Jan
Jan 10/90
21-30-00
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. PressurizationControl(continued)
1. ComponentDetailedDescriptions(continued)
(f)
Air Filter The filter elementis a cylindrical plug madeof treated paperfabric,completely enclosed in a thin aluminum case, with perforationsaroundits circumference. Thefilter effectively eliminates
entry of tobacco tar and dust particles greaterthan 0.3 micron in diameterintothe pneumatic controlelementsof the outflowvalvecontroller.
(g)
VacuumRelief Solenoid Valve Thisvalve, normally closed,is located betweenthe vacuum regulator vacuumport and the controlline from the cabin pressure controllerto the safetyvalve. When energized, the vacuumprovidedby the vacuumregulatorejectoris applied to the diaphragmof the safety valveto hold it open. The vacuum relief solenoid valve is open under either of the following conditions: (1.) On the ground with the "q" sensor system or landing gear squat switchenergized. (2.) In flight wheneverthe cabinpressure control switch is in the DUMP position.
(h)
Vacuum Regulator Vacuumto operate the safety valveand controller is obtained from the vacuum system,which usesits own regulator. The regulator,setto provide 4.5 to 5.4 inches of mercury(relativeto cabinpressure),is placed in the system betweenthe vacuum driveninstrumentsand the ejector.
(i)
Ejector Theejector is used by the vacuumsystemto provide a vacuum source. Locatedunderthe rightside floor panelsnear F.S 151.30,it is connected to the pneumatic linesfromthe intercoolers.Bleedairflowsthroughthe ejector to create the necessaryvacuum. (Referto 36-00-00and37-00-00)
(j)
ManualTest Valves The manual shutoffvalveis located below the instrumentpanel,to the right of center, alongthe brake support channel. Whenused, the valve allowsfor system groundcheckoutand is lockwiredin the open positionexceptwhenthe system is tested. The valve is installed in the vacuumline going to the controller and is used duringthe system positivedifferentialpressure reliefcheck.
(k)
CabinPressureSwitches
(1.) Cabin differentialswitch,locatedon aft pressure bulkhead, providesa warning to the pilot if cabin differential pressureexceeds6.45+ 0.05psid, by lighting the CABIN PRESS cautionlight on the master caution panel.
(2.) Cabin absolute switch, locatedon aft pressurebulkhead, provides a warning to the pilot if the cabin altitudeexceeds11,500 feet, by lighting the CABIN PRESS cautionlighton the pilot annunciator panel.
(3.) Cabin absoluteswitch for emergency pressurization,locatedon aft pressure bulkhead, turnson the emergency pressurizationvalveif cabin altitudeexceeds12,000 to 12,500 feet.
EFFECTIVITY: 040-999
21-30-00Jan
PIPER AIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. PressurizationControl(continued)
PORT"2"DEPRESSURIZATIONCONNECTION
POPPETOUTFLOWVALVE
CONTROLCHAMBER
INNER DIAPHRAGM BASE ASSEMBLY
POPPET VALVE RETURN SPRING
METERING VALVE -
DIFFERENTIALCONTROL DIAPHRAGMASSEMBLY NOISE SUPPRESSION SCREEN
PORT "1" TRUE STATIC ATMOSPHERE CONNECTIONWITH ORIFICE
CABIN AIR FILTER WITH ORIFICE ON SAFETY VALVE ONLY
DISCHARGEPRESSURE
TRUESTATIC ATMOSPHERE
REFERENCEPRESSURE GASKETINSTALLATIONDIMENSIONS
CABIN PRESSURE NOTE: THISPORT PLUGGEDON OUTFLOW VALVE
ONLY.
1 NUT 3
2 SHIM (AS REQ)3 PLACES
0.085
0.385 IN. TYPICALDIMENSIONAFTER
0.485 INSTALLATIONOF SHIM
HOLDTHIS DIMENSION_ __ _ _ _ _ _
Safety and Outflow Valves
Figure 3
EFFECTIVITY: 040-999
PAGE
1221-30-00
Jan10/9021-30-00
PIPERAIRCRAFT
PA-42-720(Advanced Trainer)
MAINTENANCEMANUAL
A. PressurizationControl(continued)
AUXILIARYVOLUME
TANKCONNECTION
REFERENCEPRESSURE
METERINGVALVE RATEDIAPHRAGM
METERINGVALVE
FOLLOWERSPRING
RATESPRING
RATECONTROLVALVE
SEALINGDIAPHRAGM
CHECKVALVE
ABSOLUTEBELLOWS RATECONTROLVALVE
POSITIONACTUATOR
CABINAIRSENSEPORT
ACTUATOR
CABINALTITUDE SELECTORKNOB CABINCONTROL SELECTORKNOB
CABINPRESSURE 3
RATEPRESSURE
REFERENCEPRESSURE
AIRCRAFTVACUUMPRESSURE FACEVIEWOFCONTROLLER
CabinAir PressureOutflowValveController
Figure 4
EFFECTIVITY:
040-999
PAGE13
21-30-00
Jan10/90
PIPER AIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCE MANUAL
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本文链接地址：夏延飞机维护手册 Cheyenne IIIA PA-42-720 AMM 1(59)
