Which NFPA code covers the purging of gas piping boundary conditions criteria and procedures?

The NFPA code that specifically addresses the purging of gas piping boundary conditions criteria and procedures is NFPA 54. This code outlines the safety requirements for the installation and maintenance of gas piping systems. The purging process is critical as it ensures that no hazardous gases are present in the system during the installation and repair work, which is essential for safety.

Each version of the NFPA 54 code may have updates or changes to procedures, but the key point here is understanding that purging is a critical element addressed in the NFPA 54 series. The correct reference based on the current structure of the codes would be found in the most recent version, which details the latest requirements and best practices for safely purging gas piping systems.

This is why the choice indicating the relevant NFPA 54 version directly correlates with standards affecting gas piping safety and includes stipulations regarding methods and conditions necessary to ensure safe purging can be conducted. The other choices, although referencing the NFPA 54 series, do not correspond to the most up-to-date practices or may refer to content not specific to purging procedures as effectively as the correct selection.