Removal of the ACT Transfer Check-Valve

TASK 28-28-41-000-001-A
Removal of the ACT Transfer Check-Valve

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

ZONE: 141
ZONE: 142
FIN: 176QM ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	CAP - BLANKING
No specific	AR	CONTAINER 3 L(3/4 USGAL)
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	SCRAPER - NON METALLIC
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
141	WING CENTER BOX
142	WING CENTER BOX
148AZ

C. Referenced Information

REFERENCE	DESIGNATION
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 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-10-00-910-002-A	Access to the Fuel Tanks and the Work Areas
TASK 28-25-00-650-001-A	Pressure Defuel
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 57-17-11-000-001-B	Removal of Access Cover 148AZ or/and the ACT-Equipment Support Door
ACT Transfer Check-Valve ** ON A/C NOT FOR ALL
ACT Transfer Check-Valve ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-28-41-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the APU section of overhead panel 25VU, make sure that the APU/MASTER SW pushbutton switch is released (the ON legend is off).
(3) On the FUEL section of overhead panel 40VU, make sure that all the L TK PUMPS and R TK PUMPS pushbutton switches are released (the OFF legends are on).
(4) Put the WARNING NOTICE(S) in position:

On the APU section of overhead panel 25VU to tell persons not to operate the APU/MASTER SW pushbutton switch
On the FUEL section of panel 40VU to tell persons not to operate the fuel system
On ACT control panel 28VU to tell persons not to operate the control system
On ENG/APU FIRE panel 1WD installed overhead panel 20VU to tell persons not to operate the fire extinguishing system.

(5) You must obey the fuel safety procedures when you do work on the fuel system (Ref. AMM TASK 28-00-00-910-001).
(6) Put a WARNING NOTICE(S) in position to tell persons not to operate the Main Landing Gear (MLG) doors.

Subtask 28-28-41-650-050-A ** ON A/C NOT FOR ALL

B. Defuel the center tank (Ref. AMM TASK 28-25-00-650-001).

Subtask 28-28-41-865-050-A ** ON A/C NOT FOR ALL

C. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	FUEL/RFL/DFL/SPLY	2QU	L24
121VU	FUEL/RFL/DFL/XFR/DEFUEL/VALVE	1QU	L23
** ON A/C NOT FOR ALL
121VU	FUEL/RFL/DFL/SPLY	2QU	L23
121VU	FUEL/RFL/DFL/XFR/DEFUEL/VALVE	1QU	L22

Subtask 28-28-41-010-050-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the right MLG door (Ref. AMM TASK 32-12-00-010-001).
(2) Put an ACCESS PLATFORM 2M (6 FT) in position at the right MLG door.
(3) Get access to the fuel center tank (Ref. AMM TASK 28-10-00-910-002).

Remove access cover 148AZ or/and the ACT-equipment support door (Ref. AMM TASK 57-17-11-000-001).

4. Procedure
Subtask 28-28-41-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Check Valve

ACT Transfer Check-Valve ** ON A/C NOT FOR ALL

(1) To remove the sealant/paint:
(a) Use a SCRAPER - NON METALLIC to remove the sealant/paint from all the applicable fasteners.
(2) Put a CONTAINER 3 L(3/4 USGAL) below the check valve (21) and the connections between the pipe (27) and the machined tee (18).
(3) Remove the bolt (9), the washer (10) and the nut (15) from the check valve (21).
(4) Remove the bonding straps (11) and (12) from the check valve (21).
(5) Remove the bolt (13), the washer (14) and the nut (17) from the flange (20).
(6) Remove the bonding strap (12) and (16) from the flange (20).
(7) Remove the bolts (25) and the washers (26).
(8) Remove the bolts (23) and the nuts (24).
(9) Remove the nut (8) of the end pipe (5).
(10) Disconnect the end pipe (5) from the check valve (21).
(11) Remove the retaining ring (7)
(12) Remove and discard the O-ring (6).
(13) Install a CAP - BLANKING on the end pipe (5).
(14) Remove the bolts (22) and the nuts (19).
(15) Remove the check valve (21) and the flange (20) from the machined tee (18).
(16) Remove the restrictor (2) from the check valve (21).
(17) Remove and discard the O-ring (3) from the flange (20).
(18) Put the PLUG-BLANKING in each disconnected line end.

Subtask 28-28-41-020-050-C ** ON A/C NOT FOR ALL

A. Removal of the ACT Transfer Check-Valve

ACT Transfer Check-Valve ** ON A/C NOT FOR ALL

(1) To remove the sealant/paint:
(a) Use a SCRAPER - NON METALLIC to remove the sealant/paint from all the applicable fasteners.
(2) Put a CONTAINER 3 L(3/4 USGAL) below the ACT transfer check-valve (7) and the connections between the pipe (29) and the machined tee (1).
(3) Remove the bolt (12), the washer (13) and the nut (16) from the ACT transfer check-valve (7).
(4) Remove the bonding leads (14) and (15) from the ACT transfer check-valve (7).
(5) Remove the bolt (17), the washer (18) and the nut (20) from the flange (5).
(6) Remove the bonding leads (15) and (19) from the flange (5).
(7) Remove the bolt (25) and the washer (24).
(8) Remove the bolt (26) and the washer (27).
(9) Remove the bolt (22) and the nut (23).
(10) Remove the nut (9) from the end pipe (21).
(11) Disconnect the end pipe (21) from the ACT transfer check-valve (7).
(12) Remove the retaining ring (10).
(13) Remove and discard the O-ring (11).
(14) Install a CAP - BLANKING on the end pipe (21).
(15) Remove the bolts (8) and the nuts (2).
(16) Remove the ACT transfer check-valve (7) and the flange (5) from the machined tee (1).
(17) Remove the restrictor (4) from the flange (5).
(18) Remove and discard the O-ring (6) from the flange (5).
(19) Remove and discard the O-ring (3) from the machined tee (1).
(20) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.02 06:17:57 UTC