Zhejiang Jingliang Copper-Tube Products Co., Ltd

Custom Copper Square Tube

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30+YEARS OF
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About Us

A Reliable Partner of the Copper Tube Industry

Zhejiang Jingliang Copper-Tube Products Co., Ltd established in 1994, is China Copper Square Tube Manufacturers and Custom Copper Square Tube Suppliers, has been deeply involved in the copper tube industry for over three decades. The company primarily produce various specifications of products such as copper tubes, brass tubes, copper square tubes, fin copper tubes, copper capillary tubes, condenser copper tubes, copper evaporator tubes, and conductive rods, which are of quality and have earned the trust and acclaim of customers both domestically and internationally.

Wide Applications:

These products are widely used in various fields including air conditioning, refrigeration, heat exchange, sanitary ware, automotive, machinery, electric furnaces, and chemical industries.

Convenient Transportation:

Strategically located in Tangpu Town, renowned as the “home of copper tubes” in East China. Our company enjoys a prime location, adjacent to the Shangsan Expressway and National Highway 104, and is conveniently situated just over 70 kilometers from Hangzhou and Ningbo, ensuring easy accessibility and a business position.

Strong Financial Resources:

With its strong financial resources and advanced copper tube processing technology, our company holds an advantageous position in market share, brand value, technological content, and product quality, becoming a preferred supplier for many listed groups.

Large Scale Production:

The company occupies an area of over 20,000 square meters, with a construction area of 12,800 square meters. In 2022, our annual production exceeded 7,500 tons, with a value output of up to 450 million yuan, demonstrating our strong production capacity and market competitiveness.

Comprehensive Industry Chain:

Jingliang has now developed into a complete industrial chain integrating smelting, extrusion, drawing, precision rolling, and annealing. It has been awarded multiple honors, including "Top Ten Copper Tube Enterprises" and "Leading Taxpayer in the Copper Tube Industry".

Smart Manufacturing:

Jingliang Copper-Tube Products will better integrate the concept of factory construction into its corporate development strategy, insist on refining technology and polishing products more finely, and the future of "intelligent manufacturing".

Genuine Cooperation:

Zhejiang Jingliang Copper-Tube Products Co.,Ltd warmly welcomes friends from all walks of life to visit and offer guidance. We look forward to joining hands with you to create a brilliant future together.

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Industry knowledge

Copper tubes are the "blood vessels" of the refrigeration system, mainly used in condensers, evaporators and connecting pipelines. Its high thermal conductivity (with a thermal conductivity coefficient of approximately 400 W/m·K) enables rapid heat transfer, enhancing the energy efficiency ratio of air conditioners and refrigerators. The promotion of environmentally friendly refrigerants such as R410A has further driven the development of copper tubes towards high pressure resistance, thin-walled and lightweight. Industry standards such as ASTM B280 (Copper Tubes for Air Conditioning) have strict regulations on indicators such as cleanliness and tensile strength to avoid refrigerant leakage and system blockage.

How to control wall thickness tolerance and straightness during copper square tube extrusion

Wall thickness tolerance control: precise control from source to forming
During the extrusion forming process of copper square tube, the key to controlling wall thickness tolerance lies in three aspects:
1. Material purity and pre-treatment control
Zhejiang Jingliang uses high-purity copper ingots as raw materials, and uses an independent smelting system for purity screening and homogenization, effectively reducing inclusions and grain segregation, and providing a stable base for subsequent forming.
2. Mold design and temperature control
The matching accuracy between the inner hole and the core rod of the extrusion die is an important factor in determining the uniformity of wall thickness. Zhejiang Jingliang uses its own mold processing center, high-precision CNC processing and CAE simulation technology to ensure the coaxiality and wear resistance of the mold. At the same time, the control of extrusion temperature is also very important-through a multi-point temperature control system, the metal flow is ensured to be uniform, thereby avoiding wall thickness deviation caused by uneven flow rate.
3. Online monitoring and intelligent adjustment
Relying on the "intelligent manufacturing" strategy, Zhejiang Jingliang introduced an online laser detection system for wall thickness to achieve real-time monitoring of the production process, and combined with a closed-loop feedback system, automatically adjust parameters such as extrusion force and feed speed, so as to stably control the wall thickness tolerance within ±0.05mm to meet high-precision industrial needs.
Straightness control: coordination and unification of mechanical precision and tension balance
Poor straightness of copper square tubes is common in the cooling or stretching process after extrusion, which can easily lead to defects such as bending and warping of the tube, affecting assembly accuracy and service life.
1. Multi-axis straightening technology
Zhejiang Jingliang uses a multi-set straightening wheel straightening system to correct the initial extrusion offset through multi-point fine-tuning to ensure that the shape of the square tube remains vertical and flat.
2. Drawing tension control
In the continuous drawing process, the system adjusts the speed difference at both ends in real time through a tension balance algorithm to avoid "drag" or "too loose" phenomena causing deformation of the tube body and improve the overall straightness stability.
3. Precision cooling system
The cooling process after extrusion adopts a circulating water cooling system to ensure that the cooling rate of the copper tube is consistent along the length direction, reducing the bending deformation caused by thermal stress.
Through the above measures, the straightness of the copper square tube produced by Zhejiang Jingliang can be controlled within the range of ≤1mm per meter, and it is widely used in scenes that are extremely sensitive to deformation, such as air conditioning heat dissipation pipes, mechanical structural parts, and electrical wiring systems.

