Abstract: A flexible valve element in the form of a flexible diaphragm movable between open and closed positions for opening or closing the drain. By operation of a control pressure chamber formed over the outer or exterior side of the diaphragm and which operates directly by application or pressure or vacuum to the same to move the diaphragm between the open and closed position. A control valve provides the connection from the control chamber to the passenger cabin to provide operating pressure for closing the valve and is alternatively connectable to an accumulator which stores vacuum normally supplied from a source such as that applied to the downstream side of the drain. The control valve is preferably operated by a solenoid which responds to an electrical signal. A manual override system is provided for closing the valve by hand.

Abstract: A method of flushing a toilet for aircraft or the line using vacuum and pressure, in which there is a toilet or other waste receiving bowl, a waste the holding tank, and a valve means for opening or closing the drain line. A vacuum is created in the waste holding tank and the drain line. The drain line is closed or opened by the action of the valve means. In the method the valve means is actuated by vacuum to open the drain line to connect the bowl to the holding tank to apply vacuum on the bowl to suck the contents from the bowl and deliver it to the holding tank. When the bowl has been emptied, pressure is applied to the valve means for closing the drain line to again build up vacuum in the system for subsequent operation.

Abstract: A non-circulating vacuum operated waste disposal system for aircraft having a toilet bowl connected to a vacuum waste holding tank by a drain connected to said bowl and to the vacuum waste holding tank. There is a flush valve in the drain having a flexible valve element movable between open and closed positions for opening or closing the drain. There is a control pressure chamber adjacent to the flexible valve element with the valve element exposed directly to the pressure or vacuum which may be within said control chamber. The valve element is held in open or closed position with respect to the drain depending upon whether there is a pressure or a vacuum in the pressure chamber. There is a connection from the pressure chamber to the cabin of the aircraft and also to the drain on the vacuum side of the flush valve. A solenoid valve is provided in the connection which is manually operable to connect cabin pressure or the vacuum in the drain to said control pressure chamber.