Definition - What does Nitrogen Purge mean?
Nitrogen purging is an air-cleaning method commonly used in the oil and gas industry. It involves displacing an undesirable or hazardous atmosphere with relatively inert nitrogen gas. In other words, nitrogen is used to push out other fluids and gases, such as water and oxygen, to help create a more stable, noncombustible climate.
Corrosionpedia explains Nitrogen Purge
The purpose of doing a nitrogen purge is to remove combustible gases to prevent the creation of a potentially unstable and ignitable environment. Nitrogen gas is suitable for this purpose because it lacks oxygen and possesses relatively low reactivity. While nitrogen is not an inert gas by definition, it is typically referred to as inert due to its strong, triple bond stability.
Some of the most critical systems that are regularly purged with nitrogen gas include process vessels, oil tankers, oil and gas pipelines and storage tanks. There are several different types of nitrogen purging methods, each lending themselves to various applications; these include:
- Pressure transfer of liquids
- The pressure-hold vacuum method
- Displacement purging
- Dilution purging