CONNECTOR
FOR THE
PRESSURE SWITCH
SOLENOID
ELECTRICAL
CONNECTOR
PRESSURE SWITCH BYPASS VALVE MANUAL OVERRIDEISOLATION VALVE LEVER
HYDRAULIC CONNECTOR DEACTIVATION (4 LOCATIONS) SLIDE
OUTBOARD STRUT INSTALLATION - ACTIVATED
FWD (INBOARD EQUIVALENT)
A
Thrust Reverser Isolation Valve
Figure 1 (Sheet 1)
C79109
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////////////////////////A / PW4000 SERIES /747-400 / ENGINES /MAINTENANCE MANUAL ////////////////////////
STREAMER PINS
BYPASS VALVE MANUAL OVERRIDE LEVER
HITCH PINS
ISOLATION VALVE DEACTIVATION SLIDE
OUTBOARD STRUT INSTALLATION - DEACTIVATED FOR GROUND MAINTENANCE (INBOARD EQUIVALENT)
Thrust Reverser Isolation Valve
Figure 1 (Sheet 2)
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D. The isolation valve has modes for reverser flight dispatch and for ground servicing. For deactivation of the reverser for flight dispatch the arming valve is locked in the closed position by inserting a retaining pin. This pin prevents the arming valve spool from allowing hydrualic fluid flow to the reverser actuators. In this mode, the PRESS port is blocked and fluid flow from CONT port to CYLINDER port is made.
E. For ground maintenance the isolation valve can be locked in the manual
bypass mode by positioning the bypass valve such that fluid flow is
allowed from the RETURN to the CONT ports. This prevents a hydraulic
lock from stopping manual operation of the reverser.
F. Manual bypass is accomplished by depressing the bypass valve lever and
inserting a lockout pin with a remove before flight streamer through the
lockout holes of the lock lever for the bypass valve.
G. A second lockout pin on the streamer assembly is inserted through the
lockout holes of the arming valve to prevent inadvertant hydraulic
powered operation of the reverser. The streamers provide ground
indication that the valve is locked in the manually deactivated mode.
H. It should be noted that the lockout pin for the manual bypass valve
should not remain installed if hydraulic components downstream of the
isolation valve are removed. Draining of the strut hydraulic reservoir
is possible through the return lines with the lockout pin for the bypass
valve installed.
HYDRAULIC HYDRAULIC
RETURN SUPPLY
HI
Figure 1 (Sheet 3)
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////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
3. Directional Control Valve (Fig. 2)
_________________________
A. The directional control valve (DCV), located in the forward upper strut, controls the deploy or retract hydraulic flow to the hydraulic actuators.
B. The directional control valve is connected by hydraulic lines from the isolation valve and to the flow control tees.
C. There are four fluid ports in valve housing:
(1)
The pressure (PRESS) port is connected to the isolation valve which provides airplane hydraulic system pressure (3000 psi, nominal).
(2)
The return (RTN) port is connected to the return line of the airplane hydraulic system (200 psi, nominal).
(a) The return line contains a hydraulic fluid filter between the Thrust Reverser System and the Hydraulic Reservoir. This Return Filter bypasses the Hydraulic System Return Filter. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 EXHAUST 2(56)
