertemperat
20、ure is low and a holding tank is not used to storepurified water. The immersion water is kept at a constanttemperature, which shall be less than 40C.NOTE 3Water spray and immersion in water are different kinds ofmoisture exposures and may produce different results.5.1.2.3 The uninsulated black panel
21、 temperature (BPT) shallbe maintained at 63 6 2.5C at the control point during the dryperiod of exposure to light. For the equivalent insulated blackpanel temperature (black standard temperature (BST), consultthe manufacturer of the apparatus.5.1.2.4 Relative humidity shall be maintained at 60 6 10
22、%at the control point during the dry period of exposure to lightin xenon arc apparatus that uses water spray for wetting.5.1.2.5 The chamber air temperature shall be maintained at48 6 2C at the control point in equipment that uses waterspray for wetting and provides for adjustment of the chamberair
23、temperature.5.1.2.6 The exposure duration shall be by agreement be-tween the parties concerned. The exposure time shall be at least1000 h, but long enough to produce a substantial change in theproperty of interest in the least stable formulation of the type ofmaterial being evaluated.NOTE 4The set p
24、oint is the target condition for the control sensor asprogrammed by the user. When a Standard calls for a particular set point,the user programs the exact number. The tolerances specified with the setpoint do not imply that the user is allowed to program a set point higheror lower than the exact set
25、 point specified. Tolerance is determined by themachine variables. The tolerance specified is the maximum deviationallowable from the set point at the control sensor during equilibriumconditions.5.2 After exposure, slight surface chalking and dulling arepermitted. Brittleness, cracking, loss of elon
26、gation, tackiness,or other deterioration affecting serviceability shall not bepermitted.6. Requirements6.1 Class PS material shall conform to the requirementsgiven in Table 1.TABLE 1 Requirements for Class PS Material Used to Seal Solar CollectorsPropertyGradeASTM Method345678Ultimate elongation, mi
27、n, % 350 300 250 200 150 100 D 412Compression set, max, %:after 70 h at MSTA30 30 30 30 30 30 D 395Bafter 166 h at 10C 60 60 60 60 60 60 D 1229CResistance to heating (for 166 h at MSTA): D 865Hardness change, max 10 10 10 10 10 10 D 1415 or D 2240Ultimate elongation change, max, % 30 30 30 30 30 30
28、D 412Tensile strength change, max, % 20 20 20 20 20 20 D 412Volatiles lost, max, % 111111see9.3Volatiles condensible, max, % 0.1 0.1 0.1 0.1 0.1 0.1 see 9.4Resistance to ozone, 100 mPa,Dfor 166 h at40Cno cracking D 1149Resistance to low temperature, Type C only,max, C40 40 40 40 40 40 D 2137AThe tes
29、t temperature is based on the maximum service temperature (MST) which normally occurs when the collector is under stagnation conditions and is receivingthe maximum radiation flux to which it will be exposed. The test temperature listed in Practice D 1349 that is between 25 and 49C above the maximum
30、service temperatureis used. These temperatures are: 150, 175, 200, 225, and 250C.BMethod B.CSet to be measured at 10 s after release. Lubricated plates or polytetrafluoroethylene film is recommended if the rubber adheres to the metal compression plates duringthe test.D100 mPa of ozone partial pressu
31、re is equivalent to 100 pphm at standard atmospheric pressure (100 kPa). See new terminology on ozone content expressionsdescribed in Test Method D 1149.D37710326.2 Class SC material shall conform to the requirementsgiven in Table 2.7. Dimensions7.1 The design of the seal shall not permit the rubber
32、 todeflect more than 25 % in any direction during thermalexpansion and contraction of the solar collector.NOTE 5If the thermal coefficient of linear expansion for the rubber isnot known, a value of 0.0003/K may be assumed for design purposes.7.2 The tolerances in dimensions shall conform to thefollo
33、wing designations in the RMA Handbook:7.2.1 Molded Seals:7.2.1.1 Commercial DimensionsRMA -F3-T.032.7.2.1.2 Critical DimensionsRMA -F3-T.032.7.2.2 Extruded Seals:7.2.2.1 Commercial DimensionsRMA -F3.8. Workmanship, Finish, and Appearance8.1 Class PS seals shall be free of blisters, checks, cracks,an
34、d other imperfections that can affect their ability to make ormaintain a watertight seal.8.2 Class SC material shall be uniform in composition andbe free of defects that may affect serviceability, such aspartially vulcanized lumps.9. Test Methods9.1 Class PS MaterialPrepare the specimens in accor-da
