Stainless Steel Coil Tube for DC Brushless Fan Coil Systems
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. (Product No. 473) offers a precision-engineered stainless steel coil tube designed specifically for integration with DC Brushless Fan Coil Unit (FCU) systems. This coil tube serves as the core heat exchange medium in modern air conditioning and thermal management applications, delivering superior thermal conductivity, exceptional corrosion resistance, and extended service life. The product is engineered to meet the demanding requirements of commercial HVAC (Heating, Ventilation, and Air Conditioning) installations where reliability and efficiency are paramount.
The coil tube is manufactured to complement DC Brushless Motor-driven fan coil units, which represent the latest advancement in energy-efficient climate control technology. The seamless integration between the coil tube and brushless motor systems ensures optimal airflow distribution, reduced energy consumption, and quiet operation—hallmarks of next-generation thermal management solutions.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, typically conforming to the following material specifications:
- Grade 304 (UNS S30400): The primary material offering excellent corrosion resistance, formability, and weldability. Chromium content of 18–20% and Nickel content of 8–10.5% provide robust passive oxide layer formation.
- Grade 316 (UNS S31600): Available upon request for applications requiring enhanced resistance to chlorides and aggressive chemical environments. Molybdenum addition (2–3%) significantly improves pitting resistance.
- Surface Finish: Available in No. 1 (hot-rolled annealed), 2B (cold-rolled bright), or BA (Bright Annealed) finishes depending on application requirements.
- Mechanical Properties: Yield strength ≥ 205 MPa (304 grade), tensile strength 515–720 MPa, elongation ≥ 40%.
- Thermal Conductivity: Approximately 16.3 W/(m·K) at 20°C, ensuring efficient heat transfer performance.
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6.35 mm / 9.53 mm / 12.7 mm (1/4" / 3/8" / 1/2") | ASTM A269 |
| Wall Thickness | 0.5 mm – 1.5 mm | ASTM A269 / GB/T 12771 |
| Coil Winding Diameter | 200 mm – 800 mm (configurable) | Custom specification |
| Coil Length | 300 mm – 3,000 mm | Custom specification |
| Number of Turns | 4 – 60 (application-dependent) | — |
| Fin Pitch (if finned) | 10 FPI – 16 FPI (Fins Per Inch) | ASHRAE 15 |
| Operating Temperature Range | -40°C to +250°C | — | Maximum Working Pressure | 1.6 MPa – 2.5 MPa (pressure rating dependent on wall thickness) | ASME B31.9 |
| Heat Exchange Capacity | Up to 12.5 kW (depending on coil configuration) | ASHRAE Standard 34 |
| Refrigerant Compatibility | R-410A, R-32, R-134a, R-407C, Water/Glycol | — |
| Material Standard | ASTM A269 / A270 / GB/T 12771 / JIS G3459 | Multi-standard compliance |
| Finish | 2B / BA / Electropolished (Ra ≤ 0.4 μm) | ASTM A478 |
Manufacturing Process
The production of the stainless steel coil tube follows a rigorous multi-stage manufacturing process to ensure dimensional accuracy, structural integrity, and performance consistency:
- Raw Material Selection: Certified stainless steel strip or tube stock is sourced from approved mills, with full chemical composition and mechanical property documentation provided (Mill Test Certificate — MTC).
- Coil Forming: Precision tube coiling is performed using CNC-controlled winding machines to achieve exact coil geometry, consistent turn-to-turn spacing, and uniform winding tension. This ensures balanced airflow distribution when integrated with the DC brushless fan coil motor assembly.
- Welding & Joining: Header connections and tube-to-plate joints are fabricated using TIG (Tungsten Inert Gas) welding or orbital welding techniques, ensuring leak-tight integrity and minimal heat-affected zone distortion.
- Finning (if applicable): Aluminum or copper fins are mechanically expanded onto the coil tube using high-precision finning presses, creating intimate metal-to-metal contact for maximum thermal transfer efficiency.
- Surface Treatment: Pickling and passivation are performed to remove oxide scale and restore the passive chromium oxide layer, enhancing long-term corrosion resistance.
- Pressure Testing: Each coil tube assembly undergoes 100% hydrostatic or pneumatic pressure testing at 1.5 times the maximum working pressure, with a minimum hold time of 30 seconds to verify leak-free integrity.
- Final Inspection: Visual inspection, dimensional verification, and surface quality assessment are conducted in accordance with ISO 9001 quality management protocols.
Applications
The stainless steel coil tube from Wenzhou Jixing Metal Materials Co., Ltd. is specifically engineered for the following applications:
- Commercial HVAC Systems: Integrated into DC Brushless Fan Coil Units for office buildings, hotels, shopping malls, and hospitals where energy efficiency and low noise operation are critical.
- Residential Climate Control: Used in concealed and exposed fan coil systems for premium residential installations requiring quiet, efficient temperature regulation.
- Industrial Process Cooling: Deployed in process chillers, condensers, and evaporators in food processing, pharmaceutical, and chemical manufacturing facilities.
- Refrigeration Systems: Serving as evaporator and condenser coils in commercial refrigeration units, cold storage facilities, and display refrigeration.
- Marine & Coastal Environments: Grade 316 coil tubes are suitable for marine HVAC systems and coastal installations where chloride-induced corrosion is a primary concern.
- Clean Room Environments: Electropolished coil tubes meet the hygienic and particulate-control requirements of pharmaceutical and semiconductor clean room installations.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality assurance framework ensuring product conformity with international and national standards:
- ISO 9001:2015 — Quality Management System certification covering design, manufacturing, and testing processes.
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to sustainable manufacturing practices.
- CE Marking — Conformity with European Health, Safety, and Environmental Protection standards.
- EN 10204 3.1 — Material Test Certificate (MTC) provided with each production batch, documenting chemical composition and mechanical properties.
- RoHS & REACH Compliance — Restricted Substances Directive and Registration, Evaluation, Authorization, and Restriction of Chemicals compliance for global market access.
- ASME Section IX — Welding procedure qualification ensuring joint integrity and pressure boundary reliability.
- ASHRAE Standard 34 — Heat Transfer Equipment Performance standards compliance for HVAC applications.
Unique Selling Points
DC Brushless Motor Compatibility: The coil tube geometry and hydraulic characteristics are specifically optimized for seamless integration with DC Brushless Motor-driven fan coil units. This design synergy enables variable-speed operation, precise temperature control, and energy consumption reductions of up to 40% compared to conventional AC motor systems.
- Superior Corrosion Resistance: Austenitic stainless steel construction provides decades of service life without degradation, even in humid or chemically aggressive environments.
- Precision Manufacturing: CNC-controlled coiling ensures dimensional accuracy within ±0.2 mm tolerance, guaranteeing optimal thermal performance and installation fit.
- Custom Configurations: Flexible manufacturing capability allows customization of coil dimensions, turn counts, fin configurations, and material grades to meet specific project requirements.
- Energy Efficiency: Enhanced heat exchange surface area and optimized flow channels contribute to lower COP (Coefficient of Performance) requirements, reducing operational energy costs.
- Low Maintenance: Corrosion-resistant construction and sealed welding joints minimize maintenance intervals and extend system uptime.
- Full Traceability: Each product batch is traceable to raw material origin through comprehensive documentation and batch tracking systems.