Welding Gases
Acetylene
| Air
| Argon
| Carbon Dioxide(C02)
Hydrogen | Nitrogen
| Oxygen
| Propane
Helium
Helium (He) is the second lightest
element (hydrogen being the lightest) with a gaseous specific gravity of
0.138. It is a colorless, odorless, tasteless inert gas at room
temperature and atmospheric pressure. Its boiling point is -452.1°F
(-268.9°C) at atmospheric pressure. Helium is present in dry air at a
concentration of 0.0005%.
Helium
is one of the noble gases. Like the other noble gases, helium is
chemically inert. Reactions with other elements occur only with
difficulty and the resulting compounds are quite unstable.
Helium
is the most difficult of all gases to liquefy and is impossible to
solidify at atmospheric pressure. These properties make liquid helium
extremely useful as a refrigerant and for experimental work in producing
and measuring temperatures close to absolute zero. Liquid helium
can be cooled almost to absolute zero at normal pressure by rapidly
removing the vapor above the liquid.
First
discovered in the spectrum of the sun's corona during an eclipse in
1868, helium was first isolated from terrestrial sources in 1895. In
1907 British physicist Sir Ernest Rutherford showed that alpha particles
are the nuclei of helium atoms.
Helium
is the second most abundant element in the universe, after hydrogen;
however, it is rare on earth. Its principal source is natural gas
wells where the helium is extracted from pockets in the crude natural
gas stream and purified. It is so light that once
released it escapes the earth's atmosphere and cannot be recovered.
Helium
is widely used as an inert gas in the arc welding process and as an
inert gas in the production of reactive materials. Its permeation
rate and ease of detectability make it an ideal medium for leak
detection. Also, its low specific gravity and nonflammability
allow its use in lighter-than-air applications such as the filling of
balloons and blimps. To reduce risk of the bends, a mixture
of helium and oxygen is used as a breathing gas for deep-sea diving,
since helium is less soluble in human blood than nitrogen. Helium
is also used in the pressurizing of rockets before takeoff and the
pressurizing of tanks of rocket fuel. Liquid helium is used in
superconducting magnet applications, including magnetic resonance
imaging (MRI).
|
DOT Information |
| DOT
Name: |
|
Helium |
| DOT
Hazard Class: |
|
Nonflammable
Gas |
| DOT
Label: |
|
Nonflammable
Gas |
| DOT
ID No.: |
|
UN1046 |
| CAS
No.: |
|
7440-59-7 |
| Valve
Outlet: |
|
CGA 580 |
| |
|
|
| Physical
State in High Pressure Cylinder: Gas |
| Major
Hazards: |
|
High
Pressure Suffocation |
|
Fire Potential: |
|
Non-Flammable |
| |
|
|
|
Physical
Properties of Helium |
| Formula: |
|
He |
| Molecular
Weight: |
|
4.003
lb/mol |
| Specific
Volume at 70°F and 1 atm: |
|
96.71 ft3/lb
(6.00 m3/kg) |
| Specific
Heat: |
|
4.97
BTU/lbmol-deg F@ 70 deg. F |
| Specific
Gravity: |
|
.138 |
| Gas
Density: |
|
.010346
lb/ ft3 @ 70 deg. F. 14.7 PSIA |
| |
|
|
|
Boiling Point |
| Temperature: |
|
-452.1
deg. F (-268.9 deg. C) |
| Liquid
Density: |
|
7.804
lb./ft3 |
| Latent
Heat: |
|
8.778BTU/lb. |
| |
|
|
|
Critical Point |
| Temperature: |
|
-450.3
deg. F |
| Pressure: |
|
33.2
PSIA |
| |
|
|
|
Melting Point |
| Temperature: |
|
455.8
deg. F |
| Pressure: |
|
.0735
PSIA |
|
Cubic
Feet Per Balloon
| BALLOONS |
Latex |
Mylar |
Large
Weather Balloons |
| Size: |
9" |
10" |
11" |
12" |
14" |
16" |
20" |
36" |
18" |
26" |
4' |
5' |
8' |
12' |
20' |
| Volume
(ft3): |
.27 |
.30 |
.50 |
.52 |
1.00 |
1.25 |
2.42 |
4.14 |
.44 |
1.5 |
33 |
65 |
268 |
905 |
4189 |
Formula:Volume
in cubic feet = 4/3 pi r3
1728
Balloons
per Cylinder
| BALLOONS |
Latex |
Mylar |
| Cylinder |
9" |
10" |
11" |
12" |
14" |
16" |
20" |
36" |
18" |
26" |
| 22
ft3 |
81 |
73 |
44 |
42 |
22 |
17 |
9 |
5 |
50 |
14 |
| 58
ft3 |
214 |
193 |
116 |
111 |
58 |
46 |
23 |
14 |
131 |
38 |
| 110
ft3 |
407 |
366 |
220 |
211 |
110 |
88 |
45 |
26 |
250 |
73 |
| 137
ft3 |
507 |
456 |
274 |
263 |
137 |
109 |
56 |
33 |
311 |
91 |
| 219
ft3 |
811 |
730 |
438 |
421 |
219 |
175 |
90 |
52 |
497 |
146 |
| 286
ft3 |
1059 |
953 |
572 |
550 |
286 |
228 |
118 |
69 |
650 |
190 |
Helium
High Pressure Cylinders
*Denotes light-weight
aluminum cylinder
|
PART
NUMBER
|
CYL.
SIZE
|
WEIGHT
OF GAS (LBS.)
|
APPROX.
WT. OF FULL
CYLINDER (LBS.)
|
PRESSURE
(PSI @ 70F)
|
GALLONS
|
LITERS
|
DIMENSIONS
(Height x Diameter)
|
|
HELE*
|
22
ft3
|
.225
|
9
|
1800
|
165
|
623
|
30"
x 4-1/2"
|
|
HEL058*
|
58
ft3
|
.59972
|
22
|
1800
|
436
|
1642
|
27"
x 8"
|
|
HEL110
|
110
ft3
|
1.1374
|
58
|
2265
|
823
|
3115
|
47"
x 7"
|
|
HEL110*
|
110
ft3
|
1.1374
|
44
|
2265
|
823
|
3115
|
41"
x 8"
|
|
HEL137*
|
137
ft3
|
1.41658
|
42
|
2265
|
1030
|
3880
|
47"
x 8"
|
|
HEL219
|
219
ft3
|
2.26446
|
135
|
2265
|
1638
|
6202
|
51"
x 9"
|
|
HEL286
|
286
ft3
|
2.95724
|
160
|
2200
|
2150
|
8099
|
55"
x 9-1/4"
|
|
SERVICE
IS OUR MAIN ITEM . . . AND WE ARE NEVER OUT OF STOCK!
Havard Welding
713-672-1743 1601 Clinton Galena Park, Texas
77547
|
