Engineered for leak-free operations, these components match the industrial integrity of Taojun brass union systems.
In modern refrigeration, thermodynamic system efficiency relies directly on fluid containment. In refrigeration loops carrying HFC, HCFC, and environmentally sustainable HFO refrigerants (such as R32, R410A, and R1234yf), operating pressures have scaled up to 4.5 MPa and above. At these levels, traditional structural fittings face severe micro-strain, thermal contraction cycles, and vibrational stresses.
A premium brass union nut acts as the primary compressive anchor of a flare fitting connection. Made of brass alloys like HPb59-1, CW617N, or C36000, it secures the flared tubing to the body without introducing structural fatigue. The precise torque translation requires flawless thread accuracy (conforming to ISO 228-1 or ANSI B1.20.1 standards) and strict control of metallurgical trace components. This prevents stress corrosion cracking (SCC) and gas bypassing over decades of field service.
Industrial refrigeration networks, automotive HVAC lines, and heavy-duty cold storage infrastructure cannot afford downtime. Taojun Refrigeration designs and manufactures heavy-pattern brass union nuts that deliver high performance even under intense pressure, ensuring long-term reliability.
Located in Ningbo's coastal industrial zone of Xiangshan, Ningbo Taojun Refrigeration Equipment Co., Ltd. was established in 1988. We originated as the Xiangshan Refrigeration Accessories Factory, working in close technical collaboration with the engineering department of Zhejiang University. Over the last 38 years, our factory has evolved from a specialized laboratory component workshop into a highly automated manufacturing center.
In 2021, Taojun was recognized as a National High-Tech Enterprise in China. Our integrated product ecosystem features premium copper filter driers under the respected "Lingshan" brand, stop valves, condensers, and precision CNC-machined brass union nuts.
Our production facilities include high-precision German CNC multi-axis automatic lathes, automated chemical cleaning lines, and digital monitoring systems. In 2012, we introduced our direct sales brand "Taojun" to support strategic partnerships with global appliance leaders such as Haier, Midea, Whirlpool, Electrolux, Gree, Xinfei, and Huarui.
Our brass union nuts are built to exceed international standards through rigorous production and testing methods.
Our core production machinery is imported directly from Germany. High-speed multi-spindle automatic lathes and robotic handlers guarantee thread precision to a class-6H tolerance and zero dimensional deviation across large production runs.
Our engineering division maintains relationships with academic institutions. We have 15 primary engineers in our dedicated R&D center, including PhDs and professors from the University of Science and Technology of China (USTC), focused on structural alloy improvements.
We source premium, certified brass billets. Liquid crystal materials, specialty lubricants, and anti-shrinkage films are imported from Japan. Our raw brass bars undergo chemical analysis to prevent lead leaching and internal porosity.
Our testing labs verify physical integrity through thermal shock tests ranging from -35°C to 75°C for 500 hours, and rapid cycling between 10°C and 90°C. Units undergo dry helium mass spectrometer leak testing and 100V high-voltage insulation tests for electrical parts.
We utilize an advanced Manufacturing Execution System (MES) to monitor production. From bar feeding to final threading, inspection, and laser marking, each step is logged and traceable for transparent quality assurance.
Our brass union nuts are manufactured in strict compliance with the following international technical parameters, ensuring perfect compatibility across global commercial HVAC/R networks.
| Parameter Class | Technical Specification / Standard Reference | Industrial Application Impact |
|---|---|---|
| Material Grade Options | HPb59-1 (UNS C37700), CW617N (EN 12165), Low-Lead Brass (<0.1% Pb) | Excellent cold-forging and machining response; high tensile strength to prevent stress fractures. |
| Thread Standard | ASME B1.1 (UNF / UN Threads) and ISO 228-1 G thread class 6H | Interchangeable fit with standard SAE 45-degree flare connectors without thread binding. |
| Nominal Pressures (PN) | Designed for pressures up to 6.5 MPa (942 PSI) | Supports modern high-pressure refrigerants like R410a and CO2 (R744) subcritical systems. |
| Operating Temperatures | Continuous duty range from -45°C (-49°F) up to +150°C (+302°F) | Prevents degradation, creep, or deformation during high-temperature discharge gas phases. |
| Dimensional Tolerances | CNC-milled thread pitch and wall thickness: ±0.02 mm | Ensures uniform torque distribution, preventing localized stress buildup. |
A robust union nut requires a reliable connection. Our copper filter driers are designed to capture system moisture, acids, and solid contaminants, protecting the compressor.
