Question: How and when is a nitrogen slug used in purging?
Answer: A nitrogen slug is a quantity of inert gas that can be initially injected when purging the air or gas from a section of piping. The procedures work like this:
- To purge air from piping, natural gas is used immediately following the nitrogen slug injection to push out the slug and air ahead of it.
- To purge natural gas from piping, air is used immediately following the nitrogen slug injection to push out the slug and gas ahead of it.
Tip: For safety, the purpose of purging with an inert gas (nitrogen) is to eliminate the formation of a combustible gas-air mixture within the pipe. Ensure that all purging procedures are followed in accordance with the company O&M Manual.