Installation of the Pack Downstream Check-Valves

TASK 21-52-43-400-001-A
Installation of the Pack Downstream Check-Valves

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.

CAUTION: YOU MUST CLOSE THE CARGO COMPARTMENT DOORS BEFORE THE WIND SPEED IS MORE THAN 65 KNOTS TO PREVENT DAMAGE TO THE DOOR OR TO THE AIRCRAFT STRUCTURE.

CAUTION: WHEN YOU OPEN AND CLOSE THE CARGO DOORS, MAKE SURE THAT THE ACCESS PLATFORM IS AT THE CORRECT HEIGHT. IF IT IS TOO HIGH, IT WILL PREVENT FREE MOVEMENT OF THE DOORS.

FIN: 15HM
FIN: 16HM

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	ACCESS PLATFORM 2M (6 FT)
FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)
No specific	Torque wrench: range to between 0.53 and 0.43 m.daN (46.90 and 38.05 lbf.in )
No specific	Torque wrench: range to between 0.56 and 0.51 m.daN (49.56 and 45.13 lbf.in )
FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)
No specific	Torque wrench: range to between 0.53 and 0.43 m.daN (46.90 and 38.05 lbf.in )
No specific	Torque wrench: range to between 0.56 and 0.51 m.daN (49.56 and 45.13 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
825
FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)
131PW, 191BB
FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)
132PW, 192FB

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)
5	SEAL	AIPC 21-52-03-08-170
5	SEAL	AIPC 21-52-83-01-060
FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)
28	PACKING-PREFORMED	AIPC 21-52-03-08-060
5	SEAL	AIPC 21-52-03-08-170
5	SEAL	AIPC 21-52-83-01-060
28	PACKING-PREFORMED	AIPC 21-52-83-01-230

D. Referenced Information

REFERENCE	DESIGNATION
TASK 12-33-21-618-001-A-01	Pre-conditioning through the HP Ground Connection
TASK 12-33-21-618-001-A-02	Pre-conditioning with the APU
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 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 25-54-12-400-001-A	Installation of the Forward Cargo-Compartment Partition
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
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
TASK 06-41-53-00	FUSELAGE-DESCRIPTION AND OPERATION
Pack Downstream Check Valve 15HM (16HM) ** ON A/C NOT FOR ALL
Pack Downstream Check Valve 15HM (16HM) ** ON A/C NOT FOR ALL
FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 20-28-00-912-803-A	Bonding Surface Preparation
FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 20-28-00-912-803-A	Bonding Surface Preparation

3. Job Set-up
Subtask 21-52-43-860-050-A

A. Aircraft Maintenance Configuration
(1) Make sure that:
(a) The ACCESS PLATFORM 2M (6 FT) is in position at forward cargo-compartment door 825.

WARNING: DO NOT OPEN OR GO NEAR PRESSURE-SEALED DOORS WHEN THE AIRCRAFT IS PRESSURIZED. A PRESSURE-SEALED DOOR THAT OPENS WHEN THE AIRCRAFT IS PRESSURIZED:

WILL CAUSE EXPLOSIVE DECOMPRESSION.
CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAUSE DAMAGE TO THE AIRCRAFT OR EQUIPMENT.

(b) Forward cargo-compartment door 825 is open
(Ref. AMM TASK 52-30-00-860-001).

(c) The access panels are removed
(Ref. AMM TASK 53-35-13-000-002):

1 FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)

191BB.

2 FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)

192FB.

(d) The forward cargo-compartment partitions are removed
(Ref. AMM TASK 25-54-12-000-001) and (Ref. AMM D/O 06-41-53-00):

1 FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)

131PW.

2 FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)

132PW.

