Flushing of the Potable Water System with Hot Water

TASK 38-10-00-170-001-A
Flushing of the Potable Water System with Hot Water

WARNING: DO NOT DO WORK ON THE TOILET WASTE SYSTEM AND THE POTABLE WATER SYSTEM AT THE SAME TIME. THIS WILL PREVENT CONTAMINATION OF THE POTABLE WATER SYSTEM. SUCH CONTAMINATION CAN BE DANGEROUS TO HEALTH.

WARNING: BEFORE YOU DO WORK ON THE POTABLE WATER SYSTEM, CLEAN YOUR HANDS WITH SOAP AND WATER. THIS WILL PREVENT INFECTION. (CONTAMINATION FROM TOILET WASTE IS DANGEROUS TO HEALTH).

WARNING: MAKE SURE THAT THE EQUIPMENT YOU USE FOR THIS PROCEDURE IS CLEAN AND APPROVED FOR THE POTABLE WATER SYSTEM. IF NOT IT CAN CAUSE CONTAMINATION OF THE POTABLE WATER SYSTEM.

WARNING: BEFORE YOU FLUSH THE POTABLE WATER SYSTEM WITH HOT WATER, PUT ON PROTECTIVE CLOTHES, GOGGLES AND GLOVES. HOT WATER CAN BURN YOUR EYES AND SKIN. IF YOU GET HOT WATER IN YOUR EYES OR ON YOUR SKIN, GET IMMEDIATE MEDICAL AID.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	2	ACCESS PLATFORM 1M(3 FT)
No specific	AR	CONTAINER 1 L (1/4 USGAL)
No specific	AR	CONTAINER 1000 L(250 USGAL)
No specific	AR	CONTAINER 500 L(150 USGAL)
No specific	AR	HOSE - VINYL
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
133AL, 171AL
192NB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 12-15-38-613-001-A	Fill the Potable Water Tank System (Aircraft Electrical Power Available)
TASK 12-16-38-613-001-A	Servicing of the Toilet System
TASK 12-24-38-680-001-A	Draining of the Potable Water System (with Electrical Power)
TASK 23-73-00-861-001-A	Energize the Cabin Intercommunication Data System (CIDS)
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 38-10-00-281-001-A	Sampling of the Potable Water
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 38-12-23-920-802-A	Replacement of the Galley Water-Filter Elements

3. Job Set-up
Subtask 38-10-00-861-062-A

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) Make sure that the Cabin Intercommunication Data System (CIDS) is energized (Ref. AMM TASK 23-73-00-861-001) (valid for pre-selection function).

Subtask 38-10-00-865-076-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
2000VU	LAV FWD & MID-HOT WATER-A	1MB	F02
** ON A/C NOT FOR ALL
2000VU	WATER SYSTEM-QANT-IND	1MA	B01
** ON A/C NOT FOR ALL
2000VU	LAV FWD-HOT WATER-A	1MB	F02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACUUM-SYS	35MG	A06
** ON A/C NOT FOR ALL
2001VU	WATER SYS-QUANT-IND	1MA	B06
** ON A/C NOT FOR ALL
2001VU	LAVATORY AFT-HOT WATER-D	2MB	B02
** ON A/C NOT FOR ALL
2001VU	WATER SYS-DRAIN	1MP	B05
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-E	34MG	A04
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-D	39MG	A03
** ON A/C NOT FOR ALL
2001VU	LAV AFT-HOT WATER-E	9MB	B03
** ON A/C ALL
2001VU	VACU TOIL SYS-LAV PWR-A	32MG	A01
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACU-SYS	35MG	A06
** ON A/C NOT FOR ALL
2001VU	WATER-SYS-DRAIN	1MP	B05
** ON A/C NOT FOR ALL
2001VU	LAV AFT-HOT WATER-D	2MB	B02
** ON A/C NOT FOR ALL
2001VU	LAV AFT-HOT WATER-G	9MB	B03
2001VU	LAV AFT-HOT WATER-D/F	2MB	B02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-G	34MG	A04
2001VU	VACU TOIL SYS-LAV PWR-F	39MG	A03
2001VU	VACU TOIL SYS-LAV PWR-D	45MG	A02
** ON A/C NOT FOR ALL
2001VU	LAV AFT-HOT WATER	9MB	B03
2001VU	LAV AFT-HOT WATER	2MB	B02
** ON A/C NOT FOR ALL
2001VU	LAV AFT-HOT WATER-E/L	9MB	B03
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-L	45MG	A02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-L	23MG	A05
2001VU	LAV AFT-HOT WATER-L	9MB	C04
** ON A/C NOT FOR ALL
2001VU	LAV AFT-HOT WATER-D/L	2MB	B02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-M	34MG	A04
2001VU	LAV AFT-HOT WATER-M	9MB	B03

