Designation:D3089−97(Reapproved2017)StandardPracticeforDeterminingtheA-DDimensionofAerosolValveDipTubes1ThisstandardisissuedunderthefixeddesignationD3089;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThispracticecoverstherapiddeterminationoftheA-Ddimensiondefinedasthecenterlinedimensionfromthetopplaneofthevalvemountingcupcurltothefarendofthediptube.2SeeFig.1.1.2Thispracticeislimitedtovalveswith1-in.(25.4-mm)mountingcups.1.3Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.2.SignificanceandUse2.1Usingdiptubesofthecorrectlengthishelpfulbyenablingtheusertodischargeessentiallyalltheproductfromthedispenser,preventingthetubefrombecomingjammedintoanincorrectpositionasaresultofgassing,preventingthe(non-dimpled)valvecupfromexcessivelyprotrudingfromthecanplugandperhapscausingproductionproblemsatthecrimperorgasser/crimper,andpreventingthetubefrombottomingontheflatbaseofsomealuminumcansinsuchawaythatasealismadethatwillacttolimitorstoptheentryofproductintothetubewhenthevalveisactuated.2.2Diptubesthatextendfullytothebottomofthedispenser,withoutexcessivedistortion,canalsoaidinretain-ingtheirconnectiontothevalvebodytailpiece,whichmaybeimportantiftheaerosolcontentexertsaverysignificantswellingactionuponthediptubeplastic.2.3ThechoiceofA-Ddimensionisinfluencedbyanumberoffactors.Thesefactorsinclude:2.3.1Tubecurvature,whichmayvaryconsiderablybetweentubes.2.3.2Variationofvalvecupandvalvecupgasketthickness.2.3.3Elevationorsuppressionofthevalvepedestal(thustopendofthediptube)uponcrimping.2.3.4Elevationofvalvepedestalduringhot-tanking,onlypartlydiminisheduponsubsequentcooling.2.3.5Swelling(orshrinking)actionoftheproductonthediptube.3.Apparat...
