2. The braze fitting has High fluidity, molten copper has good fluidity, and can only be welded at the flat welding position. If one side butt welding is to be carried out at a spatial position, a backing plate must be added to ensure penetration and good forming.
3. The thermal expansion and cold contraction of the braze fitting is large, and the linear expansion coefficient of copper is large. The thermal expansion and cold contraction phenomenon is particularly obvious during welding, so the deformation after welding is large.