13.19 Water/Waste Flashcards
Define potable water?
Water fit for drinking
What materials are water tanks made of?
Fibre–glass reinforced plastic
Stainless steel used in older aircraft
How might the tanks be heated?
Warm air from the air conditioning system
Electric heater blanket
What is the purpose of the compressor?
Automatically start when the pneumatic pressure falls below a predetermined value
Why would a riser loop be fitted with a compressor and how is this achieved?
Prevent water entering the compressor
Top of the loop is higher than the distribution ducting therefore water will always go to the distribution lines first
Why are the plastic water distribution pipes shrouded inside aluminium pipes?
Outer shroud prevents leaking water dripping onto the ceiling and conveys any leaking water to the lower fuselage area via drain tubes
What indication is there that the water heater is operating normally?
Heater switch will be on and a light will illuminate
What is the normal cycling temperature for the heater?
50°C
What is the overtemperature trip temperature for the heater and what will happen at this temperature?
90°C
Overheat switch will operate
Switch off the heater and the light
Explain the drain mast heater system?
115v AC in air
28v DC on ground
Changeover controlled by WOW switch
What is the water replenishment pressure range?
Generally above 25 psi
Maximum of 55 psi
What must be carried out after disinfecting the water system?
The system is emptied and refilled with chlorinated water
In the toilet tank, how much disinfectant solution is replenished following toilet emptying?
5 gallons
How is the filter prevented from becoming blocked on each flush cycle?
Motor will reverse its direction to prevent the rotating filter mesh becoming entangled with non–decomposable waste
What governs the level of filtration in a disc type filter?
This type of filter consists of a stack of flat wheel shaped discs, each disc separated by a spacer
The thickness of the spacer holding the discs apart determines the degree of filtration
What might cause overheating of the motors and therefore tripped CBs or fuses?
Overheating could be caused by failure of:
Control circuit
Control circuit components
Motor
Pump
How is the inside of a liquid flush tank cleaned?
A perforated tube called a flush line
Fitted around the top of the waste tank on the inside
Clean the sides of the tank when the chemical is replenished through the ground flush line, after the tank is emptied
At what altitude will the blowers of vacuum flush system cut out?
Above 16,000 feet
When would a ‘Y’ coupling be used?
When a waste line rubber bung is fitted
What is the purpose of the venturi in the galley and toilet ventilation system?
Limits the outflow of cabin air when the aircraft is pressurised
How often must toilet waste containers be inspected?
At intervals not exceeding 72 hours elapsed time
What position must the waste container flap default to?
Spring loaded closed, sealed and latched
At what temperature will the automatic fire extinguisher fusible plug within the waste container melt?
175°F
80°C approximately
How is drain flow assisted in the waste water drain system?
System uses the difference between cabin pressure and external pressure in flight to help push fluids through the tubing as well as relying on the normal forces of gravity
What are installed in the waste water drain system to catch debris that is inadvertently flushed down galley sinks and prevent it from clogging the drain further downstream?
Galley sink strainers
For how many uses will a typical charged liquid flush toilet last for before it requires to be emptied, cleansed and recharged?
One hundred usages
What is differential pressure used for in the typical vacuum flush toilet?
Used to evacuate the air from the waste tanks
