G01794
Fuel Heater Installation 533
49-31-61Page 402 Figure 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Feb 15/73
B. Position heater, spacers, and clamps on shroud, and attach loosely with screws and washers.
C. Connect all plumbing to fuel heater and valves, and tighten all fittings.
D. Tighten all support clamps securing heater and valves to shroud.
E. Pressurize fuel system and check for leakage.
(1)
Plug fuel line at fuel control unit connector.
(2)
Bleed air from fuel line.
(a)
Manually open APU fuel shutoff valve at rear wing spar, accessible at left main wheel well area.
(b)
Pressurize fuel line by operating fuel tank No. 1 forward boost pump.
NOTE: No. 1 tank boost pump requires ac power. Provide airplane with external power.
NOTE: If you must use the fuel boost pumps in the center tank, you must have a maintenance person or observer in the flight compartment to continuously monitor the LOW PRESSURE lights. Turn the applicable fuel boost pump to the OFF position if the LOW PRESSURE light for the center tank stays on.
(c)
Loosen plug at fuel supply line (fuel control unit) just enough to allow trapped air to escape. Catch dripping fuel in appropriate container. Tighten plug.
(d)
Check fuel heater, fuel heater check valve and fuel flow sensing control valve for fuel leaks. Correct as required.
(e)
Shut off No. 1 tank forward boost pump.
(f)
Manually close APU fuel shutoff valve.
4. Restore Airplane to Normal Configuration
A. Install APU (AMM 49-11-0/401).
B. Test fuel sensing flow control valve (AMM 49-31-92/501).
500
Sep 01/02 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 49-31-61 Page 403
C. Position lower shroud against upper shroud and close shroud latches.
CAUTION: MAINTAIN A MINIMUM CLEARANCE OF 0.18 INCH BETWEEN ENGINE PLUMBING, FIRE DETECTOR, CLAMPS AND INSIDE SURFACE OF LOWER SHROUD.
EXERCISE EXTREME CARE NOT TO DAMAGE SHROUD DRAIN LINES WHEN HANDLING SHROUD.
D. Disengage APU compartment access door support rods and stow rods. Close and latch access door.
E. Close the circuit breaker on M280 module-APU control unit on E3-3 electronic shelf.
F. Remove placards.
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49-31-61 Page 404 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Aug 01/95
FUEL DRAIN - INSPECTION/CHECK
1. General
A. The fuel drain system consists of the plenum drain tee, plenum union, interconnecting drain line, and the can drain union. A check should be made to ensure continuous flow of fuel. For additional fuel drain information, refer to AMM 49-12-0/701.
2. Equipment and Materials
A. Cleaning Solvent - Federal Specification P-D-680
B. Air source - Compressed dry
C. Vacuum cleaner - To clean
D. Antiseize Compound - MIL-T-83483
3. Fuel Drain Inspection (APUs without the Fuel Drain Housing) (Fig. 601)
A. Remove the drain line:
(1)
Disconnect the drain line from the drain tee.
(2)
Disconnect the drain line from the drain union on the combustion chamber cap.
(3)
Remove the drain line from the APU.
B. Remove the drain tee from the plenum union on the turbine plenum.
C. Do an inspection of the fuel drain:
(1)
Make sure the drain line has no carbon material or blockage.
(2)
Make sure the drain tee has no carbon material or blockage.
(3)
Make sure the drain union on the combustion chamber cap has no carbon material or blockage.
(4)
Make sure the plenum union on the turbine plenum has no carbon material or blockage.
D. If there is carbon material or blockage in the fuel drain, clean the applicable parts:
CAUTION: DO NOT GET THE SOLVENT IN YOUR MOUTH, OR YOUR EYES, OR ON YOUR SKIN. DO NOT BREATHE THE FUMES FROM THE SOLVENT. PUT ON A PROTECTIVE SPLASH GOGGLE AND GLOVE WHEN YOU USE THE SOLVENT. KEEP THE SOLVENT AWAY FROM SPARKS, FLAME, AND HEAT. THE SOLVENT IS A POISONOUS AND FLAMMABLE MATERIAL WHICH CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
(1)
If the drain line has blockage, remove the blockage with the compressed air.
(2) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737 AMM 飞机维护手册 机载辅助动力AIRBORNE AUXILIARY POWER(65)
