Reactivation of the Pack Flow-Control Valve

TASK 21-51-00-440-001-A
Reactivation of the Pack Flow-Control Valve

WARNING: MAKE SURE THAT AIR IS NOT SUPPLIED TO THE AIR CONDITIONING SYSTEM FROM THE MAIN ENGINE, THE APU OR A GROUND SOURCE. HOT COMPRESSED AIR CAN CAUSE INJURY TO PERSONNEL.

NOTE: The procedure is the same for the pack flow-control valve 8HB and 11HB.

FIN: 11HB ** ON A/C NOT FOR ALL
FIN: 8HB ** ON A/C NOT FOR ALL

1. Reason for the Job
MMEL 21-51-01A
PACK FLOW CONTROL VALVE
2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
No specific	corrosion-resistant steel lockwire 0.8 mm

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [11HB] (P1 FLOW CTL VALVE)
191KB
FOR [8HB] (P2 FLOW CTL VALVE)
192KB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 53-35-13-000-002-A	Removal of the Quick-Release Access Panels from the Belly Fairing Structure
TASK 53-35-13-400-002-A	Installation of the Quick-Release Access Panels on the Belly Fairing Structure

3. Job Set-up
Subtask 21-51-00-861-051-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits. (Ref. AMM TASK 24-41-00-861-002)

Subtask 21-51-00-010-052-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Remove the access panel (Ref. AMM TASK 53-35-13-000-002):
(a) FOR [8HB] (P2 FLOW CTL VALVE)

192KB,

(b) FOR [11HB] (P1 FLOW CTL VALVE)

191KB.

Subtask 21-51-00-941-052-A ** ON A/C NOT FOR ALL

C. Safety Precautions
(1) On the panel 30VU:
(a) Make sure that:

the APU BLEED pushbutton switch is in the off position (the ON legend is off),
the ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are in the off position (the OFF legends are on) and,
the PACK 1 and the PACK 2 pushbutton switches are in the off position (the OFF legends are on).

(b) Put a warning notice in position to tell persons not to operate these switches.
(2) On the HP ground connector put a warning notice in position to tell persons not to supply the ground air.

4. Procedure
Subtask 21-51-00-440-050-A ** ON A/C NOT FOR ALL

A. Reactivation of the Pack Flow-Control Valve
(1) Remove and discard the the lockwire from the special screw (1).
(2) Install the special screw (1) in the position (A) and safety it with corrosion-resistant steel lockwire 0.8 mm (0.032 in.) dia.
(3) FOR [11HB] (P1 FLOW CTL VALVE)
(a) Push the PACK 1 pushbutton switch to the on position (the FAULT and the OFF legends are off).

(4) FOR [8HB] (P2 FLOW CTL VALVE)
(a) Push the PACK 2 pushbutton switch to the on position (the FAULT and the OFF legends are off).

5. Close-up
Subtask 21-51-00-410-052-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 access panel (Ref. AMM TASK 53-35-13-400-002):
(a) FOR [8HB] (P2 FLOW CTL VALVE)

192KB,

(b) FOR [11HB] (P1 FLOW CTL VALVE)

191KB.

Subtask 21-51-00-862-053-A ** ON A/C NOT FOR ALL

B. De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:11:21 UTC