1. Conventional safety in cryogenics and operation

Safety rules have to be obeyed whenever cryogenic fluids are present. These fluids are considered as a hazard, whether they are in a liquid or gaseous state (1 L of liquid helium expands to 780 L of gas at ambient pressure and temperature). The ratio of the volume of gas formed and heated to ambient temperature and pressure to the initial volume of liquid is of the same order of magnitude for other cryogenic fluids.

A risk is the resultant of a hazard and a degree of exposure. To reduce the risk, the ideal solution is thus to eliminate or minimize the hazard. Another way is to reduce exposure of the personnel to the hazards, but this is not always feasible. In this case, prevention entails setting up first collective and then personal barriers to avert all accidents that could occur during the different steps in what we can call the “lifetime” of the fluid, i.e....