Stainless Steel Coil Tube (Coil Tube) — Product Technical Specification
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Product Category: Coil Tube / Coiltube (盘管)
Product Code: 1238
1. Product Overview
The Stainless Steel Coil Tube is a precision-engineered coiled piping component designed for use in Fan Coil Units (FCUs), Heat Exchangers, HVAC (Heating, Ventilation, and Air Conditioning) systems, and industrial thermal management applications. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd., this product represents a critical component in the current generation of Chinese fan coil unit technology, which has undergone significant advancement in thermal efficiency, compact design, and corrosion resistance.
Coil tubes serve as the primary heat transfer medium in fan coil systems, facilitating the exchange of thermal energy between a circulating fluid (typically water or refrigerant) and ambient air. The coiled configuration maximizes surface area within a confined spatial envelope, enabling high-efficiency heat exchange while maintaining structural integrity under cyclic thermal and hydraulic loading conditions.
2. Material & Properties
Wenzhou Jixing Metal Materials Co., Ltd. employs premium-grade stainless steel grades for coil tube fabrication, ensuring superior mechanical performance, corrosion resistance, and long-term service reliability.
2.1 Available Material Grades
- Austenitic Stainless Steel (奥氏体不锈钢): SUS304 / AISI 304 — General-purpose corrosion resistance; suitable for most HVAC and industrial applications
- Super-Austenitic Stainless Steel: SUS316L / AISI 316L — Enhanced resistance to chlorides and aggressive chemical environments
- High-Nickel Austenitic Steel: SUS321 / AISI 321 — Stabilized with titanium; suitable for elevated temperature applications (up to 870°C)
2.2 Key Mechanical and Physical Properties
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, water, and mild chemical exposure
- Operating Temperature Range: −196°C to +870°C (depending on grade)
- Surface Finish: 2B, BA (Bright Annealed), or custom polished finishes available
- Mechanical Strength: Tensile strength ≥ 520 MPa (SUS304); ≥ 570 MPa (SUS316L)
- Formability: High ductility enabling precise coiling without cracking or deformation
- Hygienic Properties: Non-toxic, non-leaching; suitable for potable water and food-grade applications
3. Technical Specifications
| Parameter | Specification | Unit |
|---|---|---|
| Outer Diameter (OD) | 6.0 – 32.0 | mm |
| Wall Thickness | 0.5 – 2.0 | mm |
| Coil Inner Diameter (Diameter of Coiled Bundle) | 50 – 500 | mm |
| Coil Height / Length | 100 – 2000 | mm |
| Coil Pitch (Spacing Between Turns) | 1.0 – 5.0 | mm |
| Number of Turns | 2 – 50 (customizable) | — |
| Operating Pressure (Maximum) | 1.6 – 4.0 | MPa |
| Thermal Conductivity (Stainless Steel) | 14.6 – 16.3 | W/(m·K) |
| Tolerance on OD | ±0.05 – ±0.10 | mm |
| Tolerance on Wall Thickness | ±0.02 – ±0.05 | mm |
| End Treatment | Flat cut, beveled, or threaded | — |
| Surface Roughness (Ra) | ≤ 0.8 (BA finish) | μm |
4. Manufacturing Process
The production of precision coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous multi-stage manufacturing sequence:
- Raw Material Selection and Inspection: Stainless steel strip or tube stock is sourced from certified suppliers and subjected to incoming inspection including chemical composition analysis (per ASTM E415), dimensional verification, and surface quality assessment.
- Material Preparation and Annealing: The raw material undergoes solution annealing (solution treatment at 1050–1150°C with rapid quenching) to achieve the desired austenitic microstructure and optimal formability.
- Pipe Forming / Tube Drawing: Seamless tube is produced via cold drawing or hot-rolling processes, followed by cold drawing to achieve precise outer diameter and wall thickness tolerances.
- Coiling / Bending Operation: The formed tube is precisely coiled using CNC-controlled coiling machinery. The coiling process is programmed to maintain uniform pitch, consistent bend radius, and minimal residual stress throughout the coil geometry.
- Welding and Seaming (if applicable): For multi-turn coils requiring fluid path continuity, TIG (Tungsten Inert Gas) welding or orbital welding is employed at connection points. Weld seams undergo 100% visual inspection and selective radiographic testing (RT).
- Surface Finishing: The coil tube undergoes pickling and passivation (酸洗钝化) to remove surface oxides and restore the natural chromium oxide protective layer. Bright annealing in a controlled atmosphere furnace may be applied for enhanced surface quality.
