Abstract: The open neck of a vertical container of fluid is covered by a horizontal flexible diaphragm with an outer lip detachably engaging the periphery of the neck. A top disposed concave cup-like recess centrally disposed in the diaphragm has a hole in the bottom. A vertically elongated tube open at both ends extends through the hole and is sealed thereto, these ends being interconnected by a vertical bore. The bottom end extends into the fluid. The bore has a vertically elongated enlarged region which is disposed intermediate the top and bottom tube ends. The top tube end has a plurality of horizontal spaced conduits interconnecting the bore with the interior of the recess. A sphere in said region is slidable up and down therein, being moved by gravity to the bottom of the region when the tube is upright and being moved by gravity to the top of the region when the tube is inverted. Two sealing devices are disposed in the region adjacent the top and bottom thereof respectively.