Helium (He)
DESCRIPTION (Helium):
Helium is a colorless, odorless, tasteless gas with
an extremely low density. It is usually shipped as a gas. Cylinder pressures are
approximately 2200 psig @ 70° F. Typical uses include as a shielding gas for arc welding,
fill gas for neon signs, fill gas for all types of balloons, leak detection and as a
breathing gas for diving.
PHYSICAL CONSTANTS (Helium):
| Molecular Weight: |
4.0026 |
| Specific Volume @ 70° F., 1
atm.: |
96.6 cu.ft/lb |
| Boiling Point @ 1.0 atm. : |
-452 ° F |
| Melting Point @ 25.27 atm. : |
-457.62 ° F |
| Triple Point @ 0.051 atm: |
-455.6 ° F |
| Specific Gravity, Gas @ 32°
F., 1 atm. (Air = 1): |
0.137 |
| Density, Gas @ b.p..: |
0.0164 g/ml |
| Density, Liquid @ b.p..: |
0.1248 g/ml |
| Critical Temperature: |
-450.2 ° F |
| Critical Pressure: |
33.22 psia |
| Critical Density: |
0.0693 g/ml |
| Latent Heat of Vaporization @
b.p.: |
19.4 cal/mol |
| Latent Heat of Fusion @ t.p.: |
23.04 cal/g |
| Specific Heat, Liquid @ 4° K: |
3.45 cal/(mol)(° K) |
| Specific Heat, Gas @ 25° C.,
1 atm. Cp: |
4.9680 cal/(mol)(° K) |
| Specific Heat Ratio, Gas Cp/Cv: |
1.63 |
| Thermal Conductivity, Gas @
0° C. : |
3.39 x 10-3 cal/(sec)(cm2 )(° C/cm) |
| Dielectric Constant, Gas @
67.3 ° F.: |
1.000065 |
| Dielectric Constant, Liquid @
452.1 ° F. |
1.0000969 |
| Viscosity, Gas @ 60° F., 1
atm. : |
0.0196 centipoise |
| Entropy, Gas @ 25° C., 1 atm.
: |
48.004 cal/mol ° C |
| Solubility in Water @ 20° C.,
1 atm. |
0.0086 ml/g H2O |
CYLINDER CONNECTIONS (Helium):
Standard CGA V-1 Cylinder Connection up to 3000 psig threaded: CGA 580
Standard CGA V-1 Cylinder Connection up to 3000 psig yoke: CGA 930
Standard CGA V-1 Cylinder Connection 3001 - 5500 psig: CGA 680
Standard CGA V-1 Cylinder Connection 5501 - 7500 psig: CGA 677
Standard CGA V-1 Cylinder Connection Ultra High Integrity: CGA 718
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