China Factory Copper Aluminum Connecting Pipe Suppliers for HVAC Systems【Friction & Explosion Welding】
Product Overview
A copper-aluminum connecting pipe, also known as a "copper-aluminum composite pipe" or "copper-aluminum transition pipe," is a specialized component used to connect copper and aluminum pipes in refrigeration, air conditioning, and heating systems. It's made of copper and aluminum at each end, respectively, and permanently joined in the middle using reliable processes such as friction welding or explosion welding.
Its core value lies in solving the electrochemical corrosion problem that easily occurs when copper tubes and aluminum tubes are directly connected due to different potential differences, while providing an economical and efficient system connection solution.
Product Structure & Manufacturing Process
Structure
- Copper End: Used to connect the original copper pipe part of the system (such as compressor, valve and other interfaces).
- Aluminum End: Used to connect aluminum pipe sections in the system (such as evaporator and condenser coils).
- Connection Interface: It is the technical core of the entire product and requires firm connection, good sealing, low resistivity and corrosion resistance.
Main Manufacturing Process
- Friction Welding: This is currently the most mainstream and reliable process. High-speed rotation causes the contacting surfaces of copper and aluminum to reach a plastic state under frictional heat and pressure, achieving a metallurgical bond at the molecular level. Advantages include high weld strength, the absence of flux, and the absence of pores and slag inclusions.
- Cold Pressure Welding: At room temperature, huge pressure is used to make metal atoms combine and form a connection.
- Explosive Welding: Explosive energy of explosives is used to drive metal plates to collide at high speed to achieve bonding. It is mostly used for plates and less used on pipes.
Product Features
- Effectively prevent electrochemical corrosion Root Cause: Copper and aluminum form a "copper-aluminum galvanic cell" in the presence of an electrolyte (such as moisture in the air or residual water in the system). The aluminum, acting as the anode, rapidly corrodes, leading to leaks at the joints. The copper-aluminum connecting pipe utilizes a specialized welding process to isolate the two metals from the electrolyte, thereby eliminating the path for electrochemical corrosion.
- Excellent sealing and connection strength The strength of high-quality friction welding joints can approach or even reach the strength of the parent material (aluminum or copper), and can withstand vibrations and pressure fluctuations during system operation, ensuring long-term leakage.
- Reduce costs and reduce weight Aluminum has a much lower density than copper and is therefore cheaper. In equipment such as air conditioners, the extensive use of aluminum heat exchangers, along with a small amount of copper-aluminum connecting pipes, can significantly reduce material costs and reduce product weight.
- Good processing performance Both the copper and aluminum ends retain the good ductility and weldability of their respective metals, making it convenient for on-site flaring, bending, and welding with other components.
- Extend system life By eliminating corrosion and leakage at the connection points, the long-term stable operation of the entire refrigeration/heating system is guaranteed, and the maintenance frequency and cost are reduced.
Main Application Areas
Copper-aluminum connecting pipes are key components for the following industries and products:
- Household air conditioners: Standard configuration for connecting copper pipes of outdoor unit to aluminum heat exchanger of indoor unit.
- Refrigerators/Freezers: Connect the copper tubing from the compressor to the aluminum tubing from the evaporator.
- Automobile air conditioning system: Copper pipes or components connecting the aluminum condenser and evaporator to the system.
- Central air conditioning: In modules where aluminum heat exchangers are partially used.
- Solar water heaters and other heat exchange equipment.
Technical Parameters
| Copper tube specifications | Air conditioning P-number | Air conditioning model | Copper pipe diameter (mm) | Corresponding English specifications |
|---|---|---|---|---|
| 6-10 | Small 1horsepower/1 horsepower/Large 1horsepower ；Variable frequency small 1.5 horsepower/1.5horsepower/large 1.5 horsepower | KF23/KF25/KF26/KF27/KFR23/KFR25/KFR26 | 6(6.35)*10(9.52) | 2-3 points |
| 6-12 | Small 1.5 horsepower/1.5 horsepower/Large1.5 horsepower；Small 2 horsepower/2 horsepower/Large 2horsepower | KF32/KF33/KF35/KF36/KF46/KF48/KF50/KF51/KFR32/KFR33/KFR35KFR46/KFR48/KFR50 | 6(6.35)*12(12.7) | 2-4 points |
| 6-16 | 3 small horses/3 large horsesVariable frequency 3 horsepower | KF60/KF70/KF71/KF72/KFR61/KFR70/KFR71 | 6(6.35)*16(15.87) | 2-5 points |
| 10-16 | 3 small horses/3 large horsesVariable frequency 3 horsepower | KF60/KF70/KF71/KF72/KFR61/KFR70/KFR71 | 10(9.52)*16(15.87) | 3-5 points |
Frequently Asked Questions
What is a copper-aluminum connecting pipe?
It is a specialized composite transition pipe with a copper end and an aluminum end, permanently joined in the middle using friction or explosion welding. It is used to connect copper and aluminum pipes in refrigeration, heating, and air conditioning systems.
How does this pipe prevent electrochemical corrosion?
Direct contact between copper and aluminum in the presence of an electrolyte causes the aluminum to act as an anode and corrode rapidly. The specialized welding process of the copper-aluminum connecting pipe isolates these metals from the electrolyte, effectively eliminating the path for electrochemical galvanic corrosion.
What is the benefit of using friction welding for these pipes?
Friction welding creates a strong molecular metallurgical bond between copper and aluminum under frictional heat and pressure. It requires no flux, prevents pores or slag inclusions, and results in a joint strength that approaches the parent metals, successfully withstanding system vibrations and pressure.
Can these pipes be easily processed and installed on site?
Yes. Both the copper and aluminum ends retain their respective metal ductility and weldability, making it highly convenient for installers to perform on-site flaring, bending, and welding with other system components.
How do copper-aluminum connecting pipes help reduce costs?
Since aluminum is lighter and significantly cheaper than copper, using aluminum heat exchangers combined with copper-aluminum connecting pipes allows manufacturers to greatly reduce material costs and overall product weight while maintaining system reliability.