Grade 6 (6.0 helium = 99.9999% purity)
The closest to 100% pure helium, 6.0 helium is used in the manufacturing of semiconductor chips –
Grade 5.5 (5.5 helium = (99.9995% purity)
Like 6.0 helium, 5.5 ultra pure helium gas is typically considered “research grade,” also used in chromatography and semiconductor processing
Grade 5 (5.0 helium = 99.999% purity)
This high purity grade helium is also widely used for gas chromatography, mass spectrometry, and specific laboratory research when higher purity gases are not necessary, as well as for weather balloons and blimps.
Grade 4.8 (4.8 helium = 99.998% purity)
The highest of the “industrial grade” heliums, 4.8 grade helium is often used by the military. The rest is classified...
Grade 4.7 (4.7 helium = 99.997% purity)
A “Grade-A” industrial helium, 99.997% helium is mostly used in cryogenic applications and for pressurizing and purging
Grade 4.6 (4.6 helium = 99.996% purity)
Grade 4.6 industrial helium is used for weather balloons, blimps, in leak detection
Grade 4.5 (4.5 helium = 99.995% purity)
Often the grade most commonly referred to when people say “industrial grade,” 99.995% helium is most commonly used in the balloon industry
Grade 4 (4.0 helium and lower = 99.99% purity)
Any helium that is 99.99% and down into the high 80 percents is within the range of purities referred to collectively as “balloon grade helium.”
Interesting bit from that article wrt to transport infrastructure:
"most distributors simply stick to the industry standard transport of Grade 5. That is why for and [sic] end user of helium, a lower grade can cost more than the higher grades."
Helium for diving is going to be a different mix than what's used for balloons. In diving it's used to reduce the partial pressure of oxygen, and also to quickly diffuse back out of tissues when returning to the surface. Very different application!
I believe that that's the stuff you buy in the shop, the non-refillable containers. If you buy a proper refillable balloon gas cylinder it's the higher grade stuff. Source: bought the shop stuff, got disappointed, bought the cylinder, happy.
You sure about that? Everything I've ever heard says that balloon gas is generally grade 4, which is 99.99% pure. Not good enough for MRI, but quite a lot better than 80%.
Economically I expect it wouldn't be that pure, since it doesn't have to be that pure to provide lift, and party balloons are not trying to maximize lift.
Out of curiosity I did a minor amount of research to get an idea.
Turns out that you are right, some balloon gas is 80%. Specifically, the "Balloon Time" tanks you can buy at places like Target say "not less than 80%" helium.
On the other hand, I went to AirGas and a few other suppliers and they seemed to have 95%-97.0% helium gas as their definition for balloon grade.
What is the reason that MRI needs grade 6 vs grade 4 helium? I'm imagining that the superconducting wire is within a cryostat filled with liquid helium. Doesn't seem like there would be any appreciably partial pressure of things like nitrogen or oxygen at 4 Kelvin. I imagine the reactivity of oxygen is pretty low at 4 K as well. How much dissolved oxygen or nitrogen can liquid helium support? And how much solidifies out and sinks to the bottom of the cryostat?
I can personally attest that this is not foolproof, if it is even the case. Those helium tanks you can buy for large parties knocked me out as a kid. Lost consciousness fell to the ground, blacked out. Supervise your kids if you buy one!
Same applies to every gas that isn't carbon dioxide. Your body only cares about expelling CO2, it hasn't evolved a way to detect oxygen in the breathing gas mix. Divers know all about this.
Would you like to offer a rebuttal more well reasoned and thought out than "nuh-uh"?
You have the entire collected knowledge of mankind at your fingertips. You could do 30 seconds of research and find an answer better than "I don't think that sounds right".
What is asserted without evidence may be dismissed without evidence.
(The form in which Christopher Hitchens actually stated "Hitchens' Razor" is more symmetrical but unfortunately wrong: "What can be asserted without evidence can be dismissed without evidence". Anything can be asserted without evidence! It's only when something actually has been, in a given context, that dismissing it is -- in the same context -- a reasonable course of action.)
https://www.bocgases.ie/files/balloon_grade_helium_factsheet... says 95% helium and 1% oxygen while https://dan.org/alert-diver/article/helium-gas-purity-what-i... says 97.5% helium but very unlikely for it to be as low as 80%
"An overview of the different common grades of helium" - https://zephyrsolutions.com/what-are-the-different-grades-of...
