Helium
- He
- CAS Number 7440-59-7
- UN1046 (gas)
- UN1963 (refrigerated liquid)
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Liquid / Gas Volumes
Calculate a liquid or gas volume or a mass
Liquid Phase
At boiling point at 1.013 bar
Gas Phase
In standard conditions (1,013 bar, 15°C)
Physical Properties
Molecule phase diagram showing the transition phases between solid, liquid and gas as a function of temperature and pressure
-
- Molecular weight 4.003 g/mol
- Content in dry air 5.24 ppm
-
Critical Point
- Temperature -267.95 °C
- Pressure 2.275 bar
- Density 69.85 kg/m³
-
Triple Point
- Temperature -271.38 °C
- Pressure 30.13 bar
Pressure 1.013 bar
| Latent heat of fusion (at melting point) | 12.492 kJ/kg |
| Melting point | - 271.38 °C |
Pressure 1.013 bar
| Boiling point | - 268.93 °C |
| Latent heat of vaporization (at boiling point) | 20.754 kJ/kg |
| Liquid density (at boiling point) | 124.74 kg/m3 |
| Compressibility factor Z | 1.0005 |
| Cp/Cv ratio γ | 1.6665 |
| Gas density (at boiling point) | 16.753 kg/m3 |
| Gas density | 1.784E-1 kg/m3 |
| Gas/(liquid at boiling point) equivalent | 694.83 vol/vol |
| Heat capacity Cp | 5.1931 kJ/(kg.K) |
| Heat capacity Cv | 3.116 kJ/(kg.K) |
| Specific gravity | 0.14 |
| Specific volume | 5.604 m3/kg |
| Thermal conductivity | 146.2 mW/(m.K) |
| Viscosity | 1.8695E-4 Po |
| Compressibility factor Z | 1.0005 |
| Cp/Cv ratio γ | 1.6665 |
| Gas density | 1.692E-1 kg/m3 |
| Gas/(liquid at boiling point) equivalent | 732.95 vol/vol |
| Heat capacity Cp | 5.1929 kJ/(kg.K) |
| Heat capacity Cv | 3.116 kJ/(kg.K) |
| Solubility in water | 7.123E-6 mol/mol |
| Specific gravity | 0.14 |
| Specific volume | 5.9116 m3/kg |
| Thermal conductivity | 151.69 mW/(m.K) |
| Viscosity | 1.9388E-4 Po |
| Compressibility factor Z | 1.0005 |
| Cp/Cv ratio γ | 1.6665 |
| Gas density | 1.635E-1 kg/m3 |
| Gas/(liquid at boiling point) equivalent | 758.37 vol/vol |
| Heat capacity Cp | 5.1929 kJ/(kg.K) |
| Heat capacity Cv | 3.116 kJ/(kg.K) |
| Solubility in water | 6.997E-6 mol/mol |
| Specific gravity | 0.14 |
| Specific volume | 6.1166 m3/kg |
| Thermal conductivity | 155.31 mW/(m.K) |
| Viscosity | 1.9846E-4 Po |
Applications
Examples of uses of this molecule in Industry and Healthcare
Automotive
Helium is used to inflate car airbags. It is also used for laser welding and arc welding.
Electronic components
Helium is used as a carrier gas or push gas to convey deposition precursors to the reaction chamber. Helium is used in gas mixes used for purging different lenses.
Hospital care
Helium is used by inhalation for respiratory diseases, or locally for cryoablation. It is also a component of inhaled gaseous mixtures for pulmonary function test.
Laboratories & Research Centers
Helium is the most commonly used carrier gas in gas chromatography. It is also used as cooling fluid for the MRI, NMR or EPR magnets under liquid state at -452.2 °F (-269 °C,4.15 K). Helium is also used for leakage detection applications.
Metal fabrication
Helium is used in laser welding and arc welding.
Oil & Gas
Helium is used in diving and IMR (Inspection, Maintenance & Repair) work achieved subsea for oil & gas offshore operations.
Other
Helium is used in science to cool down material below 4.2K mainly for superconductivity applications like particle accelerator, spallation source, light source, nuclear fusion, or quantum research and quantum computing. In a different field Helium is also used in the entertainment market to inflate balloons, and in gas mixtures used in diving.
Pharma & Biotech
Helium is used for leak test on process equipment.
Space
Gaseous helium is used for propellant tanks flushing before filling and liquid helium or gaseous helium is used to pressurize the cold liquid oxygen tank of space rockets. Helium is also used in satellite for cooling infrared instrument for earth observation or astronomie satellite
Safety & Compatibility
GHS04
Gas under pressure
Odor
none
Metals
| Aluminium | Satisfactory |
| Brass | Satisfactory |
| Monel | Satisfactory |
| Copper | Satisfactory |
| Ferritic Steel | Satisfactory |
| Stainless steel | Satisfactory |
| Zinc | Satisfactory |
| Titanium | No data |
Plastics
| Polytetrafluoroethylene |
strong rate of permeation
Acceptable
|
| Polychlorotrifluoroethylene | Satisfactory |
| Polyvinylidene fluoride | Satisfactory |
| Polyvinyl chloride | Satisfactory |
| Ethylene tetrafluoroethylene | Satisfactory |
| Polycarbonate | Satisfactory |
| Polyamide | Satisfactory |
| Polypropylene |
strong rate of permeation
Acceptable
|
Elastomers
| Buthyl (isobutene- isoprene) rubber | Satisfactory |
| Nitrile rubber NBR | Satisfactory |
| Chloroprene | Satisfactory |
| Chlorofluorocarbons | Satisfactory |
| Silicon |
strong rate of permeation
Acceptable
|
| Perfluoroelastomers | Satisfactory |
| Fluoroelastomers | Satisfactory |
| Neoprene | Satisfactory |
| Polyurethane | Satisfactory |
| Ethylene-Propylene | Satisfactory |
Lubricants
| Hydrocarbon based lubricant | Satisfactory |
| Fluorocarbon based lubricant | Satisfactory |
Materials compatibility
Recommendations : Air Liquide has gathered data on the compatibility of gases with materials to assist you in evaluating which materials to use for a gas system. Although the information has been compiled from what Air Liquide believes are reliable sources (International Standards: Compatibility of cylinder and valve materials with gas content; Part 1- Metallic materials: ISO11114-1 (March 2012), Part 2 - Non-metallic materials: ISO11114-2 (April 2013), it must be used with extreme caution and engineering judgement. No raw data such as these can cover all conditions of concentration, temperature, humidity, impurities and aeration. It is therefore recommended that this table is only used to identify possible materials for applications at high pressure and ambient temperature. Extensive investigation and testing under the specific conditions of use need to be carried out to validate a material selection for a given application. Contact the regional Air Liquide team for expertise service.
Learn More
More information
Helium was discovered in 1868 by Jules Janssen. Its name comes from the Greek "ἥλιος" (helios) meaning "sun". Helium is abundant in the sun's atmosphere and is found at trace levels in Earth's atmosphere. However, it may also be found in fossil form in natural gas pockets in some oil fields, extracted by drilling deep into the subsoil. Helium is an extremely light gas and is therefore very volatile. It is colorless, odorless, non-flammable and completely inert.