Stainless steel film of chromium oxide by reaction with the oxygen in air and even the small amount of dissolved oxygen in water. This passive film prevents further corrosion by blocking oxygen diffusion to the steel surface and thus prevents corrosion from spreading into the bulk of the metal. This film is self-repairing if it is scratched or temporarily disturbed by an upset condition in the environment that exceeds the inherent corrosion resistance of that grade. However, stainless steels may suffer uniform corrosion when exposed to acidic or basic solutions. Whether a stainless steel corrodes depends on the kind and concentration of
Corrugated stainless steel tubing and FAC tubing does not have a plastic sheath. On FAC tubing the corrugations are visible. CSST’s plastic sheath covers its corrugations. CSST is used as an alternative to the older standard “black iron” (steel) gas pipe. The inner stainless steel layer of typical residential CSST is .2 to .3 mm thick while the wall thickness of typical residential “black iron” gas pipe is 3 to 4 mm thick. CSST is more expensive than “black iron” gas pipe. However, CSST requires fewer joints, may be safer during earthquakes, and may be easier to install. CSST is alleged to have an