Stainless Steel Coil Tube — Boiling Roasting Furnace Cooling Application
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered tubular product specifically designed for high-temperature industrial cooling applications, particularly in boiling roasting furnaces (沸腾焙烧炉). These coil tubes serve as critical heat-exchange elements within metallurgical and chemical processing equipment, where they absorb and dissipate intense thermal loads to maintain structural integrity of furnace linings and refractory components. The product is supplied in continuous coil form, enabling seamless integration into complex furnace geometries with minimal joint points — a design philosophy that significantly reduces the risk of leakage and thermal failure.
As demonstrated in technical case studies regarding the impact of cooling coil tube leakage on furnace body structure, the reliability and corrosion resistance of these tubes directly determine the operational safety and service life of the entire roasting system. Wenzhou Jixing Metal Materials addresses this critical engineering challenge through rigorous material selection, advanced manufacturing processes, and comprehensive quality assurance protocols.
Material & Properties
The coil tubes are fabricated from premium-grade austenitic stainless steels, selected for their exceptional combination of thermal stability, corrosion resistance, and mechanical strength under extreme operating conditions.
- Primary Grades: AISI 304 (UNS S30400), AISI 316 (UNS S31600), AISI 310 (UNS S31000), and custom alloy variants (e.g., 316L, 321, 347) depending on application-specific requirements.
- Key Alloying Elements: Chromium (Cr: 18–26%), Nickel (Ni: 8–22%), Molybdenum (Mo: up to 3%), Titanium (Ti), and Stabilized Carbon (C ≤ 0.03% for low-carbon grades).
- Operating Temperature Range: Up to 1100°C (2012°F) for 310-grade alloys; sustained service temperatures typically between 800–1050°C for boiling roasting furnace applications.
- Corrosion Resistance: Superior resistance to sulfidation, oxidation, acid attack, and chloride-induced pitting — essential in environments containing sulfur compounds common in non-ferrous metal smelting.
- Mechanical Properties: High tensile strength at elevated temperatures (retaining ≥60% of room-temperature strength at 800°C), excellent creep resistance, and dimensional stability under cyclic thermal loading.
- Thermal Conductivity: Optimized for efficient heat transfer while maintaining structural integrity; thermal expansion coefficient of approximately 17–18 × 10⁻⁶/°C.
Technical Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | Φ6 mm – Φ50 mm (custom sizes available) | ASTM A213 / GB/T 12771 |
| Wall Thickness (WT) | 0.5 mm – 4.0 mm | ASTM A269 / EN 10216 |
| Coil Width | Standard and custom configurations | Manufacturer Specification |
| Coil Length | Continuous coil — 50 m to 500 m per roll | — |
| Surface Finish | Ba&E (Bright & Annealed), No. 4 Brushed, 2B | ASTM A480 / GB/T 4237 |
| End Condition | Plain, beveled, or threaded per customer requirement | — |
| Tolerance (OD) | ±0.1 mm (precision grade available) | ASTM A213 Class 1/2 |
| Tolerance (WT) | ±10% of nominal | ASTM A213 |
| Heat Treatment | Solution Annealed (1050–1150°C) + Water Quenched | ASTM A213 |
| Maximum Operating Pressure | Up to 2.5 MPa (application-dependent) | ASME B31.3 |
| Maximum Operating Temperature | 1100°C (grade-dependent) | — |
Manufacturing Process
The production of high-performance stainless steel coil tubes follows a meticulously controlled multi-stage manufacturing workflow designed to ensure dimensional accuracy, microstructural homogeneity, and freedom from defects that could compromise in-service performance.
- Raw Material Selection & Incoming Inspection: Virgin stainless steel strip or hot-rolled coil is sourced from certified mills. Each batch undergoes spectroscopic analysis (OES) to verify chemical composition compliance with specified grade requirements.
- Slitting & Leveling: Wide coils are precision-slitted to target strip widths using high-speed slitting lines, followed by tension-leveling to eliminate coil set and ensure flatness.
- Forming & Welding: The leveled strip is fed through a series of progressively reducing forming rolls to achieve the target tube geometry. Seam welding is performed via High-Frequency Induction Welding (HFW) or TIG welding, producing weld seams with mechanical properties equivalent to the base metal.
