by the introduction of nitrogen at 200 psi
and then the addition of a proper charge of
carbon dioxide.
The addition of nitrogen in carbon dioxide
cylinders provides additional pressure. This
pressure expels the carbon dioxide at extremely
cold temperatures (below 0°F) at a much higher
rate than would the pressure of the carbon
dioxide itself. Winterized cylinders have a carbon
dioxide charge less than rated capacity. As a result
the total pressure is lower at high temperatures
than with rated charge, even though nitrogen has
been added. Thus winterized cylinders can be
subjected to 160°F without the safety disc
rupturing.
REPLACING SAFETY DISCS AND
WASHERS ON INFLATION VALVES
If you are not familiar with the flotation
equipment, replacing safety discs and washers on
the various CO2 cylinders can be very difficult.
You will need some special tools to replace the
.
safety disc and washers on inflation valve
a s s e m b l i e s A - 1 2 8 / 8 1 7 4 4 4 , M I L - V - 8 1 7 2 2
(Flu-6/P), and MIL-V-25492 (figure 3-9). You
will require a torque wrench, a five-sixteenth
inch socket, and apiece of hex stock 5/16 x 2
inches long.
O n c e y o u h a v e t h e s e t o o l s,
changing the safety disc will be a simple process.
W A R N I NG
Before you perform any work on inflation
v a l v e s,
e n s u r e t h a t C O2 i n f l a t i o n
assemblies are completely discharged. Do
not remove the valve or valve safety disc
p l u g f r o m a c h a r g e d CO2 a s s e m b l y.
Insert the 5/16- x 2-inch stock into the
disc plug and remove the safety disc
plug. Then insert the safety disc and washer
as shown in figure 3-9. To replace these
items, simply reinstall them into the infla-
tion valve. Remember to install new
washers and safety discs. Use a torque
wrench to make the following torque valve
adjustments.
Valve
Torque (lb)
A-18
29
MIL-V-81722 (Flu-6/P)
15-17
MIL-V-25492
28-35
(Hood valve)
NOTE: While you are tightening the
disc plug, align the insert with the plug.
safety
3-13