Subtask 38-10-00-010-066-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an ACCESS PLATFORM 1M(3 FT) in position at Zone 133 and Zone 171.
(2) Open the service door 171AL and the drain panel door 133AL.

Subtask 38-10-00-941-061-A ** ON A/C NOT FOR ALL

D. Job Setup
(1) Put a WARNING NOTICE(S) at the lavatories and galleys to tell persons not to use the potable water system.
(2) Put these containers in position:

One CONTAINER 1000 L(250 USGAL) below the forward potable-water drain-panel and the forward drainmast 4DU.
One CONTAINER 1000 L(250 USGAL) below the Potable-Water Service Panel (PWSP) and aft drainmast 14DU.

(3) Connect a HOSE - VINYL to the forward and aft drainmast.
(4) Put the end of the hoses in the containers below the drain masts.
(5) Connect a HOSE - VINYL:

To the drain nipple at the forward potable-water drain-panel
To the overflow nipple at the PWSP.

(6) Put the end of the hoses in the containers below the panels.

Subtask 38-10-00-010-066-B ** ON A/C NOT FOR ALL

E. Get Access
(1) Put an ACCESS PLATFORM 1M(3 FT) in position at Zone 133 and Zone 171.
(2) Open the service door 171AL and the drain panel doors 133AL, 192NB.

Subtask 38-10-00-941-061-B ** ON A/C NOT FOR ALL

F. Job Setup
(1) Put a WARNING NOTICE(S) at the lavatories and galleys to tell persons not to use the potable water system.
(2) Put these containers in position:

One CONTAINER 500 L(150 USGAL) below the forward potable-water drain-panel and the forward drainmast 4DU.
One CONTAINER 500 L(150 USGAL) below the mid potable-water drain and overflow panel.
One CONTAINER 500 L(150 USGAL) below the Potable-Water Service Panel (PWSP) and the aft drainmast 14DU.

(3) Connect a HOSE - VINYL to the forward and aft drainmast.
(4) Put the end of the hoses in the containers below the drain masts.
(5) Connect a HOSE - VINYL:

To the drain nipple at the forward potable-water drain-panel
To the drain nipple at the mid potable-water drain-panel
To the overflow nipple at the PWSP.

(6) Put the end of the hoses in the containers below the panels.

Subtask 38-10-00-680-055-A

G. Draining of the Potable Water System (PWS)
(1) Drain the PWS (Ref. AMM TASK 12-24-38-680-001).

Subtask 38-10-00-941-062-A

H. Job Setup
(1) Make sure that the water faucets in the lavatories and, if installed, in the wet galleys are in the cold position.
(2) Make sure that the switches on all of the water heaters are set to the OFF position.
(3) In the wet galleys, remove the galley water-filter elements or canister (if installed) (Ref. AMM TASK 38-12-23-920-802):
(a) Remove the caps and the filter elements or canister (if installed) from the galley filter housings or interface. Do not install new filter elements or canister at this time.
(b) Install the caps on the galley filter housings and tighten the clamps.

4. Procedure
Subtask 38-10-00-560-073-A ** ON A/C NOT FOR ALL

A. Infrared Controlled Water Faucet
(1) An activation of the infrared controlled water faucet for longer than 60 seconds permanently deactivates the faucet. It can be reactivated by operation of the power switch at the electronic control unit.

