Copper tube welding
Copper tube welding generally uses 50%, 45%, 35% or 25% silver welding rods, all of which need to have good mobility and the assistance of flux. The flux used should be a flexible mixture or powder.
Copper tube welding uses a carburizing flame. The welding sequence is:
(1) Before heating, apply the flux to the part to be welded.
(2) Heat the inserted copper tube and sleeve, and move the flame nozzle back and forth between the two points continuously. Do not allow the flame to directly contact the flux. The temperature when heating the steel tube is slightly higher than that when heating the copper tube.
(3) When the copper tube is heated and the flux melts into liquid, immediately place the preheated welding rod on the welding point. As soon as the welding rod begins to melt, move the flame nozzle back and forth between the two until the solder flows into the gap between the two tubes.
(4) Move the flame away, let the solder contact the welding point, and keep it for a few seconds before removing it. If it is suspected or found that there is still space between the two tubes, you can heat it again and move the flame nozzle continuously between the two points. If necessary, add a small amount of solder.
