Anyway it seems like there has to be more to it than just pressure. The bulk of the acetylene is dissolved in acetone sitting in the clay in the bottom of the tank, and bubbles out into the space above the clay. When I turn on the valve, the pressure gauge tells me there is approx 200psi of gas pressure if the tank is full. That gas has to be acetylene, in a free gaseous state. And it doesn't go boom.
Those tanks are completely filled with porous material.
There's no oxygen inside the tank, you dunderhead!