Helium prices ...

[Wookie]

Grades of helium: the differences and uses

5.0 is the lowest grade I ever accepted for selling to clients.

 

[Storker]

Quenching the magnetic field (occationally for maintenance and rarely for emergency) involves heat dissipation and boiling a lot of helium.

It's also quite spectacular

https://m.youtube.com/results?search_query=quenching+mri

 

[taimen]

It's also quite spectacular

Yeah. Recapturing helium even for a good purpose would be quite boring...

 

[Storker]

Yeah. Recapturing helium even for a good purpose would be quite boring...

I think it's kinda cool to watch. YMMV.

 

[taimen]

I think it's kinda cool to watch

Absolutely! And the feeling when you push a red button, releasing 1500 liters of liquid helium into air...

 

[rjack321]

5.0 is the lowest grade I ever accepted for selling to clients.

At least around here its all grade 5. The industrial tanks are vacuumed once before refilling while the UHP tanks get two vacuums pulled. I dont know how strong of a vacuum they pull.

There is no balloon grade and any grade higher than UHP (5 nines) would be a special order.

 

[taimen]

We have balloon grade available, as well as UHP from 46 to 60 and BIP. But for diving they sell N46 in 50 liter 300 bar cylinders.
Regarding shortage, last time I remember encountering a backorder for liquid helium (an unexpected MRI fill) was something like 2007.
For the past couple of years, despite shortages, we always get what we need for MRIs. Latest next morning if needed.

 

[Storker]

For the past couple of years, despite shortages, we always get what we need for MRIs.

Me, I don't have a problem with MRI scanners getting priority over sport divers.

*dons flameproof suit*

 

[Seaross]

2.75 cu/foot ottawa

 

[rjack321]

I was under the understanding helium is a product of nuclear decay far under the earth, hence its source from natural gas deposits and the reason there is a dive classification was to filter out the free radical helium to prevent cancer causing particles from entering your lungs and for purity of the gas mix(other noble gases etc.)

canada 2.75cu/foot

It is a product of radioactive decay of uranium and thorium and found in natural gas deposits. It is separated from methane (natural gas) cryogenically. There is no such thing as "radioactive" or "free radical" helium atoms that have to be filtered out and there is no filter that could do that anyway.