Welding skills and methods of copper tube

The welding skills and methods of copper pipes are as follows:

(1) Use gas flame to heat the joint evenly until it reaches the welding temperature. When soldering, the joint can also be heated to the welding temperature by electric heating.

(2) Contact the joint heated to high temperature with solder to determine the joint temperature. If the solder does not melt, it means that the joint temperature has not reached the welding temperature, and it is necessary to continue heating the joint.

(3) If the solder can melt quickly, it means that the temperature at the joint has reached the welding temperature. You can continue to heat the joint to keep the temperature at the joint above the welding temperature, and add solder to the joint gap, and use the heat at the joint to melt the solder into the gap until the solder gap is filled. Never melt the solder directly with flame and coat it on the surface of the gap.

And (4) removing the heat source and stopping heating, so that the joint is cooled and crystallized in a static state, so as to avoid the influence of vibration on the brazing quality when the solder is cooled and crystallized. Clean up the residue at the brazed joint and brush it with varnish for protection if necessary.

Get ready.

(1) Clean the oxide film on the outer surface of the copper pipe joint and the inner surface of the pipe joint. Apply solder paste or liquid brazing flux evenly on the clean outer surface of the pipeline and the inner surface of the pipe fitting. When brazing copper tubes and copper tubes with copper-phosphorus flux or low silver-copper-phosphorus flux, there is no need to coat flux.

(2) Insert the copper tube into the pipe fitting, insert it into the bottom and rotate it appropriately to keep the gap even. If it is coated with flux, use a clean rag to wipe off the excess flux at the extruded joint.

Matters needing attention in copper tube welding:

1, when welding, wait for the solder to solidify before moving the copper tube, otherwise the welded part will crack. Welding can only be carried out after the refrigerant is completely discharged, otherwise the refrigerant will produce toxic phosgene when it meets an open flame, which is harmful to human body.

2, copper pipe welding need to use flame, gas cylinders should be placed upright, the distance from the open flame is more than 5 meters, so as to avoid fire accidents, welding torch and gas cylinders should be connected correctly.

3. When welding copper pipes, the construction should be carried out in a well-ventilated place. Construction personnel need to wear professional protective glasses, and there should be fire-fighting equipment at the welding site.