AMRAD at Hamvention

Mike O'Dell mo at
Sun May 13 14:24:01 CDT 2012

Yeppir - "catastrophic reconfiguration" at 3200 psi
is likely quite impressive, assuming you are far
enough away to survive it.

just a single 2200psi O2 cylinder suddenly losing
it's valve makes a spectacular a mess, and the one I saw was just
from energetic acceleration of the bottle as a simple rocket.

Even when i "understand" the physics, the massive dynamic range
of Natural Forces is certainly beyond my meager comprehension.

i know a guy who designs connectors for mating power,
hydraulic, and fiber umbilicals to boxes that get deployed
on the bottom of the ocean. he says he never gets over
how badly the water wants inside when there's an 8,000 psi pressure 
difference between inside and outside.


On 5/13/12 12:05 PM, wb5mmb wrote:
> I seem to remember photos of a tube trailer that disassembled its self
> in a compressed gasses safety course I took once. I have talked to a
> couple of people who worked with H2 at gas and chemical plants and they
> hated it with a passion.
> Sandy
> At 11:48 AM 5/13/2012, Mike O'Dell wrote:
>> D'OH!, i have seen the tube trailers and seen the legends.
>> 3200 PSI or so. "The look of real steel!"
>> found this in passing.....
>> -mo
>> On 5/13/12 8:31 AM, Robert E. Seastrom wrote:
>>> Mike ODELL<mo at> writes:
>>>> A big issue with H2 tankage is that embrittlement is a serious
>>>> problem which is magnified by the high pressure need to get much H2
>>>> a given volume.
>>> Why didn't I think of that? Answer: I only think about hydrogen
>>> embrittlement when I've got an electrode holder in my hand and am
>>> reaching for the E7018 rather than the E6010 or 6011. So I only
>>> associate it with high temperatures. Funny how high pressure makes
>>> the same thing happen.
>>>> I suspect that makes cylinder re-use a rather riskier proposition,
>>>> enough so that it probably wrecks the usual cylinder gas economics.
>>>> Most places I know of that really use externally supplied H2 take it
>>>> as a cryo-slurry because of the volumetric efficiency of storage and
>>>> transport.
>>> But folks take delivery in tube trailers too. You'd think they'd
>>> suffer from the same issues. Hydrogen damages both steel and aluminum
>>> - what are the tube trailers made out of?
>>> I know the valves for He are "special" and not just with the outlet
>>> threading (that's connector conspiracy for a good reason, don't want
>>> to hook up dry nitrogen to the medical oxygen line lest you have a
>>> hospital full of dead people). Is it the tanks themselves that you'd
>>> be more worried about? Maybe they just don't last "forever" and need
>>> to be aged out - I've fairly routinely gotten pool tanks for less
>>> aggressive stuff that had ICC approval stamps instead of DOT and first
>>> hydro test stamps that were in the 1930s.
>>>> Btw - it was NASA that figured out how to slurry H2 because that's the
>>>> only way to carry enough to actually use it fuel. Even pure LH2 has
>>>> crappy
>>>> density compared to slurry. The most amazing part is that it's done
>>>> easily with a catalyst
>>>> instead of insane pressure and the slurry is far more stable and
>>>> flows better
>>>> In the fuel lines than pure LH2.
>>>> Just one more area of technology that barely existed at all before
>>>> Project Apollo -
>>>> Producing, handling, and using cryogens in industrial quantities.
>>> Too cool for the 50s, had to wait for the 60s. I'm hip. :)
>>> -r
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