Under what circumstances are sanitary ball valves easily corroded?

Under what circumstances are sanitary ball valves easily corroded? Sanitary ball valves have the ability to resist atmospheric oxidation (stainlessness), and also have the ability to resist corrosion (corrosion resistance) in media containing acids, alkalis and salts. The anti-corrosion ability of sanitary ball valves varies with the chemical composition of the stainless steel material, the use conditions and the type of environmental media. Such as 304 stainless steel butterfly valve, in a dry and clean atmosphere, it has absolutely excellent rust and corrosion resistance, but used in coastal areas, in the sea fog containing a lot of salt, it will quickly rust. The 316 sanitary ball valve performed well. The sanitary ball valve is an extremely thin, strong, dense and stable chromium-rich oxide film (protective film) formed on the surface of the stainless steel material to prevent the oxygen atoms from continuing to penetrate and continue to oxidize, thereby obtaining the ability to resist rust. Once this film is continuously destroyed for some reason, oxygen atoms in the air or liquid will continue to infiltrate or iron atoms in the metal will continue to separate out, forming loose iron oxide, and the stainless steel butterfly valve will continue to be rusted. The chromium content of general stainless steel is generally not less than 12%, and even as high as 18%. After adding chromium and other elements to the stainless steel, the fluorine-lined sanitary ball valve can change the performance of the steel, and it is easier to form a dense oxide protective film on the surface of the steel, thereby greatly improving the corrosion resistance of the sanitary ball valve.