Removal of the Pack Flow-Control Valve/ Pack Flow-Control Unit

TASK 21-51-51-000-001-A
Removal of the Pack Flow-Control Valve/ Pack Flow-Control Unit

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 1 and pack 2 flow-control valve/ pack 1 and pack 2 flow-control unit.

FIN: 11HB ** ON A/C NOT FOR ALL
FIN: 23HB ** ON A/C NOT FOR ALL
FIN: 24HB ** ON A/C NOT FOR ALL
FIN: 8HB ** 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	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [11HB] (P1 FLOW CTL VALVE)
191BB, 191KB
FOR [23HB] (FLOW CTL UNIT-PACK 1)
191BB, 191KB
FOR [24HB] (FLOW CTL UNIT-PACK 2)
192FB, 192KB
FOR [8HB] (P2 FLOW CTL VALVE)
192FB, 192KB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-51-41-000-001-A	Removal of the Ozone Filter
TASK 21-51-51-200-001-A	Attachment Components (In-Service Wear Limits) - Flow Control Valve (Unit)
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 53-35-13-000-002-A	Removal of the Quick-Release Access Panels from the Belly Fairing Structure
Pack Flow-Control Unit ** ON A/C NOT FOR ALL
Pack Flow-Control Valve ** ON A/C NOT FOR ALL
Pack Flow-Control Valve ** ON A/C NOT FOR ALL
Attachment Components - Pack Flow-Control Valve

3. Job Set-up
Subtask 21-51-51-861-050-A

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

Subtask 21-51-51-865-071-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41
121VU	APU/FIRE/EXTIG/SQUIB/B	2WF	L39
121VU	APU/FIRE/EXTIG/SQUIB/A	1WF	L38
** ON A/C NOT FOR ALL
FOR FIN: 11HB (P1 FLOW CTL VALVE)
49VU	AIR COND/FLOW/CTL &/IND1	1HB	D07
122VU	AIR COND/PACK TEMP/CTL SYS1/1/115VAC	1HH	X22
122VU	AIR COND/PACK TEMP/CTL SYS1/1/28VDC	3HH	X21
122VU	AIR COND/PACK TEMP CTL SYS2/1/28VDC	4HH	Y19
122VU	AIR COND/PACK TEMP CTL SYS2/1/115VAC	2HH	Y18
FOR FIN: 8HB (P2 FLOW CTL VALVE)
122VU	AIR COND/FLOW/CTL AND IND/2	2HB	V21
122VU	AIR COND/PACK TEMP/CTL SYS1/2/115VAC	21HH	W22
122VU	AIR COND/PACK TEMP/CTL SYS1/2/28VDC	23HH	W21
122VU	AIR COND/PACK TEMP CTL SYS2/2/28VDC	24HH	Y21
122VU	AIR COND/PACK TEMP CTL SYS2/2/115VAC	22HH	Y20
** ON A/C NOT FOR ALL
FOR FIN: 23HB (FLOW CTL UNITPACK 1)
49VU	AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC	52HH	D08
122VU	AIR COND/TEMP CTL SYS 1/CHAN A/115VAC	49HH	X22
122VU	AIR COND/TEMP CTL SYS 1/CHAN A/28VDC	51HH	X21
122VU	AIR COND/TEMP CTL SYS 1/CHAN B/115VAC	50HH	Y18
FOR FIN: 24HB (FLOW CTL UNITPACK 2)
122VU	AIR COND/TEMP CTL SYS 2/CHAN A/115VAC	53HH	W22
122VU	AIR COND/TEMP CTL SYS 2/CHAN A/28VDC	55HH	W21
122VU	AIR COND/TEMP CTL SYS 2/CHAN B/28VDC	56HH	Y21
122VU	AIR COND/TEMP CTL SYS 2/CHAN B/115VAC	54HH	Y20

Subtask 21-51-51-941-050-A

C. Safety Precautions
(1) Put the WARNING NOTICE(S) in the cockpit to tell persons not to start the APU.
(2) In the cockpit, on AIR COND panel 30VU, make sure that:

The APU BLEED pushbutton switch is released (the OFF legend is on).
The ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are released (the OFF legends are on).

