Installation of the Inward Pressure Relief Valve

TASK 28-12-56-400-001-A
Installation of the Inward Pressure Relief Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

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.

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. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03FAB1)	Mineral Oil base Grease-- Vaseline or Petrolatum -

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
4	FLAT SEALING	AIPC 28-12-04-12-220
7	O-RING	AIPC 28-12-04-12-230

D. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied 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)
TASK 28-11-27-400-001-A	Installation of the Additional Center Tank (ACT)
TASK 28-28-00-720-002-A	Operational Check of ACT(S) Inward Relief Valve
Inward Pressure Relief Valve

3. Job Set-up
Subtask 28-12-56-860-051-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) Make sure that the ground service network is energized
(Ref. AMM TASK 24-42-00-861-001)
(3) Make sure that the WARNING NOTICE(S) are in position on:

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

(4) Make sure that the applicable ACT is removed (Ref. AMM TASK 28-11-27-000-001).

4. Procedure
Subtask 28-12-56-420-050-A ** ON A/C NOT FOR ALL

A. Installation of the Inward Pressure Relief Valve (IPRV)
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Apply Mineral Oil base Grease-- Vaseline or Petrolatum - (Material No.03FAB1) to the new O-ring (7).
(4) Install the new AIPC 28-12-04-12-230 O-RING (7) on the flange in the valve housing (8) of the relief valve (6).

NOTE: Make sure that the O-ring (7) is correctly installed.

(5) Put the relief valve (6) in position on the flange (9) in the valve housing (8).
(6) Install the washers (5) and (10) and the screws (11) in the relief valve (6).
(7) Apply Mineral Oil base Grease-- Vaseline or Petrolatum - (Material No.03FAB1) to the new flat sealing (4).
(8) Install the new AIPC 28-12-04-12-220 FLAT SEALING (4) on the valve housing (8).
(9) Put the cover (3) on the valve housing (8).

NOTE: Make sure that the flat sealing (4) is correctly installed.

(10) Install the screws (1), the washers (2) and (12) in sequence opposite to one another in the cover (3) of the valve housing (8) and hand tighten only.
(11) When all the screws (1) are installed, then fully tighten them in sequence opposite to one another.

Subtask 28-12-56-410-050-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the ACT in the AFT cargo compartment (Ref. AMM TASK 28-11-27-400-001).

Subtask 28-12-56-710-050-A ** ON A/C NOT FOR ALL

C. Test
(1) Do the Functional Test of the ACT Inward Pressure Relief Valve (Ref. AMM TASK 28-28-00-720-002).

5. Close-up
Subtask 28-12-56-860-052-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to the serviceable condition.
(1) Remove the WARNING NOTICE(S).
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001)

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