On Fri, 31 Oct 2008 14:53:19 +1100, "Grumpy"
wrote:

CO2 can be dangerous.

I spent a lot of time as an engineer in the brewing industry,and we worked
with it all the time. The 1000psi solenoid is pretty low as co2 can reach
1200 psi on a hot day. We used conventional steel pipe and flaged fittings,
but as you are only using small sizes flared stainless steel would probably
be appropriate.

Vent the room or you may kill someone

1200 PSI at hot room temperatures in a steel cylinder yes, but not
in a Cryo Dewar style bottle - for those the 300 PSI solenoid would be
plenty. And if you are getting it in bulk they will deliver in a big
truck-mount tank and pump it into your dewar.

Plus, most steel cylinders do not have a siphon inside for
delivering liquid CO2 for use. For an enviro chamber you will be
using the "Liquid" tap on the dewar, and counting on internal pressure
to deliver the product - might even have to pressurize the dewar with
shop air or Nitrogen to keep the flow constant. Or have an electric
heater inside to keep the pressure up.

-- Bruce --