Liquid argon

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Liquid Argon (LAR) is tasteless, colorless, odorless, non-corrosive, nonflammable and extremely cold. Argon is used in its gaseous state more frequently than in its liquid state, but is commonly stored and moved in liquid form due to cost effectiveness. Argon becomes a cryogenic liquid when it is converted to liquid form, meaning it is a liquefied gas with a normal boiling point that is below -238°F (-150°C).^[1]

The welding industry uses argon as a shielding gas to protect metal from oxidation during welding. Argon is also used extensively in the semiconductor manufacturing process as a purge gas.^[2]

Physical Properties

• Molecular weight: 39.95
• Boiling point @ 1 atm: -302.6°F (-185.9°C, 87oK)
• Freezing point @ 1 atm: -308.8°F (-189.4°C, 85oK )
• Critical temperature: -188.4°F (-122.4°C)
• Critical pressure: 705.8 psia (48.0 atm)
• Density, liquid @ BP, 1 atm: 87.40 lb/scf
• Density, gas @ 68°F (20°C), 1 atm: 0.1034 lb/scf
• Specific gravity, gas (air=1) @ 68°F (20°C), 1 atm: 1.38
• Specific gravity, liquid (water=1) @ 68°F (20°C), 1 atm: 1.40
• Specific volume @ 68°F (20°C), 1 atm: 9.67 scf/lb
• Latent heat of vaporization: 2804 BTU/lb mole
• Expansion ratio, liquid to gas, BP to 68°F (20°C): 1 to 840^[1]

References

1. http://www-safety.deas.harvard.edu/services/argon.html
2. Air Products Safetygrams - Liquid Argon