Subtask 21-52-43-865-051-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 15HM (P1 CHECK VALVE DOWNSTREAM)
49VU	AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC	52HH	D08
** ON A/C NOT FOR ALL
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
** ON A/C NOT FOR ALL
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
** ON A/C NOT FOR ALL
FOR FIN: 16HM (P2 CHECK VALVE DOWNSTREAM)
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
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

4. Procedure
Subtask 21-52-43-420-050-A

A. Installation of the Pack Downstream Check-Valve

NOTE: Two persons are necessary for this procedure.

(1) Make sure that you have access from the inside and the outside of the aircraft.
(2) Install the pack downstream check-valves:
(a) FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)
1 Remove the protective covers from the bellows (1), the pack downstream check-valve (6) and the flange (8).
2 Make sure that the valve flaps in the pack downstream check-valve (6) are in the correct condition.
3 Clean the component interfaces and the adjacent area.
4 Make sure that the parts retained from the removed component are clean and in the correct condition.
5 Prepare the surface of the bonding point(s)
(Ref. AMM TASK 20-28-00-912-803).
6 Make sure that the seal (5) is in a good condition. If necessary, replace the AIPC 21-52-03-08-170 SEAL (5) or AIPC 21-52-83-01-060 SEAL (5).
7 Put the seal (5) in position on the pack downstream check-valve (6).
8 Hold the pack downstream check-valve (6) in position on the aircraft structure.
9 Install the washers (4) and the bolts (3).
10 TORQUE the bolts (3) to between 0.53 and 0.43 m.daN (46.90 and 38.05 lbf.in )

.
11 Put the bellows (1) in the correct position on the fitting of the pack downstream check-valve (6).
12 Install and tighten the clamp (2).
13 Put the flange (8) in the correct position on the pack downstream check-valve (6) and install the clamp (7).
14 TORQUE the clamp (7) to between 0.56 and 0.51 m.daN (49.56 and 45.13 lbf.in )

.
15 Put the bonding strap (11) in position and install the bolt (9), the washer (10) and the nut (12).
16 Tighten the nut (12).
17 Do the electrical resistance measurement and the final protection of the bonding point(s)
(Ref. AMM TASK 20-28-00-912-802).
18 Make sure that the work area is clean and clear of tools and other items.

(b) FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)
1 Remove the protective covers from the bellows (21), pack downstream check-valve (26), duct assembly (29) and flange (42).
2 Make sure that the valve flaps of the pack downstream check-valve (26) are in the correct condition.
3 Clean the component interfaces and the adjacent area.
4 Make sure that the parts retained from the removed component are clean and in the correct condition.
5 Prepare the surface of the bonding point(s)
(Ref. AMM TASK 20-28-00-912-803).
6 Make sure that the seal (5) and the packing (28) are in a good condition. If necessary, replace the AIPC 21-52-03-08-170 SEAL (5) or AIPC 21-52-83-01-060 SEAL (5) and/or the AIPC 21-52-03-08-060 PACKING-PREFORMED (28) or AIPC 21-52-83-01-230 PACKING-PREFORMED (28) .
7 Put the seal (5) in position on the pack downstream check-valve (26).
8 Hold the pack downstream check-valve (26) in position on the aircraft structure.
9 Install the washers (25) and the bolts (24).
10 TORQUE the bolts (24) to between 0.53 and 0.43 m.daN (46.90 and 38.05 lbf.in )

.
11 Put the bellows (21) in the correct position on the fitting of the pack downstream check-valve (26).
12 Install and tighten the clamp (23).
13 Put the packing (28) in the correct position on the duct assembly (29).
14 Hold the duct assembly (29) in position between the pack downstream check-valve (26) and the flange (42).
15 Install the clamps (27) and (41).
16 Do not fully tighten the clamps (27) and (41) at this time.
17 Put the tie-rods (43) and (44) in position.
18 Install the bolts (35) and (38), the washers (36) and (39) and the nuts (37) and (40).
19 TORQUE the clamps (27) and (41) to between 0.56 and 0.51 m.daN (49.56 and 45.13 lbf.in )

.
20 Put the bonding straps (32) and (33) in position and install the bolt (30), the washer (31) and the nut (34).
21 Tighten the nut (34).
22 Do the electrical resistance measurement and the final protection of the bonding point(s)
(Ref. AMM TASK 20-28-00-912-802).
23 Make sure that the work area is clean and clear of tools and other items.

