Stainless Steel Coil Tube (Coiltube) — Ice Storage Air Conditioning Grade
Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd., specifically designed for ice-storage coil-tube air conditioning systems (Ice Storage Coil Tube Air Conditioning Systems). This product is supplied in continuous coil form, enabling efficient forming, welding, and assembly into large-scale thermal storage units. The coil tube serves as the primary heat exchange conduit within ice storage air conditioning systems, where it facilitates the transfer of thermal energy between the refrigerant circuit and the phase-change ice storage medium.
Based on experimental research findings (as documented in the study "Experimental Research on Ice Storage Coil Tube Air Conditioning"), this coil tube has been validated for reliable performance under cyclic freezing and thawing conditions, demonstrating excellent thermal conductivity, dimensional stability, and long-term structural integrity in demanding HVAC (Heating, Ventilation, and Air Conditioning) environments.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its superior combination of corrosion resistance, mechanical strength, and thermal performance:
- Material Grade: SUS304 / SUS316L (Austenitic Stainless Steel)
- Composition (SUS304): Chromium (Cr) ≥ 18%, Nickel (Ni) ≥ 8%, Carbon (C) ≤ 0.08%
- Composition (SUS316L): Chromium (Cr) ≥ 16%, Nickel (Ni) ≥ 10%, Molybdenum (Mo) ≥ 2%, Carbon (C) ≤ 0.03%
- Thermal Conductivity: 14–16 W/(m·K) at 20°C
- Operating Temperature Range: −196°C to +870°C
- Corrosion Resistance: Excellent resistance to chloride-induced pitting (especially SUS316L), acidic condensate, and deicing brine solutions
- Yield Strength: ≥ 205 MPa (SUS304), ≥ 170 MPa (SUS316L)
- Surface Finish: 2B / No.4 / Electropolished (Ra ≤ 0.4 μm available upon request)
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6 mm – 50 mm (custom sizes available) | GB/T 14976 / ASTM A269 |
| Wall Thickness | 0.5 mm – 3.0 mm | GB/T 14976 / ASME B36.19M |
| Coil Inner Diameter | 400 mm – 1200 mm | Manufacturer Specification |
| Coil Length per Spool | Up to 500 m (continuous) | Manufacturer Specification |
| Tolerance on OD | ±0.1 mm (OD ≤ 25 mm); ±0.15 mm (OD > 25 mm) | GB/T 14976 |
| Tolerance on Wall Thickness | ±10% of nominal | GB/T 14976 |
| Roundness | ≤ 1% of OD | GB/T 14976 |
| Hardness | ≤ 210 HV (Annealed Condition) | ASTM A269 |
| Delivery Condition | Annealed (A), Solution Treated | ASTM A269 |
| End Form | Plain cut / Chamfered / Threaded (upon request) | — |
| Protective Packaging | VCI (Vapor Corrosion Inhibitor) film, wooden spool | ISO 4180 |
Manufacturing Process
The production of this stainless steel coil tube follows a rigorous, multi-stage manufacturing workflow ensuring dimensional accuracy and metallurgical quality:
- Hot Rolling: Stainless steel strip is hot-rolled to approximate dimensions under controlled temperature conditions.
- Pickle & Passivation: The strip undergoes acid pickling to remove mill scale, followed by passivation to form a protective chromium oxide layer.
- Cold Forming / Seamless Tube Making: The strip is formed into a tubular shape using a seamless tube-forming process (e.g., roll-bonded or weld-seam methods), maintaining tight dimensional tolerances.
- Precision Cold Drawing: The formed tube is cold-drawn through calibrated dies to achieve exact OD, wall thickness, and roundness specifications.
- Intermediate Annealing: Periodic annealing at 1050°C–1100°C relieves work hardening and restores ductility during multi-pass drawing.
- Final Annealing & Pickling: The finished tube undergoes final solution annealing and acid pickling to achieve the required mechanical properties and surface finish.
- Coiling: The continuous tube is wound onto precision steel spools using a tension-controlled coiling head to prevent deformation or kinking.
- Quality Inspection: Each spool undergoes dimensional measurement, hydrostatic pressure testing, and surface inspection prior to packaging.
Applications
This coil tube is purpose-engineered for the following industrial and commercial applications:
- Ice Storage Air Conditioning Systems: Primary application — the coil tube forms the serpentine heat exchange coils within ice storage tanks, enabling off-peak cooling energy storage and peak-load demand reduction.
- Commercial HVAC Systems: Large-scale commercial refrigeration and air conditioning installations requiring high-efficiency thermal storage.
- Industrial Process Cooling: Thermal management in chemical processing, pharmaceutical manufacturing, and food preservation facilities.
- Heat Exchanger Fabrication: Raw material for manufacturing shell-and-tube heat exchangers, plate-fin coils, and condensing/evaporating units.
- Specialty Applications: Cryogenic systems, medical equipment, and food-grade fluid transport where corrosion resistance and hygiene are critical.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring product traceability and conformance to international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- Product Standards Compliance: GB/T 14976 (China National Standard), ASTM A269/A269M, EN 10217-7, JIS G3446
- Material Certification: Each batch is accompanied by a Mill Test Certificate (MTC) per EN 10204 3.1, including chemical composition analysis and mechanical property verification.
- Non-Destructive Testing (NDT): Electromagnetic (Eddy Current) testing and hydrostatic pressure testing performed on all production lots.
- Third-Party Inspection: Available upon customer request (SGS, Bureau Veritas, TÜV Rheinland).
Unique Selling Points
1. Validated for Ice Storage Applications: This coil tube has been experimentally validated in ice storage air conditioning systems, demonstrating reliable thermal cycling performance through hundreds of freeze-thaw cycles without degradation of mechanical or thermal properties.
2. Superior Corrosion Resistance: The austenitic stainless steel construction provides outstanding resistance to brine solutions, condensate acids, and chlorinated deicing agents commonly encountered in ice storage environments.
3. Precision Continuous Supply: Available in continuous coil lengths up to 500 meters, minimizing weld joints and reducing potential leak points in large-scale coil assembly.
4. Customizable Specifications: Flexible customization of OD, wall thickness, surface finish, and coil dimensions to meet specific project requirements.
5. Full Traceability: Complete material traceability from raw material to finished product, with comprehensive test documentation provided for every shipment.
Conclusion
The Wenzhou Jixing Stainless Steel Coil Tube represents a premium-grade tubular solution specifically suited for ice storage air conditioning and high-performance thermal management applications. Its combination of metallurgical excellence, dimensional precision, and validated field performance makes it an ideal choice for engineers and OEMs (Original Equipment Manufacturers) seeking reliable, long-life heat exchange components in demanding HVAC and industrial cooling systems.