R-113, trichlorotrifluoroethane. R-113 is a heavy
colorless liquid, which, at room temperature, has a slight
ethereal odor. R-113 is only used as a solvent, degreaser,
and flushing agent. It is not used as a shipboard
refrigerant.
These refrigerants, liquid and vapor, are
nonflammable and nonexplosive. Air mixtures of these
refrigerants are not capable of producing a flame. The
products of decomposition have a pungent odor and are
very irritating in minute quantities. They give ample
warning before dangerous concentrations are reached.
R-12, R-22, and R-114 are shipped under pressure
in steel cylinders. R-11 and R-113 are normally shipped
in drums, although some R-11 is shipped in cylinders
for submarine use. The refrigerant cylinders are easily
identified by their orange-colored bodies. In addition,
the following markings are made on the cylinder to
minimize the possibility of misidentification of the gas:
l The name of the gas is stenciled longitudinally
on two diametrically opposite sides of the
cylinder.
. A decal bearing the name of the gas may be
attached to the shoulder of the cylinder 90
degrees from the stenciling.
WARNING
Do not smoke, braze, or weld when refrigerant
vapors are present. Vapors decompose to
phosgene, acid vapors, and other products when
exposed to an open flame or a hot surface.
The following safety precautions and warnings
apply to all of the refrigerants listed in the previous
paragraphs.
l Exposure to large concentrations of fluorocarbon
refrigerants can be fatal. Vapors displace air (oxygen) in
a space and result in asphyxia. In high concentrations,
these vapors have an anesthetic effect, causing
stumbling, shortness of breath, irregular or missing
pulse, tremors, convulsions, and death. Fluorocarbon
refrigerants and solvents should, therefore, be treated as
toxic gases.
. Initial adverse anesthetic effects of R-113 can be
experienced at much lower levels than those of other
refrigerants, even though all refrigerants listed here have
a threshold limit value (TLV) of 1,000 parts of
refrigerant per million parts of air (ppm).
l Personnel overcome by inhalation of
fluorocarbon vapors may develop cardiac problems.
Remove exposed personnel to fresh air immediately. If
breathing has stopped, apply artificial respiration. Do
not permit affected personnel to exert themselves or
to exercise.
TLVs refer to airborne concentrations of substances
and represent conditions under which it is believed that
nearly all workers may be repeatedly exposed for an
8-hour day, 40 hours per week without adverse effects.
In addition to the precautions previously stated, there are
other safety measures that should be followed. A few of
these methods and precautions are as follows:
. Because refrigerants R-12 and R-22 boil at such
low temperatures, they may freeze if they are splashed
into the eyes or onto the skin. Always wear chemical
safety goggles or a full face shield when you work with
any refrigerant. Wear along-sleeved shirt and protective
gloves.
l Vapors of fluorocarbon refrigerants are four to
five times heavier than air and tend to collect in low
places. Perform refrigerant detection within 2 feet of the
deck and in possible air pockets.
. Refrigeration machinery spaces should be well
ventilated, especially when personnel are servicing
machinery. Use portable blowers if necessary to keep
the refrigerant vapor levels below the TLV of 1,000
ppm.
. Always have two people present when work is
being done on refrigeration systems. Use a halide
monitor with an alarm so you can be sure refrigerant
vapor concentrations in a space do not exceed safe
limits.
SEWAGE SYSTEM
In a continuing effort to control pollution of inland
and coastal waters, the Navy is installing sewage
treatment systems on board naval ships. These marine
sanitation systems are composed of three subsystems:
l
l
l
Flushing water system (provides flushing water)
Collection system (collects waste)
Treatment disposal system (treats and disposes
of waste)
Sewage discharged by naval ships into rivers,
harbors, and coastal waters and the environmental
effects of sewage pollution are of great concern to the
Navy. In fact, the Navy is required to control sewage
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