EngA AF Series - Piping Connection Sizing; Refrigerant Traps; Liquid Line Considerations; Discharge Line Requirements

A
AF / DCU MANUAL
IOM-52 8 of 23 Apr 13 R2
PIPINGCONNECTIONSIZES

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.

Note:

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.

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.

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.