Subtask 38-10-00-170-056-A

B. Flushing of the Potable Water System (PWS) with Hot Water

(1) Connect the water-heating device to the fill/drain nipple at the PWSP.
(2) Adjust the water-heating device until the filling water is at the correct temperature of 70.0 deg.C (158.00 deg.F) (Refer to the manual of the water-heating device).
(3) Fill the PWS with 70.0 deg.C (158.00 deg.F) hot potable water and with a filling pressure of approximately 3.5 bar (50.7632 psi) up to the overflow as described (Ref. AMM TASK 12-15-38-613-001).

NOTE: The filling pressure during the filling process must not exceed 6.0 bar (87.0226 psi).

(4) Make sure that the PWS is filled until water comes out of the overflow nipple and let it flow for 10 seconds.
(5) Close the fill drain valve 8MA manually.
(6) Pressurize the PWS (Ref. AMM TASK 38-10-00-614-001).
(7) Open the forward drain valve (4MP) manually until approximately 100 L of water is discharged, then close the forward drain valve (4MP).

NOTE: This makes sure that the main supply line heats up before flushing the equipment.

(8) Make sure that the shut off valves of all lavatories and galleys are open.
(9) Operate the vent valve on the top of the water filter housings (if installed) of the lavatories and the galleys to remove the remaining air in the housings.
(10) For the system flushing operate each faucet in all lavatories and galleys and lavatory flush as follows.

NOTE: Start this procedure at the farthest aft potable water supplied equipment and continue to the forward equipment.

(a) For a standard warm and cold water supply faucet:
1 Adjust the faucet to maximum hot water supply.
2 Operate the faucet to let approximately 30.0 l (7.9251 USgal) of water flow.
a Fill a CONTAINER 1 L (1/4 USGAL) 30 times by appropriate operation of each faucet.
b The unwanted water from the container can be discarded into a washbasin.
3 Adjust the faucet to cold water supply.
4 Operate the faucet to let approximately 5.0 l (1.3208 USgal) of water flow.
a Fill a CONTAINER 1 L (1/4 USGAL) 5 times by appropriate operation of each faucet.
b The unwanted water from the container can be discarded into a washbasin.

NOTE: It is recommended that you flush more than one faucet at the same time. This decreases the total operational time and the cooling effect to a minimum.

(b) For the lavatory flush:
1 Flush each lavatory a minimum of 10 times.
(11) Depressurize the PWS (Ref. AMM TASK 38-10-00-614-002).
(12) Drain the PWS (Ref. AMM TASK 12-24-38-680-001).
(13) Make sure that the containers for water drainage do not overflow. Replace the containers if necessary.
(14) Make sure that the PWS is complete drained.
(15) Do the steps (3) to (12) three times.
(16) Make sure that the water which flows out of each faucet during the third flushing cycle will be examined for:

Unusual smell
Water clarity
General contamination.

(17) If the water quality is not satisfactory, do the steps (3) to (12) again until the water quality is satisfactory.
(18) Disconnect the water-heating device from the fill/drain nipple at the PWSP.

Subtask 38-10-00-613-063-A

C. Do the servicing of the toilet system (Ref. AMM TASK 12-16-38-613-001).

Subtask 38-10-00-281-054-A

D. Sampling
(1) Do a sampling of the potable water (Ref. AMM TASK 38-10-00-281-001).

5. Close-up
Subtask 38-10-00-410-069-A

A. Close Access
(1) Disconnect the HOSE - VINYL from the drain masts, the overflow nipple and the drain nipples.
(2) Close the access doors of the PWSP and the drain panels.
(3) Make sure that the latches are correctly locked and that the doors are flush with the skin of the aircraft.
(4) In the wet galleys, install new galley water-filter elements or canister (if installed) (Ref. AMM TASK 38-12-23-920-802).

Subtask 38-10-00-942-061-A

B. Removal of the Ground Support Equipment
(1) Remove the WARNING NOTICE(S).
(2) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

Subtask 38-10-00-862-055-A

C. De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.04.02 06:25:36 UTC