Helium (He)
Helium is the second lightest element. It is a colourless, odourless, and tasteless, inert gas present in dry air at a concentration of 0.0005%. Its principal source is natural gas wells where the Helium is extracted from the crude natural gas stream and purified.
| Properties | U.S. Units | S.I. Units |
|
Chemical formula |
He |
He |
|
Molecular weight |
4.003 |
4.003 |
|
Density of the gas at 70°F(21.1°C) and 1atm. |
0.0103 lb/ft3 |
0.165 kg/m3 |
|
Specific gravity of the gas 70°F (21.1°C) and 1 atm (air = 1) |
0.138 |
0.138 |
|
Specific volume of the gas 70°F (21.1°C) and 1 atm |
97.07 ft3/lb |
6.601 m3/kg |
|
Density of the liquid saturated at 70°F (21.1°C) |
7.802 lb/ft3 |
124.98 kg/m3 |
|
Critical temperature |
-450.3 °F |
-267.9 °C |
|
Critical pressure |
33.0 psia |
227 KPa, abs |
|
Critical density |
4.347 lb/ft3 |
69.64 kg/m3 |
|
Boiling point at 10psig (170 kpa abs) |
-452.1 °F |
-268.9 °C |
|
Solubility in water vol/vol at 32°F(0°C)& 1 atm. |
0.0094 |
0.0094 |
|
Industry |
Usage |
|
Laboratories and calibration |
It is used as carrier in gas chromatography. |
|
Diving |
Breathing mixtures for divers. |
|
Health care |
As a cooling fluid for MRI, NMR or EPR magnets and breathing mixtures for those with impaired lung functions. |
|
Metal fabrication |
Used as a protective atmosphere for arc welding |
|
Electrical |
Used for cooling superconducting magnets. Used in growing crystals to make silicon wafers. |
|
Other |
Balloon inflation, electronics industry. |
|
Grade |
Cylinder type |
Pressure (Barg) |
|
4.5 |
50L |
200 |
|
40L |
150 |
|
|
6.0 |
50L |
200 |
|
40L |
150 |
|
|
5.5 |
50L |
200 |
|
40L |
150 |
|
|
5.0 |
50L |
200 |
|
40L |
150 |
|
Specification Grade |
Impurities (ppmv) |
Certification Specification |
||||
|
H2O |
O2 |
N2 |
CO + CO2 |
CnHm |
||
|
4.5 |
5 |
10 |
5 |
1 |
1 |
* |