For what reason must containers that have been in a fire be requalified?

Containers that have been in a fire must be requalified primarily to verify structural integrity. During a fire, the intense heat can cause significant changes to the metal structure of the container, including warping, weakening, and even compromising the safety of its materials. This alteration may not be visible to the naked eye but can lead to catastrophic failure if the container is put back into service without proper evaluation.

Requalification involves a thorough inspection process to assess the container's ability to safely contain propane under pressure. This is critical not only for the functionality of the container but also for ensuring the safety of its operation in the future. Therefore, requalification focuses on confirming that the structural integrity of the container remains intact and capable of handling the demands placed on it.