1、Designation: D3903 03 (Reapproved 2007)D3903 15Standard Specification forRubber Seals Used in Air-Heat Transport of Solar EnergySystems1This standard is issued under the fixed designation D3903; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the general requirements for the rubber seals used in solar energy s
3、ystems employing air-heattransport. Examples are duct and damper seals. Particular applications may necessitate other requirements that would takeprecedence over these requirements when specified.NOTE 1Rubber seals for the collector are covered in Specifications D3667 and D3771.1.2 Design requiremen
4、t pertains only to permissible deflections of the rubber during thermal expansion or contraction of the sealin use and the tolerances in dimensions of molded and extruded seals.1.3 This specification does not include requirements pertaining to the fabrication or installation of the seals.1.4 The val
5、ues stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 The following safety hazards caveat pertains only to the test methods portion, Section 10, of this specification:This standarddoes not purport to address the safety concerns associa
6、ted with its use. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C661 Test Method for Indentation Hardness of Elastomeric-Type
7、Sealants by Means of a DurometerC717 Terminology of Building Seals and SealantsC719 Test Method for Adhesion and Cohesion of Elastomeric Joint Sealants Under Cyclic Movement (Hockman Cycle)D395 Test Methods for Rubber PropertyCompression SetD412 Test Methods for Vulcanized Rubber and Thermoplastic E
8、lastomersTensionD865 Test Method for RubberDeterioration by Heating in Air (Test Tube Enclosure)D1149 Test Methods for Rubber DeteriorationCracking in an Ozone Controlled EnvironmentD1229 Test Method for Rubber PropertyCompression Set at Low TemperaturesD1349 Practice for RubberStandard Conditions f
9、or TestingD1415 Test Method for Rubber PropertyInternational HardnessD1566 Terminology Relating to RubberD2137 Test Methods for Rubber PropertyBrittleness Point of Flexible Polymers and Coated FabricsD2240 Test Method for Rubber PropertyDurometer HardnessD3182 Practice for RubberMaterials, Equipment
10、, and Procedures for Mixing Standard Compounds and Preparing StandardVulcanized SheetsD3183 Practice for RubberPreparation of Pieces for Test Purposes from ProductsD3667 Specification for Rubber Seals Used in Flat-Plate Solar CollectorsD3771 Specification for Rubber Seals Used in Concentrating Solar
11、 CollectorsG7 Practice for Atmospheric Environmental Exposure Testing of Nonmetallic MaterialsG151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources1 This specification is under the jurisdiction of ASTM Committee D11 on Rubber and is the direct
12、 responsibility of Subcommittee D11.37 on Coated Fabrics, RubberThreads and Seals.Current edition approved Nov. 1, 2007June 1, 2015. Published January 2008August 2015. Originally approved in 1980. Last previous edition approved in 20032007 asD3903 03.D3903 03 (2007). DOI: 10.1520/D3903-03R07.10.1520
13、/D3903-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intend
14、ed only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current
15、 versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1G155 Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials2.2 Oth
16、er Standards:RMA HandbookRubber Products: Molded, Extruded, Lathe Cut, and Cellular (Third Edition)33. Terminology3.1 DefinitionsRefer to the definitions of terms in Terminology C717 and Terminology D1566.4. Classification4.1 Types:4.1.1 Type C, intended for use in cold climates (below 10C in winter
17、).4.1.2 Type W, intended for use in warm climates (above 10C in winter).4.2 GradesGrade designations represent differing degrees of hardness as follows:4.2.1 Grade 2, hardness of 20 6 5.4.2.2 Grade 3, hardness of 30 6 5.4.2.3 Grade 4, hardness of 40 6 5.4.2.4 Grade 5, hardness of 50 6 5.4.2.5 Grade
18、6, hardness of 60 6 5.4.2.6 Grade 7, hardness of 70 6 5.4.2.7 Grade 8, hardness of 80 6 5.NOTE 2The grade to be used in a particular application depends on the design of the seal and must be specified by the designer.4.3 ClassesSeals shall be classified as follows:4.3.1 Class PS, preformed rubber se
19、al.4.3.2 Class SC, sealing compound.NOTE 3Class SC material should not be used in designs where the seal is under mechanical stress.5. Ordering Information5.1 Orders for material under this specification shall include the following information:5.1.1 Type,5.1.2 Grade,5.1.3 Class,5.1.4 Shape and dimen
