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Figure 4-1.—Oxygas cutting outfit. | Up
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Figure 4-3.—A portable oxygas cutting and welding outfit.
ACETYLENE
Acetylene is a flammable fuel gas composed of
carbon and hydrogen having the chemical formula
C2H2.Whenburned with oxygen, acetylene produces a
hot flame, having a temperature between 5700°F and
6300°F. Acetylene is a colorless gas, having a disagree-
able odor that is readily detected even when the gas is
highly diluted with air. When a portable welding outfit,
similar to the one shown in figure 4-3 is used, acetylene
is obtained directly from the cylinder. In the case of
stationary equipment, similar to the acetylene cylinder
bank shown in figure 4-4, the acetylene can be piped to
a number of individual cutting stations.
Hazards
Pure acetylene is self-explosive if stored in the free
state under a pressure of 29.4 pounds per square inch
(psi). A slight shock is likely to cause it to explode.
WARNING
Acetylene becomes extremely dangerous
if used above 15 pounds pressure.
Figure 4-4.—Stationary acetylene cylinder bank.
Cylinder Design
Acetylene can be safely compressed up to 275 psi
when dissolved in acetone and stored in specially de-
signed cylinders filled with porous material, such as
balsa wood, charcoal, finely shredded asbestos, corn
pith, portland cement, or infusorial earth. These porous
filler materials aid in the prevention of high-pressure gas
pockets forming in the cylinder.
Acetone is a liquid chemical that dissolves large
portions of acetylene under pressure without changing
the nature of the gas. Being a liquid, acetone can be
drawn from an acetylene cylinder when it is not upright.
You should not store acetylene cylinders on their side,
but if they are, you must let the cylinder stand upright
for a minimum of 2 hours before using. This allows the
acetone to settle to the bottom of the cylinder.
NOTE: Acetone contaminates the hoses, regula-
tors, torch, and disrupts the flame.
Acetylene is measured in cubic feet. The most com-
mon cylinder sizes are 130-, 290-, and 330-cubic-foot
capacity. The standard size cylinder the Navy uses holds
4-3
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