When brazing medical-gas copper joints, what type of gas should flow continuously to prevent copper oxide formation?

When brazing medical-gas copper joints, using oil-free, dry nitrogen as a continuous flow is crucial because it helps to prevent the formation of copper oxide during the brazing process. Copper easily oxidizes at high temperatures, which can lead to significant issues in medical gas systems, such as reduced integrity of the joints and potential contamination of the gas being transported.

Dry nitrogen acts as an inert atmosphere that keeps oxygen away from the heated copper joint. This is essential because if copper oxide forms, it can weaken the joint, leading to leaks and other reliability issues in the medical gas delivery systems. Using an oil-free nitrogen supply ensures that no contaminants enter the brazing area, further safeguarding the integrity of the joint.

Other gases, while they may have specific applications in welding or brazing, do not offer the same degree of protection as nitrogen in this context. For example, while argon is used in various welding processes due to its inert character, it is not typically used for brazing copper in medical gas applications.