Safety insert for storage vessels of low-boiling liquified gases

Claim 1

In a safety insert for storage vessels for low boiling, liquified gases wherein the vessel has a neck, a safety tube disposed longitudinally within said neck in flow communication with the contents of the vessel, an annular space being formed between said neck and said safety tube, a flange closing off the outer end of said neck and said safety tube, a fill and extraction opening in said flange for the liquified gas, a safety valve in said flange, a vent pipe having a stop cock in said neck communicating with said annular space and the atmosphere, a gas outlet hole in said safety tube, said gas outlet hole having its flow cross-section adjustably by manipulating means external of said vessel, and said gas outlet hole communicating with said annular space and by way of said pipe also communicating with the atmosphere whereby a portion of vaporized gas flows through said annular space and exits from said vent pipe and a remaining portion of vaporized gas flows through said safety tube and exits from said outlet hole so as to prevent any stationary column from being in either said annular space or said safety tube and thus reducing heat transfer to the liquified gas and minimizing evaporation losses.