Structural Breakdown: The outer shell is made of high-purity deoxidized copper pipe, providing corrosion resistance and thermal conductivity. The inner chamber holds a dual-action core: a 3A molecular sieve (adsorption capability ≥ 20%) combined with an activated alumina/carbon layer to neutralize system acids.
We use automated orbital argon-arc welding to join the copper shell to the connection ports. This ensures complete fusion without thermal damage to the internal molecular sieve, preventing gas bypass or external micro-leaks.
Our brass union nuts and copper refrigeration accessories are used in key industries worldwide, delivering reliable connection performance.
Secures split-system air conditioner lines and variable refrigerant flow (VRF) networks. Withstands vibration and pressure fluctuations during outdoor seasonal changes.
Used in walk-in freezers and supermarket refrigeration racks. The brass structure remains stable under low-temperature cycling, preventing system leaks.
Supports ice-making machinery and process chillers. Designed to handle mechanical vibration and high flow rates, maintaining a secure seal.
Used in automotive air conditioning systems using R134a/R1234yf. Resistant to road vibration and engine compartment heat, preventing refrigerant loss.
From a local laboratory supplier to a global components partner, our milestones reflect our commitment to engineering quality.
Foundation: Established as Xiangshan Refrigeration Accessories Factory of Zhejiang University. Dedicated to manufacturing specialized scientific refrigeration components and testing equipment for research institutes.
Industrial Scale: Built our first dedicated manufacturing factory in Ningbo, moving from laboratory-scale supply to high-volume industrial OEM component production.
Digital Transition: Implemented the MES Intelligent Workshop Management System. This enabled real-time monitoring of raw materials, CNC cycle metrics, and testing diagnostics for major manufacturing batches.
Global Brand Launch: Formally incorporated Ningbo Taojun Refrigeration Equipment Co., Ltd. and introduced the "Taojun" brand. We expanded our sales network across Europe, North America, South America, and Southeast Asia.
National Recognition & Growth: Awarded National High-Tech Enterprise status. We expanded partnerships with global appliance brands, including Haier, Midea, Whirlpool, Electrolux, and Gree.
At Taojun, we believe a globally trusted brand is built on a strong corporate culture. Our identity has developed through years of commitment to our core values: Honesty, Innovation, Responsibility, and Cooperation.
We prioritize reliable quality and transparent business practices, establishing long-term, trusted relationships with our global clients.
Innovation drives our development. We continuously refine our concepts, production technologies, and administrative processes to adapt to changing market requirements.
We maintain a strong sense of responsibility toward our partners, team members, and the environment, ensuring sustainable manufacturing practices.
We cooperate closely with our clients to optimize resources and develop customized solutions for mutual success.
Verifiable quality control frameworks and international compliance standards for reliable global supply chain integration.
Ningbo Taojun Refrigeration operates a certified quality management system under GB/T19001-2016 / ISO9001:2015 (Registration No.: 41325Q00065R0S). Our compliance certifications are registered and verifiable through the Certification and Accreditation Administration of the People's Republic of China (CNCA) and partner auditor databases.
Global OEM/ODM Customization: We offer customized design services for brass union configurations, custom lengths, specific thread types, and specialized refrigeration accessories. We support low minimum order quantities (MOQ starting at 500 units) to meet diverse project requirements.
Our logistics networks support global delivery, and we provide technical support for quick integration into customer assembly processes.
ISO 9001 Main Certification
Certified Scope of Work
We perform material composition verification on our products to ensure compliance with international environmental standards, including RoHS, REACH, and WEEE directives.
Our ongoing R&D efforts are focused on three primary areas to address evolving demands in global industrial refrigeration.
We are developing lead-free brass formulations containing bismuth or silicon to comply with stricter drinking water and environmental regulations in North America and Europe, while maintaining mechanical machinability.
We are researching brass fittings with integrated micro-sensors to monitor line pressures and temperatures in real time, aiding proactive leak detection in commercial cold storage facilities.
We are working toward integrating artificial intelligence into our production lines. Using machine vision, our systems will perform automated CCD visual inspections to verify thread tolerances down to the micrometer level.
Technical information regarding material grades, torque specifications, and system integration for our brass union components.
Explore our full line of refrigeration accessories, condensers, and adapter kits designed for reliable commercial installation.
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