Hi! I am George Xanthopoulos. The gaseous substance: diatomic molecules of fluorine is the most powerful oxidising agent known, and has an electronegativity of 3.98 paulings. Fluorine is the most reactive oxidising agent amongst diatomic molecules of oxygen, diatomic molecules of chlorine, chlorine tri fluoride, chlorine pentafluoride, etc. Type 316 stainless steel comprises an alloy of iron, chromium, and nickel, and these metallic constituents of type 316 stainless steel will react with, and reduce diatomic molecules of fluorine; for instance, it is deemed necessary to passivate the internal walls of a pressure vessel for fluorine service. The 316 stainless steel pressure vessel designed to be filled with compressed fluorine to an operating pressure of 200 bar (gauge pressure) or 20 MPa (gauge pressure) at a temperature of 298.15 Kelvin or 25 degrees Celsius must first be passivated by the following method: the 316 stainless steel pressure vessel must be filled with compressed fluorine over four incremental stages up to maximum operating pressure of 200 bar (gauge pressure), starting at 50 bar, then 100 bar, then 150 bar, and then 200 bar, all gauge pressure. This method of passivation of 316 stainless steel will ensure that the respective fluorides of iron, nickel, and chromium formed will be a uniform and cohesive layer, and will prevent any further oxidation of the parent metal alloy.