Stainless Steel Coil Tube (Coiltube) — Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered continuous-length tubing product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is supplied in a coiled configuration, offering superior flexibility in downstream forming, bending, and fabrication processes. The coil tube is specifically designed for applications requiring high thermal conductivity, corrosion resistance, and mechanical durability, including but not limited to heat exchange systems, ice-melting trough systems (such as those studied in external ice-melting trough ice-melting process research), refrigeration circuits, and industrial fluid transport systems.
The coiled delivery format eliminates the need for field splicing or welding during installation, thereby reducing leak points, minimizing thermal resistance at joints, and improving overall system reliability. This makes the product particularly suitable for applications where uninterrupted fluid flow and uniform heat transfer are critical, such as the coil-type external ice-melting trough systems investigated in thermal engineering research on heat absorption characteristics.
2. Material & Properties
2.1 Base Material
The coil tube is manufactured from high-grade austenitic stainless steel, with 304 (UNS S30400) and 316 (UNS S31600) being the primary grades offered. Additional grades such as 321, 316L, and custom alloys are available upon request to meet specific service environment requirements.
2.2 Mechanical Properties
- Tensile Strength: 515–720 MPa (depending on grade and cold-work condition)
- Yield Strength (0.2% offset): 205–310 MPa
- Elongation at Break: 35–60%
- Hardness: 80–120 HRB (annealed condition)
2.3 Thermal Properties
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 20°C
- Specific Heat Capacity: 0.50 J/(g·K)
- Thermal Expansion Coefficient: 16–17.5 × 10⁻⁶ /°C
- Operating Temperature Range: −196°C to +870°C (304 grade); −196°C to +925°C (316 grade)
2.4 Corrosion Resistance
The austenitic microstructure provides excellent resistance to pitting, crevice corrosion, and general atmospheric corrosion. The 316 grade, with its 2–3% molybdenum content, offers enhanced resistance to chloride-induced stress corrosion cracking (SCC) and is recommended for marine, chemical processing, and de-icing fluid environments.
3. Specifications
| Parameter | Specification |
|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) |
| Product Code | No. 1298 |
| Material Grades | 304, 304L, 316, 316L, 321, Custom Alloy |
| Outer Diameter (OD) | Φ3 mm – Φ102 mm |
| Wall Thickness | 0.3 mm – 6.0 mm |
| Coil Length | 50 m – 500 m (custom lengths available) |
| Coil Inner Diameter (CID) | Φ200 mm – Φ600 mm |
| Surface Finish | 2B, BA (Bright Annealed), No. 4, No. 8 (Mirror), Custom |
| Tolerance (OD) | ±0.05 mm to ±0.10 mm (precision grade) |
| Tolerance (Wall Thickness) | ±10% (standard); ±5% (precision) |
| Standards Compliance | ASTM A269, ASTM A213, GB/T 12771, EN 10216-5 |
| Packaging | Wooden pallet with moisture-proof wrapping; export-grade packaging available |
4. Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous multi-stage manufacturing workflow to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection: Hot-rolled stainless steel strip of certified composition is procured from qualified mill suppliers and subjected to incoming inspection for chemical composition and mechanical properties.
- Coiling & Straightening: The strip is coiled onto precision-mandrel coils and undergoes straightening to ensure uniform tension and eliminate residual stress from the coiling process.
- Piercing / Extrusion: The coil is fed through a precision extrusion die to form the initial tube geometry at controlled temperatures to prevent work hardening and maintain microstructural homogeneity.
- Cold Drawing: The extruded tube is cold-drawn through a series of dies to achieve the final outer diameter and wall thickness specifications with tight dimensional tolerances.
- Solution Annealing: The drawn tube is solution-annealed at 1050°C–1150°C followed by controlled cooling to relieve residual stresses, restore full austenitic ductility, and achieve the desired mechanical properties.
- Pickling & Passivation: The annealed tube undergoes acid pickling to remove oxide scale, followed by passivation treatment to form a protective chromium oxide layer, ensuring optimal corrosion resistance.
- Surface Finishing: Depending on the order specification, the tube may receive additional surface treatments including mechanical polishing, electropolishing, or chemical brightening to achieve the required surface finish grade.
