10 Jun
2007
10 Jun
'07
2:19 p.m.
I do recall some computer equipment that had helium in
the enclosure. At least
that's what the labels said.
I have a DDC 7301 drive (same manufacturer as Guy's, but different model),
and it is definitely filled with helium. Well, it was filled with helium
30 years ago ...
The DDC maintenance manual says it requires oil-free 99.995% pure helium.
The preventive maintenance procedure indicates that the helium tank is
good for about 6 months (dropping from 2200psi to 300psi).
James Markevitch
11 Jun
11 Jun
11:18 a.m.
James A. Markevitch wrote:
Just a thought, but while He does leak out of just about everything,
unless something is leaking in I suspect its still He around 1 atm.
I do recall
some computer equipment that had helium in the enclosure. At least
that's what the labels said.
I have a DDC 7301 drive (same manufacturer as Guy's, but different model),
and it is definitely filled with helium. Well, it was filled with helium
30 years ago ...
The DDC maintenance manual says it requires oil-free 99.995% pure helium.
The preventive maintenance procedure indicates that the helium tank is
good for about 6 months (dropping from 2200psi to 300psi).
James Markevitch 
12:39 p.m.
On 11 Jun 2007 at 10:18, Mike Ford wrote:
Just a thought, but while He does leak out of just
about everything,
unless something is leaking in I suspect its still He around 1 atm.
It would seem that the partial pressure of He in the atmosphere is
much less than one atm, no? So, barring inward leaks, would not a
lot less than one atm. of He would be left inside?
Perhaps I've disremembered Dalton's Law or just hallucinated (seems
to happen more and more as I grow older) that I endured high school
physics?
Cheers,
Chuck
12:56 p.m.
Chuck Guzis wrote:
On 11 Jun 2007 at 10:18, Mike Ford wrote:
The docs that I've found on the helium replenishment is that you'll go
through a bottle of helium in about 6 months (when it drops from 3300psi
to 300psi). It's hooked up to the drive (there are fittings and such)
all of the time.
Fortunately, the drive I have (6200X) uses nitrogen and the person I got
it from said that they never replaced the nitrogen the entire time the
drive was in service.
--
TTFN - Guy
Just a thought, but while He does leak out of
just about everything,
unless something is leaking in I suspect its still He around 1 atm.
It would seem that the partial pressure of He in the atmosphere is
much less than one atm, no? So, barring inward leaks, would not a
lot less than one atm. of He would be left inside?
Perhaps I've disremembered Dalton's Law or just hallucinated (seems
to happen more and more as I grow older) that I endured high school
physics?
9:07 p.m.
From: "Chuck Guzis" <cclist at
sydex.com>
On 11 Jun 2007 at 10:18, Mike Ford wrote:
Hi Chuck
So long as the leak was small, there would be close to a vacuum inside.
So, as Chuck says much less than one atm.
If it was a large leak, it would be atmophere with no detectable He.
Dwight
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Just a thought, but while He does leak out of
just about everything,
unless something is leaking in I suspect its still He around 1 atm.
It would seem that the partial pressure of He in the atmosphere is
much less than one atm, no? So, barring inward leaks, would not a
lot less than one atm. of He would be left inside?
Perhaps I've disremembered Dalton's Law or just hallucinated (seems
to happen more and more as I grow older) that I endured high school
physics?
6403
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