Removal of the Inward Pressure Relief Valve

TASK 28-12-56-000-001-A
Removal of the Inward Pressure Relief Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

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.

WARNING: BE CAREFUL NOT TO GET AIRCRAFT FUEL IN YOUR MOUTH OR IN YOUR EYES. IF YOU GET FUEL ON YOUR SKIN OR ON YOUR CLOTHES, FLUSH IT IMMEDIATELY WITH WATER. IF NECESSARY, GET MEDICAL HELP. AIRCRAFT FUEL IS POISONOUS.

WARNING: DO NOT GET YOUR CLOTHES SOAKED WITH FUEL.

WARNING: MAKE SURE THAT YOU HAVE THE CORRECT FIRE FIGHTING EQUIPMENT AVAILABLE.

ZONE: 150
ZONE: 160
FIN: 172QM1 ** ON A/C NOT FOR ALL
FIN: 172QM2 ** 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	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
160	BULK CARGO COMPARTMENT AFT BULKHEAD OF AFT CARGO COMPARTMENT TO AFT BULKHEAD OF BULK CARGO COMPARTMENT

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-11-27-000-001-A	Removal of the Additional Center Tank (ACT)
Inward Pressure Relief Valve

3. Job Set-up
Subtask 28-12-56-860-050-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 ground service network
(Ref. AMM TASK 24-42-00-861-001)
(3) Put the WARNING NOTICE(S) in position on:

the refuel/defuel control panel 801VU,
the fuel control panel 40VU,
to tell persons not to operate the refuel/defuel system.

Subtask 28-12-56-010-051-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Remove the applicable ACT from the AFT cargo compartment (Ref. AMM TASK 28-11-27-000-001).

4. Procedure
Subtask 28-12-56-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Inward Pressure Relief Valve
(1) Remove the screws (1) and the washers (2) and (12) from the cover (3).
(2) Remove the cover (3) from the valve housing (8).
(3) Remove and discard the flat sealing (4) from the valve housing (8).
(4) Remove the screws (11) and the washers (5) and (10) from the flange of the relief valve (6).
(5) Remove the relief valve (6) from the flange (9) of the valve housing (8).
(6) Remove and discard the O-ring (7).

[Rev.10 from 2021] 2026.04.05 10:35:11 UTC