While brazing medical-gas copper joints, a purge gas shall flow continuously to prevent the formation of copper oxide on the inside surface of the joint. What shall be used as a purge gas?

The most suitable choice for a purge gas when brazing medical-gas copper joints is nitrogen NF (medical-grade nitrogen). Nitrogen serves as an inert gas that effectively prevents oxidation of the copper surfaces during the brazing process. This is crucial, as copper oxide can compromise the integrity of the joint, leading to potential leaks or failures in the medical gas system.

Using medical-grade nitrogen ensures that the gas is free from contaminants that could adversely affect the quality of the brazed joint. Moreover, nitrogen NF is widely recognized and used in the industry for purging applications due to its non-reactive nature, making it an ideal choice for maintaining the purity and functionality of medical gas systems.

While argon and helium are also inert gases used in various welding and brazing applications, nitrogen NF is specifically preferred in this context for medical applications due to its availability and established safety standards in the medical field.