What is the procedure for purging air from a newly installed gas line?

The procedure for purging air from a newly installed gas line involves opening the gas valve and allowing gas to flow until a steady flame is observed. This method ensures that any air trapped in the line is expelled and replaced with gas. When the gas is flowing and a steady flame is achieved, it indicates that the line is now filled with gas and any residual air has been eliminated, reducing the risk of an explosive mixture within the gas line.

Proper purging is crucial in ensuring safe operation, as air mixed with gas can lead to dangerous combustion conditions. In practice, technicians will often use specific procedures and tools to monitor the gas flow and confirm that the air is adequately purged before any equipment is put into operation.

The other options do not align with safe or accepted practices for purging gas lines. Waiting 24 hours would not effectively clear air from the system. Vacuuming the line might not effectively remove all the air and is not a standard method used in gas line maintenance. Using a blowtorch to ignite gas is not a safe method and poses a significant risk of explosion and fire. Thus, the correct choice reflects the safest and most effective method to ensure the gas line is properly purged.