Oxygen tanks are cylinder-shaped. At the top of the tank there is an attached valve. If you do not plan to reuse the tank, it can be disassembled. However, if you want to completely disassemble the tank, it will need to be cut. Cutting the tank will allow you to use it for other purposes.
Connect an air hose to the valve on the oxygen tank. Partially fill the tank with air from a compressor.
Open the valve to allow the air to escape from the tank.
Place the adjustable wrench over the fitting for the valve. Turn the wrench counterclockwise to loosen the valve.
Remove the valve from the tank and set it aside.
Mark the ends of the oxygen tank with a felt tip marker where it will need to be cut.
Cut the cylinder on the mark with a band saw. If you do not have a band saw, use a metal cutting wheel.