There is a recent project I have been working on that requires the use of Isobutane as a propellant/solvent, so I have come up with a way to study the chemical compatibility of isobutane: I have a pressure chamber that I built from transparent PVC and opaque PVC with a tire valve as an inlet for air and isobutane: I use r600a refrigerant for isobutane (420 grams, 720 liters) I can put solid objects into the top of the chamber. I use anti-air loss tire valve connectors. The procedure is as follows: 1. connect r600a refrigerant canister to pressure chamber and wait a little bit. 2. remove the connection quickly. 3. connect air compressor to the pressure chamber and pressurize to 50 psi. 4. optional: remove the connection quickly. I know that the vapor pressure of Isobutane is about 43 psi, so I should see a liquid in the chamber, but I don't. Please this is making no sense to me.