Helium Grade

[opcode66]

I was using Zero Grade Helium. I need to get shorter tanks since I moved my cutting room and it is up stairs now. No way I can lift 5' tanks up two flights of stairs.

My supplier only has Zero Grade in the 5' variety. Since I can only carry a 3' tank up stairs I need to switch to standard Helium.

Does anyone use standard Helium? Will I have issues? Is it a bad idea? Input would be great!

I'm guessing it doesn't matter. And, that the minor impurities in the Helium won't be a problem for the cutterhead. But, I don't know.

[Nickou]

I still used standard helium

[Aussie0zborn]

In the old days we used helium from the local helium balloon shop. The helium is simply to fill the gap and transfer heat. The grade is not important.

[Serif]

Standard, here. Someone posted that compressed air would be almost as effective, since the air being constantly streamed through the head would be yet unheated, so some thermal "transfer work" would get done, which is the goal. However, the He is more effective - almost as effective as H. (But H is too dangerous to use while cutting, since the operator might nod during a fiery mishap. 0: )

Been happy with Praxair since they bought out my local Weldco. Been thinking about buying the bottle, since it matches the shag wall carpet.


- Andrew

[markrob]

Hi,

Not sure where you got that, but He is much more thermally conductive than air.

http://www.electronics-cooling.com/1998/09/the-thermal-conductivity-of-gases/

I'm sure they would have used air if it was even close in value to H or He.

Mark

[Serif]

Hi,

Not sure where you got that, but He is much more thermally conductive than air.

http://www.electronics-cooling.com/1998/09/the-thermal-conductivity-of-gases/

I'm sure they would have used air if it was even close in value to H or He.

Mark

Hi Mark,
I got that information from Ortofon. Also, Andy Bee reminded me of that with his post in the Helium shortage thread. Floka also confirmed it. That one use dry air, he added, is important. He is better. But using air is, nevertheless, much better than not cooling actively.


http://www.etec.dk/foto/ortofon/Cutterhead-txt4.jpg


- Andrew

[concretecowboy71]

The Neumann manual states two things I have always thought were interesting.

1) Helium cooling was considered optional at some point. The manual when talking about helium cooling always says (optional).

2) The manual also states that you shuld buy the lowest grade that you can get.

Helium here is currently costing me 160.00+ a tank and there is only one place that will sell it to me.

Am I really the only person having this issue? Maybe the Cleveland Clinic get all of it for MRI magnet cooling.

[Masterlabs]

The problem with non medical grade He is that it contains water which will rust the head over time.Check with your supplier to the He % of their non medical grade.My BOC supplier guarantees 99% He for the non medical, which is perfect for me at a 1/4 of the price.

[atmasphere]

Considering that the relative humidity of normal air is anywhere from 30-80 % from season to season, would a helium source blowing onto hot surfaces be more likely to cause rusting problems than still air?

Besides, how necessary is that helium tap? Just because my Westrex head has a tube that allows for forced helium cooling doesn't mean the head will burn up without it. I see excessive excursion long before I see heavy current draw.