DOC AIRBUS | AMM A320FAdjustment of the Pressure Reducing and Relief Valve
TASK 38-41-00-820-001-A
Adjustment of the Pressure Reducing and Relief Valve
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 38-41-00-861-051-A Subtask 38-41-00-865-051-A
Subtask 38-41-00-860-051-A
Subtask 38-41-00-080-051-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.02 07:19:44 UTC
Adjustment of the Pressure Reducing and Relief Valve
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 1M(3 FT) |
| No specific | 1 | ACCESS PLATFORM 2M (6 FT) |
| No specific | 1 | CART - GROUND, NITROGEN |
| No specific | 1 | GAGE 5 BAR (75 PSI) - PRESSURE |
| No specific | AR | PLUG - BLANKING |
| No specific | AR | SAFETY CLIP - CIRCUIT BREAKER |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 171AL | |
| 131NW, 131PW | |
| 161DW |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 12-15-38-613-001-A | Fill the Potable Water Tank System (Aircraft Electrical Power Available) |
| 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 38-10-00-614-001-A | Pressurization of the Potable Water System from a Ground Air Supply |
| TASK 38-10-00-614-002-A | Depressurization of the Potable Water System |
| TASK 38-41-00-710-001-A | Operational Test of the Air Supply System (with ground air supply) |
| TASK 38-42-44-000-001-A | Removal of the Depressurization Valve |
| TASK 38-42-44-400-001-A | Installation of the Depressurization Valve |
| 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 |
Pressure Reducing Valve - AdjustmentSubtask 38-41-00-861-051-A Subtask 38-41-00-865-051-A
B. Make sure that this(these) circuit breaker(s) is(are) closed:
Subtask 38-41-00-865-052-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 2000VU | WATER SYSTEM-DEPRESS | 1MD | B02 |
| 2000VU | WATER SYSTEM-QANT-IND | 1MA | B01 |
| ** ON A/C NOT FOR ALL | |||
| 2001VU | WATER-SYSTEM-DEPRESS | 1MD | F03 |
| ** ON A/C NOT FOR ALL | |||
| 2001VU | WATER SYS-QUANT-IND | 1MA | B06 |
| ** ON A/C NOT FOR ALL | |||
| 2001VU | WATER-SYSTEM-DEPRESS | 1MD | D05 |
C. Open, safety and tag this(these) circuit breaker(s):
Subtask 38-41-00-010-052-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 2001VU | WATER SYS-AIR-COMPRESSOR | 19MD | F01 |
D. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position at Zone 171.
(2) Open the access panel 171AL.
(3) Open the AFT cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) Remove the access panel 161DW.
(5) Remove the blanking plug from the test port downstream of the pressure reducing and relief valve 4200MM.
Subtask 38-41-00-010-052-B ** ON A/C NOT FOR ALL (1) Put the ACCESS PLATFORM 2M (6 FT) in position at Zone 171.
(2) Open the access panel 171AL.
(3) Open the AFT cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) Remove the access panel 161DW.
(5) Remove the blanking plug from the test port downstream of the pressure reducing and relief valve 4200MM.
D. Get Access
(1) Put the ACCESS PLATFORM 1M(3 FT) in position at Zone 138.
(2) Open the access panel 171AL.
(3) Open the FWD cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) Remove the access panels 131PW 131NW.
(5) Remove the blanking plug from the test port downstream of the pressure reducing and relief valve 4200MM.
Subtask 38-41-00-010-054-A ** ON A/C NOT FOR ALL (1) Put the ACCESS PLATFORM 1M(3 FT) in position at Zone 138.
(2) Open the access panel 171AL.
(3) Open the FWD cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) Remove the access panels 131PW 131NW.
(5) Remove the blanking plug from the test port downstream of the pressure reducing and relief valve 4200MM.
E. Remove for Access
(1) Remove the pressure depressurization valve 4MD (Ref. AMM TASK 38-42-44-000-001).