20、sions,5.1.5 Quantity,5.1.6 ASTM designation and year of issue, and5.1.7 Other requirements.6. Materials and Manufacture6.1 Resistance to solar radiation can be determined by one of the following:6.1.1 Desert outdoor exposure, in accordance with recommended Practice G7 using the exposure rack at an a
21、ngle of 45 forunbacked exposure of the specimens. Desert outdoor exposure shall be for at least six months including at least one monthpreceding and following the summer solstice.6.1.2 Xenon arc laboratory exposure, in accordance with recommended Practice G151 and G155 using daylight filters andoper
22、ating conditions as described below:6.1.2.1 The irradiance level shall be maintained at 0.55 6 0.02 W/(m2nm) at 340 nm at the control point. For equivalent broadband irradiance levels and tolerances at 300 to 400 nm and 300 to 800 nm, consult the manufacturer of the apparatus.6.1.2.2 The default exp
23、osure cycle shall be 102 min light only followed by 18 min light plus either water spray on the frontsurface or immersion in water. The water spray temperature is typically 21 6 5C, but may be lower if ambient water temperatureis low andspray water can be fresh or recirculated from a holding tank. T
24、he temperature of the spray water is uncontrolled andfor fresh water typically ranges between 16 and 26C. Recirculated spray water can be at a higher temperature. Immersion wateris generally in a holding tank is not used to store purified water. The immersion water is kept at a constant temperature,
25、 which shallbe less than 40C.for recirculation. The uncontrolled temperature of the recirculated immersion water during operation of theweathering device typically ranges between 45 and 55C.NOTE 4Water spray and immersion in water are different kinds of moisture exposures and may produce different r
26、esults.3 Available from the Rubber Manufacturers Association (RMA), 1901 Pennsylvania Ave. N.W., Washington, DC 20006.D3903 1526.1.2.3 The uninsulated black panel temperature (BPT) shall be maintained at 63 6 2.5C at the control point during the dryperiod of exposure to light. For the equivalent ins
27、ulated black panel temperature (black standard temperature (BST), consult themanufacturer of the apparatus.6.1.2.4 Relative humidity shall be maintained at 60 6 10 % at the control point during the dry period of exposure to light inxenon arc apparatus that uses water spray for wetting.6.1.2.5 The ch
28、amber air temperature shall be maintained at 48 6 2C at the control point in equipment that uses water sprayfor wetting and provides for adjustment of the chamber air temperature.6.1.2.6 The exposure duration shall be by agreement between the parties concerned. The exposure time shall be at least 10
29、00h, but long enough to produce a substantial change in the property of interest in the least stable formulation of the type of materialbeing evaluated.NOTE 5The specified set point is the target condition for the control sensor as programmed by the user. When a Standardstandard calls for a particul
30、arset point, the user programs the exact number. The tolerances (maximum allowed operational fluctuations) specified with the set point do not imply thatthe user is allowed to program a set point higher or lower than the exact set point specified. Tolerance is determined by the machine variables. Th
31、etolerance specified is the maximum deviationThe operational fluctuations specified are the maximum deviations allowable from the set point at the controlsensor during equilibrium conditions. The machine variables determine the operational fluctuations. If under equilibrium conditions they exceed th
32、oseallowed, stop the test and correct the problem before continuing.6.2 After exposure, slight surface chalking and dulling are permitted. Brittleness, cracking, loss of elongation, tackiness, or otherdeterioration affecting serviceability shall not be permitted.7. Requirements7.1 Class PS material
33、shall conform to the requirements given in Table 1.7.2 Class SC material shall conform to the requirements given in Table 2.8. Dimensions8.1 The design of the seal shall not permit the rubber to deflect more than 25 % in any direction during thermal expansion andcontraction of the solar collector.NO
34、TE 6If the thermal coefficient of linear expansion for the rubber is not known, a value of 0.0003/K may be assumed for design purposes.8.2 The tolerances in dimensions of molded seals shall conform to the following designations in the RMA Handbook:8.2.1 Molded Seals:8.2.1.1 Commercial DimensionsRMA-
