EngA AF Series

A
AF / DCU MANUAL
IOM-52 8 of 23 Apr 13 R2
PIPINGCONNECTIONSIZES
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Refrigerantpipingmustbeselectedtomeettheconditionsrequiredforyourspecificinstallation.The
tubingconnectionsizesontheequipmentmayormaynotbethecorrectsizeforyourspecificapplication.
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Note:
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DONOTselecttubingsizesbasedonthesizeoftheconnectionstubs.
Thecorrecttubingsizeforyourinstallationmustbecheckedandselectedforeachandevery
job.
TRAPS
Itisrecommendedthattrapsbeinstalledonallsuctionordischargegasrisers.
LIQUIDLINE
Selectthelinesizeusingpipingtables.
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Liquidlinesshouldhaveamaximumrefrigerantvelocityof350feetperminute(1.78m/s)toavoidliquid
hammer.Selectpressuredropforatemperaturepenaltyoflessthan2°F(1°C).Ifaliquidlinetravels
throughawarmarea,suchasaboilerroom,insulatethelinetopreventheatgain.
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Ensurethetemperaturepenaltydoesnotexceedthesubcoolingprovidedbythecondensingunit.
AsightglassshouldbeinstalledattheTXvalvetoensurethevalveisreceivingasolidcolumnofliquidif
adequatesubcoolingisaconcern.AnEngAIntercoolermaybeorderedandinstalledtohelpreducethe
effectsofinadequatesubcooling.
DISCHARGELINE
Dischargelinesmustbeselectedtobalancetworequirements;minimizepressuredropandensure
adequatelinevelocitytoallowforoilreturn.Horizontaldischargelinesshouldbeslopeddowninthe
directionofflow.Usesizingtablestoselecttubingsizesbasedoncapacity,equivalentlengthand
maximumsizeforoilreturn.
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