On 19 Jan 2006 10:34:47 -0800, jim rozen
wrote:

In article ,
=?ISO-8859-1?Q?Nick_M=FCller?= says...

Don't tell me, that the pressure regulator is filled with acetone.

Somebody *always* says this.

They're right of course. The inlet stage of the regulator
has no liquid acetone in it.

Why doesn't the acetlyene decompose in the regulator then?

Basically because the passage dimensions are too small. The
mean free path length for them at room temperature is quite
long, they do not develop enough kinetic energy to get over
their activation curve to disassemble while inside the
regulator. The tank dimensions are much longer so there's
statistically a very good probability that one fast one will
light off the reaction.

Basically you are depending on boltzman statistics to keep
your O/A rig from going boom.

Jim

Thank you! That question has puzzled me for decades. It also
explains why the calcium carbide depth charges I once made did not go
boom at 30 feet but just kept sinking.