(2) Put the PLUG-BLANKING in each disconnected line end.
Subtask 38-41-00-480-052-A ** ON A/C NOT FOR ALL (1) Remove the pressure depressurization valve 4MD (Ref. AMM TASK 38-42-44-000-001).
(2) Put the PLUG-BLANKING in each disconnected line end.
F. Installation of Test Equipment
(1) Connect a GAGE 5 BAR (75 PSI) - PRESSURE to the test port.
(2) Connect the CART - GROUND, NITROGEN to the ground air connection at the service panel 2023VU.
Subtask 38-41-00-480-052-B ** ON A/C NOT FOR ALL (1) Connect a GAGE 5 BAR (75 PSI) - PRESSURE to the test port.
(2) Connect the CART - GROUND, NITROGEN to the ground air connection at the service panel 2023VU.
F. Installation of Test Equipment
(1) Connect a GAGE 5 BAR (75 PSI) - PRESSURE to the disconnected line end.
(2) Connect the CART - GROUND, NITROGEN to the ground air connection at the service panel 2023VU.
Subtask 38-41-00-613-052-A 4. Procedure(1) Connect a GAGE 5 BAR (75 PSI) - PRESSURE to the disconnected line end.
(2) Connect the CART - GROUND, NITROGEN to the ground air connection at the service panel 2023VU.
Subtask 38-41-00-860-051-A
A. Preparation for Test
(1) Pressurize the potable water system (Ref. AMM TASK 38-10-00-614-001).
(2) Make sure that the pressure becomes stable.
(3) Examine the pressure at the manometer and monitor the error.
(4) Depressurize the potable water tank (Ref. AMM TASK 38-10-00-614-002)
Subtask 38-41-00-820-050-A ** ON A/C NOT FOR ALL (1) Pressurize the potable water system (Ref. AMM TASK 38-10-00-614-001).
(2) Make sure that the pressure becomes stable.
(3) Examine the pressure at the manometer and monitor the error.
(4) Depressurize the potable water tank (Ref. AMM TASK 38-10-00-614-002)
B. Adjust the Pressure Reducing and Relief Valve
(1) Operate the ground air supply to a pressure between 41 psi (2.8269 bar) and 47 psi (3.2405 bar) until the pressure is stable.
(2) Make sure that the pressure at the manometer shows between 22 psi (1.5168 bar) and 25 psi (1.7237 bar).
(3) Turn the pressure regulator adjuster clockwise to increase the pressure or counterclockwise to decrease the pressure as necessary.
(4) Turn the control handle on the potable-water service panel from the NORMAL to the FILL position to release the pressure from the system.
(6) If necessary, do the procedure again until the pressure is correct
Subtask 38-41-00-820-050-B ** ON A/C NOT FOR ALL (1) Operate the ground air supply to a pressure between 41 psi (2.8269 bar) and 47 psi (3.2405 bar) until the pressure is stable.
(2) Make sure that the pressure at the manometer shows between 22 psi (1.5168 bar) and 25 psi (1.7237 bar).
(3) Turn the pressure regulator adjuster clockwise to increase the pressure or counterclockwise to decrease the pressure as necessary.
(4) Turn the control handle on the potable-water service panel from the NORMAL to the FILL position to release the pressure from the system.
NOTE: Air will flow from the overflow port. If there is water in the system, water will flow from the fill port.
NOTE: When the pressure in the potable water system decreases, the reducing valve starts the air supply to the system again.
(5) Make sure that the pressure at the manometer shows between 22 psi (1.5168 bar) and 25 psi (1.7237 bar). (6) If necessary, do the procedure again until the pressure is correct
NOTE: It is not necessary to adjust the relief pressure of the valve after you adjust the reducing pressure.
