Industrial grade tubing, condensers, valves, and refrigeration accessories manufactured to strict international standards.
Ningbo Taojun Refrigeration Equipment Co., Ltd. is located in Xiangshan, Ningbo, a beautiful tourist city. Founded in 1988, our predecessor was the Xiangshan Refrigeration Accessories Factory of Zhejiang University. Over more than three decades of structural expansion and rapid technological evolution, we have established ourselves as a premier high-tech enterprise specializing in the design, development, production, sales, and service of high-precision refrigeration accessories.
Our leading product lines consist of high-efficiency copper filter driers, check valves, air conditioning valves, wire tube condensers, brass and copper accessories, and specialized HVAC piping. Awarded the National High-Tech Enterprise status in 2021, Taojun Refrigeration works with a relentless focus on process innovation, manufacturing modernization, and advanced management methodologies. Customer satisfaction remains our core standard. Under the industry-recognized "Lingshan" brand, our filters and parts have achieved major prominence across China and global markets.
Certifications & Standards: Our facility is fully certified under ISO9001:2015 for quality management systems, EU RoHS/REACH environmental safety directives, and holds UL safety certifications for US market compliance.
An in-depth look at metallurgical structure, anti-corrosion properties, and procurement metrics for engineering procurement managers.
Bundy tubes, also known as double-walled low-carbon steel tubes, are manufactured by laterally wrapping a copper-coated steel strip through 720 degrees. This double-wrap method creates a concentric double-walled tube. Under highly controlled furnace operations at approximately 1100°C in a reducing atmosphere of hydrogen or nitrogen, the copper layers melt and flow, molecularly brazing the seams together. The resulting structural weld provides exceptional pressure resistance, structural stability, and resistance to fatigue.
The standard 8mm Outer Diameter (OD) Bundy tube is a core component within heat-exchange systems, automotive brake lines, and home refrigeration loops due to its optimal balance of wall strength, hydraulic efficiency, and thermal conductivity.
Sourcing 8mm Bundy tubes from China, particularly from integrated manufacturers like Ningbo Taojun, provides several key strategic advantages:
✓ Domestic Refrigeration: Static wire-on-tube condensers, evaporators, hot gas loops, and compressor connector lines.
✓ Automotive Engineering: High-pressure hydraulic brake lines, fuel line networks, transmission cooling systems, and power steering loops.
✓ Industrial HVAC: High-durability heat exchanger coils, chillers, and commercial freezer fluid lines.
Below are the typical mechanical properties and dimensional tolerances adhered to by Ningbo Taojun in compliance with international standards such as ASTM A254, SAE J527, and DIN 74234.
| Parameter / Specification | Value / Range | Testing Protocol / Compliance Standards |
|---|---|---|
| Outer Diameter (OD) | 8.00 mm (±0.08 mm) | Micrometer / Optical CCD Scanning |
| Wall Thickness (WT) | 0.50 mm - 1.00 mm (±0.05 mm) | Ultrasonic Wall Thickness Gauging |
| Tensile Strength (Rm) | ≥ 290 MPa | ASTM E8 Tensile Testing Method |
| Yield Strength (Rp0.2) | ≥ 180 MPa | ASTM E8 Tensile Testing Method |
| Elongation (A5) | ≥ 25 % | Ductility Evaluation |
| Burst Pressure Limit | ≥ 110 MPa (Dependent on Wall Thickness) | Destructive Hydrostatic Burst Test |
| Inner Surface Cleanliness | Residual Impurities < 0.20 g/m² | Refrigerant Compatibility Solvents Test |
Steel piping is naturally vulnerable to atmospheric oxidation and chemical corrosion. To maintain reliability throughout a long service life, specialized coating layers are applied to our Bundy tubes:
Electrolytic copper plating (typically 3μm thickness minimum) is applied internally and externally. This helps optimize heat transfer and ensures clean joints during vacuum brazing.
A zinc protective layer is applied to the exterior. This coating offers sacrificial galvanic protection, helping to withstand up to 72–120 hours of salt spray testing before showing signs of red rust.
Polyvinyl Fluoride (PVF) or high-grade epoxy polymer wraps are applied over the zinc coating. This barrier system is designed for automotive and marine projects, helping to survive up to 1000+ hours in salt spray environments.
Ningbo Taojun has been producing precision refrigeration parts and double-wall steel tube assemblies for decades. Our internal engineering department and academic partnerships allow us to implement robust, modern production practices.
Leveraging high-tech equipment and strict quality control measures to maintain a factory defect rate under 0.05%.
Our core production lines and automated detection apparatus are sourced from Germany and Japan, ensuring dimensional precision.
We work in collaboration with research institutes and hold over 15 utility patents. Our engineering team specializes in thermodynamics and metallurgy.
We supply custom tube lengths, bend radiuses, end flare profiles, and bracket styles to match specific refrigeration layouts.
Every product batch is tested under thermal shock (-35°C to 75°C), high pressure, and humidity before leaving the warehouse.
We provide full pre-sales engineering consultation to help optimize your tube configurations, bend radii, and wall thickness choices. Our service guidelines include:
1. Technical Consulting: Dedicated project managers coordinate with your design engineers to review CAD drawings, evaluate pressures, and select appropriate coatings.
2. After-Sales Support: All orders are covered by a comprehensive warranty. We provide on-site and remote technical support to assist with brazing, line integration, and quality audits.
Over the years, the development of our group has been guided by our core values: Honesty, Innovation, Responsibility, and Cooperation.
Through close technical collaborations and resource sharing, we aim to build robust, long-term partnerships with our clients, helping them optimize costs and streamline operations.
Our quality management systems are certified to GB/T19001-2016 / ISO9001:2015 (Registration No.: 41325Q00065R0S). This certification covers the design and fabrication of our refrigeration parts, wire-tube condensers, and access valves.
All certifications are verified via the Certification and Accreditation Administration of China (CNCA - www.cnca.gov.cn), ensuring high compliance, reliability, and traceablity across our entire supply chain.
Providing custom solutions for the world's leading brands in domestic and commercial refrigeration.
Our products are used in residential refrigerators, HVAC systems, automotive fluid loops, and industrial heat exchangers. Over the years, we have built relationships with well-known domestic and international home appliance enterprises, including Midea, Haier, Gree, Whirlpool, Electrolux, and Xinfei.
Technical answers to common queries regarding 8mm Bundy tubing properties, customization, and factory operations.
Explore our full range of copper filter driers, brass fittings, charging valves, and mounting brackets.
Taojun