- Final Coiling: The finished tube is coiled onto a precision core with controlled tension to prevent ovality, kinking, or deformation during storage and transportation.
- Quality Inspection: Each coil undergoes 100% visual inspection, dimensional verification, hydrostatic pressure testing (where applicable), and sampling for chemical analysis and mechanical testing.
5. Applications
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. is engineered for demanding industrial and commercial applications, including:
- Heat Exchange Systems: The coil configuration provides an extended surface area within a compact volume, making it ideal for air-to-fluid and fluid-to-fluid heat exchangers, condensers, evaporators, and reboilers.
- Ice-Melting & De-Icing Systems: As demonstrated in research on coil-type external ice-melting trough systems, the continuous coiled tube geometry enables uniform heat distribution across the trough surface, achieving efficient and controlled ice-melting with optimized heat absorption characteristics. The seamless coil eliminates thermal bridging at joints, ensuring consistent melt performance.
- Refrigeration & HVAC: Used as refrigerant lines and condenser coils in commercial and industrial refrigeration systems, as well as in HVAC air handling units.
- Food & Pharmaceutical Processing: The hygienic surface finish and corrosion resistance make the coil tube suitable for food-grade fluid transfer, CIP (Clean-In-Place) systems, and pharmaceutical process lines.
- Chemical & Petrochemical Processing: Resistant to a wide range of corrosive media, the coil tube is employed in chemical reactor circulation loops, heat recovery systems, and process fluid transport.
- Automotive & Aerospace: Used in fuel lines, exhaust systems, hydraulic circuits, and thermal management systems where lightweight, corrosion-resistant tubing is required.
- Marine & Offshore: The 316 and 316L grades provide the necessary resistance to chloride-laden marine environments for ballast water systems, seawater cooling loops, and desalination plants.
6. Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system to ensure product consistency and compliance with international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ASTM A269 / A213 — Compliance with American Society for Testing and Materials standards for austenitic stainless steel tubing
- EN 10216-5 — Compliance with European standard for austenitic seamless and welded tubes
- GB/T 12771 — Compliance with Chinese National Standard for stainless steel seamless tubes
- Mill Test Reports (MTR) — Full chemical analysis and mechanical property documentation provided with each shipment
- Third-Party Inspection — Available upon request (SGS, BV, TÜV)
- Material Traceability — Full heat-number traceability from raw material mill through final product delivery
7. Unique Selling Points
Seamless Continuous Coil Geometry: The uninterrupted coil configuration eliminates field welds and mechanical couplings, significantly reducing the risk of leakage and thermal resistance discontinuities — a critical advantage in heat-exchange and ice-melting applications where uniform thermal performance is paramount.
Research-Validated Thermal Performance: The coil tube geometry has been validated through experimental research on coil-type external ice-melting trough systems, demonstrating superior heat absorption characteristics and uniform temperature distribution compared to segmented or straight-pipe configurations.
Precision Dimensional Control: Tolerances as tight as ±0.05 mm on outer diameter ensure seamless integration into precision-engineered systems, reducing assembly time and improving system reliability.
Multi-Grade Material Flexibility: Availability in 304, 316, 316L, and custom alloy grades allows engineers to tailor material selection to specific corrosive environments, operating temperatures, and regulatory requirements.
Full Supply Chain Traceability: Every coil is backed by complete mill documentation, chemical analysis reports, and mechanical test certificates, ensuring full compliance with stringent industry regulations and enabling rapid root-cause analysis if required.
Custom Fabrication Capability: Wenzhou Jixing Metal Materials Co., Ltd. offers custom coil diameters, lengths, wall thicknesses, and surface finishes to meet project-specific requirements, supported by an experienced engineering team for application-specific consultation.
8. Conclusion
The Stainless Steel Coil Tube (Coiltube, Product No. 1298) from Wenzhou Jixing Metal Materials Co., Ltd. represents a high-performance, precision-manufactured solution for industrial applications demanding corrosion resistance, thermal efficiency, and mechanical reliability. Backed by rigorous quality control, international standard compliance, and research-validated thermal performance, this product is an optimal choice for heat exchange, de-icing, and fluid transport systems across diverse industries.