Properties Of Argon ( Ar )

Chemical, physical and thermal properties of Argon - Ar :

Molecular Weight 39.948
Specific Gravity 1.38
Specific Volume (ft3/lb, m3/kg) 9.8, 0.622
Density of liquid at atmospheric pressure (lb/ft3, kg/m3) 87.0, 1400
Absolute Viscosity (lbm/ft s, centipoises) 13.4 10-6, 0.02
Sound velocity in gas (m/s) 322
Specific Heat - cp - (Btu/lboF or cal/goC, J/kgK) 0.125, 523
Specific Heat Ratio - cp/cv 1.67
Gas constant - R - (ft lb/lboR, J/kgoC) 38.7, 208
Thermal Conductivity (Btu/hr ft oF, W/moC) 0.0102, 0.0172
Boiling Point - saturation pressure 14.7 psia and 760 mm Hg - (oF, oC) -303, -186
Latent Heat of Evaporation at boiling point (Btu/lb, J/kg) 70, 163000
Freezing or Melting Point at 1 atm (oF, oC) -308.5, -189.2
Critical Temperature (oF, oC) -187.6, -122
Critical Pressure (psia, MN/m2) 707, 4.87
Critical Volume (ft3/lb, m3/kg) 0.0299, 0.00186
Flammable no

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Properties Of Acetylene (Ethyne)

Chemical, physical and thermal properties of Acetylene (Ethyne) - C2H2

Molecular Weight 26.04
Specific Gravity 0.90
Specific Volume (ft3/lb, m3/kg) 14.9, 0.93
Density of liquid at atmospheric pressure (lb/ft3, kg/m3) 43.0, 693
Absolute Viscosity (lbm/ft s, centipoises) 6.72 10-6, 0.01
Sound velocity in gas (m/s) 343
Specific Heat - cp - (Btu/lboF or cal/goC, J/kgK) 0.40, 1674
Specific Heat Ratio - cp/cv 1.25
Gas constant - R - (ft lb/lboR, J/kgoC) 59.3, 319
Thermal Conductivity (Btu/hr ft oF, W/moC) 0.014, 0.024
Boiling Point - saturation pressure 14.7 psia and 760 mm Hg - (oF, oC) -103, -75
Latent Heat of Evaporation at boiling point (Btu/lb, J/kg) 264, 614000
Freezing or Melting Point at 1 atm (oF, oC) -116, -82.2
Latent Heat of Fusion (Btu/lb, J/kg) 23, 53500
Critical Temperature (oF, oC) 97.1, 36.2
Critical Pressure (psia, MN/m2) 907, 6.25
Flammable yes
Heat of combustion (Btu/ft3, Btu/lb, kJ/kg) 1450, 21600, 50200

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Laser Welding And Cutting Safety

Safety and Health
Fact Sheet No. 19
© 1998 American Welding Society

INFORMATION SOURCES
American National Standards Institute (ANSI). Safe Use of Lasers, Z136.1, available
from American National Standards Institute, 11 West 42nd Street, New York, NY 10036.
Kokosa, J. Hazardous Chemicals Produced By Laser Materials Processing, Journal of
Laser Applications, 6 (1994) pp. 195–201.

Laser Institute of America (LIA). Guide for the Selection of Laser Eye Protection, available
from Laser Institute of America, 12424 Research Parkway, Orlando, FL 32826.

________. OSHA Instruction Publication 8-1.7, Guidelines for Laser Safety and Hazard
Assessment, available from Laser Institute of America, 12424 Research Parkway,
Orlando, FL 32826.

________. Industrial Laser Safety Reference Guide, available from Laser Institute of
America, 12424 Research Parkway, Orlando, FL 32826.

________. Laser Safety Guide, available from Laser Institute of America, 12424
Research Parkway, Orlando, FL 32826.

Shannon, G., et al. Investigation Into the Underwater Laser Welding of Steel, Journal of
Laser Applications, 6 (1994), pp 112-229.

Sliney, D. and Wolbarsht, M. Safety with Lasers and Other Optical Sources, Plenum
Press, New York, available from Laser Institute of America, 12424 Research Parkway,
Orlando, FL 32826.

Varanelli, A. Electrical Hazards Associated with Lasers, Journal of Laser Applications, 7
(1995) pp. 62–64.

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Welding And Joining

Welding and joining technology is fundamental to engineering and manufacturing. Without the ability to make strong and durable connections between materials it would not be possible to produce the many different items upon which we all rely in our everyday lives, from the very large (buildings, pipelines, trains and bridges) to the very small (medical implants and electronic devices).

TWI has its roots in welding and joining technology, and over many years has been responsible for developing and encouraging the adoption of new techniques and best practice in all sectors of industry.

TWI's welding and joining expertise is broad, ranging from fusion welding processes such as arc, laser, electron beam and resistance welding; brazing; and soldering to non-fusion techniques such as friction and ultrasonic welding, and diffusion and adhesive bonding.

TWI also has specialist knowledge in welding and joining a variety of materials including metals, plastics, composites and ceramics, and has even developed processes to weld wood.

Source : http://www.twi.co.uk/content/welding_index.html

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