Using oxygen to purge copper tubing after brazing could cause an explosion.

Using oxygen to purge copper tubing after brazing could cause an explosion.

• A. True
• B. False
• C. Not advisable
• D. Only with pressure

Answer: (A)

Oxygen is a strong oxidizer, and when copper tubing is hot from brazing, any residual oil, grease, flux, or solvents inside the tube can ignite in an oxygen-rich environment. Purging with pure oxygen creates the potential for rapid combustion or a flash/explosion if a fuel source is present or a spark occurs. Because of this risk, using oxygen to purge is dangerous, so the statement is true. In practice, inert purge gases like nitrogen are used to displace air without providing an oxidizer, which is why purging with oxygen is avoided.

Oxygen is a strong oxidizer, and when copper tubing is hot from brazing, any residual oil, grease, flux, or solvents inside the tube can ignite in an oxygen-rich environment. Purging with pure oxygen creates the potential for rapid combustion or a flash/explosion if a fuel source is present or a spark occurs. Because of this risk, using oxygen to purge is dangerous, so the statement is true. In practice, inert purge gases like nitrogen are used to displace air without providing an oxidizer, which is why purging with oxygen is avoided.