Operational Check of the Pressure Holding Valves

TASK 28-28-00-710-013-A
Operational Check of the Pressure Holding Valves

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

FIN: 241QM ** ON A/C NOT FOR ALL
FIN: 242QM ** ON A/C NOT FOR ALL
FIN: 243QM ** 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	AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY
No specific	1	WARNING NOTICE(S)
98D28108563000	1	COVER, FUEL VENT-ACT

B. 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 28-11-27-000-002-A	Removal of Additional Center Tank No.1 (ACT AFT1)
TASK 28-11-27-000-003-A	Removal of the Additional Center Tank No.2 (ACT AFT2)
TASK 28-11-27-400-002-A	Installation of Additional Center Tank No.1 (ACT AFT1)
TASK 28-11-27-400-003-A	Installation of the Additional Center Tank No.2 (ACT AFT2)
TASK 28-28-72-000-001-A	Removal of the ACT Vent-Valve Actuator
TASK 28-28-72-400-001-A	Installation of the ACT Vent-Valve Actuator
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
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

3. Job Set-up
Subtask 28-28-00-860-110-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) Open the forward and the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) Open the main landing-gear doors (Ref. AMM TASK 32-12-00-010-001).
(5) Put the WARNING NOTICE(S) is(are) in position on:
- Refuel/defuel panel 800VU,
- Fueling panels 28VU and 40VU,
to tell persons not to operate the refuel/defuel system.

Subtask 28-28-00-010-067-H ** ON A/C NOT FOR ALL

B. Get Access
(1) Remove all Additional Center Tanks:

For ACT AFT2 (Ref. AMM TASK 28-11-27-000-003)
For ACT AFT1 (Ref. AMM TASK 28-11-27-000-002)
For ACT FWD (Ref. AMM D/O 28-11-27-00).

(2) Close the ACT Vent Valve (234QM):
(a) In the Main Landing Gear (MLG) bay, on the RH center-tank access-panel, remove the ACT vent-valve actuator (91QH) (Ref. AMM TASK 28-28-72-000-001).
(b) Use a screwdriver to turn the valve to the close position.

4. Procedure
Subtask 28-28-00-710-066-A ** ON A/C NOT FOR ALL

A. Test
(1) In the aft cargo compartment, install a 98D28108563000 COVER, FUEL VENT-ACT with a Ground Pressure Generator (GPG) test port on the ACT vent line connection.
(2) Connect an AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY with a flowmeter air to the test connection.
(3) Do this Test:

ACTION	RESULT
1.On the GPG: Start the GPG.
2.On the GPG: Slowly pressurize the vent line until the two aft pressure holding valves open ( 0.25 bar (3.6259 psi) to 0.31 bar (4.4962 psi)).	On the flowmeter: The flowmeter shows an air flow of more than 800 l (211.3359 USgal) in one minute.
3.On the GPG: Stop the GPG. Depressurize the ACT vent line.
4.In the aft cargo compartment: Disconnect the GPG and the flowmeter from the test connection. Remove the ACT FUEL VENT-COVER with the test connection from the ACT vent line.
5.In the forward cargo compartment: Install the ACT FUEL VENT-COVER with the test connection on the ACT vent line. Connect the flowmeter and the GPG to the test connection.
6.On the GPG: Start the GPG. Carefully pressurize the ACT vent line until the two forward pressure holding valves open ( 0.25 bar (3.6259 psi) to 0.31 bar (4.4962 psi)).	On the flowmeter: The flowmeter shows an air flow of more than 800 l (211.3359 USgal) in one minute.
7.On the GPG: Stop the GPG. Depressurize the ACT vent line.

5. Close-up
Subtask 28-28-00-410-058-H ** ON A/C NOT FOR ALL

A. Close Access
(1) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(2) Remove the 98D28108563000 COVER, FUEL VENT-ACT with the test connection from the ACT vent line.
(3) Open the ACT vent valve (234QM):
(a) Use a screwdriver to turn the valve to the open position.
(b) Install the ACT vent-valve actuator (91QH) (Ref. AMM TASK 28-28-72-400-001).
(4) Install all Additional Center Tanks (ACT):

For ACT FWD (Ref. AMM D/O 28-11-27-40)
For ACT AFT1 (Ref. AMM TASK 28-11-27-400-002)
For ACT AFT2 (Ref. AMM TASK 28-11-27-400-003).

Subtask 28-28-00-860-111-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the forward and the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(3) Close the MLG doors (Ref. AMM TASK 32-12-00-410-001).
(4) Remove the WARNING NOTICE(S).
(5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(6) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.04.02 06:17:51 UTC