- Heat Treatment (Solution Annealing): Welded tubes undergo solution annealing at 1050–1150°C followed by rapid water quenching. This process dissolves carbide precipitates, restores full austenitic structure, and maximizes corrosion resistance and ductility.
- Pickling & Passivation: Post-annealing oxide scale is removed through acid pickling (HNO₃/HF blend), followed by passivation treatment to establish a protective chromium oxide film on the surface.
- Precision Sizing & Straightening: Cold-drawing or cold-rolling sizing ensures dimensional tolerances are met. Final straightening eliminates any residual curvature.
- Non-Destructive Testing (NDT): Every coil undergoes 100% inline inspection including Eddy Current Testing (ECT) for wall thickness and internal defects, Hydrostatic Pressure Testing for seam integrity, and Visual Inspection for surface quality.
- Coiling & Packaging: Finished tubes are coiled on appropriate mandrels, wrapped in protective film, and palletized with moisture-absorbent desiccants for shipment.
Applications
The stainless steel coil tubes produced by Wenzhou Jixing Metal Materials Co., Ltd. find extensive application across demanding industrial sectors where thermal management and corrosion resistance are paramount:
- Boiling Roasting Furnaces (沸腾焙烧炉): Primary application — cooling tubes embedded in furnace walls and hearths to protect refractory linings from excessive thermal degradation during copper, zinc, lead, and nickel concentrate roasting operations.
- Non-Ferrous Metallurgy: Sintering furnaces, reduction shafts, and calcination kilns in copper, zinc, and nickel processing plants.
- Chemical Processing: Reactor cooling coils, heat exchanger bundles, and process piping in acid production (H₂SO₄), chlor-alkali, and petrochemical facilities.
- Power Generation: Boiler tubes, superheater elements, and condenser tubes in thermal power stations operating under high-temperature flue gas conditions.
- Cement & Ceramics Industry: Kiln cooling systems and preheater tubes in rotary kiln lines.
- Food & Pharmaceutical Processing: Sanitary-grade heat exchange coils requiring high purity and corrosion resistance (316L grade).
- Environmental Protection: Flue gas desulfurization (FGD) system components and scrubber internals.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework aligned with international standards to ensure every product batch meets the stringent demands of industrial end-users.
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO 45001:2018 — Occupational Health & Safety Management System
- EN 10204 3.1 — Third-party Material Test Certificate compliance for all product shipments
- Material Standards Compliance: ASTM A213, ASTM A269, GB/T 12771, GB/T 14976, EN 10216-5, JIS G3459
- Industry-Specific Approvals: PED (Pressure Equipment Directive) compliance for pressure-containing applications; ASME certification for export to North American markets
- In-House Testing Capabilities: Spectroscopy (OES), mechanical testing (tensile, hardness, impact), hydrostatic testing, ECT scanning, and metallographic analysis
Unique Selling Points
1. Engineering-Led Design for Furnace Integrity: Drawing upon documented technical case studies — including analyses of cooling coil leakage impacts on furnace body structural integrity — the product design prioritizes leak-free performance through optimized wall thickness, superior weld quality, and corrosion-resistant alloy selection. This proactive engineering approach minimizes unplanned shutdowns and extends furnace campaign life.
2. Customizable Geometry: The coil form factor allows for flexible on-site bending and shaping to accommodate complex furnace geometries without requiring field welding — reducing potential failure points.
3. Extended Service Life: Solution-annealed austenitic stainless steel with high Cr/Ni content provides resistance to sulfidation and thermal cycling fatigue, delivering service lives 2–3× longer than conventional carbon steel alternatives in the same operating environment.
4. End-to-End Traceability: Every coil is traceable to its mill heat number through a digital quality record system, enabling full lifecycle accountability.
5. Technical Support & After-Sales Engineering: The manufacturer provides application engineering support for coil routing design, thermal stress analysis, and installation guidance specific to boiling roasting furnace configurations.
Conclusion
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. represents a purpose-engineered solution for the critical challenge of cooling system reliability in high-temperature metallurgical furnaces. By integrating premium alloy chemistry, precision manufacturing, rigorous quality assurance, and application-specific engineering expertise, the product delivers the durability, corrosion resistance, and dimensional precision required to safeguard furnace structural integrity and maximize operational uptime in the most demanding industrial environments.