Installation of the Pressure-Holding Valve

TASK 28-16-41-400-001-A
Installation of the Pressure-Holding Valve

WARNING: MAKE SURE THAT THE FLIGHT CONTROL SAFETY-LOCKS AND THE WARNING NOTICES ARE IN POSITION.

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

FIN: 124QM ** ON A/C NOT FOR ALL
FIN: 125QM ** 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	ACCESS PLATFORM 3M (10 FT)
No specific	AR	SAFETY BARRIER(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.01ABA1)	Turbine Fuel-- Kerosene -
(Material No.03FAB1)	Mineral Oil base Grease-- Vaseline or Petrolatum -
(Material No.06HAA1)	Coating Sealant-Fuel Tank Brushable -
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [124QM] (VALVE-PRESSURE HOLDING, L WING TANK)
540MB
FOR [125QM] (VALVE-PRESSURE HOLDING, R WING TANK)
640MB

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
1	O-RING	AIPC 28-16-05-10-310
1	O-RING	AIPC 28-16-85-01-730

E. Referenced Information

REFERENCE	DESIGNATION
TASK 12-11-28-650-003-A	Pressure Refuel with Automatic Control
TASK 28-10-00-910-001-A	Safety Procedures When You Do Work in a Fuel Tank
TASK 28-10-00-910-002-A	Access to the Fuel Tanks and the Work Areas
TASK 28-25-00-650-001-A	Pressure Defuel
TASK 28-25-00-650-003-A	To Drain Remaining Fuel from the Wing Tanks and the Center Tank
TASK 28-25-00-650-003-A-01	To Drain Remaining Fuel from the Wing Tanks and the Center Tank
TASK 28-25-00-869-001-A	Fuel Transfer
TASK 57-27-11-000-002-A	Removal of the Access Panel
TASK 57-27-11-400-002-A	Installation of the Access Panel
Pressure Holding Valve

3. Job Set-up
Subtask 28-16-41-941-053-A ** ON A/C NOT FOR ALL

A. Safety Precautions

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.

(1) You must obey the fuel safety procedures (Ref. AMM TASK 28-10-00-910-001) when you do work in a fuel tank.
(2) Make sure that the SAFETY BARRIER(S) are in position.

Subtask 28-16-41-860-051-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) Make sure that the applicable fuel tank is defueled (Ref. AMM TASK 28-25-00-650-001) .
(2) Make sure that the remaining fuel has been drained from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
(3) Make sure that the ACCESS PLATFORM 3M (10 FT) is below the applicable zone 540(640).
(4) Make sure that the applicable access panel is removed (Ref. AMM TASK 28-10-00-910-002), (Ref. AMM TASK 57-27-11-000-002):
(a) FOR [124QM] (VALVE-PRESSURE HOLDING, L WING TANK)
540MB
(b) FOR [125QM] (VALVE-PRESSURE HOLDING, R WING TANK)
640MB.

4. Procedure
Subtask 28-16-41-420-051-A ** ON A/C NOT FOR ALL

A. Preparation for Installation
(1) Clean the component interfaces and the adjacent area with a Textile-Lint free Cotton - (Material No.14SBA1) made moist with Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(2) Make sure that the parts retained from the removed component are clean and in the correct condition.
(3) Do an inspection of the component interfaces and the adjacent area.
(4) Lubricate the new AIPC 28-16-05-10-310 O-RING (1) or AIPC 28-16-85-01-730 O-RING (1) with Turbine Fuel-- Kerosene - (Material No.01ABA1) or Mineral Oil base Grease-- Vaseline or Petrolatum - (Material No.03FAB1) .

Subtask 28-16-41-420-050-A ** ON A/C NOT FOR ALL

B. Installation of the Pressure Holding Valve 124QM(125QM)
(1) Install the O-ring (1) on the pressure holding valve (3) and hold them against the connector.
(2) Install the bolts (2).
(3) Apply Coating Sealant-Fuel Tank Brushable - (Material No.06HAA1) to the bolt heads (2) and the anchor nuts.

5. Close-up
Subtask 28-16-41-410-050-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the applicable access panel (Ref. AMM TASK 28-10-00-910-002), (Ref. AMM TASK 57-27-11-400-002):

(a) FOR [124QM] (VALVE-PRESSURE HOLDING, L WING TANK)
install 540MB
(b) FOR [125QM] (VALVE-PRESSURE HOLDING, R WING TANK)
install 640MB.

Subtask 28-16-41-860-052-A ** ON A/C NOT FOR ALL

B. Aircraft Configuration
(1) Refuel, defuel or transfer fuel as necessary (Ref. AMM TASK 12-11-28-650-003), (Ref. AMM TASK 28-25-00-650-001) or (Ref. AMM TASK 28-25-00-869-001).

Subtask 28-16-41-942-050-A ** ON A/C NOT FOR ALL

C. Removal of Equipment
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the safety barriers.
(3) Remove the WARNING NOTICE(S).
(4) Remove the access platform(s).
(5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

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