AMRAD at Hamvention

Robert E. Seastrom rs at
Sun May 13 16:57:38 CDT 2012

Did you tell 'em to man up and be glad it's not HF?  :)


wb5mmb <wb5mmb at> writes:

> 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
>     WB5MMB
> 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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