Abstract: This invention relates to the protection of the teeming flow or stream of molten metal contained in a vessel and passing through a plate-type valve or cut-off device of the kind comprising a stationary plate and a displaceable plate that is provided with at least one output nozzle. A gas which is substantially inert with respect to the metal and has a pressure slightly higher than atmospheric pressure is fed into the aforesaid device, and this gas surrounds the metal while the latter passes through the said device, in such manner as to isolate the same from the ambient air by an uninterrupted protective gaseous barrier.

Abstract: The invention relates to the protection of a casting jet of molten metal, flowing between an upper storage tank and a lower receiving vessel. At least one inert liquefied gas is injected above and close to the surface of the molten metal contained in the lower vessel, and, at the same time, at least one inert gas is injected into the molten metal through the base or the walls of the lower vessel. The process of this invention protects metal casting jets from oxidation, for example, jets between ladle and manifold, between ladle and ingot mold, between ladle and ladle, or between converter (or furnace) and ladle.