Liquid nitrogen freezing coolant

USE In manuf of ammonia, nitric acid, nitrates, cyanides, etc. in manuf explosives in filling high-temp thermometers, incandescent bulbs to form an inert atm for preservation of materials, for use in dry boxes or glove bags. Liquid nitrogen in food-freezing processes iu the laboratory as a coolant. Pharmaceutic aid (air displacement). Caution In high concns it is a simple asphyxiant. 

Freeze seals are used to isolate components (such as inboard isolation valves) for maintenance in locations that cannot otherwise be isolated. The seal is created and maintained by applying a cooling agent such as liquid nitrogen to the exterior of the pipe. The cooling agent freezes the water within the pipe section, thus sealing the pipe. When used in the reactor coolant system (RCS) pressure boundary, these freeze seals become a temporary part of the pressure boundary. 

Liquid nitrogen is used in the cold-trapping of material such as carbon dioxide from gas streams, as a coolant for electronic equipment, for pulverizing plastics or rubber materials, and for simulating the conditions of outer space. It is used to freeze liquids in pipelines... 

Note 9—Acetone and either methyl, eth or isopropyl aloohdb are suitable. All of these require cautious hanging. Liquid nitrogen may also be used as a coolant instead of liquids cooled with solid carbon dioxide for fuel samples whidi have a freezing point below -6S C. Mechanical refrigeration is permitted. Where used the refrigerant temperature should be -70 C to 80 C. 

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