High-precision manufactured refrigeration motors, piping fittings, and cooling line assemblies from ISO 9001 certified facilities.
Bundy tubes, originally patented as double-walled brazed steel tubing, represent the engineering cornerstone of structural reliability and high thermal efficiency in low-pressure fluid transport. Constructed by continuous copper plating of low-carbon steel strip, precision wrapping it 720 degrees, and subsequently fusing it at temperatures exceeding 1080°C in a protective atmosphere furnace, Bundy pipes provide superior resistance to high burst pressures and continuous vibrations.
For over three decades, Ningbo Taojun Refrigeration Equipment Co., Ltd. (initially founded in 1988 as the Xiangshan Refrigeration Accessories Factory of Zhejiang University) has positioned itself as one of the definitive architectural minds in the production of refrigeration assemblies utilizing customized Bundy piping systems and copper filter driers.
Under the collaborative guidance of the University of Science and Technology of China and Zhejiang University, our engineering teams ensure strict material alignment.
| Parameter / Standard | Double-Walled Bundy Pipe Specifications | Single-Walled Bundy Pipe Specifications | Compliance Standards | ||||
|---|---|---|---|---|---|---|---|
| Outer Diameter Range | Ø3.18mm - Ø10.0mm | Ø4.0mm - Ø12.0mm | ASTM A254 / EN 10291 | Wall Thickness | 0.50mm - 1.00mm (Tolerance: ±0.05mm) | 0.60mm - 1.20mm (Tolerance: ±0.05mm) | JIS G3482 |
| Tensile Strength | ≥ 290 MPa (Typical value: 310-340 MPa) | ≥ 280 MPa | GB/T 24187-2009 | ||||
| Yield Strength | ≥ 180 MPa | ≥ 170 MPa | ISO 9001:2015 Approved | ||||
| Coating Types | PVF, Electro-zinc coating, Copper Plating | Hot-dip galvanized, Copper Plated | RoHS & REACH Compliant |
Our raw sheets utilize SPCD/SPCE aluminum-killed low carbon steel, providing ideal cold forming, double wrapping, and extreme flaring resilience. The inner layers of our copper filter driers utilize a premium 3A molecular sieve with a water absorption threshold exceeding 20%, ensuring low dew point operations within hermetic compressors.
To assure a defect rate of under 0.05% in our wire-tube condensers, Taojun utilizes automated roll-forming mills directly imported from Germany, yielding precise tolerances down to ±0.02mm.
With an electro-galvanized layer combined with Polyvinyl Fluoride (PVF) polymer coatings, our Bundy pipes offer resistance to salt sprays for over 1000 hours, keeping cooling circuits clear in humid environments.
Bridging OEM pipeline expectations with specialized manufacturing delivery structures.
We work directly alongside tier-one home appliance companies, including Haier, Midea, Whirlpool, Electrolux, and Gree, to develop custom piping manifolds and cooling configurations.
Our double-walled carbon steel tubing processes comply with IATF 16949 standards, fulfilling the safety margins required for hydraulic brake line routing in light vehicles.
Our heavy-duty wire-on-tube condenser bundles and copper filter driers protect high-pressure R600a and R290 circuits from internal contaminants and moisture.
Experience our MES intelligent workshop processes and advanced testing laboratory facilities.
Ningbo Taojun Refrigeration operates continuous-brazing atmosphere lines alongside advanced CCD optical dimension sorting tools, automated leak detection cells, and high-vacuum baking chambers.
Addressing environmental regulations and the shift toward higher-pressure natural refrigerants.
The industry shift from hydrofluorocarbons (HFCs) to natural working fluids like propane (R290) and isobutane (R600a) demands absolute pipe integrity. Taojun's enhanced double-walled brazed steel tubing prevents structural micro-fractures, mitigating flammable gas leaks.
By shifting from standard hexavalent chromate passivations to next-generation trivalent zinc and silicon-nano hybrid layers, we help clients meet WEEE and EU REACH regulations without compromising weather resistance.
In 2025, Taojun is upgrading its copper-fusing lines to digital, low-carbon induction induction heaters, reducing energy footprint by 30% while raising bonding uniformity metrics across all produced Bundy tubing coils.
Ensuring our components meet global safety and reliability standards.
Our quality verification processes check every production lot. From material input checks on imported Japanese liquid crystal and high-purity copper to environmental simulation testing chambers, we check every part before dispatch.
GB/T19001-2016/ISO9001:2015
Certified Manufacturing Scope
From a local accessories shop to a recognized national high-tech manufacturing facility.
Founded originally as the Xiangshan Refrigeration Accessories Factory of Zhejiang University. Over 30 years of development led to the creation of the Ningbo Taojun brand in 2012, focused on high-efficiency condensers and refrigeration line valves.
A global brand is supported by its culture. Through honest business practices, active innovation, and quality control, we build lasting partnerships with international buyers.
Our production facilities utilize a Manufacturing Execution System (MES) to monitor production rates and manage raw material allocation across our lines.
We work closely with clients from initial design review through post-sales deployment. Our 1-year product warranty is backed by lifetime technical assistance, helping resolve integration issues in under 24 hours.
Our products are used in light commercial refrigeration, residential refrigeration, central HVAC systems, and automotive fluid circuits.
Direct answers to common engineering questions regarding Bundy pipes and refrigeration components.
Single-walled steel tubing is produced by roll-forming a single steel strip into a tube shape and high-frequency resistance welding the seam. Double-walled Bundy pipe (ASTM A254) uses a single steel strip coated on both sides with copper, wrapped 720 degrees (double-wrapped), and brazed at high temperatures. The double-walled design offers higher burst resistance and fatigue limits compared to single-walled variants.
All finished Bundy pipe assemblies and wire-on-tube condensers undergo inline non-destructive testing (NDT), eddy current testing, and helium mass spectrometer leak detection. Our testing processes are designed to detect leakage rates down to 0.1 grams of refrigerant per year, ensuring long-term hermetic seal performance.
Yes. Our filter driers and condenser assemblies are fully compatible with R290 (Propane) and R600a (Isobutane). The desiccants we use (3A molecular sieves) selectively absorb water without reacting with the natural hydrocarbon molecules, preventing chemical breakdown inside the system.
We provide multiple coating options, including copper-plated surfaces, galvanized zinc coatings (minimum 13 µm thickness), electro-zinc coatings with trivalent chrome passivation, and PVF (polyvinyl fluoride) protective layers. These help the components withstand up to 1000 hours in neutral salt spray testing.
Our standard Minimum Order Quantity (MOQ) for custom OEM Bundy tube components is 500 units. For typical orders, we can arrange shipment within 14-21 days of drawing approval, and we offer a 72-hour air freight service for urgent prototype components.
Explore our full catalog of copper accessories, condenser coils, brazing rods, and charging lines.
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