MONOGRAM SYSTEMS
COMPONENT MAINTENANCE MANUAL with ILLUSTRATED PARTS LIST
BASIC PN 15900
Page 3
Monogram Proprietary – See title page for details
38-31-37
May
17/02
3. Operation
A.
The operation of the toilet begins with the initiation of the flush cycle. The electric
motor of the motor-pump-filter unit assembly is energized for approximately 10
seconds. Throughout the flush cycle, flushing fluid is drawn through the filter by
the pump and discharged into the toilet bowl in a swirling action to wash waste
into the tank assembly.
B.
Toilet Assemblies must be serviced after each scheduled flight by emptying,
flushing, and recharging the tanks with fluid containing a dye-deodorant-
disinfectant-chemical-water solution. Draining, cleaning and filling of the toilet
assemblies is controlled from the aircraft toilet ground servicing panel. During
toilet tank draining and cleaning, the tank drain valve is opened. The drain valve
is a plunger type valve that is spring loaded to the closed position. A pull force of
approximately 35 pounds (15,91 Kg) is required to open the valve. During tank
cleaning and filling, fresh water is pumped into the toilet tank from an aircraft
lavatory servicing vehicle. The water enters the toilet tank through an inlet fitting
of the solenoid valve assembly, before going into the rotating spray nozzle via
hose connection to the pump inlet. The rotating spray nozzle is part of the motor-
pump-filter assembly. The pressurized fluid is jettisoned through spray nozzle
openings and cleanses the inside of the filter basket and tank side walls at same
time precharge fluid is added. After the cleaning operation the Liquid Level
Transmitter will indicate when the fluid reaches the proper pre-charge level.
