Despatch 926E Equipment Manual (C-155)Rev 2/11 User Manual
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gaseous constituents of the air which liquefy above -196
C (-320
F),
including oxygen. Therefore, supply lines, clothes and equipment which are
subject to this temperature can absorb or liquefy oxygen, which will cause a
severe fire if ignited and which can become explosive when in contact with
grease.
LN
2
should not be left in sealed containers or hoses. When the LN
2
turns to
nitrogen gas, it will build up very high pressure. Unless LN
2
is being actively
used in test chamber operations, care should be taken that an adequate vent
is provided and that excessive pressure is bled off.
The concentration of liquid oxygen suspended in the LN
2
builds up as the LN
2
is used. Consequently, nearly empty LN
2
containers should be handled as if
they were liquid oxygen containers. The presence of liquid oxygen in LN
2
can
be determined by the milky appearance of the liquid. LN
2
is normally clear.
If parts of the body are frozen by contact with these cold liquids, first-aid
treatment for frostbite should be given, with slow thawing of the frozen parts.
Severe cases should be referred to a physician for treatment.