WATER STORAGE - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General
The potable water tank is installed in the pressurized underfloor area LH behind the rear cargo compartment. Air, which is tapped from the bleed air cross-feed line, pressurizes it (Ref. AMM 38-41-00). An indication system monitors the quantity of water in the tank (Ref. AMM 38-13-00).
The potable water tank is installed in the pressurized underfloor area RH behind the forward cargo compartment. Air, which is tapped from the bleed air cross-feed line, pressurizes it (Ref. AMM 38-41-00). An indication system monitors the quantity of water in the tank (Ref. AMM 38-13-00).

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2. Component Location

Water Storage System - Component Location ** ON A/C NOT FOR ALL

FIN	FUNCTIONAL DESIGNATION	PANEL	ZONE	ATA REF
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3MA	TRANSMITTER,QUANTITY	161DW	171	38-13-11
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3MP	LIM SW-DRAIN HANDLE		171	38-14-17
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3MA	TRANSMITTER,QUANTITY		137	38-13-11
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3MA	TRANSMITTER,QUANTITY		171	38-13-11
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4MP	VALVE,DRAINAGE	131HW	133	38-14-41
5MA	MSW-LIMIT SW		171	38-13-16
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6MA	INDICATOR,QUANTITY		171	38-13-21
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7MA	PRESELEC.-CONTR.-UNIT		171	38-13-34
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8MA	FILL/DRAIN VALVE	161DW	171	38-14-43
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8MP	VALVE-OVERFLOW	132PW	138	38-14-44
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10MA	IND-FULL	2023VU	171	38-11-00
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10MD	SWITCH,PRESSURE	161DW	171	38-42-16
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10MA	IND-FULL 1		171	38-11-00
14MP	VALVE-DRAIN	132PW	138	38-14-45
16MA	FILL/DRAIN VALVE	161DW	171	38-14-46
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2023VU	CTL PNL-WATER QTY IND		171	93-00-00
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3000MM	TANK-POTABLE WATER	161DW	171	38-11-41
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3000MM	TANK-POTABLE WATER	161DW	138	38-11-41
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3000MM	TANK-POTABLE WATER		171	38-11-41
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3254MM	CONTROL CABLE,FILL/DRAIN	161DW	171	38-14-47

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3. System Description

A. Potable Water

(1) The potable water is kept in the water storage system.

Potable-Water System Service-Panel - Component Location ** ON A/C NOT FOR ALL

You can fill the potable water tank with water from potable-water service panel 2023VU.
The potable-water service panel is installed in the left lower fuselage between FR65 and FR66. The panel has:

A connection for the ground air-pressure unit
A heated fill/drain port for the potable water
A heated overflow drain-port for the potable water
The fill/drain and overflow control handle(s)
Quantity indicator 6MA
Tank full control-light 10MA
Control light 2MP for motorized drain valve 4MP
Limit switch drain-handle 3MP
Limit switch 5MA.

When door 171AL of potable-water service panel 2023VU is open, door microswitch 5MA switches on the quantity indicating system (Ref. AMM 38-13-00). When fill/drain control handle 3254MM is set to the "DRAIN" position, limit switch 3MP closes to energize and open motorized drain valve 4MP. Motorized drain valve 4MP and its panel is in Zone 133. The placards are installed adjacent to all the service panel connections and the fill/drain and overflow control handle(s) to identify their operation.

(2) The potable Water is kept in the storage system.

Potable-Water System Service-Panel - Component Location. ** ON A/C NOT FOR ALL

You fill the potable water tank from the potable-water service panel-2023VU.
The potable-water service panel is located in the left-hand lower fuselage, between FR65 and FR66. The panel has:

a connection for the ground air-pressure unit
a fill/drain port for the potable water
the fill/drain control handle
a water quantity indicator (Ref. AMM 38-13-00)
Control light 2MP for the motorized drain valve 4MP
Control light 12MP for the motorized drain valve 14MP
Control light 6MP for the motorized overflow valve 8MP
Limit switch 5MA
Limit switch drain-handle 3MP
Limit switch fill-condition 5MP.

When the door 171AL of the service panel 2023VU is opened, the limit switch 5MA switches on the quantity indicating system (Ref. AMM 38-13-00).
When the control handle 3254MM is selected to the "DRAIN" position it operates:

Fill/drain valve 16MA
Limit switch drain-handle 3MP.

Limit switch 3MP is then energized and operates:

Motorized drain valve 14MP
Motorized overflow/ventilation valve 8MP
Motorized drain valve 4MP.

When the control handle is selected to the "FILL" position limit switch 5MP operates the overflow valve 8MP.

Placards are installed adjacent to all the service panel connections and the fill/drain control handle to identify their operation.

(3) The potable-Water is kept in the water storage system.

Potable-Water System Service-Panel - Component Location ** ON A/C NOT FOR ALL

You can the potable water tank from the potable-water service panel 2023VU.
The potable-water system service-panel is located in the left-hand lower fuselage, between FR65 and FR66. The panel contains:

A connection for the ground air-pressure unit
A fill/drain port for the potable water
An overflow drain port for the potable water
The fill/drain and overflow control handle
Tank full control-light 10MA
Control light 2MP for the motorized drain valve
Limit switch drain-handle 3MP
Limit switch 5MA.

When the door of the service panel is opened, the microswitch 5MA switches on the quantity indicating system. Limit switch drain-handle 3MP closes to energize and open the motorized drain valve when the service-panel control handle is selected to DRAIN. The motorized drain valve and its panel are in Zone 133. Placards are installed adjacent to all the service panel connections and the fill/drain overflow control handle.

