If you are building a new pipeline, as a section is completed, it is typically hydrotested. After hydrotest, many owners will dry the section and purge the atmosphere with Nitrogen. Often, these lines are not completely dry and the combination of water, oxygen and bacteria, can have a negative corrosion effect on this new steel, even if the line has a Nitrogen blanket. Maintaining the Nitrogen can take time and be expensive, espe-cially if the line will not be commissioned for a period of time.
Existing lines can be preserved by VCI after cleaning.