Cryogenics

The term cryogenics is used to de­scribe the use of, or the creating of, temperatures in the range of -250 F. to absolute zero. The term is also applied to the low-temperature liquefication of gases, handling and storage, insulation of containers, instrumentation, and techniques used in such work. The present extensive use of liquid helium and liquid hydrogen has increased the common use of the term cryogenics. Fig. 1-22 shows the boiling temperature

Fig. 1-22. Boiling temperatures of some common refrigerants and some other fluids at atmospheric pressure.

 Note the difference between the boiling points of some commonly used refrigerants and the boiling
points of the fluids in the cryogenic range.

At atmospheric pressure of some of the common fluids and also indicates the cryogenic range of temperatures.