35、F3-T.032.8.2.1.2 Critical DimensionsRMA-F3-T.032.8.2.2 Extended Seals:8.2.2.1 Commercial DimensionsRMA-F3.9. Workmanship, Finish, and Appearance9.1 Class PS seals shall be free of blisters, checks, cracks, and other imperfections that can affect their ability to make ormaintain a tight seal.TABLE 1
36、Requirements for Class PS Material Used to Seal Air-Heat Transport SystemsProperty Grade ASTM Method3 4 5 6 7 8Ultimate elongation, min, % 350 300 250 200 150 100 D412Compression set, max, %:after 70 h at 125C 30 30 30 30 30 30 D395Aafter 166 h at 10C 60 60 60 60 60 60 D1229BResistance to heating (1
37、66 h at 125C):C D865Hardness change, max 10 10 10 10 10 10 D1415 or D2240Ultimate elongation change, max, % 30 30 30 30 30 30 D412Volatiles lost, max, % 2 2 2 2 2 2 see 10.3Resistance to ozone, 100 mPa,D for 166 h at 40C no cracking D1149Resistance to low temperature, D2137Type C only, max, C 40 40
38、40 40 40 40Type C only, max,C 40 40 40 40 40 40Resistance to Outdoor or Xenon Arc Exposure No brittleness, cracking, tackiness, or other deterioration affecting serviceability. G7 or G155A Method B.B Set to be measured at 10 s after release. Lubricated plates or polytetrafluoroethylene film is recom
39、mended if the rubber adheres to the metal compression plates duringtest.C The test temperature of 125C should cover most applications in air ducts of solar energy systems.Aseal in an air-heat transport system operating at temperatures above100C should be tested at a standard test temperature listed
40、in Practice D1349 at least 25C above the maximum temperature in service. The higher test temperaturesare: 150, 175, 200, 225, and 250C.D 100 mPa of ozone partial pressure is equivalent to 100 pphm at standard atmospheric pressure (100 kPa). See new terminology on ozone content expressions describedi
41、n Test Methods D1149.D3903 1539.2 Class SC material shall be uniform in composition and be free of defects that may affect serviceability.10. Test Methods10.1 Class PS MaterialPrepare the specimens as prescribed in Practice D3183 and test the material in accordance with thetest methods given in Tabl
42、e 1. For control of production, specimens may be taken from standard test sheets prepared in accordancewith Practice D3182, using the same unvulcanized material used to prepare the seals and vulcanizing the material at the sametemperature used for the seals to an equivalent state of vulcanization.10
43、.2 Class SC MaterialPrepare five sheets approximately 150 by 150 by 2 mm in accordance with the instructions suppliedwith the sealing material. Also, prepare five adhesion specimens in accordance with Test Method C719. Preferably, prepare eachsheet and adhesion specimen from material in a different
44、container. Condition the sheets and adhesion specimens for 14 days ata temperature of 23 6 2C and relative humidity of 50 6 5 %. Test the material in accordance with the test methods given in Table2.10.3 Determine the volatiles lost from the difference in mass of the specimens before and after heati
45、ng for 166 h at thetemperature given in Table 1 or Table 2 and in accordance with Test Method D865.11. Inspection and Rejection11.1 Class PS MaterialManufacturers of preformed seals may use their quality control systems for production inspection toassure the seals conform with this specification, pr
46、ovided appropriate records are kept. In case of dispute regarding the quality ofa delivered product, a sample of five seals shall be taken from the lot and tested for compliance with this specification. If one ofthe five seals does not conform, a second sample of five seals may be taken and tested.
47、If two or more of the ten seals do notconform, the lot shall be rejected.11.2 Class SC MaterialManufacturers may use their quality control systems to assure production conforms with thisspecification. In case of dispute regarding the quality of a delivered product, five test sheets and five adhesion
48、 specimens shall beprepared from five different packages, in accordance with the instructions supplied with the sealing material. If one of the fivesheets or adhesion specimens does not conform, an additional five sheets or adhesion specimens may be prepared and tested. Iftwo or more of the ten shee
49、ts or adhesion specimens do not conform, the lot shall be rejected.12. Product Marking12.1 The following information may be marked on either the seal, packaging, label, or tag:12.1.1 Name, brand, or trademark of the manufacturer,12.1.2 Type, grade, and class,12.1.3 Compliance with this standard, Specification D3903, and12.1.4 Other information required by the manufacturer or the purchaser.TABLE 2 Requirements for Class SC Material Used to Seal Flat-Plate Solar CollectorsProperty Grade ASTMMethod2 3 4Ultimate elo
