An air vent valve assembly for a tank assembly of a beverage maker for aircraft, comprising: an air vent valve housing comprising an interior chamber within said air vent valve housing, an outlet flow passage connected in fluid communication with said interior chamber of said air vent valve housing, and a lower valve adapter configured to be attached to the tank assembly of the beverage maker, and said lower valve adapter having a flow inlet connected in fluid communication with the interior chamber of said air vent valve housing; an upper planar valve seat member disposed within the interior chamber of the air vent valve housing adjacent to said outlet flow passage of the air vent valve housing, the upper planar valve seat member having a surface defining a central flow aperture in fluid communication between said outlet flow passage of the air vent valve housing and said interior chamber of said air vent valve housing; a lower notched valve seat member disposed within the interior chamber of the air vent valve housing adjacent to said flow inlet of said lower valve adapter, said lower notched valve seat member including a central flow aperture in fluid communication between said flow inlet of said lower valve adapter and said interior chamber of said air vent valve housing; a tubular collar having a lumen disposed within the interior chamber of the air vent valve housing between said upper planar valve seat member and said lower notched valve seat member; a ball float movably disposed within the lumen of the tubular collar, the ball float being movable between a first position and a second position, said ball float being positioned within said tubular collar so as to be seated on said upper planar valve seat member in said first position, abutting and closing the central flow aperture of the upper planar valve seat member in said first position, and said ball float being seated on said lower notched valve seat member and spaced apart from and opening said central aperture of said upper planer valve seat member in said second position. characterized in that said lower notched valve seat member has a surface defining a plurality of oblique notches in fluid communication between said central flow aperture and said interior chamber of said air vent valve housing, and a plurality of frustoconical projections each including an upper shoulder, each of said plurality of frustoconical projections defining an outwardly flaring radially inner oblique edge and said tubular collar is configured to be seated on said upper shoulders of said plurality of frustoconical projections. an air vent valve housing comprising an interior chamber within said air vent valve housing, an outlet flow passage connected in fluid communication with said interior chamber of said air vent valve housing, and a lower valve adapter configured to be attached to the tank assembly of the beverage maker, and said lower valve adapter having a flow inlet connected in fluid communication with the interior chamber of said air vent valve housing; an upper planar valve seat member disposed within the interior chamber of the air vent valve housing adjacent to said outlet flow passage of the air vent valve housing, the upper planar valve seat member having a surface defining a central flow aperture in fluid communication between said outlet flow passage of the air vent valve housing and said interior chamber of said air vent valve housing; a lower notched valve seat member disposed within the interior chamber of the air vent valve housing adjacent to said flow inlet of said lower valve adapter, said lower notched valve seat member including a central flow aperture in fluid communication between said flow inlet of said lower valve adapter and said interior chamber of said air vent valve housing; a tubular collar having a lumen disposed within the interior chamber of the air vent valve housing between said upper planar valve seat member and said lower notched valve seat member; a ball float movably disposed within the lumen of the tubular collar, the ball float being movable between a first position and a second position, said ball float being positioned within said tubular collar so as to be seated on said upper planar valve seat member in said first position, abutting and closing the central flow aperture of the upper planar valve seat member in said first position, and said ball float being seated on said lower notched valve seat member and spaced apart from and opening said central aperture of said upper planer valve seat member in said second position. characterized in that said lower notched valve seat member has a surface defining a plurality of oblique notches in fluid communication between said central flow aperture and said interior chamber of said air vent valve housing, and a plurality of frustoconical projections each including an upper shoulder, each of said plurality of frustoconical projections defining an outwardly flaring radially inner oblique edge and said tubular collar is configured to be seated on said upper shoulders of said plurality of frustoconical projections.