The invention provides a non-leakage reversible automatic
exhaust valve invented by utilizing
atmospheric pressure principle. The non-leakage reversible automatic
exhaust valve comprises a
valve seat and a valve cover which are hermetically connected together to form a valve body; the valve body is internally provided with a convex floating cylinder which is opened wide at the lower part and is provided with a check ring
liquid tank; a sealing
gasket is arranged on the top of the floating cylinder opposite to the exhaust port; a check ring is arranged on the edge of the top outside the floating cylinder to form a floating cylinder liquid groove. When the liquid level of air
discharge rises, a liquid sealing is formed at the bottom of the floating cylinder, the floating cylinder rises therewith relying on
buoyancy and the exhaust port at the top of the valve cover is closed; when the pressure is increased and the liquid level exceeds the check ring of the floating cylinder, the feed liquor in the floating cylinder liquid groove form a liquid sealing, the valve cover
air chamber forms barometric pressure, ensuring that the liquid level can not rise and achieves the purpose of no leakage; and when the liquid level drops to the position that no
buoyancy is formed to the floating cylinder, the exhaust port is opened, and when the liquid level drops below the check ring of the
valve seat, the bottom of the floating cylinder drops to the bottom of the
valve seat liquid groove. A liquid sealing is formed by utilizing the residue liquid of the valve seat liquid groove and the valve seat check ring, and the barometric pressure principle is utilized to ensure that the air outside the floating cylinder can not enter to form inversion.