Waste Water Tank

A single waste water tank receives waste water from the ARS humidity separator and the waste collection system. The tank is located beneath the crew compartment middeck floor next to the potable water tanks.

The waste water tank holds 165 pounds, is 35.5 inches long and 15.5 inches in diameter, and weighs 39.5 pounds dry. It is pressurized by gaseous nitrogen from the same source as the potable water tanks.

Waste water is directed to the waste water tank 1 inlet valve, which is controlled by the waste H 2 O tank 1 switch on panel ML31C. When the switch is positioned to open , waste water is directed to the waste water tank. A talkback indicator next to the switch indicates op when the valve is open, barberpole when the valve is in transit and cl when the valve is closed. The switch positioned to off closes the waste water tank inlet, isolating the waste water tank from the waste water collection system. When the valve is open, waste water from the tank can also be directed to the waste water dump for overboard dumping.

The waste water dump isolation valve and waste water dump valve in the waste water dump line allow waste water to be dumped overboard through the waste water dump. The waste H 2 O dump isol valve switch on panel ML31C positioned to open allows waste water to be directed to the waste water dump valve. A talkback indicator above the waste H2O dump isol valve switch indicates op when the valve is open, barberpole when the valve is in transit and cl when the valve is closed.

In order for waste water to be dumped overboard, the waste water dump valve must be opened. It is controlled by the waste H 2 O dump valve enable/nozzle heater switch and the waste H 2 O dump valve switch on panel ML31C. When the waste H 2 O dump valve enable/nozzle heater switch is positioned to on , electrical power is supplied to the waste water dump heaters and the waste H 2 O dump valve switch. When the waste H 2 O dump valve switch is positioned to open, the dump valve allows waste water to be dumped overboard. A talkback indicator above the dump switch indicates op when the valve is open, barberpole when the valve is in transit and cl when the valve is closed. If waste water is dumped overboard, the dump isolation valve switch is positioned to cl upon completion of the dump. The waste H2O dump valve is positioned to cl , and the waste H2O dump valve enable/nozzle heater switch is set to off . (If the heater switch is positioned to off before the dump valve switch is positioned to close, the dump valve will remain open.) The heaters at the waste water dump prevent waste water from freezing at the overboard dump.

The waste water dump line, upstream of the waste dump nozzle, has electrical heaters on the line to prevent waste water from freezing. The A and B heaters are powered by the H 2 O line htr A and B circuit breakers on panel ML86B and are thermostatically controlled. (These circuit breakers also provide power to thermostatically controlled heaters on the supply water line and waste collection system vacuum vent line.)

The contingency crosstie quick disconnect in the waste water overboard dump line between the dump isolation valve and dump valve permits waste water to be joined with the supply water system through a flexible hose for emergency dumping of supply water through the waste water dump or using waste water for the flash evaporators.

The waste water tank 1 drain valve controls the draining of the waste water tank during ground operations through the ground support equipment flush and drain. When the waste H 2 O drain tank 1 valve switch on panel ML31C is positioned to open , the valve permits the draining and flushing of the waste water tank. The drain line is capped during flight. A talkback indicator above the switch indicates op when the valve is open, barberpole when the valve is in transit and cl when the valve is closed.

Personal hygiene accommodations for flight crew members include personal hygiene kits, pressure-packed personal hygiene agents and towel tissue dispensers. The personal hygiene kits have provisions for tooth brushing, hair care, shaving, nail care, etc. The pressure-packaged personal hygiene agents are for cleaning the hands, face and body.