So, I'm an electronics guy and this problem has me stumped. If there's a cylinder of gas at 150 Bar, and I have a regulator on that cylinder. I'm pumping gas from 150 Bar to Atmospheric Pressure. What pressure does the regulator need to be set at in order to get 15 Liters per minute as my flow rate? I'm not even sure exactly how to set up this problem. It's a bit embarrassing, but it got me on this forum. Thanks! PS: Also, just so we can add some extra calculus here: Assuming a single-stage regulator, at what rate would my flow rate drop off as gas is being released? I love a chance to use second derivatives. So, again assuming a single-stage regulator, after half an hour, what would the new flow rate be, of my 16 Liter tank which was originally at 150 Bar pressure and set for 15L per minute? PPS: REALLY, thanks for the help.