AMRAD at Hamvention

wb5mmb wb5mmb at
Sun May 13 11:05:05 CDT 2012

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.

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
>>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.  :)
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