COMAC ARJ21-700 - Potable Water System - Drain Water

ARJ21-SVV19-13120-00
RampServicingOperation
Instruction
Potablewatersystem-Drainwater
1.CommonInformation
A.Thisprocedureprovidesthepotablewatersystemdrainwater.
B.TheWater/WasteStatusPanel(WWSP)islocatedabovethefwdpassengerentrydoorattendant
seats.Itisusedtoindicatetheoperatingconditionofthesystemandthewaterlevelinthepotable
watertank.
C.Whentheairplaneisonthegroundforservicing,thewaterlevelsensordetectsthatthewaterquantity
islessthan5%andthewatersysteminterfacecontroller(WSIC)controlstheaircompressornotto
pressurize,theserviceneedstodraintheremainingwatercleanthroughwaterdrainagewithpres-
sure.
D.Incoldweather,ifthewaterinthetankorpipeisnotdischargedclean,thepipemayfreezeandburst.
2.PreliminaryRequirements
WorkZones
ZoneLocation
130STA218-STA560.722FwdCargoCompartment,Middle
EquipmentCompartment
AccessPanels
NumberName
135ALWWaterServiceDoor
3.Procedures
A.Procedure
(1)T ankdrain(Normallineservice)
(a)Beforedrainwaterfortheaircraft,conrmtheaircraftinspectionwiththesitemaintenance
operator,andstartdraining.
(b)OpenWaterServiceDoor135ALW.
(c)MakesurethatthemanualisolationvalvesinthelavatoriesandgalleysareintheOPEN
position.
(d)TurntheselectorswitchonthewatersysteminterfacepaneltotheTANKDRAINposition.
(e)Thewastewaterowsfromthedrainportonthefuselagebelly,itisrecommendedtouse
apropercontainertocollectthewater.
(f)Makesurethatthewaterowatthedrainportofthefuselageisstopped.
(g)Openthewaterllingnippletodrainthewaterfromthewaterllinglines.
(h)CheckthepotablewaterquantityindicationshowszeroontheWWSPthatislocatedabove
thefwdpassengerentrydoorattendantseats.
(i)Closethewaterllingnipple.
ARJ21-A-13-12-23-01A-226A-A
Issue001,2023-01-29
Applicableto:ALL
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