A brief analysis of the welding process of copper and aluminum pipe butt welding machines

Looking atCopper and aluminum pipe butt welding machineBefore welding process, let’s talk about why copper and aluminum tubes are used.

Existing shut-off valves used in household air conditioners are all copper valves, which are directly connected with aluminum pipes. Under the influence of water and air, electrochemical reactions will occur and cause corrosion. Especially in humid coastal areas, the air contains high moisture and salt content, which is more likely to cause the aluminum to be corroded, forming pits or small holes, thus affecting use.
The solution is to weld a section of copper pipe, or copper-aluminum pipe, at both ends of the aluminum pipe, so that the copper pipe is still in contact with the copper valve during installation to solve the corrosion problem. And it makes the connection between the connecting pipe and the valve body reliable; there is no need to change the existing outdoor machine production process. In addition, the price of aluminum pipes is 4 times lower than that of copper pipes. Substituting aluminum for copper can save 90% of copper, reduce temperature loss, improve the insulation effect, and make it easier to achieve energy saving.

Analysis of copper and aluminum pipe welding process

Since the butt welding of copper and aluminum tubes is mainly at the ports of the copper tube and the aluminum tube, only the fusion shape near the ports of the two tubes needs to be considered. The port of the copper tube is processed into a tapered shape, while the aluminum tube remains cylindrical, as shown in the figure below. During the welding process, the copper tube advances towards the aluminum tube; when the copper tube is inserted into the aluminum tube and comes into contact with it, the welding circuit is connected, and a large current is generated between the copper and aluminum tubes, causing the contact surface of the two tubes to heat up.

A schematic diagram of the welded copper-aluminum pipe joint is given.

The main advantage of this butt welding method is that
1. During the advancement process, the outer surface of the copper tube rubs against the inner surface of the aluminum tube, which can wipe off the dense oxide film on the aluminum surface and expose pure aluminum metal, thus improving the welding strength.
2. The copper-aluminum pipe has a large fusion surface and a strong combination; it is easy to implement and has low production cost; it is not limited by the overall shape of the pipe; it is well formed in one go and has a beautiful appearance; and the equipment productivity is high.
3. Especially suitable for refrigeration fields such as refrigerators and automobile air conditioners.

Wuxi Xinxing Welding Equipment Factory has been engaged in resistance welding machines for 29 years. Its core technical products include: semi-automatic butt welding machine, pneumatic-flash butt welding machine, multi-strand wire welding machine, foot pedal spot welding machine, pneumatic spot welding machine, Medium frequency spot welding machine, row welding machine mesh welding machine, resistance automatic welding machine, energy storage welding machine, copper rod aluminum rod disc circular welding machine, auto parts spot welding machine, sheet metal spot welding machine, home appliance hardware spot welding machine, small electrical appliance spot welding machine,Copper row copper pipe welding machine, nut spot welding machine, stainless steel welding machine, foil strip spot welding machine, aluminum spot welding machine, multi-head spot welding machine, bag cage spot welding machine, mesh welding machine, ton rack welding production line, resistance automatic welding machine, brazing machine, diffusion welding machine, projection welding machine, seam welding machine, wire and cable optical cable supporting equipment, etc., reaching more than 300 kinds. If you are interested in our welding equipment, please contact us.