1. What is a Copper Tube?
A Copper Tube is a seamless pipe manufactured through pressing and drawing processes. Known for its light weight, excellent thermal conductivity, and high corrosion resistance, it is a premier choice for the electrical, electronic, and HVAC industries.
Core Classifications
By Shape: Round tubes and Shaped tubes (including oval, square, rectangular, triangular, hexagonal, spiral, inner/outer rib, and plum blossom shapes).
By Production Method: Extruded, drawn, welded, flexible (hoses), and semi-rigid tubes.
By Alloy Composition: Red copper (pure), brass, bronze, and cupronickel tubes.
By Application: Condenser tubes, air conditioning tubes, waveguide tubes, aerospace tubing, and antenna tubes.
2. Primary Manufacturing Methodologies
A. Extrusion Process
Operators use a copper tube extruder to force the material through a die. This method ensures a uniform density distribution and consistent wall thickness, significantly enhancing the tube’s pressure resistance.
B. Continuous Casting and Rolling (CCR)
This process integrates casting and rolling into a single automated line. The system pours high-temperature liquid copper into a continuous casting machine to produce a billet, which then enters a soaking furnace for temperature maintenance before immediately moving into a hot continuous rolling unit.
Advantages: It eliminates the traditional cooling and reheating cycles, reducing labor costs, increasing metal yield, and saving energy.
C. Up-Drawing Method
The hallmark of the up-drawing method is the production of “oxygen-free” copper (oxygen content below 10 ppm).
Technical Execution: Throughout the melting and molding stages, operators use charcoal reduction and flake graphite covering to isolate oxygen. At high temperatures, the charcoal deoxidizes the molten copper, ensuring a high-purity final product.
3. Technical Requirements for Processing
Design Compliance: Fabricate all pipelines strictly according to design drawings. Ensure all shapes and dimensions meet specified requirements.
Deformation Control: Maintain diameter changes at the cut point within 2% of the standard diameter. Ensure the fracture is free of flash or burrs.
Surface Integrity: Degrease and decontaminate all fittings. Both internal and external surfaces must be smooth and free of oil, scars, copper shavings, or scale.
Welding Protection: Fill the tube with nitrogen during welding to prevent oxidation. After welding, clear the interior using 2.8–3.0 MPa dry compressed air.
4. Specialized Processing Capabilities
Our facility performs the following precision operations on small-diameter tubing:
End-Face Finishing: Precision cutting, grinding, and sharpening.
Forming: Expansion, necking (closing), bending, and multi-station stretch forming.
Structural Modification: Side-surface processing and porous wall machining for hollow products.
Assembly: Specialized welding, assembly, and industrial polishing.
5. Standard Operating Procedure (SOP): Cutting & Deburring
Step 1: Precision Cutting
Preparation: Use a tube cutter, a calibrated ruler, and positioning blocks. Measure the required length and secure the positioning block.
Execution: Fix the copper tube in place before engaging the cutter. Feed the blade evenly to ensure a flush, non-deformed cut.
Batching Rules:
$\Phi \le 12\text{mm}$: Operators may cut multiple tubes simultaneously (up to 10).
$\Phi > 12\text{mm}$ or Length $< 60\text{mm}$: Cut each tube individually.
Safety: Do not wear gloves during the cutting operation to prevent entanglement.
Step 2: Deburring and Cleaning
Mechanical Finishing: Immediately debur the ports after cutting using a wire sanding machine.
Speed Control: Adjust the frequency converter based on the tube diameter to optimize the machine’s rotational speed.
Pneumatic Cleaning: After deburring, use 2.8–3.0 MPa dry compressed air to blow away all copper chips and debris from both the interior and exterior of the tube.
Contamination Prevention: Operators should wear gloves during deburring to prevent hand oils or skin particles from entering the tube.