Engineered to exact global standards for cooling, automotive, and refrigeration systems.
Bundy tubes, also known as double-walled copper-brazed steel tubes, represent the pinnacle of fluid carrying reliability in high-pressure environments. Originally developed for automotive braking systems and domestic refrigeration cycles, these pipes are manufactured by continuously roll-forming a double-sided copper-coated steel strip through 720 degrees.
Under a strict reducing hydrogen atmosphere at high temperatures, the copper coating melts and diffuses with the low-carbon steel core, producing a metallurgical bond that guarantees high burst pressure, superior vibration resistance, and structural homogeneity. Our Bundy tubes strictly comply with ASTM A254 standards, offering extreme durability for demanding industrial applications.
Detailed performance parameters of global standard Bundy pipes versus copper alternatives.
| Property / Dimension | Double-Wall Bundy Pipe (ASTM A254) | Single-Wall Steel Tubing | Phosphorus-Deoxidized Copper (C12200) |
|---|---|---|---|
| Outer Diameter (OD) Range | 4.0 mm - 10.0 mm | 4.76 mm - 8.0 mm | 2.0 mm - 22.0 mm |
| Wall Thickness Tolerance | ±0.05 mm | ±0.08 mm | ±0.03 mm |
| Yield Strength (MPa) | ≥180 MPa | ≥150 MPa | ≥65 MPa |
| Burst Pressure Resistance | Up to 110 MPa (High Safety Margin) | Up to 60 MPa | Up to 45 MPa |
| Internal Cleanliness (Residue) | <0.19 mg/dm² (DIN 8964 compliant) | <0.25 mg/dm² | <0.20 mg/dm² |
| Corrosion Protection Coating | Copper Plating + Zinc + PVF Coating | Galvanized / Plain | Natural Oxide Layer (Self-protecting) |
Founded in 1988, Ningbo Taojun Refrigeration Equipment Co., Ltd. originated as the Xiangshan Refrigeration Accessories Factory of Zhejiang University. For over three decades, we have evolved into a national high-tech enterprise specializing in the design, development, production, and distribution of high-performance refrigeration parts.
Our core product line includes copper filter driers, check valves, air conditioning valves, wire-tube condensers, and precision copper/brass accessories. Through continuous innovation, we have established long-term global partnerships with Tier-1 appliance manufacturers including Haier, Midea, Whirlpool, Electrolux, Gree, and Xinfei.
Why global appliance giants consolidate their supply chains in Ningbo with Taojun.
Our collaborative foundation with Zhejiang University and the University of Science and Technology of China (USTC) brings academic rigour to daily factory floor engineering, allowing us to solve thermodynamic challenges faster.
Equipped with imported German core manufacturing systems, we run real-time MES workshop management, CCD visual tracking, and online helium mass spectrometer leak detection units to maintain consistent quality.
Based in Xiangshan, Ningbo, our facility sits directly in the heart of China’s premium industrial clusters. This offers access to high-purity copper refineries and provides a direct gateway to global shipping lanes through Ningbo Port.
Tracing our evolution from a specialized workshop to a global refrigeration component pioneer.
Our early manufacturing headquarters expanded, integrating basic copper extrusion and heat exchanger assembly lines to meet surging local cooling demands.
We transitioned to digital management with the integration of our MES workshop system, allowing real-time tracking of manufacturing, metallurgy, and leak testing protocols.
Leveraging deep industrial partnerships across continents, we expanded to automate global fulfillment channels, serving high-precision HVAC applications globally.
Modern refrigeration is undergoing structural changes driven by global environmental policies, including the F-Gas regulation and the transition toward natural refrigerants like Isobutane (R600a) and Propane (R290). These flammable, highly efficient gases operate under tighter thermodynamic parameters, demanding zero leakage and absolute internal dryness.
Consequently, Bundy pipes and copper filter driers must meet higher cleanliness metrics. Any residual paraffin, dust, or moisture inside the tube loop can trigger capillary clogging or compressor failure. Taojun meets these requirements by processing tubes inside clean rooms and using 3A molecular sieves with water absorption capacity exceeding 20%.
Global procurement teams looking for refrigeration component manufacturers require more than just low-cost parts; they require supply security, engineering compliance, and operational reliability. Taojun addresses these needs directly through our comprehensive certification suite:
Every batch undergoes testing to withstand severe temperature and environmental conditions.
We perform 500-hour environmental endurance testing across extreme temperature variations, cycling between +75°C and -35°C to verify that copper-steel bonds and joints remain clear of micro-fractures.
Our components undergo 30-minute rapid thermal shocks from 10°C to 90°C along with 500-hour damp heat exposures, confirming resistance to oxidation and localized galvanic corrosion.
We test smart films in sheet form with a 24-hour aging process, and rolls undergo a 100V high-voltage test to prevent electrical breakdown. For fluid loops, high-pressure helium mass-spectrometers guarantee zero leakage.
At Ningbo Taojun Refrigeration, we believe that sustainable global growth is supported by a strong corporate culture. We focus on four core values: Honesty, Innovation, Responsibility, and Cooperation.
Supporting your engineering and logistics teams from initial design through life-cycle service.
Receive direct support from our sales engineers, who bring years of technical pump and refrigeration expertise. We offer detailed drawing reviews, chemical compatibility analyses, and responses within 8 hours.
We optimize design parameters for wall thickness, copper coating thickness, and bending radius, adapting components to your assembly setups to streamline production and minimize waste.
Our service continues after delivery. We offer a one-year warranty, ongoing technical advice, and assistance with system improvements to ensure long-term performance.
Verifiable ISO credentials for HVAC engineering and parts manufacturing.
Our quality system is verified by Zhongci International (www.zcgirz.com) and registered under China's CNCA database (www.cnca.gov.cn). The certification covers the design and manufacture of filter driers, condensers, and access valves.
We also maintain current UL certifications and RoHS compliance, helping our clients clear international regulatory and import requirements.
Technical answers to common engineering and sourcing questions.
Bundy tubes feature a double-walled construction formed by wrapping a copper-coated steel strip through 720 degrees. When brazed, the copper coating diffuses with the steel, producing high yield strength, excellent burst pressure resistance, and reliable structural integrity that prevents leaks under high pressures.
We use high-purity copper shells containing 3A molecular sieves, which are optimized for modern refrigerants like R134a, R600a, and R290. Our molecular sieves feature a moisture absorption capacity of ≥20% and incorporate activated carbon layers to filter out moisture, acid, and impurities that could degrade the refrigerant loop.
Yes. As an ISO 9001 certified OEM/ODM provider, we customize ODs, wall thicknesses, end flares, and bends to match your specifications. Our engineering team, supported by academic collaborations with Zhejiang University, assists from early prototypes through high-volume production.
Every condenser, valve, and filter drier undergoes helium mass spectrometer leak detection and high-pressure nitrogen testing. These tests verify the integrity of all welded joints, helping us maintain a field defect rate of under 0.05%.
Yes, all our copper, brass, and steel components comply with EU RoHS and REACH directives, ensuring they are free of hazardous materials. We also use 100% recyclable packaging materials to support sustainable supply chain requirements.
Premium components engineered for long-term cooling performance and system safety.
Taojun