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Phone:
713.672.1743 |
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| Component | % by Mole | % by weight |
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Nitrogen |
78.084 | 75.5 |
| Oxygen | 20.946 | 23.2 |
| Argon | 0.934 | 1.33 |
| Carbon Dioxide | 0.0335 | 0.045 |
| Neon | 0.001818 | - |
| Helium | 0.000524 | - |
| Methane | 0.0002 | - |
| Krypton | 0.000114 | - |
| Nitrous Oxide | 0.00005 | - |
| Xenon | 0.0000087 | - |
Atmospheric air also contains varying amounts of water vapor. For most practical purposes, the air composition is taken to be 78 percent nitrogen and 21 percent oxygen by volume, and to be 75.5 percent nitrogen and 23.2 percent oxygen by weight. The other "atmospheric trace gases" together compromise less than one percent. Trace impurity levels may vary with geographic locations or with proximity to industrial areas or highways carrying dense traffic. This composition remains relatively consistent in altitudes up to 70,000 feet.
Air meeting particular purity specifications has many important applications. Some of these applications include medical, undersea, aerospace, and atomic energy fields. It is also employed in self-contained breathing apparatus used by industrial, emergency response, and fire-fighting personnel, and as a power source for some kinds of pneumatic equipment.
Air may be compressed from the atmosphere and purified by chemical and mechanical means. It may also be synthetically produced from already purified major components nitrogen and oxygen.
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DOT Information |
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| DOT Name: | Air, compressed | |
| DOT Hazard Class: | Nonflammable Gas (2.2) | |
| DOT Label: | Nonflammable Gas | |
| DOT ID No.: | UN 1002 | |
| CAS No.: | None. (for nitrogen, 7727-37-9; for oxygen 7782-44-7) | |
| Valve Outlet: | CGA 346, CGA 950 pin-indexed | |
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Physical State in High Pressure Cylinder: Gas |
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| Toxicity: | Nontoxic | |
| Fire Potential: | Non-flammable | |
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Physical Properties of Air |
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| Chemical Name: | Air | |
| Molecular Weight: | 28.975 lb/mol | |
| Specific Volume at 70°F and 1 atm: | 13.346 ft3/lb (0.8333 m3/kg) | |
| Specific Heat: | 6.96 BTU/lbmol-deg F@ 70 deg. F | |
| Specific Gravity: | 1.000 | |
| Gas Density: | 0.07992 lb/ ft3 @ 70 deg. F. 14.7 PSIA | |
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Boiling Point |
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| Temperature: | -317.7 deg. F (-194.3 deg. C) | |
| Liquid Density:3 | 54.60 lb./ft | |
| Latent Heat: | 87.9 BTU/lb. | |
| Critical Point: | ||
| Temperature: | n/a | |
| Pressure: | n/a | |
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Melting Point: |
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| Temperature: | n/a | |
| Pressure: | n/a | |
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Industrial Cylinders
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SERVICE IS OUR MAIN ITEM . . . AND WE ARE NEVER OUT OF STOCK!
Havard Welding 713-672-1743 1601 Clinton Galena Park, Texas 77547