TM 5-3655-210-12
d. Amount of Carbon Dioxide Required to Fill
dioxide inside the pressure vessel be kept no higher
than the bottom of the vapor equalizing line dip tube.
Tank.
If the pumping rate is known, it can be
After complete filling of the. pressure vessel and after
determined from the liquid level gage reading before
the hoses have been disconnected, open the vapor
pumping is started how much carbon dioxide will be
equalizing line valve (23, fig. 2-8) slightly to discharge
required to fill the tank and approximately how long it
carbon dioxide to atmosphere. If the discharge is clear
will take to pump this among of carbon dioxide. Be alert
for the indications outlined in (b) and (c) above, several
or only slightly foggy, the tank has not been overfilled.
However, if the discharge is a dense, white cloud
minutes before this time has elapsed. Stop the pump
containing particles of dry ice, the liquid level in the tank
immediately when either indication is observed.
is too high. To remedy this, carbon dioxide discharge
2-16.
Checking For Overfilling It is important that
from the vapor equalizing line connection should be
the level of the liquid carbon
allowed to continue slowly until the dense white
discharge changes to a clear or blue fog discharge.
Section ll. OPERATION OF AUZILIARY MATERIAL
USED IN CONJUNCTION WITH CONVERSION AND STORAGE UNIT.
2-17. Fire Extinguisher
ide upon contact with the air turns into gas which has a
smothering effect on fire.
b. Operation. Open the quick release clamp and
a. Description. The conversion and storage unit is
lift out the extinguisher. Pull the pin which locks the
equipped with a 15 pound (1.0545 kg per sq cm) carbon
handle, point the nozzle at the base of the fire and
dioxide fire extinguisher (7, fig. 2-18) or (7, fig. 2-19)
squeeze the handle to discharge the contents of the
located in the left side of the storage compartment. It is
extinguisher at the fire. As soon as possible after use,
held in with a quick release clamp (8) for easy access.
recharge the extinguisher as instructed: NOTE
Fifteen pounds (1.0545 kg per sq cm) of liquid carbon
Do not put the extinguisher back in place in the
dioxide is held in the cylinder at 800 psi (56.24 kg per sq
equipment after use without recharging it.
cm) at 70F. (21C.). When the extinguisher valve is
opened, the carbon dioxide is released. The liquid
carbon diox-
Section lll. OPERATION UNDER UNUSUAL
CONDITIONS
2-18. Operation In Extreme Cold
grease. For lubrication at low temperatures refer to LO
a. General. Operating the conversion and storage
5-3655-210-12.
c. Operating Precautions. Avoid all unnecessary
unit in extreme cold temperatures presents special
shocks when operating the equipment. Metal becomes
problems. Careful inspection is necessary, particularly
brittle at very low temperatures, and its ability to
for the lubrication and electrical systems. Spend more
withstand shock becomes less as the temperature
time performing such operations as preventive
drops.
maintenance and take extra care with pre-starting
d. Low Temperature Operation. Perform the
precautions. Failure to give this extra service may
steps given below when liquid carbon dioxide is
result in starting failures, inefficient operation, and
contained in both pressure vessels, and the surrounding
serious or permanent damage to the unit.
b. Lubrication.
temperature is below -38.9C. (20F.). If the unit has
At extreme low temperatures,
been subject to low temperatures for considerable time,
lubricants that are too heavy a grade can make the
install warm, fully charged batteries.
operating machinery difficult to start or to operate.
(1) Position the valves as indicated in Figure 2-
Operating with too heavy a grade of grease or oil will
26. Valves 38 and 39 are open to the compartment
cause rapid wear of the moving parts, as they receive
heater (valve handles turned 900 clockwise from
no initial lubricating from heavy cold oils or
2-25
