Stainless Steel Coil Tube (Coiltube) — HVAC & Refrigeration Grade
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered tubular product designed primarily for use in heating, ventilation, and air conditioning (HVAC) systems, refrigeration circuits, and thermal energy exchange applications. This product is engineered to meet the rigorous demands of modern cooling and heating systems, particularly in non-standard fan coil unit (FCU) assemblies where unit comprehensive power consumption cooling capacity coefficient (COP) and heating capacity coefficient (HPF) performance metrics are critical evaluation parameters.
The coil tube is supplied in continuous coil form, enabling efficient downstream forming, cutting, and assembly operations. Its stainless steel composition provides superior corrosion resistance, mechanical integrity, and long-term thermal stability, making it an ideal choice for both indoor and outdoor HVAC applications where durability and energy efficiency are paramount.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its outstanding combination of formability, weldability, and resistance to pitting and crevice corrosion in aggressive environments. Key material characteristics include:
- Base Alloy: Austenitic stainless steel (typically Grade 304 or 316 depending on application requirements)
- Corrosion Resistance: Excellent resistance to atmospheric, aqueous, and chemical corrosion; superior performance in chlorinated environments (Grade 316)
- Mechanical Strength: High tensile strength with favorable ductility, enabling tight coil winding without cracking or deformation
- Thermal Conductivity: Moderate thermal conductivity suitable for heat exchange applications while maintaining structural integrity at elevated temperatures
- Hygienic Surface: Low surface roughness (Ra ≤ 0.8 μm) minimizing fouling and biofilm formation
- Temperature Range: Operational range from cryogenic temperatures (-196°C) to 870°C (Grade 304) or 870°C (Grade 316)
Specifications
| Parameter | Specification | Unit |
|---|---|---|
| Outer Diameter (OD) | 6.35 – 25.4 (customizable) | mm |
| Wall Thickness | 0.3 – 1.2 (customizable) | mm |
| Coil Diameter | 200 – 1200 (customizable) | mm |
| Coil Length | 50 – 500 (customizable) | m |
| Material Grade | SUS304 / SUS316 / SUS321 | — |
| Surface Finish | Mirror polish / Matte / Brushed | — |
| Tensile Strength | ≥ 520 | MPa |
| Yield Strength | ≥ 205 | MPa |
| Elongation | ≥ 40 | % |
| Heat Transfer Coefficient | 16.3 – 16.8 | W/(m·K) |
| Tolerance (OD) | ± 0.05 | mm |
| Tolerance (Wall Thickness) | ± 0.02 | mm |
Manufacturing Process
The production of the stainless steel coil tube follows a rigorous multi-stage manufacturing process to ensure dimensional accuracy, material homogeneity, and surface quality:
- Raw Material Selection: Virgin stainless steel wire rod sourced from certified mills, inspected for chemical composition (spectrometric analysis) and mechanical properties.
- Wire Drawing: Cold drawing of wire rod through precision tungsten carbide dies to achieve exact wire diameter with controlled reduction ratios, ensuring uniform grain structure.
- Heat Treatment: Solution annealing at 1050°C followed by controlled water quenching to relieve internal stresses and restore full austenitic microstructure.
- Tube Forming: Wire is wound and formed into tubular geometry using precision forming dies, with continuous inline monitoring of OD and wall thickness.
- Pipe Welding (if applicable): High-frequency induction welding (HFW) or laser welding with inert gas (argon) shielding to produce full-penetration, defect-free welds.
- Precision Sizing: Post-weld sizing through calibrated rollers to achieve final dimensional tolerances within ± 0.05 mm.
- Surface Treatment: Electropolishing or mechanical polishing to achieve specified surface finish (Ra ≤ 0.8 μm), followed by passivation treatment for enhanced corrosion resistance.
- Coil Winding: Final product is wound onto precision cores with controlled tension to prevent deformation, then secured with protective wrapping.
- Quality Inspection: 100% inline inspection including dimensional measurement, visual examination, eddy current testing, and hydrostatic pressure testing.
Applications
The stainless steel coil tube finds extensive application across multiple industries, with particular relevance to HVAC and refrigeration systems:
- Fan Coil Units (FCU): Used as heat exchange coils in standard and non-standard fan coil unit assemblies, where efficient heat transfer and low power consumption are critical for achieving optimal COP and HPF ratings.
- Refrigeration Systems: Evaporator and condenser coils in commercial refrigeration, cold storage facilities, and industrial cooling systems.
- Water Heating Systems: Immersion heating elements and heat exchanger coils in domestic and industrial water heating applications.
- Automotive HVAC: Air conditioning condenser tubes and evaporator coils in vehicle climate control systems.
- Food & Pharmaceutical Processing: Sanitary-grade heat exchange coils in food processing, brewing, and pharmaceutical manufacturing equipment.
- Solar Thermal Systems: Absorber tubes in concentrated solar thermal collectors and solar water heating systems.
- Marine Applications: Heat exchanger coils in marine HVAC and refrigeration systems where corrosion resistance is essential.
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system ensuring product conformity to international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- GB/T 14976 — Chinese National Standard for Seamless Stainless Steel Tubes for Fluid Transport
- GB/T 12771 — Chinese National Standard for Welded Stainless Steel Tubes for Fluid Transport
- ASTM A213 / A269 — American Standards for Stainless Steel Tubing
- EN 10216-5 — European Standard for Welded Stainless Steel Tubes
- JIS G3446 / G3459 — Japanese Industrial Standards for Stainless Steel Tubes
- SGS Testing — Third-party material composition and performance verification
Unique Selling Points
- Optimized for Energy Efficiency: Designed to minimize unit comprehensive power consumption while maximizing cooling and heating capacity coefficients, directly contributing to improved system COP and HPF performance in fan coil unit applications.
- Customizable Specifications: Flexible manufacturing capability allows customization of OD, wall thickness, coil diameter, and surface finish to meet specific project requirements.
- Superior Corrosion Resistance: Austenitic stainless steel composition ensures decades of service life even in aggressive chemical environments, eliminating maintenance-related downtime.
- Precision Dimensional Control: Tight manufacturing tolerances (± 0.05 mm) ensure reliable fit and function in automated assembly systems and precision heat exchanger applications.
- Environmental Sustainability: 100% recyclable material with minimal environmental impact during production, supporting green building and sustainable manufacturing initiatives.
- Hygienic Design: Low surface roughness and smooth internal bore prevent bacterial growth and fouling, ensuring consistent thermal performance throughout the product lifecycle.