(b)
Refer to (FIg. 805) to find the necessary tube cutout length when you use a single flareless MS21902 union to replace a damaged tube area.
(c)
To use assembled tube ends or a center section to do a repair, find the cutout length and install as follows: 1) Make an estimate of the total length (L1) of the repair
section necessary to replace the damaged tube (Figs.
806,809).
2) Cut and trim the repair tube as follows: (Fig. 804) a) Use the correct size ratchet chipless cutter. b) Turn the cutter drive screw counter clockwise to
retract the cutter wheel.
c) Put the cutter over the tube.
d) Turn the screw clockwise until the cutter touches the
tube at the necessary cut location.
e) Turn the cutter screw 1/8 to 1/4 turn and rotate the cutter until the cutter is easy to rotate. The tube should now be cut.
f) Remove the tool.
g) To deburr the tube, use the correct stem subassembly and deburring tool. To assemble the tool refer to (Fig. 804).
h) Push down on the plunger and install the tool into the end of the tube. i) Release the plunger. Let the plug fill the inside of the tube. j) Rotate the deburring tool until the inside burr is removed.
k) Remove the tool with the plug expanded. The expanded plug should remove particles from the inside of the tube.
NOTE: Make sure you do not drop metal particles in
____ area of the repair.
3) Swage the necessary flareless BACS13BX sleeves to the repair tube using the applicable section: Swage BACS13BX Flareless Sleeves with the Harrison Elastomer Swagers 5175, 5570, 5720.
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20-11-05
ALL ú ú 06 Page 837 ú Oct 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
4) Assemble and tighten the flareless fittings which are part of the repair section Removal/Installation (AMM 20-11-05/401).
5) Measure all of the tube assembly length with BACS13BX sleeves (L1) (Figs. 806, 809).
6) To find the necessary cutout length (L2) as shown in (Figs. 806, 809), use the procedure given in (Fig. 810) for BACS13BX sleeves and Harrison Portable Swagers with MS21902 unions.
7) Remove the pressure from the systems where you will do the repairs. 8) Cut out the damaged tube (L2). Trim the tube ends as shown in (Fig. 804).
9) When you make the installation, refer to the section: "Swage the BACS13BX Flareless Sleeves with the Harrison Elastomer Swagers 5175, 5570, 5720".
10) Install the repair section and tighten the nuts (AMM 20-11-05/401).
TASK 20-11-05-208-413
14. Aluminum Fuel Tubes - Temporary Weld Repair Method__________________________________________________
A. General
CAUTION: REPLACE THE TUBE WITH A TEMPORARY REPAIR WITH A NEW SECTION OF
_______ TUBE WITHIN A MAXIMUM OF 250 FLIGHT HOURS. IF YOU DO NOT REPLACE THE TUBE, DAMAGE COULD OCCUR.
(1)
This is a temporary repair method approved for 6061 and 5052 aluminum fuel system tubing, and is applicable only to tubes with wear-through damage, cracks, or punctures.
(2)
Repair is accomplished with tubing removed from airplane.
B.
Consumable Materials
(1)
B01000 Solvent, Series 80
(2)
B01008 Solvent, Series 88
C.
Aluminum Fuel Tube Repair
S 018-414
(1) Remove aluminum fuel tube to be repaired by referring to applicable maintenance manual removal and installation procedure.
S 118-415
CAUTION:_______FULLY CLEAN THE TUBING. IF YOU DO NOT CLEAN THE TUBING, THE WELD CAN GET CONTAMINATED AND THE WELD QUALITY DECREASES.
(2)
Completely clean the inner and outer surfaces of all the tube section with solvent, Series 80 (AMM 20-30-80/201).
S 358-416
(3)
If tubing is cracked, drill 3/32-inch stop holes at each end of crack.
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