(7) Close the ground air supply. B. Adjust the Pressure Reducing and Relief Valve
(1) Operate the ground air supply to a pressure between 41 psi (2.8269 bar) and 47 psi (3.2405 bar) until the pressure is stable.
(2) Make sure that the pressure at the manometer shows between 25 psi (1.7237 bar) and 28 psi (1.9305 bar).
(3) Turn the pressure regulator adjuster clockwise to increase the pressure or counterclockwise to decrease the pressure as necessary.
(4) Turn the control handle on the potable-water service panel from the NORMAL to the FILL position to release the pressure from the system.
(6) If necessary, do the procedure again until the pressure is correct
Subtask 38-41-00-865-053-A (1) Operate the ground air supply to a pressure between 41 psi (2.8269 bar) and 47 psi (3.2405 bar) until the pressure is stable.
(2) Make sure that the pressure at the manometer shows between 25 psi (1.7237 bar) and 28 psi (1.9305 bar).
(3) Turn the pressure regulator adjuster clockwise to increase the pressure or counterclockwise to decrease the pressure as necessary.
(4) Turn the control handle on the potable-water service panel from the NORMAL to the FILL position to release the pressure from the system.
NOTE: Air will flow from the overflow port. If there is water in the system, water will flow from the fill port.
NOTE: When the pressure in the potable water system decreases, the reducing valve starts the air supply to the system again.
(5) Make sure that the pressure at the manometer shows between 25 psi (1.7237 bar) and 28 psi (1.9305 bar). (6) If necessary, do the procedure again until the pressure is correct
NOTE: It is not necessary to adjust the relief pressure of the valve after you adjust the reducing pressure.
(7) Close the ground air supply. C. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 38-41-00-710-052-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 2001VU | WATER SYS-AIR-COMPRESSOR | 19MD | F01 |
D. Do the operational test of the pressure reducing and relief valve 4200MM (Ref. AMM TASK 38-41-00-710-001).
Subtask 38-41-00-614-052-A ** ON A/C NOT FOR ALL E. Move the fill/drain and overflow handle from the NORMAL to the FILL position to depressurize the potable water system.
Subtask 38-41-00-614-052-B ** ON A/C NOT FOR ALL E. Move the fill/drain handle from the NORMAL to the FILL position to depressurize the potable water system.
5. Close-upSubtask 38-41-00-080-051-A ** ON A/C NOT FOR ALL
A. Removal of the Test Equipment
(1) Remove the manometer from the test port and install the blanking plug.
(2) Remove the air supply cart.
Subtask 38-41-00-080-051-B ** ON A/C NOT FOR ALL (1) Remove the manometer from the test port and install the blanking plug.
(2) Remove the air supply cart.
A. Removal of the Test Equipment
(1) Remove the manometer from the disconnected line end of the depressurization valve 4MD.
(2) Remove the air supply cart.
Subtask 38-41-00-410-055-A ** ON A/C NOT FOR ALL (1) Remove the manometer from the disconnected line end of the depressurization valve 4MD.
(2) Remove the air supply cart.
B. Installation after Access
(1) Install the depressurization valve 4MD (Ref. AMM TASK 38-42-44-400-001).
Subtask 38-41-00-410-053-A ** ON A/C NOT FOR ALL (1) Install the depressurization valve 4MD (Ref. AMM TASK 38-42-44-400-001).
C. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the access panel 161DW.
(3) Close the AFT cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(4) Close the access panel 171AL.
(5) Remove the access platform(s).
Subtask 38-41-00-410-053-B ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the access panel 161DW.
(3) Close the AFT cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(4) Close the access panel 171AL.
(5) Remove the access platform(s).
C. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the access panels 131PW 131NW.
(3) Close the FWD cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(4) Close the access panel 171AL.
(5) Remove the access platform(s).
Subtask 38-41-00-862-054-A (1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the access panels 131PW 131NW.
(3) Close the FWD cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(4) Close the access panel 171AL.
(5) Remove the access platform(s).