Aircraft waste system drain valve

A drain valve assembly for sealing an aircraft waste system drain line, comprising:

• a valve body to be mounted on the aircraft including a tubular coupling portion having an outer end for releasable coupling engagement with a drain hose coupling into which the valve body coupling portion is inserted, said coupling portion terminating in an annular outer end edge, and said valve body containing a drain passage having an inlet end for receiving waste from said drain line and an opposite outlet end extending axially through and opening through the outer end of said coupling portion, whereby waste flow through said passage occurs in a flow direction toward said passage outlet end, and
• sealing means including a valve seat within the outer end of said coupling portion circumferentially surrounding said passage outlet end axially inward of said end edge of the coupling portion, whereby said valve seat is shielded against damage by contact with a drain hose coupling during connection of the hose coupling to and disconnection of the hose coupling from said valve body coupling, a valve cover, seal means on one side of said valve cover, and means pivotally mounting said valve cover on said valve body at one side of said coupling portion for swinging between (a) a closed position wherein said valve cover is located opposite said outer end of said coupling portion with said one side of the cover facing and disposed in close proximity to said outer end and said cover seal means is disposed within the outer end of coupling portion and engages said valve seat in fluid sealing relation to block flow through said passage, and (b) an open position wherein said valve cover is located at said one side of said coupling portion to permit connection of a drain hose to said valve body coupling for drainage flow through said passage into the drain hose.