11.17 Water & Waste Flashcards
What are the 3 subsystems of a water & waste system?
potable water system, toilet system, water waste system
Where is potable water stored?
below the cabin floor in the cargo area sidewalls
What is potable water used for?
galley & lavatory components
What can be used to pressurize the potable water system?
a water tank pressurization system, or an electric pump
What is the most common air filter used in a water tank pressurization system?
replaceable 10-micron filtration cellulose element
What is the function of an air filter?
prevent contamination & dirt, from the air supply, entering the portable water system
What is the function of the check valves?
prevent reverse pressurization to air supply when its pressure is lower than the water tank pressure
Where is the PRV located?
between the pressure switch & water storage tanks
When must you completely drain the water system?
before disinfecting the system, when parking in freezing weather, every 3 days to prevent bacteria growth
Which 2 places can you service the portable water system from?
water service panel & water drain panel
Where is the water service panel located & why is it located there?
in a recess on the lower part of the fuselage, covered by an access door - wont interfere with other servicing activities during turn-arounds
What are the 2 ways a faucet assembly is controlled?
mechanically or infrared
How is an infrared faucet controlled?
by a reflective sensor unit with 2 lenses
What happens when water is required in an infrared system?
the reflective sensor unit opens a solenoid-operated SOV on the mixer valve
What is the purpose of a water heater?
provides hot water to the washbasin in each lavatory
How much water can a heater tank hold?
1.5litres
What is the function of a waste water system?
removes used water from washbasins in lavatory & galley areas & drains it out the aircraft through drains & drain masts
What makes the wastewater flow?
gravity
What prevents water freezing in drain masts & wastewater lines?
they are electically-heated
What is wastewater also known as?
grey water
What is not classified as greywater & what is greywater used for?
toilet waste - assist toilet flushing
What are the 2 types of toilet waste systems?
flush motor toilets & vacuum toilet systems
What does a separator do & where is it located in a flush motor toilet?
prevents splash & vision of tank contents - between tank & bowl
How long is the flush time on a flush motor toilet?
8-12secs
What is the motor described as in a flush motor toilet & what is it controlled by?
high power 3-phase electric motor - timer
What type of pump does a flush motor toilet system contain?
impeller
What is the liquid in a flush motor toilet waste tank a mixture of?
water & a chemical
How many times can flush motor toilets be used & what must happen after this is exceeded?
100 times - tank must be drained from an external service panel
How is a vacuum toilet system controlled?
electronically by a FCU (Flush Control Unit)
How many central waste tanks does a vacuum waste system have & where are they located?
2 or more - cargo compartment
When is blue ice phenomenon formed in a vacuum toilet system & what is the associated danger?
if there is a leak at the waste drain valve assembly whilst aircraft is flying at altitude - blue ice formed can cause damage on ground
How much chemical solution can the flush motor toilet system tank be charged with during servicing & what is used to do this?
13-31litres - connect chemical line from service cart to ground flush line fitting
What is CPF (Corrosion Preventative Fluid)?
water-displacing fluid that adheres to the surface of clean/primed aluminum & its alloys
