Hi all, I am having trouble grasping the phenomenon on why the LPG tank freezes as you use up more and more of the gas inside. My understanding is this. Initially, the tank is full of liquefied gas, and as you use up the gas, the pressure inside the tank drops, and since the temperature inside the tank did not change, the liquid should flashes into gas. But I don't understand how this can make the tank itself become cold? Is it maybe because the liquid inside the tank used the surrounding energy to change into gas? Thanks.