Stainless Steel Spiral Coil Tube — Composite Diaphragm Rising Tube Heat Exchanger Series
1. Product Overview
The Stainless Steel Spiral Coil Tube (Coil Tube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. (Product No. 584) is a precision-engineered tubular component designed for advanced heat exchanger systems. This product is specifically engineered for use in Composite Diaphragm Spiral Coil Structure Rising Tube Heat Exchangers (复合间壁螺旋盘管结构上升管换热器), where it serves as the primary heat transfer medium within a composite inter-wall configuration. The spiral coil geometry provides an exceptionally high surface-area-to-volume ratio, enabling superior thermal performance in both liquid-liquid and gas-liquid heat exchange applications.
This coil tube product has been developed based on rigorous research into the heat transfer characteristics of composite diaphragm spiral coil structures, incorporating findings on flow distribution uniformity, thermal resistance optimization, and pressure drop management within the rising tube configuration.
2. Material & Properties
2.1 Base Material Composition
- Primary Grade: Austenitic Stainless Steel (奥氏体不锈钢)
- Standard Grades: SUS304, SUS316, SUS316L, SUS321, and custom alloy compositions
- Compliance: ASTM A213/A213M, ASTM A269/A269M, GB/T 12771, EN 10216-5
2.2 Mechanical Properties (Typical for SUS316L)
- Tensile Strength (抗拉强度): ≥ 515 MPa
- Yield Strength (屈服强度): ≥ 205 MPa
- Elongation (伸长率): ≥ 40%
- Modulus of Elasticity (弹性模量): 193 GPa
- Thermal Conductivity (导热系数): 16.3 W/(m·K) at 20°C
2.3 Corrosion Resistance
- Pitting Resistance (点蚀抗力): PREN ≥ 24 (for SUS316L)
- Intergranular Corrosion Resistance (晶间腐蚀抗力): Certified per ASTM A240 Practice
- Chloride Stress Corrosion Cracking Resistance (氯化物应力腐蚀开裂抗力): Verified per ASTM G48
- Operating Temperature Range (工作温度范围): −196°C to +870°C
3. Technical Specifications
| Parameter | Specification | Standard / Note |
|---|---|---|
| Outer Diameter (OD) | Φ6 mm – Φ50 mm (customizable) | ±0.1 mm tolerance |
| Wall Thickness (壁厚) | 0.5 mm – 3.0 mm | ±0.05 mm tolerance |
| Coil Pitch (螺旋节距) | 5 mm – 50 mm | Configurable per application |
| Helix Diameter (螺旋直径) | Φ100 mm – Φ2000 mm | Custom fabrication available |
| Coil Length (盘管长度) | Up to 500 m continuous coil | Seamless drawing process |
| Surface Finish (表面光洁度) | Ra ≤ 0.4 μm (electropolished) | Or Ra ≤ 1.6 μm (passivated) |
| Pressure Rating (压力等级) | Up to 4.0 MPa (design) | Hydrostatic test at 1.5× design pressure |
| Thread End / Connection (端部连接) | Butt weld, threaded (BSP/NPT), flanged | Per customer specification |
| Composite Diaphragm Configuration (复合间壁结构) | Multi-layer spiral winding with inter-wall spacer | Per heat exchanger design |
| Insulation Layer (保温层) | Optional — ceramic fiber or PTFE coating | For thermal isolation applications |
4. Manufacturing Process
4.1 Raw Material Selection
High-purity stainless steel strip or seamless tube stock is sourced from certified mill suppliers with full traceability documentation (Mill Test Reports per EN 10204 Type 3.1). Incoming materials undergo spectroscopic verification (PMI testing) to confirm chemical composition compliance.
4.2 Coil Forming Process
- Coil Drawing (盘管拉拔): Seamless tube is cold-drawn through precision tooling to achieve target OD and wall thickness with controlled dimensional accuracy.
- Spiral Winding (螺旋卷绕): Automated CNC winding equipment forms the tube into a precise helical geometry with controlled pitch and helix diameter. The winding process maintains consistent curvature radius to prevent wall thinning or ovality.
- Composite Diaphragm Assembly (复合间壁装配): Multiple coil layers are wound with precision spacers or diaphragm plates between layers, creating the characteristic multi-channel rising tube structure. This composite configuration enhances flow distribution and thermal contact.
- Welding & Brazing (焊接与钎焊): End connections and layer-to-layer joints are fabricated using TIG (GTAW) welding or silver brazing, with full radiographic inspection (RT) for weld integrity.
4.3 Post-Processing
- Stress Relief Annealing (去应力退火): Solution annealing at 1050–1150°C followed by water quenching to restore full austenitic properties and relieve residual stresses from cold forming.
- Pickling & Passivation (酸洗钝化): Chemical treatment to remove oxidation scale and establish a protective chromium oxide passive layer (minimum Cr₂O₃ film thickness of 5 nm).