(4) The potable water tank is kept in the water storage system.

Potable-Water System Service-Panel - Component Location ** ON A/C NOT FOR ALL

You can fill the potable water tank with water from potable-water service panel 2023VU.
Potable-water service panel 2023VU is installed on the left side of the lower fuselage, between FR65 and FR66. The panel has:

A connection for the ground air-pressure unit
A fill/drain port for the potable water
A heated overflow drain-port for the potable water
The fill/drain control handle
Quantity indicator 6MA
Tank full control-light 10MA
Control light 2MP for motorized drain valve 4MP
Limit switch drain-handle 3MP
Limit switch 5MA.

When door 171AL of potable-water service panel 2023VU is open, limit switch 5MA sets the quantity indicating system to on TSM 38130003. Limit switch drain-handle 3MP closes to energize and open motorized drain valve 4MP when control handle 3254MM is set to DRAIN. The placards are installed adjacent to all the service panel connections and the fill/drain control handle identifies their operation.

** ON A/C NOT FOR ALL

4. Component Description

A. Water Tank FIN: 3000-MM
The potable water tank is installed in the pressurized underfloor area of the RH fuselage, behind the forward cargo compartment. It is made of Glassfiber Reinforced Plastic (GFRP). It is strengthened to accept the rated pressure for the potable water system of between 22 and 25 psi (1.5 and 1.72 bar). The tank has a capacity of 200 l (53 USgal).
The tank is assembled with:

an overflow port,
an installation port for the water-contents quantity transmitter 3MA,
a connection for fill/drain/distribution plumbing,
a connection for air pressurization plumbing.

The potable water tank is made of Carbon Fiber Reinforced Plastic (CFRP). It is strengthened to accept the rated pressure for the potable water system (Ref. AMM 38-41-00). The capacity of the tank is 200 l (53 USgal).
The potable water tank is attached to the aircraft structure with the clamps.
The potable water tank has:

An overflow port
An installation port for the fill/overflow drain valve
An installation port for water-contents quantity transmitter 3MA
A connection for the air pressurization system with an air-no water valve.

B. Fill Valves

(1) Fill/Drain Valve 16MA
The fill/drain valve is installed below the cabin floor in Zone 171. The valve is attached to the outer left support strut at STA3158/FR66. Tube assemblies connect the valve to the potable water tank and to the potable water service-panel. The fill function of the valve also operates as a system drain facility. You can manually select the fill and drain facilities on the service panel.

(2) Fill/Overflow Drain Valve 8MA:
The fill/overflow drain valve is installed between the water service panel and the potable water tank. The tube assemblies connect the valve to the tank and to the ports on the potable-water service panel. The fill function of the valve will also operate as a system drain facility. You can manually select the fill and drain facilities on the service panel. The overflow function will operate as an overflow outlet and a vent for the tank.
The fill/drain valve control-handle will open the overflow port, when it is selected to the 'FILL' or 'DRAIN' position.

C. Overflow Valve 8MP
The overflow valve is installed below the cabin floor in the area of the potable water tank at STA1536/FR35. The fill and drain limit switches 3MP and 5MP, which are installed on the potable water service-panel operates the valve.

** ON A/C NOT FOR ALL

5. Operation

Potable Water System - Fill/Drain Procedures ** ON A/C NOT FOR ALL

A. Fill System (with Electrical Power)
You fill the water tank, when fill/drain valve 16MA is open. The valve opens when you turn the control handle on the potable water service-panel from "NORMAL" to "FILL" and pull the control handle out. With the control handle pulled out to its stop, fill/drain valve 16MA opens. Limit switch 5MP is energized and opens overflow/ventilation valve 8MP and control light 6MP comes on.
The maximum pressure required to fill the tank is 50 psi (3 bar).
When the tank is full, the quantity transmitter closes the fill/drain valve. The control handle is automatically pulled in and returns to the normal position. In this position, limit switch 5MP is de-energized and closes the motorized overflow/ventilation valve 8MP.
You can only fill the water tank when fill/overflow drain valve 8MA is open. The valve opens when you turn the control handle on the service panel from 'NORMAL' to 'FILL' and pull the control handle out. With the control handle pulled out to its stop, the 'fill-drain' and 'overflow' ducts open.
The maximum pressure necessary to fill the tank is 50 psi (3.4 bar). When the tank is full, the quantity transmitter closes the fill/overflow drain valve. The control handle automatically goes back to the 'NORMAL' position and the tank full control-light comes on.

When you fill the system without electrical power, there is no indication when the tank is full. The control handle will stay in the PULL TO FILL position. You must manually turn the control handle to the NORMAL position to close fill/overflow drain valve 8MA.

** ON A/C NOT FOR ALL

6. Operation

Potable Water System - Fill/Drain Procedures ** ON A/C NOT FOR ALL

A. Fill System (without Electrical Power)
You can also fill the water tank, when there is no electrical power. To do so you must open fill/drain valve 16MA and overflow valve 8MP manually.
To open fill/drain valve 16MA, you turn the control handle on the potable water service-panel from "NORMAL" to "FILL". Then pull the control handle out to its stop.
To open overflow/ventilation valve 8MP, you turn the control handle at the overflow and drain panel 192NB from "SHUT" to "OPEN".
There are no indications that the valves are open.
The maximum pressure required to fill the tank is 50 psi (3 bar).
When the tank is full, you must close the valves manually again.

B. Drain System
(Ref. AMM 38-14-00).

[Rev.10 from 2021] 2026.04.02 06:25:37 UTC