Air filling station flash (or any animation) application

I need a flash (or any animation product) desktop application that simulates filling scuba (or any other high pressure air) tanks. The application will also have to calculate pressure changes during the transfer process. We will start with something simple such as filling from a bank (several) large tanks pressurized to 5000psi filling a small tank to 3000psi without any stops. There will simply be a couple of animated pressure guages and on/off valves. I need the "flow" of air to be animated during the filling process. Attached is a visio drawing of what the final product will look like in a very rough draft. This application will then develop to allowing the users to fill from multiple sources. This will be more complicated because the "target" tank will then have different levels of gas mixes. The program will have to calculate them during the process.