COMAC ARJ21-700 - Page 190

ARJ21-SVV19-13120-00
RampServicingOperation
Instruction
CAUTION:AFTERDRAINAGEANDDEPRESSURIZATIONOFTHEPOTABLEWATER
SYSTEM,YOUMUSTTURNTHEKNOBONTHEWATERSYSTEMINTERFACE
PANELTOFLIGHTREADYFIRST .AFTERABOUT10SECONDS,REMOVE
THEELECTRICALPOWERANDCLOSETHEACCESSPANEL,OTHERWISE,
DAMAGETOTHEAIRPLANEMAYOCCUR.
(j)TurntheselectorswitchonthewatersysteminterfacepaneltotheFLIGHTREADYposi-
tion.
(2)Waterdrainagewithpressure(Coldweatheradditionaloperation)
(a)MakesuretheselectorswitchonthewatersysteminterfacepaneltotheFLIGHTREADY
position.
(b)Removetheprotectivecoverfromairservicevalve.
(c)Connectthegroundairconnectorandtheairservicevalve.
NOTE:
TheinputportoftheairservicevalveconformstoStandardMS20813.
(d)Adjustpressuregageofthegroundhydraulicpowercartto36psi.
(e)Openthegroundairsource,andcontinuouslypressurizethewatersystemfor3min-5min.
NOTE:
Therecommendedinputpressurerangeis33psi~37.5psi.
(f)Closethegroundpneumaticinterfacecap.
(g)Openthewaterllingnipple.
NOTE:
WhileturningtheselectknobonthewatersysteminterfacepaneltoTANKDRAIN,
payattentionasmoisturemaysprayfromthewaterlltting.
(h)TurntheselectknobonthewatersysteminterfacepaneltoTANKDRAINtodrainwaterin
thewatersupplylinesandwatertank.
(i)Repeatabovesteps(d)to(g)untilthereisnoobviousresidualwaterowsout.
(j)Disconnectthegroundairconnectorandtheairservicevalve.
(k)Installtheprotectivecoverfromairservicevalve.
(l)TurntheselectorswitchonthewatersysteminterfacepaneltotheFLIGHTREADYposi-
tion.
B.Finalprocedure
(1)CloseWaterServiceDoor135ALW.
(2)Makesurethattheworkareaisclean.Removealltools,equipmentandunwantedmaterials
fromtheworkarea.
ARJ21-A-13-12-23-01A-226A-A
Issue001,2023-01-29
Page2of4
Applicableto:ALL