air tank question?

i have a medical regulation oxygen cylinder it is a dark green i am wondering if i can turn it into a compression cylinder by drilling into it would this compromise the tanks integrity please respond. sorry if i left anything out, fidgety2

Those tanks are aluminum and designed to take around 3,000 psi. Poking a hole in it will reduce the max psi some, but not as much as you would think. You didn't indicate operating pressures or any other details such as the size of the holes you'd be drilling, which would allow us to better help you.