NETZSCH LFA 447 Nanoflash Operating Instructions Manual page 11

TM
LFA 447
PRECAUTIONS
Operations and maintenance
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General Information
It is essential that operations involving the use of gaseous or liquid
nitrogen, particularly where large quantities are used, are
conducted in well-ventilated areas to prevent the formation of
oxygen-deficient atmospheres.
Ideally, nitrogen should be vented into the open air well away
from areas frequented by personnel. Nitrogen should NEVER be
released or vented in enclosed areas or buildings where the
ventilation is inadequate.
Before entering areas, vessels or other equipment for maintenance
or other purposes in which the atmosphere is, or may become
deficient in oxygen, action should be taken to make the
equipment safe. Preparatory work will include equipment
isolation from hazardous processes, purging and continued
ventilation with air as appropriate.
flammable gases should be purged with nitrogen prior to purging
with air to avoid the formation of flammable mixtures.
NEVER USE OXYGEN AS A SUBSTITUTE FOR AIR AS A PURGING
MEDIUM. Prior to entry, the atmospheres should be tested with a
portable oxygen analyzer (calibrated before use) to ensure that
the oxygen lies between 20% and 22% by volume. The use of a
safety work permit system is strongly recommended (Note: The
latter two recommendations need not apply when entering a
Cryo-Guard vehicle for normal loading or unloading purposes. For
details see Cryo-Guard Drivers Instruction Manual).
It should be recognized that although nitrogen is slightly lighter
than air at equal temperatures, liquid nitrogen and cold nitrogen
vapor are denser than air and can accumulate in low-lying areas
such as pits and trenches. Where large spills of liquid nitrogen
occur, a fog is formed in the vicinity of the spill caused by the
condensation of water vapor in the surrounding air. The fog, in
addition to severely reducing visibility, may contain oxygen
concentrations appreciably lower than those of air, thus
presenting a local asphyxiation hazard.
IF IT IS NECESSARY FOR A PERSON TO ENTER AN OXYGEN-
DEFICIENT ATMOSPHERE
PURPOSES, IT IS ESSENTIAL THAT HE/SHE WEAR, AND BE TRAINED
IN THE USE OF, A SELF-CONTAINED BREATHING APPARATUS.
Persons entering an oxygen-deficient area are advised to wear a
safety belt with a manned safety line attached. Standby personnel
should have ready access to self-contained breathing apparatus
should emergency assistance be required.
Equipment in service with
FOR MAINTENANCE OR OTHER
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