- Pressure Testing and Quality Verification: Each coil tube unit is subjected to hydrostatic pressure testing at 1.5× the maximum operating pressure. Dimensional verification is performed using precision gauges and CMM (Coordinate Measuring Machine) equipment.
- Packaging and Dispatch: Finished products are packaged with protective end caps, anti-corrosion wrapping, and secured in export-grade wooden crates or pallets for safe transit.
5. Applications
The stainless steel coil tube is integral to a broad spectrum of thermal management and fluid handling applications:
- Fan Coil Units (FCUs): Primary heat exchanger element in commercial and residential HVAC systems. The coil tube transfers thermal energy between the circulating chilled/ heated water and the air stream driven by the fan assembly.
- Air Handling Units (AHUs): Used as cooling and heating coils in large-scale air distribution systems for commercial buildings, hospitals, and data centers.
- Industrial Heat Exchangers: Employed in shell-and-tube heat exchangers, plate heat exchangers, and custom thermal management systems across chemical, pharmaceutical, and food processing industries.
- Refrigeration and Cryogenic Systems: Suitable for evaporator and condenser coils in refrigeration systems requiring resistance to corrosive refrigerants and low-temperature operation.
- Water Heating Systems: Integral to instant water heating, solar thermal collectors, and domestic hot water recirculation loops.
- Process Cooling: Utilized in industrial process cooling loops for machinery, electronics cooling, and thermal regulation in manufacturing environments.
6. Quality Certifications and Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring compliance with international and national standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO 45001:2018 — Occupational Health and Safety Management System
- GB/T 14976 — Chinese National Standard for Cold-Rolled Seamless Stainless Steel Tubes
- GB/T 13296 — Chinese National Standard for Heat-Exchanger and Condenser Tubes
- ASTM A269 / A270 — American Standards for Seamless and Welded Austenitic Stainless Steel Tubing
- EN 10216-5 — European Standard for Stainless Steel Tubes for Heat Exchangers
- JIS G3459 — Japanese Industrial Standard for Austenitic Stainless Steel Tubes
All coil tube products are accompanied by a full Mill Test Certificate (MTC) in accordance with EN 10204 3.1, including chemical composition analysis, mechanical test results, dimensional verification data, and non-destructive testing (NDT) reports where applicable.
7. Unique Selling Points
- Superior Corrosion Resistance: Unlike carbon steel alternatives, the stainless steel coil tube eliminates the risk of internal corrosion, scaling, and fluid contamination — critical for potable water, food-grade, and pharmaceutical applications.
- Extended Service Life: With proper installation and maintenance, stainless steel coil tubes offer a service life exceeding 20–30 years, significantly outperforming conventional copper or carbon steel coils.
- Customizable Geometry: Wenzhou Jixing Metal Materials Co., Ltd. provides fully customizable coil dimensions, pitch configurations, and end treatments to meet specific OEM and ODM requirements.
- Energy Efficiency: The optimized coil geometry and high thermal conductivity of stainless steel contribute to improved heat transfer coefficients, reducing system energy consumption in fan coil and heat exchanger applications.
- Hygienic and Food-Safe: The smooth, non-porous surface of stainless steel coil tubes prevents bacterial growth and biofilm formation, meeting FDA and EHEDG hygiene standards.
- Sustainability: Stainless steel is 100% recyclable without loss of material properties, supporting circular economy principles and reducing environmental footprint.
8. Technical Notes and Recommendations
Installation Guidance: Coil tubes should be installed with proper support to prevent vibration-induced fatigue. Flexible connectors are recommended at inlet/outlet connections to absorb thermal expansion. All weld joints must be performed by certified welders using appropriate filler metals matched to the base material grade.
Maintenance: Periodic inspection of coil surfaces for signs of pitting or crevice corrosion is advised, particularly in high-chloride environments. Descaling procedures should use approved non-abrasive chemical methods compatible with stainless steel.
Storage: Store coil tubes in a dry, well-ventilated area away from direct contact with carbon steel to prevent galvanic staining. Maintain original protective packaging until installation.
9. Ordering Information
Wenzhou Jixing Metal Materials Co., Ltd. supports both standard catalog orders and custom-engineered coil tube solutions. Customers are encouraged to provide detailed specifications including material grade, dimensional requirements, quantity, and intended application for optimal product selection and quotation.
Product Reference: 序号 1238 — 盘管 (Coil Tube)
Company: Wenzhou Jixing Metal Materials Co., Ltd. (温州吉兴金属材料有限公司)