There is one thing that bothers me a lot. Recently our lab ordered a Nitrogen cylinder from AirGas. When I am using it, I understand that when the nitrogen comes out, the pressure equals the delivery pressure, which is set by me as 65psi. However, when the nitrogen comes out of it, the pressure will get smaller until it reaches equilibrium with the ambient pressure (1atm). How do I know the pressure distribution after nitrogen comes out? Can I see it equals 1atm in a very very short distance?