1、Designation:F265707(Reapproved 2012)Standard Test Method forOutdoor Weathering Exposure of Crosslinked Polyethylene(PEX)Tubing1This standard is issued under the fixed designation F2657;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,
2、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 test method describes the procedure for exposingcrosslinked polyethylene(PEX)tubing produced in accordance
3、with Specification F876 to natural(sunlight)ultraviolet(UV)radiation and evaluating the effects of the exposure.This testmethod outlines the requirements for specimen size andpreparation,exposure orientation,minimum UV exposureenergy,post exposure testing and reporting.NOTE1While other laboratory UV
4、 exposure systems are available,this test method relies on natural sunlight as the UV radiation source.Laboratory methods may be added in the future if testing confirms acorrelation between natural sunlight and laboratory exposure.1.2 PEX tubing is not designed for outdoor use.Data fromshort-term ex
5、posure testing per this test method can be used tojudge the relative performance of PEX tubing stored outdoorsfor short periods of time prior to installation completelyshielded from sunlight.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in
6、 thisstandard.1.4 The following precautionary caveat pertains only to thetest method and post exposure testing portions,Sections 8 and9 of this test method.This standard does not purport to addressall of the safety concerns,if any,associated with its use.It isthe responsibility of the user of this s
7、tandard to establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1435 Practice for Outdoor Weathering of PlasticsD1598 Test Method for Time-to-Failure of Plastic PipeUnder Constant Internal Pr
8、essureD1600 Terminology forAbbreviated Terms Relating to Plas-ticsF412 Terminology Relating to Plastic Piping SystemsF876 Specification for Crosslinked Polyethylene(PEX)Tub-ingF2023 Test Method for Evaluating the Oxidative Resistanceof Crosslinked Polyethylene(PEX)Tubing and Systemsto Hot Chlorinate
9、d WaterG147 Practice for Conditioning and Handling of Nonmetal-lic Materials for Natural and Artificial Weathering Tests3.Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology F412 and abbreviations are in accordance with Termi-nology D1600,unless otherwise indicated.3.2 Definiti
10、ons of Terms Specific to This Standard:3.2.1 nominal exposure time period,nthe number ofmonths corresponding to the measured TUV as defined inTable 1.3.2.2 polar orientation,nthe longitudinal direction of thespecimens with respect to the Equator.3.2.3 solar UV radiation,nthe portion of the light spe
11、c-trum falling within the range of 295nm to 385nm.3.2.4 total solar UV radiation(TUV),nthe sum of mea-sured UV Energy for the time period specimens are exposed,expressed in MJ/m2.The historical average monthly TUVvalues for CentralArizona,5 off horizontal exposure are listedin Table 1.3.2.5 tubing b
12、ow,nthe resultant curvature of a tubingsample taken from a coil.3.2.6 UV energy,nthe amount of solar UV radiation perunit time based on a 5 off horizontal specimen placement forCentral Arizona expressed as MJ/m2.3.2.6.1 DiscussionUV Energy for Central Arizona wasselected as it represents the worst c
13、ase North Americanlocation based on a 4-year average of 1998 through 2001.Thisinformation was provided by Atlas Material Testing Technol-ogy LLC.1This test method is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.40 on TestM
14、ethods.Current edition approved March 1,2012.Published April 2012.Originallyapproved in 2007.Last previous edition approved in 2007 as F265707.DOI:10.1520/F2657-07R12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book
15、 of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 PEX tubing specimens are exposed to solar UV radia-tion for a
16、 period of time and then removed.The exposedspecimens are then tested in accordance with one of thefollowing methods:4.2 Potable Water ApplicationsUV exposed specimensare tested at one temperature and pressure condition in accor-dance with Test Method F2023 to determine the average timeto failure.The average time to failure for the UV-exposedspecimens is then compared to the average time to failure ofnon UV-exposed specimens of the same PEX material or to thepredicted time to failure for the sam
