Installation of the Dual-Flapper Check Valve

TASK 47-20-43-400-001-A
Installation of the Dual-Flapper Check Valve

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

WARNING: YOU MUST WEAR SAFETY BREATHING EQUIPMENT WHEN YOU DO WORK IN THIS AREA. THIS AREA CAN CONTAIN AIR FROM THE TANK INERTING SYSTEM. AIR FROM THIS SYSTEM HAS A LOW-OXYGEN CONTENT AND CAN CAUSE INJURY AND DEATH.

WARNING: THIS PROCEDURE USES A FUEL SYSTEM ITEM THAT IS IN A CATEGORY KNOWN AS A CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION (CDCCL). CDCCL IDENTIFIES AN ITEM THAT CAN BE THE SOURCE OF A POSSIBLE FUEL TANK IGNITION. YOU MUST KEEP ALL CDCCL ITEMS IN THE APPROVED CONFIGURATION. DAMAGE, WEAR OR CHANGES TO A CDCCL ITEM CAN CAUSE A POSSIBLE FUEL TANK EXPLOSION.

WARNING: MAKE SURE THAT:

THERE ARE NO CAPS OR COVERS ON THE FUEL TANK VENTILATION DUCTS. CAPS OR COVERS WILL CAUSE OVERPRESSURE OR UNDERPRESSURE DAMAGE TO THE FUEL TANK.
NO PERSONS ARE NEAR THE FUEL TANK OR VENTILATION DUCTS OF THE FUEL TANK.

WARNING: BEFORE YOU INSTALL/REMOVE THE GSE-TOOL, READ THE INSTRUCTIONS IN THE APPLICABLE GSE INSTRUCTION MANUAL. WHILE YOU OPERATE THIS TOOL, CAREFULLY OBEY THEM. IF YOU DO NOT OBEY THE INSTRUCTIONS, INJURY AND/OR DAMAGE CAN OCCUR.

ZONE: 145
FIN: 4YM ** ON A/C NOT FOR ALL

1. Reason for the Job

NOTE: Two persons are necessary to do this task.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	Torque wrench: range to between 0.47 and 0.43 m.daN (41.59 and 38.05 lbf.in )
No specific	Torque wrench: range to between 0.48 and 0.43 m.daN (42.48 and 38.05 lbf.in )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03GEE1)	Synthetic Oil base Grease-Fuel and Oxidized Environment Fluorinated -
(Material No.04TMB2)	Varnish-- Electrical Bonding Structure
(Material No.06ABA1)	Polysulfide Sealant-Fuel Tank Brushable -
(Material No.14CCB6)	Testing Medium-Leak Detection - Oxygen System
(Material No.14QDB1)	Wire-Locking Dia: 0.5 mm (0.020 inch) CRES Nickel Alloy -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
145	PRESS ZONE BETW WING CTR BOX MAIN GEAR
241EF

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
3	O-RINGS	AIPC 47-20-04-01-070
6	O-RING	AIPC 47-20-04-01-090
11	O-RING	AIPC 47-20-04-01-100
13	PACKING	AIPC 47-20-43-01-020
3	O-RINGS	AIPC 47-20-84-01-070
11	O-RING	AIPC 47-20-84-01-100
6	O-RING	AIPC 47-20-84-01-110

E. Referenced Information

REFERENCE	DESIGNATION
TASK 20-11-11-911-001-A	Safetying with Lockwire
TASK 20-21-12-911-001-A	Tightening Torques for Pipe Unions (not for OXYGEN Unions)
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 47-20-43-370-001-A	FINCH painting of the IGGS Dual-Flapper Check Valve
TASK 47-20-43-370-002-A	FINCH painting after re-installation of the IGGS Dual-Flapper Check Valve
TASK 47-31-34-740-001-A	BITE Test of the IGGS with Bleed Air
TASK 47-31-34-740-001-A-01	BITE Test of the IGGS without Bleed Air
TASK 53-32-12-000-002-A	Removal of the Cabin Floor Panels
TASK 53-32-12-400-002-A	Installation of the Cabin Floor Panels
Dual-Flapper Check Valve - Location and Detail

3. Job Set-up
Subtask 47-20-43-860-053-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Make sure that the aircraft electrical circuits are de-energized (Ref. AMM TASK 24-41-00-862-002).

Subtask 47-20-43-865-053-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	N28
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	P28
** ON A/C NOT FOR ALL
122VU	CSAS / CTRL	1HW	U17

Subtask 47-20-43-010-052-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Make sure that the cabin floor panel 241EF is removed (Ref. AMM TASK 53-32-12-000-002).

4. Procedure
Subtask 47-20-43-420-050-B ** ON A/C NOT FOR ALL

A. Installation of the Dual-Flapper Check Valve
(1) Remove the blanking cover from the opening of the dual-flapper check valve (4).

WARNING: BEFORE YOU DO WORK IN OR NEAR A FUEL TANK, MAKE SURE THAT YOU OBEY ALL THE SAFETY PROCEDURES. THIS WILL PREVENT INJURY TO PERSONS AND/OR DAMAGE TO THE AIRCRAFT.

CAUTION: BE CAREFUL WHEN YOU TOUCH THIS ASSEMBLY. IT HAS PRECISION- TOLERANCE COMPONENTS WITH VERY POLISHED SURFACES. IF YOU ARE NOT CAREFUL, IT IS VERY EASY TO CAUSE DAMAGE TO THESE COMPONENTS (INTERNAL CONTAMINATION, EXTERNAL IMPACT DAMAGE).

