3.6 Corrosion Resistance
RAUPEXpipeisnon-reactiveanddisplaysexcellentcorrosion
resistance.Corrosionisaprocessthatrequireselectricallyconductive
materialsandoccursonmetals.PEXa,beingadielectric,doesnot
corrodelikemetalpipes.PEXaalsoresiststhebuildupofscalewhich
iscommonwithcopperpipe.
3.7 Chlorine Resistance
RAUPEXpipehasbeentestedinaccordancewithASTMF2023,
Standard Test Method for Evaluating the Oxidative Resistance of
Crosslinked Polyethylene (PEX) Tubing and Systems to Hot Chlorinated
Water asrequiredinASTMF876.RAUPEXpipeexceedstheminimum
extrapolatedtestlifetimeascertiedbyNSFandPPIforcoldwater
applications,intermittenthotwaterapplicationsandtimedhotwater
applications.
Basedonthistesting,whenusingRAUPEXUVshieldpipefor
plumbingapplicationswithoutcontinuoushotwaterrecirculation,the
followingwaterqualityconditionsmustbemet:
-ThepHofwateris7.0orhigher
-Theconcentrationoffreechlorineis4.0ppmorlower
-Watertemperatureis140°F(60°C)orlower
-Waterpressureis80psig(550kPa)orlower
-Oxidativereductionpotential(ORP)of825mVorlower
ThisrecommendationappliestoRAUPEXUVshieldplumbingpipesfor
coldwaterandintermittenthotwaterapplications(25%@140°F,
75%@73°F)andfortimedhotwaterrecirculationsystemsforupto
12hoursperday(50%@140°F,50%@73°F).TheASTMF876
standardincludesdesignationcodesfortheseapplicationswhichare
includedontheprintlineofRAUPEXpipes.
WhenusingRAUPEXUVshieldpipeforplumbingapplicationswith
continuoushotwaterrecirculation,thefollowingwaterquality
conditionsmustbemet:
-ThepHofthewateris7.9orhigher
-Theconcentrationoffreechlorineis2.4ppmorlower
-Watertemperatureis140°F(60°C)orlower
-Waterpressureis80psig(550kPa)orlower
-Oxidativereductionpotential(ORP)of750mVorlower
Iftheseconditionsarenotmet,itisnecessarytoincorporateatime
controlsothesystemoperatesatamaximum50%@140°Fand
50%@73°F.
Itshouldalsobenotedthatinrareandisolatedcases,othercharac-
teristicsofthemakeupofdrinkingwatercanimpactthelong-term
performanceofplumbingsystemcomponentsevenwhenthewater
qualitylevelsarewithinthepermissiblerangesetforthbythe
EPANational Primary Drinking Water RegulationsandtheGuidelines
for Canadian Drinking Water QualitybyHealthCanada.Thelicensed
installingcontractormusthavepracticalexperiencewithintheregion
ofintendeduse.Inaddition,consultationwiththelocalplumbing
authorityandlocalwaterauthorityregardingtheperformanceof
plumbingsystemcomponentsshouldoccurbeforetheselectionand
installationofsystemswithinthatspecicgeographicregion.
Therefore,thespecicapplicationshouldalsobetakenintoconsider-
ationwhendesigningandinstallingplumbingsystems.
3.8 Ultraviolet Resistance
Allpolymersaresusceptibletodamagefromexposuretothe
ultraviolet(UV)radiationinsunlight.PEXpipescanbedesignedto
protectagainstshort-termUVdamage,butaftersometime,UV
radiationwillreducethelifetimeofthepipe.Theextentofthe
reductiondependsonfactorssuchastemperature,pressureand
chlorinationlevelsinpotablewater.
REHAUhasperformedextensivetestingofRAUPEXpipesexposedto
naturalsunlight,leadingtothemaximumUVexposuretimesex-
pressedinaccumulateddays.Oncethepipesleavethemanufacturing
plant,anyexposuretoUV,includingtransportationandstoragebythe
wholesaler,ispartoftheaccumulatedexposuretime.
AlthoughASTMF876onlycategorizesupto6monthsofUVresis-
tance(MaterialDesignationCode=3306),REHAUhastestedand
certiedRAUPEXUVshieldpipeaccordingtoASTMF2657forthe
followingmaximumUVexposureperiod:
-RAUPEXred,whiteandblueUVshieldpipe:Maximumexposure
timeofoneyearaccumulated
RAUPEXpipesmustbekeptintheoriginalpackaginguntilthetimeof
installation.RAUPEXmustnotbestoredoutdoorsandisnotdesigned
forpermanentoutdoorexposure(withtheexceptionofnon-exposed
buriedapplications).ExcessiveUVexposurewillreducethelifetimeof
PEXapipe.
3.8.1 UV Emitted by Fluorescent Lamps
ASTMF2657wasestablishedtotesttotheworstcasescenariofor
UVexposurebytestingindirectsunlight.UVemittedbyuorescent
lampsisinsignicantwhencomparedtoUVpresentinsunlight.GE
Lightinghasstated“SolarUVisenormouslymorephotoactiveand
damagingthantheUVfromlinearuorescentlamps.SolarUV
includesUV-A,UV-BandUV-C.UV-AisnearUV,notveryenergetic
andisthebulkofUVemittedbyorescentlamps.”Therefore,when
8