Cryogenic gases

Cryogenic Gases, usually liquefied, that induce freezing temperatures of -150 degrees F and below such as liquid oxygen, liquid helium, liquid natural gas, and liquid hydrogen. 

Cryogens Gases that must be cooled to a very low temperature in order to bring about a change from a gas to a liquid. 

The Compressed Gas Association (CGA) is composed of members from firms that produce and distribute compressed, liquefied, and cryogenic gases. The association develops and publishes recommendations to improve safety concerning the transportation, storing, and handling of gases. The CGA provides handbooks, technical publications, videotapes, and posters relating to safety. 

TABLE 27.2 Cryogenic Gases Boiling Point and Concentration in Air... 

The responder should also be aware of special circumstances. For example, some chemicals react with water (from air moisture or if the spill is over water), in which case the modeling should be done with the reaction products with water. In addition, release of some cryogenic gases may result in ground-hugging aerosols that may increase concentrations downwind more than that predicted by models. The toxic cloud plume may also be confined by a valley or by buildings and travel further downwind. 

Cryogenic Gases. Cryogenic gases are stored in a completely liquid state. They must be maintained in their containers as low-temperature liquids at relatively low pressure. Cryogenic gases must be stored in special containers that allow the gas from the liquid to escape in order to prevent a pressure buildup caused by the production of the gaseous state within the container, which would result in container failure. 

Such materials have zero resistance for electricity when they fall below a specific critical temperature. Cryogenic gases play an important role to reach and maintain these temperatures of superconductivity. 

Liquefied cryogenic gases are transported and stored in thermally insulated compressed gas vessels. The insulation of the vessels is achieved by their design with cylinder jacket insulation. Here, the inner vessel is concentrically arranged in the outer vessel and the insulation is located in the clearance. This helps to minimize heat penetration into the cryogenic gas of inner vessel which results from thermal conductivity, thermal radiation and convection ... 

By Rail In cylinders. As a liquid in tank cars designed for cryogenic gases, shipped under TC or DOT exemption. 

CRYOGENIC GASES Gases that are cooled to extremely cold temperatures (below -150°C) to change them into liquids. 

Assure adequate ventilation. Since liquified cryogenic gases have a high volume expansion ratio (see Table 17.1) when evaporated (in other words, a very small amount of liq-... 

---