35、nce with Practice D 3183 and test the specimens in accor-dance with the test methods given in Table 1. For control ofproduction, specimens may be taken from standard test sheetsprepared in accordance with Practice D 3182, using the sameunvulcanized material used to prepare the seals and vulcaniz-ing
36、 the material at the same temperature used for the seals to anequivalent state of vulcanization.9.2 Class SC MaterialPrepare five sheets approximately150 by 150 by 2 mm in accordance with the instructionssupplied with the sealing material. Also, prepare five adhesionspecimens in accordance with Test
37、 Method C 719. Preferably,prepare each sheet and adhesion specimen from material in adifferent container. Condition the sheets and adhesion speci-mens for 14 days at a temperature of 23C and relativehumidity of 50 %. Test the material in accordance with the testmethods given in Table 2.9.3 Determine
38、 volatiles lost from the difference in mass ofthe specimens before and after heating for 166 h at thetemperature given in Table 1 or Table 2 and in accordance withTest Method D 865.9.4 Determine volatiles condensible at 23C from the dif-ference in mass of the outlet tubes before and after heating th
39、especimens for 166 h at the temperature given in Table 1 orTable 2 and in accordance with Test Method D 865. Ifnecessary, cool the exposed portion of the outlet tube with astream of air to maintain a temperature of 23 6 2C. If anyvolatiles condense on the inlet tube or other parts of theapparatus, a
40、dd the mass of this condensed material to the massof the material on the outlet tube.10. Inspection and Rejection10.1 Class PS MaterialManufacturers of preformed sealsmay use their quality-control systems for production inspectionto ensure the seals conform with this specification, providedappropria
41、te records are kept. In case of dispute regarding thequality of a delivered product, a sample of five seals shall betaken from the lot and tested for compliance with this specifi-cation. If one of the five seals does not conform, a secondsample of five seals may be taken and tested. If two or more o
42、fthe ten seals do not conform, the lot may be rejected.10.2 Class SC MaterialManufacturers may use theirquality-control systems to ensure production conforms withthis specification. In case of dispute regarding the quality of adelivered product, five test sheets and five adhesion specimensshall be p
43、repared, preferably from five different packages, inaccordance with the instructions supplied with the sealingmaterial. If one of the five sheets or adhesion specimens doesnot conform, an additional five sheets or adhesion specimensmay be prepared and tested. If two or more of the ten sheets oradhes
44、ion specimens do not conform, the lot may be rejected.TABLE 2 Requirements for Class SC Material Used to Sieal Solar CollectorsPropertyGradeASTM Method234Ultimate elongation, min, % 200 150 100 D 412Resistance to heating (for 166 h at MSTA): D 865Hardness change, max 10 10 10 C 661Ultimate elongatio
45、n change, max, % 30 30 30 D 412Tensile strength change, max, % 20 20 20 D 412Volatiles lost, max, % 1 1 1 see 9.3BVolatiles condensible, max, % 0.1 0.1 0.1 see 9.4BResistance to ozone, 100 mPa,Cfor 166 h at 40C no cracking D 1149Resistance to low temperature, Type C only, max, C 40 40 40 D 2137Adhes
46、ion loss (max, cm2)D9 9 9 C 719EAThe test temperature is based on the maximum service temperature (MST) which normally occurs when the collector is under stagnation conditions and is receivingthe maximum radiation flux. The test temperature listed in Practice D 1349 that is between 25 and 49C above
47、the maximum service temperature is used. Thesetemperatures are: 150, 175, 200, 225, and 250.BThis test is not required if the design precludes condensing of the volatiles on the cover plate(s) of the solar collector.C100 mPa of ozone partial pressure is equivalent to 100 pphm at standard atmospheric
48、 pressure (100 kPa). See new terminology on ozone content expressionsdescribed in Test Method D 1149.DThe combined loss in bond and cohesion areas for the three specimens tested shall not exceed 9 cm2.EThe temperature in 6.3 of Test Method C 719 shall be modified to the MST (see footnoteA).D37710331
49、1. Product Marking11.1 The following information shall be marked either onthe seal, packaging, label, or tag:11.1.1 Name, brand, or trademark of the manufacturer,11.1.2 Type and grade,11.1.3 Compliance with Specification D 3771, and11.1.4 Other information required by the manufacturer orpurchaser.12. Packaging and Package Marking12.1 Material shall be protected by suitable packaging toprevent damage during shipment or storage prior to installationin the solar collector.13. Keywords13.1 concentrating solar collectors; preforme
