Q. Show Corrosion Loss?
Additional metal thickness must be added, to compensate for anticipated loss due to metal reacting with the environments to which it is subjected, including cleaning operations, shutdowns, etc.
Internal corrosion loss due to the process conditions affects all pressure containing parts. Internal structural parts may experience corrosion loss on more than one surface. Bolted parts are frequently constructed of different materials, and need to be assessed separately.
External corrosion may result from exposure of bare metal to the atmosphere, especially in coastal areas and under insulation. Other equipment operating nearby may influence corrosion (e.g. cooling towers).