Toilet 7900101

1. General
A. Vacuum Toilet Assemblies, Part Number 7900101 (LH),7900102 (RH),7900253-101 (LH), and 7900253-102 (RH), hereinafter referred to as the toilet assembly (Fig. 1), are designed for use in aircraft lavatory compartments. The toilet assemblies are dependent on the aircraft's systems for a source of electrical power, water supply and vacuum.

2. Descripton
A. The toilet assembly consists of an electronic flush control unit, a flush valve assembly, a rinse water valve assembly, rinse header with nozzles and a bowl and support weldment that provides a manual shut-off mechanism.

Note: Vacuum toilets part numbers 7900253-101 and 7900253-102 include a vacuum-operated
Enviroclean™ system mounted to the rinse header and the flush control unit mounting bracket.
The Enviroclean™ replaces the rinse hose assembly, and connects the rinse valve to the rinse
header assembly through a vacuum-operated fluid metering pump.

B. lnterface connections are made to the aircraft by the water inlet port of the rinse water valve (MS33514-8 flareless connection), waste discharge line (Hydraflow 14F02-32C flange connection), the power supply/signalcable (MS24266R14B12PN electrical connector), and the bonding stud (10-32 UNF male connection). The support assembly has four mounting holes (0.291/0.279 in.) (7.391/7.086 mm) for deck attachment.

C. The bowl and support weldment is constructed of stainless steel and is designed for floor mounting. The internal surface of the bowl is coated with Teflon. The 1.5-in. (38.1 mm) diameter bowl outlet is designed to constitute the narrowest passage of the piping system.

CAUTION: ELECTROSTATIC SENSITIVE ASSEMBLY; USE PRECAUTIONARY PROCEDURES WHEN HANDLING ELECTRONIC FLUSH CONTROL UNIT.

D. The electronic flush control unit (FCU) is mounted on the toilet support assembly. The FCU is powered from an external 28 VDC supply. Connections are made to a normally open, momentarily closed flush switch, blower control circuit, solenoid operated rinse valve and flush valve actuator motor by means of MS connectors. Refer to paragraph 3 below for description of the program function.

E. The flush valve connects the bowl outlet to the aircraft waste piping. The valve is an electrically actuated, reversible, rotating disk gate valve. All metal parts in contact with the toilet waste are 300 series stainless steel. The actuator motor is a permanent magnet DC type with builtin thermal overload protection. The actuator linkage has a hand operated lever for closing the flush valve manually (manual override).

F. The rinse water valve connects the aircraft water supply to the bowl rinse header and provides washdown water for toilet flushing. The valve is a flow through, solenoid operated, poppet valve with integral antisiphon valve and filter. The valve opens and self-drains through the inlet port when the supply pressure is 0 psig or lower. The valve is self-closing with the solenoid de-energized and an inlet pressure of 0 psig (0 kPa). The solenoid enclosure is water tight. All wetted metal parts are stainless steel.

G. The rinse header consists of a stainless steel tube with three nozzles. The header is mounted on the outside, upper rim of the bowl. A tube assembly connects the header to the rinse valve.