- Electropolishing (电解抛光): Optional electrochemical surface finishing to achieve Ra ≤ 0.4 μm for hygienic and low-fouling applications.
- Purity Cleaning (洁净清洗): Final degreasing and drying to ensure contamination-free interior surfaces.
5. Applications
5.1 Primary Application Domains
- Chemical Processing (化工工艺): Reactor cooling, distillation column condensers, and heat recovery systems where corrosion resistance and thermal efficiency are critical.
- Pharmaceutical Industry (制药行业): Clean-in-place (CIP) compatible heat exchangers for GMP-compliant processes, leveraging electropolished surfaces for sanitary requirements.
- Food & Beverage (食品饮料): Pasteurization, sterilization (UHT), and pasteurization heat exchangers with compliant surface finishes.
- Petrochemical (石油化工): Crude oil fractionation, refinery heat recovery, and LNG (Liquefied Natural Gas) processing equipment.
- Power Generation (发电): Waste heat recovery systems, economizers, and superheaters in combined cycle power plants.
- HVAC & Refrigeration (暖通空调): Compact heat exchangers for industrial cooling and chiller systems.
5.2 Specific Heat Exchanger Configurations
- Shell-and-tube heat exchangers (管壳式换热器) with spiral coil bundle
- Plate-and-fin (板式翅片) compact exchangers
- Double-pipe (套管式) heat exchangers with spiral inner tube
- Rising tube evaporators (上升管蒸发器) for refrigerant boiling applications
- Composite multi-wall heat exchangers with diaphragm-separated flow channels
6. Quality Certifications & Compliance
6.1 Management System Certifications
- ISO 9001:2015 — Quality Management System
- ISO 14001:2015 — Environmental Management System
- ISO 45001:2018 — Occupational Health & Safety Management System
6.2 Product & Material Certifications
- EN 10204 Type 3.1 — Mill Test Certificate with full chemical and mechanical analysis
- ASME Section IX — Welding procedure qualification (where applicable)
- PED (Pressure Equipment Directive) 2014/68/EU — CE marking for pressure equipment
- CRN (Canadian Registration Number) — For Canadian pressure vessel applications
- NSF/ANSI 61 — Drinking water system components (for food-grade applications)
- 3-A Sanitary Standards — For dairy and food processing applications
6.3 Testing & Inspection Protocols
- Hydrostatic Pressure Test (水压试验): 1.5× design pressure, 30-minute hold with zero leakage
- Helium Leak Detection (氦气检漏): Sensitivity ≤ 1×10⁻⁹ Pa·m³/s for critical applications
- Radiographic Testing (射线检测, RT): 100% inspection of all welded joints per ASTM E94
- Dimensional Inspection (尺寸检测): CMM (Coordinate Measuring Machine) verification of coil geometry
- Corrosion Testing (腐蚀试验): Salt spray (ASTM B117), intergranular corrosion (ASTM A240), and crevice corrosion testing
- Surface Roughness Verification (表面粗糙度验证): Contact profilometer measurement at multiple points along coil length
7. Unique Selling Points
7.1 Advanced Composite Diaphragm Design
The spiral coil tube incorporates a proprietary composite diaphragm structure that optimizes the balance between heat transfer coefficient enhancement and pressure drop minimization. Research into the thermal-hydraulic performance of multi-layer spiral coil configurations has yielded designs achieving 20–35% improvement in overall heat transfer coefficient (OTHC) compared to conventional single-layer coil arrangements, while maintaining acceptable frictional pressure losses.
7.2 Precision Manufacturing Capability
- Automated CNC winding ensures geometric consistency across entire production runs
- Full traceability from raw material mill certificate through final product delivery
- Customization capability for non-standard dimensions, pitch configurations, and multi-layer assemblies
- In-house laboratory for non-destructive testing (NDT) and chemical analysis
7.3 Engineering Support
- Thermal-hydraulic simulation and CFD (Computational Fluid Dynamics) analysis for application-specific optimization
- Material selection guidance based on process fluid compatibility (chloride content, pH, temperature)
- Finite Element Analysis (FEA) for mechanical integrity under thermal cycling and vibration conditions
- Field installation support and commissioning assistance
8. Conclusion
The Wenzhou Jixing Metal Materials Co., Ltd. Stainless Steel Spiral Coil Tube (Product No. 584) represents a state-of-the-art solution for high-efficiency heat exchange applications. Its composite diaphragm spiral coil structure, combined with premium austenitic stainless steel materials and rigorous quality assurance protocols, delivers exceptional thermal performance, long service life, and reliability in demanding industrial environments. The product's design is grounded in fundamental research into heat transfer characteristics of rising tube configurations, ensuring that engineering performance meets or exceeds theoretical predictions across the full operating envelope.