Nitrox Scuba Tank

The most common (and cheapest) method of blending Nitrox is the partial pressure method. This involves adding pure oxygen to the tank first and then filling it with double-filtered air.  We all learned at school that oxygen is a highly inflammable gas. Consequently a Nitrox tank must be oxygen-cleaned, have an oxygen compatible valve, and be labelled with the distinctive green and yellow Nitrox band.  Typically Nitrox tanks are steel 12 or 15 litre cylinders with high-pressure DIN valves that are rated to 232 Bar.