What problems may copper square tubes encounter during welding, and how to avoid them

Common problems in copper square tube welding
1. Oxidation problem
Copper is easy to react with oxygen in the air during high-temperature welding to form an oxide film, which affects the bonding strength of the weld and leads to quality problems such as cold welding, pores, and slag inclusions. In particular, the edges and corners of the square structure are more likely to form heat accumulation, which aggravates oxidation.
2. Thermal deformation
The high thermal conductivity of copper leads to rapid conduction of welding heat, making it difficult to maintain a stable molten pool temperature locally, which easily causes uneven weld width or burn-through. At the same time, the cross-section of the copper square tube is irregular, and it is easier to produce thermal stress concentration than the round tube, resulting in deformation problems such as twisting and warping after welding.
3. Difficulty in filling
When welding copper square tubes, especially at corners or T-shaped connections, it is difficult to control the gap between the welds, and it is not easy to fill them completely, which can easily cause weld nodules or undercuts.
4. Welding cracks
If the thermal cycle is not properly controlled or the cooling is too fast during welding, cold cracks are likely to form at the joints, especially for high-strength copper alloy square tubes.
Zhejiang Jingliang Copper-Tube Products Co., Ltd always adheres to customer-oriented thinking and fully considers the adaptability of the back-end processing before the product leaves the factory, especially in terms of welding operability, and effectively reduces the incidence of welding defects through the following means.
1. Surface pretreatment and anti-oxidation protection
During the extrusion and drawing process, the copper square tubes produced by the company have undergone multi-stage cleaning and surface brightening treatment to minimize the surface oxide layer, and provide anti-oxidation solutions such as tinning and phosphating according to customer needs to make the welding surface cleaner and more adherent.
2. Precisely control tolerances and optimize splicing gaps
With advanced extrusion die design and online dimension control systems, the wall thickness tolerance of Zhejiang Jingliang copper square tubes is controlled within ±0.05mm, and the corner transition is highly rounded, which greatly improves the tightness of the welding structure and avoids weld defects caused by uneven gaps.
3. Welding support services: process suggestions + customized matching
The company's technical team provides application guidance for different welding methods including brazing, TIG welding, laser welding, etc. to customers in multiple industries, and can customize reserved welding grooves and auxiliary fixture positioning structures to improve welding efficiency and consistency.
4. High-purity copper ensures excellent weldability
Through its own smelting system and raw material screening mechanism, the copper materials used by Zhejiang Jingliang reach the C11000 purity standard or higher, ensuring that alloy elements do not precipitate and brittle phases do not form during welding, ensuring welding performance from the source.

What are the advantages and precautions of using copper square tubes in refrigeration systems

Significant advantages of copper square tubes in refrigeration systems
1. Efficient heat transfer performance
The thermal conductivity of copper is as high as 390~400 W/m·K, which is much higher than common metals such as aluminum and stainless steel. Under the same flow rate, copper square tubes can achieve faster heat exchange, improve refrigeration efficiency, and reduce system energy consumption.
In addition, the square structure has a larger heat transfer surface per unit area, which can make better use of space in compact heat exchangers to achieve "smaller volume, stronger capacity".
2. Stable structure and easy connection
The copper square tube has sharp edges and a flat surface, which is suitable for close arrangement and welding fixation. It is often designed as a heat flow channel or bracket assembly in the condenser, evaporator or cooling module, which has both heat conduction and structural functions, and improves the modular assembly efficiency of the product.
3. Excellent corrosion resistance
The refrigeration system has a mixed environment of refrigerant, water vapor, and oil for a long time. Copper square tubes naturally have good corrosion resistance and are compatible with a variety of refrigerants (such as R134a, R410A, and R32), effectively extending the life of the system.
4. Easy to weld and form
After precision extrusion and annealing treatment at Zhejiang Jingliang Copper-Tube Products Co., Ltd, the copper square tube has good ductility and weldability. The copper square tubes produced by the company are often used in connection processes such as brazing and TIG welding. The welding interface is flat and airtight, meeting the strict requirements of the refrigeration system for sealing.
Precautions in practical applications
Although the copper square tube has excellent performance, the following points should still be noted when it is used in the refrigeration system to ensure that its function is in the best state:
1. Tube wall thickness control
In condensers and evaporators operating under pressure conditions, the wall thickness selection of copper square tubes is particularly critical. Too thin wall thickness can easily lead to bursting or fatigue cracks, while too thick wall thickness affects heat exchange efficiency and processing feasibility. Zhejiang Jingliang uses CNC extrusion and online laser detection to control the wall thickness within ±0.05mm, and can customize products of different pressure levels according to customer needs.
2. Avoid inner wall contamination
If the inner wall of the copper square tube is damp or contaminated by oil before transportation or installation, it is easy to form a corrosion source. Zhejiang Jingliang cleans, dries and seals before leaving the factory. At the same time, it is recommended that customers perform secondary cleaning before welding to ensure that the system is dry and free of impurities.
3. Thermal expansion compensation design
The thermal expansion coefficient of copper material is 16.5×10⁻⁶/K. The refrigeration system changes frequently between hot and cold. Expansion space must be reserved in the structural design to avoid stress concentration and weld cracking caused by constraints during thermal expansion and contraction of the square tube.
4. Installation gap and support
Square tubes are more easily deformed by lateral forces than round tubes. Support points and gaps should be set reasonably during installation. The Zhejiang Jingliang technical team provides customers with matching installation suggestions and anti-vibration solutions to ensure that the copper square tube maintains good geometric stability during long-term operation.