Subtask 21-52-43-865-053-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 15HM (P1 CHECK VALVE DOWNSTREAM)
49VU	AIR COND/FLOW/CTL &/IND1	1HB	D07
** ON A/C NOT FOR ALL
49VU	AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC	52HH	D08
** ON A/C NOT FOR ALL
122VU	AIR COND/FLOW/MIXER/FLAP	3HB	V22
122VU	AIR COND/FLOW/CTL AND IND/2	2HB	V21
122VU	AIR COND/ZONE TEMP CTL/28VDC/SYS2	4HK	V20
122VU	AIR COND/ZONE TEMP CTL/28VDC/SYS1	3HK	V19
122VU	AIR COND/ZONE TEMP CTL/115VAC/SYS2	2HK	V18
122VU	AIR COND/ZONE TEMP CTL/115VAC/SYS1	1HK	V17
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
** ON A/C NOT FOR ALL
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
** ON A/C NOT FOR ALL
FOR FIN: 16HM (P2 CHECK VALVE DOWNSTREAM)
49VU	AIR COND/FLOW/CTL &/IND1	1HB	D07
122VU	AIR COND/FLOW/MIXER/FLAP	3HB	V22
122VU	AIR COND/FLOW/CTL AND IND/2	2HB	V21
122VU	AIR COND/ZONE TEMP CTL/28VDC/SYS2	4HK	V20
122VU	AIR COND/ZONE TEMP CTL/28VDC/SYS1	3HK	V19
122VU	AIR COND/ZONE TEMP CTL/115VAC/SYS2	2HK	V18
122VU	AIR COND/ZONE TEMP CTL/115VAC/SYS1	1HK	V17
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
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 21-52-43-710-050-A

C. Test
(1) Do the pre-conditioning through the HP ground connector
(Ref. AMM TASK 12-33-21-618-001)
or with the APU
(Ref. AMM TASK 12-33-21-618-001).
(2) Do a leak check of the pack downstream check-valve-connections.
Make sure that there are no leaks.
(3) After approximately 15 minutes stop the pre-conditioning
(Ref. AMM TASK 12-33-21-618-001) (Ref. AMM TASK 12-33-21-618-001).

5. Close-up
Subtask 21-52-43-410-053-A

A. Close Access
(1) Install the forward cargo-compartment partitions
(Ref. AMM TASK 25-54-12-400-001) and (Ref. AMM D/O 06-41-53-00):

(a) FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)

131PW.

(b) FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)

132PW.

(2) Install the access panels
(Ref. AMM TASK 53-35-13-400-002):

(a) FOR [15HM] (P1 CHECK VALVE DOWNSTREAM)

191BB.

(b) FOR [16HM] (P2 CHECK VALVE DOWNSTREAM)

192FB.

WARNING: BEFORE YOU CLOSE THE CARGO DOOR, BLEED THE DOOR HYDRAULIC SYSTEM IF:

THE DOOR WAS OPEN FOR MAINTENANCE WORK ON THE YELLOW HYDRAULIC SYSTEM, AND/OR
THE DOOR WAS OPEN FOR MORE THAN 12 HOURS.

IF YOU DO NOT BLEED THE DOOR HYDRAULIC SYSTEM, THE CARGO DOOR CAN CLOSE SUDDENLY (WHEN YOU PUT THE OPERATION LEVER IN THE CLOSED POSITION) AND THUS CAUSE INJURY AND/OR DAMAGE.

(3) Close forward cargo-compartment door 825
(Ref. AMM TASK 52-30-00-860-002).

(4) Remove the access platform.

Subtask 21-52-43-862-051-A

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

[Rev.10 from 2021] 2026.03.31 23:07:27 UTC