Grade 6 (6.0 helium = 99.9999% purity) The closest to 100% pure helium, 6.0 helium is used in the manufacturing of semiconductor chips – Grade 5.5 (5.5 helium = (99.9995% purity) Like 6.0 helium, 5.5 ultra pure helium gas is typically considered “research grade,” also used in chromatography and semiconductor processing
Grade 5 (5.0 helium = 99.999% purity) This high purity grade helium is also widely used for gas chromatography, mass spectrometry, and specific laboratory research when higher purity gases are not necessary, as well as for weather balloons and blimps.
Grade 4.8 (4.8 helium = 99.998% purity) The highest of the “industrial grade” heliums, 4.8 grade helium is often used by the military. The rest is classified...
Grade 4.7 (4.7 helium = 99.997% purity) A “Grade-A” industrial helium, 99.997% helium is mostly used in cryogenic applications and for pressurizing and purging
Grade 4.6 (4.6 helium = 99.996% purity) Grade 4.6 industrial helium is used for weather balloons, blimps, in leak detection
Grade 4.5 (4.5 helium = 99.995% purity) Often the grade most commonly referred to when people say “industrial grade,” 99.995% helium is most commonly used in the balloon industry
Grade 4 (4.0 helium and lower = 99.99% purity) Any helium that is 99.99% and down into the high 80 percents is within the range of purities referred to collectively as “balloon grade helium.”
Interesting bit from that article wrt to transport infrastructure:
"most distributors simply stick to the industry standard transport of Grade 5. That is why for and [sic] end user of helium, a lower grade can cost more than the higher grades."
I wonder if one of you could be going by number of atoms, and the other could be going by weight?
Helium for diving is going to be a different mix than what's used for balloons. In diving it's used to reduce the partial pressure of oxygen, and also to quickly diffuse back out of tissues when returning to the surface. Very different application!
Sorry i was referencing "Balloon grade H is the least pure at 97.5 percent." from the diving article
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I believe that that's the stuff you buy in the shop, the non-refillable containers. If you buy a proper refillable balloon gas cylinder it's the higher grade stuff. Source: bought the shop stuff, got disappointed, bought the cylinder, happy.
You sure about that? Everything I've ever heard says that balloon gas is generally grade 4, which is 99.99% pure. Not good enough for MRI, but quite a lot better than 80%.
Economically I expect it wouldn't be that pure, since it doesn't have to be that pure to provide lift, and party balloons are not trying to maximize lift.
Out of curiosity I did a minor amount of research to get an idea.
Turns out that you are right, some balloon gas is 80%. Specifically, the "Balloon Time" tanks you can buy at places like Target say "not less than 80%" helium.
On the other hand, I went to AirGas and a few other suppliers and they seemed to have 95%-97.0% helium gas as their definition for balloon grade.
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>99.99% pure. Not good enough for MRI
What is the reason that MRI needs grade 6 vs grade 4 helium? I'm imagining that the superconducting wire is within a cryostat filled with liquid helium. Doesn't seem like there would be any appreciably partial pressure of things like nitrogen or oxygen at 4 Kelvin. I imagine the reactivity of oxygen is pretty low at 4 K as well. How much dissolved oxygen or nitrogen can liquid helium support? And how much solidifies out and sinks to the bottom of the cryostat?
source? the value I found is 97.5%+ helium for party balloons: https://www.grecogas.com/learn-our-industry/your-complete-gu...
I can personally attest that this is not foolproof, if it is even the case. Those helium tanks you can buy for large parties knocked me out as a kid. Lost consciousness fell to the ground, blacked out. Supervise your kids if you buy one!
People commit suicide with it because it's supposedly painless and quick.
Same applies to every gas that isn't carbon dioxide. Your body only cares about expelling CO2, it hasn't evolved a way to detect oxygen in the breathing gas mix. Divers know all about this.
We're dumb enough now to have forgotten history.
Moar hydrogen party balloons. Making partying fun again!
[flagged]
This is very likely not true.
Would you like to offer a rebuttal more well reasoned and thought out than "nuh-uh"?
You have the entire collected knowledge of mankind at your fingertips. You could do 30 seconds of research and find an answer better than "I don't think that sounds right".
What is asserted without evidence may be dismissed without evidence.
(The form in which Christopher Hitchens actually stated "Hitchens' Razor" is more symmetrical but unfortunately wrong: "What can be asserted without evidence can be dismissed without evidence". Anything can be asserted without evidence! It's only when something actually has been, in a given context, that dismissing it is -- in the same context -- a reasonable course of action.)
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> You could do 30 seconds of research
So could you, right?