Operational Test of the ACT Pressure Holding Valves

TASK 28-28-00-710-016-A
Operational Test of the ACT Pressure Holding Valves

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

FIN: 191QM1 ** ON A/C NOT FOR ALL
FIN: 191QM2 ** 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	AR	GAGE - ABSOLUTE PRESSURE, DIGITAL, 0.001 BAR ACCURACY
No specific	AR	GROUND PRESSURE GENERATOR - 0 TO 2 BAR (0 TO 30 PSI)
No specific	AR	PLUG - BLANKING
No specific	1	WARNING NOTICE(S)

B. Referenced Information

REFERENCE	DESIGNATION
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 28-28-54-000-001-A	Removal of the ACT Fuel Inlet Valve Actuator
TASK 28-28-54-400-001-A	Installation of the ACT Fuel Inlet Valve Actuator
TASK 28-28-55-000-001-A	Removal of the ACT Vent Shut-off Valve Actuator
TASK 28-28-55-400-001-A	Installation of the ACT Vent Shut-off Valve Actuator
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
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 28-28-00-860-134-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) Open the main landing gear doors (Ref. AMM TASK 32-12-00-010-001).
(3) Put the WARNING NOTICE(S) in position on:
- the refuel/defuel panel 800VU,
- the fuel panel 40VU,
to tell persons not to operate the refuel/defuel system.

Subtask 28-28-00-010-075-A ** ON A/C NOT FOR ALL

B. Get Access
(1) For the test of the ACT1 Pressure Holding Valve:
(a) Remove the ACT2 (Ref. AMM TASK 28-11-27-000-001).
(b) Remove the ACT1 (Ref. AMM TASK 28-11-27-000-001).
(2) For the test of the ACT2 Pressure Holding Valve:
(a) Remove the ACT2 only (Ref. AMM TASK 28-11-27-000-001).

Subtask 28-28-00-010-075-B ** ON A/C NOT FOR ALL

B. Get Access
(1) Remove the Additional Center Tank (ACT) (Ref. AMM TASK 28-11-27-000-001).

4. Procedure
Subtask 28-28-00-710-071-A ** ON A/C NOT FOR ALL

A. Test
(1) Install a PLUG - BLANKING on one side of the ACT fuel transfer line.
(2) Install a GAGE - ABSOLUTE PRESSURE, DIGITAL, 0.001 BAR ACCURACY on the other side of the ACT fuel transfer line.
(3) Connect a GROUND PRESSURE GENERATOR - 0 TO 2 BAR (0 TO 30 PSI) to the ACT Pressurization Check Valve (177QM).
(4) Make sure, that ACT vent line is open on one side (no blanking plug installed).
(5) Close the ACT Vent Valve.
(a) Remove the ACT Vent-Valve Actuator (4QH) (Ref. AMM TASK 28-28-55-000-001).
(b) Use a screwdriver to close the ACT Vent Valve manually.
(c) Make sure that the position indicator shows the closed position (cross-line).
(6) Open the ACT Fuel Inlet Valve.
(a) Remove the ACT Fuel Inlet Valve Actuator (5QH) (Ref. AMM TASK 28-28-54-000-001).
(b) Use a screwdriver to open the ACT Fuel Inlet Valve manually.
(c) Make sure that the position indicator shows the open position (in-line).
(7) Do this test:

ACTION	RESULT
1.On the GPG: start the GPG.
2.On the GPG: slowly pressurize the vent line until the ACT Pressure Holding Valve opens ( 0.22 bar (3.1908 psi) to 0.335 bar (4.8588 psi)).	On the ACT vent line: air blows off the vent line.
3.On the GPG: increase the air flow	On the pressure gage: make sure that the pressure is not more than 0.335 bar (4.8588 psi). NOTE: If the pressure indication on the pressure gage is more then 0.335 bar (4.8588 psi), the burst disc will damage and must be replaced.
4.On the GPG: stop the GPG,	On the ACT fuel transfer line: the airflow stops.
	On the pressure gage: the pressure stays stable between 0.335 bar (4.8588 psi) and 0.22 bar (3.1908 psi).
5.Wait 15 minutes	On the pressure gage: the pressure inside the ACT does not decrease by more than 0.02 bar (0.2901 psi).
6.On the ACT: open the ACT Vent Valve to depressurize the ACT.

5. Close-up
Subtask 28-28-00-410-068-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Disconnect the GPG from the ACT Pressurization Check Valve (177QM).
(2) Remove the pressure gage from the ACT fuel transfer line.
(3) Remove the blanking plug from the ACT fuel transfer line.
(4) Install the ACT Vent Valve Actuator (4QH) (Ref. AMM TASK 28-28-55-400-001).
(5) Install the ACT Fuel Inlet Valve Actuator (5QH) (Ref. AMM TASK 28-28-54-400-001).
(6) If you did a test on the ACT1:
(a) Install the ACT1 (Ref. AMM TASK 28-11-27-400-001).
(b) Install the ACT2 (Ref. AMM TASK 28-11-27-400-001).
(7) If you did a test on the ACT2:
(a) Install the ACT2 (Ref. AMM TASK 28-11-27-400-001).

Subtask 28-28-00-410-068-B ** ON A/C NOT FOR ALL

Subtask 28-28-00-860-135-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 AFT cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(3) Remove the WARNING NOTICE(S).
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

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