• If the nitrogen gas does not pass through the tubes during welding, a film of oxidized material (scale) will form on the inner surfaces of the tubes. The presence of such a film in the system will adversely affect the operation of the refrigerant system valves and compressor and will prevent the system from functioning normally.
• To prevent this from occurring, nitrogen gas is passed through the pipes while welding is in progress.
This process of replacing the air in the tubes with nitrogen is called “blowing the nitrogen gas”.
This is the basic method used for welding work.
1. Nitrogen gas must be used. (Oxygen, carbon dioxide and fluorocarbons cannot be used)
2. Be sure to always use a pressure reducing valve.
