Welding Gases
Acetylene | Air | Argon | Carbon Dioxide(CO2) | Helium
Hydrogen | Nitrogen | Oxygen | Propane
Nitrogen
Nitrogen (N2) constitutes 78.03% of the air, has a gaseous specific
gravity of 0.967, and has a boiling point of -320.5°F (-195.8°C) at
atmospheric pressure. It is colorless, odorless, and tasteless.
Nitrogen is often used as an "inert" gas due to its
nonreactive nature with many materials. Common uses of
gaseous nitrogen are found in electrical systems, chemical
manufacturing, purging, and air-powered tools. Liquid nitrogen,
produced by the cryogenic air separation process, finds wide use as a
refrigerant gas in applications such as cryogenic grinding of plastics
and food packaging.
Commercial nitrogen is produced by a variety of air separation processes, including cryogenic liquefaction and distillation, pressure swing adsorption (PSA), and membrane separation.
Nitrogen can react to form certain compounds under the influence of chemicals, catalysts, or high temperature; therefore it is not used as a shielding gas in the welding industry.
| DOT Information | ||
| DOT Name: | Nitrogen | |
| DOT Hazard Class: | Nonflammable Gas | |
| DOT Label: | Nonflammable Gas | |
| DOT ID No.: | UN1066 | |
| CAS No.: | 7727-37-9 | |
| Valve Outlet: | CGA 580 | |
| Physical State in High Pressure Cylinder:Gas | ||
| Major Hazards: | High Pressure, Suffocation | |
| Fire Potential: | Nonflammable | |
Physical Properties of Nitrogen |
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| Formula: | N2 | |
| Molecular Weight: | 28.013 lb/mol | |
| Specific Volume at 70°F and 1 atm: | 13.8 ft3/lb (12.00 m3/kg) | |
| Specific Heat: | 6.97 BTU/lbmol-deg F@ 70 deg. F | |
| Specific Gravity: | .967 | |
| Gas Density: | 0.07247 lb/ ft3 @ 70 deg. F. 14.7 PSIA | |
| Boiling Point | ||
| Temperature: | -320.5 deg. F (-195.8 deg. C) | |
| Liquid Density: | 50.50 lb./ft3 | |
| Latent Heat: | 85.5 BTU/lb. | |
Critical Point |
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| Temperature: | -232.4 deg. F | |
| Pressure: | 492.9 PSIA | |
Melting Point |
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| Temperature: | -346.0 deg. F | |
| Pressure: | 1.82 PSIA | |
Industrial
Compressed Gas Cylinders
Medical Compressed Gas Cylinders
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