(a) Put the WARNING NOTICE(S) in position to tell persons not to operate these switches.
(3) On the HP ground connector, put the WARNING NOTICE(S) in position to tell persons not to supply the ground air.

Subtask 21-51-51-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Remove the access panels (Ref. AMM TASK 53-35-13-000-002):
(a) FOR [11HB] (P1 FLOW CTL VALVE)
191KB and 191BB.
(b) FOR [8HB] (P2 FLOW CTL VALVE)
192KB and 192FB.

Subtask 21-51-51-010-051-B ** ON A/C NOT FOR ALL

D. Get Access
(1) Remove the access panels (Ref. AMM TASK 53-35-13-000-002):
(a) FOR [23HB] (FLOW CTL UNIT-PACK 1)
191KB and 191BB.
(b) FOR [24HB] (FLOW CTL UNIT-PACK 2)
192KB and 192FB.

Subtask 21-51-51-010-057-B ** ON A/C NOT FOR ALL

E. Removal of the Ozone Filter for Access
(1) Remove the ozone filter upstream of the flow control valve (Ref. AMM TASK 21-51-41-000-001).

Subtask 21-51-51-010-057-D ** ON A/C NOT FOR ALL

E. Removal of the Ozone Filter upstream of the Flow Control Unit for Access
(1) Remove the ozone filter (Ref. AMM TASK 21-51-41-000-001).

4. Procedure
Subtask 21-51-51-020-057-D ** ON A/C NOT FOR ALL

A. Removal of the Pack Flow-Control Unit

Pack Flow-Control Unit ** ON A/C NOT FOR ALL

Pack Flow-Control Valve ** ON A/C NOT FOR ALL

(1) Disconnect the electrical connectors (2), (3) and (4).
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Remove the nut (23), the washer (24), the screw (18) and disconnect the bonding strap (25).
(4) Remove the clamp (16).
(5) Move the flange (13) and the sleeve (14) as far to the heat exchanger unit as they will go.
(6) Hold the pack flow-control unit (17) and remove the nuts (22), the washers (21), if fitted the washers (26), the bolts (19) and the spacers (20).
(7) Carefully remove the pack flow-control unit (17) from the aircraft.
(8) Remove the flange (13) together with the sleeve (14) from the heat exchanger unit connecting-end (15).
(9) Remove the flange (13) from the sleeve (14).
(10) Remove and discard the seals (31) and (131) from the sleeve (14).
(11) Put protective covers on the open ends of the pack flow-control unit (17) and the heat exchanger unit connecting-end (15).

Subtask 21-51-51-020-057-E ** ON A/C NOT FOR ALL

A. Removal of the Pack Flow-Control Valve

Pack Flow-Control Valve ** ON A/C NOT FOR ALL

(1) Disconnect the electrical connector (3).
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Release the sense line quick-disconnects (2) and (4).
(4) Release the sense line connection (5).
(5) Put the PLUG-BLANKING in each disconnected line end.
(6) Remove the nut (23), the washer (24), the screw (18) and disconnect the bonding strap (25).
(7) Remove the clamp (16).
(8) Move the flange (13) and the sleeve (14) as far to the heat exchanger unit as they will go.
(9) Hold the pack flow-control valve (17) and remove the nuts (22), the washers (21), if fitted the washers (26), the bolts (19) and the spacers (20).
(10) Carefully remove the pack flow-control valve (17) from the aircraft.
(11) Remove the flange (13) together with the sleeve (14) from the heat exchanger unit connecting-end (15).
(12) Remove the flange (13) from the sleeve (14).
(13) Remove and discard the seals (31(131)) from the sleeve (14).
(14) Put protective covers on the open ends of the pack flow-control valve (17) and the heat exchanger unit connecting-end (15).

Subtask 21-51-51-020-062-A

B. Removal of the Attachment Components

Attachment Components - Pack Flow-Control Valve

(1) Remove the nut (3), washer (4), bolt (5), washer (7) (if installed) and bushing (6) from the brackets (11).
(2) Remove the fitting (12) from the brackets (11).
(3) Do the inspection of the components for in-service wear (Ref. AMM TASK 21-51-51-200-001).

[Rev.10 from 2021] 2026.04.01 04:09:47 UTC