Removal of the ACT Pressure Reducing Valve

TASK 28-28-42-000-002-A
Removal 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. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. 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

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

3. Job Set-up
Subtask 28-28-42-860-053-A ** 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) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(3) On refuel/defuel control panels 801VU and 800VU, fuel control panel 40VU and Additional Center Tank (ACT) control panel 28VU:
(a) Put the WARNING NOTICE(S) in position to tell persons not to operate the refuel/defuel system.

Subtask 28-28-42-865-056-A ** ON A/C NOT FOR ALL

B. Open, safety and tag 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 28-28-42-010-051-B ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) in position at aft cargo-compartment door 826.
(2) Open aft cargo-compartment door 826 (Ref. AMM TASK 52-30-00-860-001).
(3) Set CARGO COMPT LIGHT switch 8LU to the ON position.
(4) Remove ceiling panel 151BC in the aft cargo compartment (Ref. AMM TASK 25-55-11-000-002).

4. Procedure
Subtask 28-28-42-020-051-B ** ON A/C NOT FOR ALL

A. Removal of the Pressure Reducing Valve

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.

(1) Loosen the union nuts (1), (2) and (3) and disconnect them from the ports of the pressure reducing valve (4).
(2) Remove the nuts (8), the washers (7) and the screws (5).
(3) Remove the pressure reducing valve (4) from the support bracket (6).
(4) Put the PLUG-BLANKING in each disconnected line end.

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