CAUTION: DO NOT LET PAINT PARTICLES GO INTO THE FUEL TANK. REMOVE THE PARTICLES WITH A VACUUM CLEANER (IF YOU CANNOT USE A VACUUM CLEANER, USE AN AIR BLOWER).

(2) Install the new AIPC 47-20-04-01-090 O-RING (6) or AIPC 47-20-84-01-110 O-RING (6) and AIPC 47-20-04-01-100 O-RING (11) or AIPC 47-20-84-01-100 O-RING (11) on the dual-flapper check valve (4).
(3) Hold the dual-flapper check valve (4) in position and install the new AIPC 47-20-04-01-070 O-RINGS (3) or AIPC 47-20-84-01-070 O-RINGS (3), the washers (2) and the nuts (1).
(4) TORQUE the nuts (1) to between 0.48 and 0.43 m.daN (42.48 and 38.05 lbf.in )

.
(5) Apply Polysulfide Sealant-Fuel Tank Brushable - (Material No.06ABA1) to the nuts (1) and washers (2).
(6) Remove the PLUG-BLANKING from each disconnected line end.
(7) Connect the union (5) on the dual-flapper check valve (4) (Ref. AMM TASK 20-21-12-911-001).
(8) Install the bonding leads (9) and (10) with the washers (8) and the screws (7) (Ref. AMM TASK 20-28-00-912-802).
(9) Apply Varnish-- Electrical Bonding Structure (Material No.04TMB2) on the screw heads (7).

Subtask 47-20-43-865-054-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	N28
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	P28
** ON A/C NOT FOR ALL
122VU	CSAS / CTRL	1HW	U17

Subtask 47-20-43-790-065-A ** ON A/C NOT FOR ALL

C. Leak Test Procedure

NOTE: Two persons are necessary to do this subtask.

(1) Apply Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to the dual-flapper check valve.
(2) Do the BITE test of the IGGS with bleed air (Ref. AMM TASK 47-31-34-740-001).
(3) During this test, make sure that there is no air leak on the joints of the dual-flapper check valve.

NOTE: Air leaks are not permitted.

Subtask 47-20-43-790-066-A ** ON A/C NOT FOR ALL

CAUTION: DO NOT LET PAINT PARTICLES GO INTO THE FUEL TANK. REMOVE THE PARTICLES WITH A VACUUM CLEANER (IF YOU CANNOT USE A VACUUM CLEANER, USE AN AIR BLOWER).

D. Double Barrier Check

NOTE: Two persons are necessary to do this subtask.

(1) Carefully remove the FINCH painting from around the DFCV flange test port plug (12) and fully clean the area around the DFCV (4).

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(2) Remove and discard the lockwire of the plug (12).
(3) Remove the plug (12) and the packing (13).
(4) Discard the packing (13).
(5) Install a 98D47209001000 PRESSURE VACUUM TESTER, IGGS to the flange test port.
(6) Supply 0.69 bar (10.01 psi) at pressure conditions during five minutes.
(7) Stop the pressure supply.
(8) After two minutes, do a check of the pressure.
(9) The test is satisfactory if:

The pressure does not decrease,
or
The pressure decreases less than 5%.

(10) If the test is not satisfactory:
(a) Replace all of the O-rings and washers of the DFCV (4).
(b) Do this Double Barrier Check again.
(11) If the test is satisfactory:
(a) Remove the 98D47209001000 PRESSURE VACUUM TESTER, IGGS from the flange test port.
(b) Apply a thin layer of Synthetic Oil base Grease-Fuel and Oxidized Environment Fluorinated - (Material No.03GEE1) to a new AIPC 47-20-43-01-020 PACKING (13) and install it on the plug (12).
(c) Install the plug (12) on the flange test port.
(d) TORQUE the plug (12) to between 0.47 and 0.43 m.daN (41.59 and 38.05 lbf.in )

.
(e) Safety the plug (12).

1 Safety the plug (12) with 14QDB1Wire-Locking Dia: 0.5 mm (0.020 inch) CRES Nickel Alloy - with the double wirelocking method (Ref. AMM TASK 20-11-11-911-001).

Subtask 47-20-43-370-053-A ** ON A/C NOT FOR ALL

E. FINCH Painting

WARNING: THIS INSTRUCTION IS APPLICABLE TO A CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION (CDCCL) ITEM. CAREFULLY OBEY ALL GIVEN INSTRUCTIONS WHEN YOU DO THIS STEP. IF YOU DO NOT OBEY THESE INSTRUCTIONS, A DANGEROUS CONDITION CAN OCCUR THAT CAN CAUSE A POSSIBLE FUEL TANK EXPLOSION.

(1) Apply FINCH painting on the plug (12) and around the dual-flapper check valve (4) base perimeter and the fuel tank upper skin:

After installation of a new dual-flapper check valve (Ref. AMM TASK 47-20-43-370-001)
After re-installation of the same dual-flapper check valve (Ref. AMM TASK 47-20-43-370-002).

5. Close-up
Subtask 47-20-43-410-051-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the cabin floor panel (241EF) (Ref. AMM TASK 53-32-12-400-002).

Subtask 47-20-43-860-054-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to its initial configuration.
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 06:26:18 UTC