Installation of the ACT Pressure Reducing Valve

TASK 28-28-42-400-002-A
Installation of the ACT Pressure Reducing Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

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.

ZONE: 150
FIN: 171QM ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
150	AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT
151BC, 826

B. Referenced Information

REFERENCE	DESIGNATION
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 25-55-11-000-002-A	Removal of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-400-002-A	Installation of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-25-00-710-002-A	Operational Test of the Defuel System
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
Pressure Reducing Valve 171QM

3. Job Set-up
Subtask 28-28-42-860-054-B ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) Make sure that the aircraft electrical circuits are energized.
(Ref. AMM TASK 24-41-00-861-002).
(3) Make sure that the ACCESS PLATFORM 2M (6 FT) is below aft cargo compartment 826.
(4) Make sure that aft cargo-compartment door 826 is open (Ref. AMM TASK 52-30-00-860-001).
(5) Make sure that CARGO COMPT LIGHT switch 8LU is in the ON position.
(6) On refuel/defuel control panels 801VU and 800VU, on fuel control panel 40VU and Additional Center Tank (ACT) control panel 28VU:
(a) Make sure that the warning notices are in position to tell persons not to operate the refuel/defuel system.
(7) Make sure that ceiling panel 151BC is removed (Ref. AMM TASK 25-55-11-000-002).

Subtask 28-28-42-865-057-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	FUEL/ACT AIR SOV/MAN/SPLY	64QH	J20
121VU	FUEL/ACT AIR SOV/AUTO/SPLY	63QH	J19
121VU	FUEL/ACT XFR VLV/MOT2	66QH	J18
121VU	FUEL/ACT XFR VLV/MOT1	65QH	J17
121VU	FUEL/HI/LVL/SPLY	1QJ	L24
121VU	FUEL/RFL/DFL/SPLY	2QU	L23
121VU	FUEL/RFL/DFL/XFR/DEFUEL/VALVE	1QU	L22
121VU	FUEL/ACT VENT VLV/MAN/SPLY	62QH	L21
121VU	FUEL/ACT VENT VLV/AUTO/SPLY	61QH	L20
121VU	FUEL/ACT/FUEL PUMP/SPLY	25QH	Q29

4. Procedure
Subtask 28-28-42-420-051-B ** ON A/C NOT FOR ALL

A. Installation of the Pressure Reducing Valve
(1) Remove the PLUG-BLANKING from each disconnected line end.
(2) Clean the component interfaces and the adjacent area.
(3) Do an inspection of the component interfaces and the adjacent area.
(4) Make sure that the parts retained from the removed component are clean and in the correct condition.
(5) Prepare equipment for electrical bonding (Ref. AMM TASK 20-28-00-912-802).
(6) Put the pressure reducing valve (4) in position at the support bracket (6).
(7) Put the screws (5) in position and install the washers (7) and the nuts (8).
(8) Tighten the nuts (8).
(9) Apply surface protection to the bonding screw (5) (Ref. AMM TASK 20-28-00-912-802).
(10) Loosely install the union nuts (1), (2) and (3) on their related ports of the pressure reducing valve (4).

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT EQUIPMENT FROM FLEXIBLE HOSES AND RIGID TUBING. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL CAUSE DAMAGE TO THE HOSES AND TUBES.

(11) Tighten the union nuts (1), (2) and (3).

Subtask 28-28-42-865-058-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	FUEL/ACT AIR SOV/MAN/SPLY	64QH	J20
121VU	FUEL/ACT AIR SOV/AUTO/SPLY	63QH	J19
121VU	FUEL/ACT XFR VLV/MOT2	66QH	J18
121VU	FUEL/ACT XFR VLV/MOT1	65QH	J17
121VU	FUEL/HI/LVL/SPLY	1QJ	L24
121VU	FUEL/RFL/DFL/SPLY	2QU	L23
121VU	FUEL/RFL/DFL/XFR/DEFUEL/VALVE	1QU	L22
121VU	FUEL/ACT VENT VLV/MAN/SPLY	62QH	L21
121VU	FUEL/ACT VENT VLV/AUTO/SPLY	61QH	L20
121VU	FUEL/ACT/FUEL PUMP/SPLY	25QH	Q29

Subtask 28-28-42-710-051-A ** ON A/C NOT FOR ALL

C. Test(s)
(1) Do the operational test of the pressure reducing valve (Ref. AMM TASK 28-25-00-710-002).

5. Close-up
Subtask 28-28-42-410-050-B ** 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 ceiling panel 151BC in the aft cargo compartment (Ref. AMM TASK 25-55-11-400-002).
(3) Set CARGO COMPT LIGHT switch 8LU to the OFF position.
(4) Close aft cargo-compartment door 826 (Ref. AMM TASK 52-30-00-860-002).
(5) Remove the access platform(s).

Subtask 28-28-42-860-055-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to the serviceable condition.
(1) From refuel/defuel control panels 801VU and 800VU, fuel control panel 40VU and Additional Center Tank (ACT) control panel 28VU:
(a) Remove the WARNING NOTICE(S).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:17:58 UTC