1. Attach a reducing valve and flow meter to the nitrogen gas cylinder.
2. Use a copper tube to direct the piping material and attach a flow meter to the cylinder.
3. Place a seal in the gap between the piping material and the inserted Nitrogen copper tube to prevent the flow of Nitrogen gas.
4. When the Nitrogen gas is flowing, be sure to keep the end of the tube open.
5. Adjust the flow rate of the Nitrogen gas so that it is less than 0.05 m3 / Hr or 0.02 MPa (0.2kgf / cm2) with the reducing valve.
6. After performing the steps above, keep the Nitrogen gas flowing until the tube cools to one of the end points. (at a temperature where it can be touched by hand).
7. After welding, completely remove the flux.
