ABSTRACT
Atmospheric corrosion refers to the corrosive action that occurs on the surface of a metal in an atmospheric environment. It occurs when the surface is wet by moisture formed due to rain, fog, condensation, dew, precipitation, and relative humidity. Atmospheric corrosion occurs at pipe bodies, pipe supports, pipe fittings, above-ground pipe transitions, valve and valve bodies, and so on. To prevent all forms of atmospheric corrosion, there is a need to specify and consider the conditions of exposure at the design stage. Atmospheric corrosion evaluation includes a visual inspection of all above-ground metallic facilities. Most atmospheric corrosion can be prevented by maintaining relative humidity below 60 percent. The normal considerations of design against corrosion apply to atmospheric exposure. Parts should be designed to avoid trapping moisture in hollow sections, crevices, or joints, all of which may lead to locally increased time of wetness.
