How much of a 10" natural gas main pipe must be purged with inert gas before work can begin?

For a natural gas main pipe, purging with inert gas is a critical safety step to ensure that any flammable gases are removed before work begins. The correct answer emphasizes that purging can occur over any length of the pipe that will not involve significant risk of flammable gas exposure.

When preparing a gas main pipe for maintenance or repairs, the key concern is safety and preventing potential explosions or fires caused by the presence of natural gas. The purpose of purging is to displace the combustible gas in the section where work is to be done.

Purging the entire installation is not necessary in most cases, as it can be done efficiently over just the specific section being worked on. This targeted approach keeps both the operation efficient and safe, minimizing the amount of gas that must be displaced while still achieving the necessary safety standards.

In summary, while it is essential to purge before work, only the section where work will be performed is generally required to be treated, given that proper purging techniques are followed to ensure that hazardous gases are adequately removed.