Welding Gases
Acetylene | Air | Argon | Carbon Dioxide(CO2) | Helium
Hydrogen | Nitrogen | Oxygen | Propane
Acetylene
Acetylene (C2H2),
a compound of carbon and hydrogen, is a colorless, highly flammable gas.
It is slightly lighter than air and has a garlic-like odor.
Acetylene is stored in high pressure cylinders filled with a porous
material and containing acetone, into which the acetylene is dissolved.
Unless dissolved in a solvent, acetylene will dissociate at pressures
above 15 psig and form lamp black and hydrogen. Heat is generated
with dissociation, which in turn, produces a danger of explosion.
Acetylene is manufactured by the reaction of water with calcium carbide. It is also manufactured by thermal cracking of hydrocarbons, or by partial combustion of methane and oxygen.
Approximately 80% of the annual acetylene production of the United States is used for chemical syntheses. Acetylene has become increasingly prominent as a raw material for a whole series of organic compounds, among them acetaldehyde, acetic gas, and acetic anhydride. The remaining 20% of the acetylene production is principally used for oxy-acetylene cutting, heat treating, and welding.
DOT Information |
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| DOT Name: | Acetylene | |
| DOT Hazard Class: | Flammable Gas | |
| DOT Label: | Flammable Gas | |
| DOT ID No.: | UN1001 | |
| CAS No.: | 74-86-2 | |
| Valve Outlet: | CGA 510 | |
Physical State in High Pressure Cylinder: Gas |
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| Toxicity: | Simple Asphyxiant | |
| Fire Potential: | Flammable | |
Physical Properties of Acetylene |
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| Formula: | C2H2 | |
| Molecular Weight: | 26.04 lb/mol | |
| Specific Volume at 70°F and 1 atm: | 14.76 ft3/lb (0.918 m3/kg) | |
| Specific Heat: | 10.53 BTU/lbmol-deg F@ 70 deg. F | |
| Specific Gravity: | .920 | |
| Gas Density: | 0677 lb/ ft3 @ 70 deg. F. 14.7 PSIA | |
| Psat: | 586.2 psia @ 70 deg F | |
| Liquid Density: | 23.61 lb/ ft3 @ 70 deg F | |
Boiling Point |
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| Temperature: | -120.6 deg. F ( deg. C) | |
| Liquid Density: | 38.4 lb./ft3 | |
| Latent Heat: | (none) | |
Critical Point |
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| Temperature: | 95.36 deg. F | |
| Pressure: | 897.8 PSIA | |
Melting Point |
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| Temperature: | -113.0 deg. F | |
| Pressure: | 18.5 PSIA | |
Industrial Cylinders
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