Stainless Steel Coil Tube (盘管) — Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The Stainless Steel Coil Tube (盘管, Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered continuous tubular product formed into a helical or spiral coil configuration. This product is designed for demanding thermal-fluid exchange applications where uniform flow distribution, high thermal efficiency, and long-term corrosion resistance are critical performance parameters. The coil geometry inherently provides an extended heat transfer surface area within a compact spatial footprint, making it an ideal solution for heat screen exchangers, process heating systems, and high-temperature industrial environments.
Based on extensive experimental research into flow distribution characteristics (流量分配) in heat screen heat exchangers (热屏换热器), this coil tube product is specifically optimized to ensure homogeneous fluid distribution across parallel channels, thereby minimizing flow maldistribution-induced thermal stress and improving overall system reliability and heat transfer performance.
2. Material & Properties
The Stainless Steel Coil Tube is fabricated from high-purity austenitic and austenitic-ferritic stainless steel grades, selected for their exceptional combination of mechanical strength, oxidation resistance, and thermal stability at elevated operating temperatures.
2.1 Available Grades
- ASTM 304 / 304L — General-purpose corrosion resistance with excellent formability
- ASTM 316 / 316L — Enhanced chloride resistance for aggressive chemical environments
- ASTM 321 — Stabilized against intergranular corrosion for high-temperature service
- ASTM 347 — Titanium-stabilized grade for sustained high-temperature applications
- ASTM 310 / 310S — High-temperature creep resistance for furnace and heat screen applications
- ASTM 316L Ti — Low-carbon titanium-stabilized grade for welded coil assemblies
2.2 Key Mechanical Properties
- Tensile Strength (抗拉强度): 515–720 MPa (depending on grade)
- Yield Strength (屈服强度): 205–310 MPa
- Elongation (延伸率): ≥30% (annealed condition)
- Operating Temperature Range (工作温度范围): −196°C to +1150°C
- Thermal Conductivity (热导率): 14.9–16.3 W/(m·K)
- Specific Heat Capacity (比热容): 498–502 J/(kg·K)
2.3 Corrosion Resistance
- Outstanding resistance to atmospheric, acidic, and alkaline corrosion
- Superior resistance to intergranular corrosion (IGC) in stabilized grades
- Effective resistance to stress corrosion cracking (SCC) in chloride-containing environments
- Long-term oxidation resistance at temperatures up to 1100°C
3. Specifications
| Parameter (参数) | Specification Range | Standard / Reference |
|---|---|---|
| Outer Diameter (外径, OD) | 6.0 mm – 159.0 mm | ASTM A213 / ASME B36.19M |
| Wall Thickness (壁厚) | 0.5 mm – 6.0 mm | ASTM A213 |
| Coil Diameter (盘管直径) | 100 mm – 2000 mm | Custom (按需定制) |
| Coil Pitch (螺距) | 5 mm – 50 mm | Custom (按需定制) |
| Tube Length per Coil (单圈长度) | Up to 500 m continuous | ASME B36.19M |
| Surface Finish (表面光洁度) | Ra ≤ 0.4 μm (polished) / Ra ≤ 1.6 μm (annealed) | ASTM A240 |
| End Condition (端部状态) | Plain, beveled, or threaded | ASME B31.3 |
| Pressure Rating (压力等级) | Up to 40 MPa (design dependent) | ASME B31.3 / PED 2014/68/EU |
| Heat Treatment (热处理) | Solution annealed at 1040°C–1120°C with water or air quench | ASTM A213 |
| Tolerance (公差) | ±0.05 mm (OD) / ±0.05 mm (wall thickness) | ASTM A213 |
| Welding Quality (焊接质量) | 100% radiographic testing (RT) or ultrasonic testing (UT) | ASME Section IX / EN 12513 |
| Coil Packing (盘管包装) | Wooden crate with desiccant, protective wrapping | ISO 4180 |
4. Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous multi-stage manufacturing workflow adhering to international quality standards:
4.1 Process Flow
- Raw Material Inspection (原材料检验): Incoming stainless steel bar stock or seamless tube is verified for chemical composition (spectroscopic analysis), mechanical properties, and dimensional conformity per ASTM A213 specifications.
- Heat Treatment (热处理): Solution annealing at 1040°C–1120°C followed by rapid water or air quenching to achieve the desired austenitic microstructure and eliminate residual stresses.
- Pipe Drawing / Seamless Forming (拉拔/无缝成型): Multi-pass cold drawing or hot forming to achieve precise outer diameter and wall thickness tolerances.
- Coil Winding (盘绕成型): Computer-controlled coil winding machine forms the tube into the specified helical geometry with uniform pitch, diameter, and curvature radius. CNC precision ensures geometric accuracy critical for flow distribution performance.
- Post-Winding Stress Relief (盘绕后应力消除): Controlled tempering to relieve residual bending stresses while maintaining dimensional stability of the coil geometry.
- Surface Treatment (表面处理): Electropolishing, passivation (nitric acid or citric acid treatment), or pickling to achieve the required surface finish and enhance corrosion resistance.
- Quality Inspection (质量检测): Comprehensive testing including dimensional measurement, hydrostatic pressure testing (水压试验), radiographic testing (RT), and visual inspection.
- Packaging (包装): Protective wrapping, moisture-proof packaging, and secure wooden crate assembly for safe transportation.
4.2 Flow Distribution Optimization
Incorporating findings from heat screen heat exchanger flow distribution experiments (热屏换热器流量分配实验), the coil geometry is engineered to promote uniform flow allocation across parallel flow channels. Key design considerations include:
- Optimized coil pitch and diameter to minimize pressure drop maldistribution
- Smooth curvature transitions to reduce secondary flow effects
- Consistent wall thickness to ensure uniform hydraulic resistance
- Proper end-connection design for balanced inlet/outlet flow entry
5. Applications
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. serves a wide range of high-performance industrial applications:
5.1 Primary Applications
- Heat Screen Heat Exchangers (热屏换热器): Primary application — protection of boiler tubes and process equipment from high-temperature radiant heat
- Boiler Systems (锅炉系统): Economizers, superheaters, and air preheaters in power generation plants
- Petrochemical Processing (石化加工): Reactor internals, process heating coils, and heat recovery systems
- Food and Beverage Industry (食品饮料行业): Sanitary-grade heat exchangers for pasteurization and sterilization
- Pharmaceutical Manufacturing (制药行业): Clean-in-place (CIP) compatible thermal processing equipment
- Marine Engineering (海洋工程): Seawater heat exchangers and condensate recovery systems
- Automotive Industry (汽车工业): Exhaust heat recovery and thermal management systems
- Renewable Energy (可再生能源): Solar thermal collectors and geothermal heat exchange systems
5.2 Operating Conditions
- High-temperature environments (up to 1150°C)
- High-pressure systems (up to 40 MPa)
- Corrosive chemical environments (acids, alkalis, chlorides)
- Vacuum conditions (cryogenic to ambient)
- Continuous and cyclic thermal loading
6. Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system ensuring full traceability and compliance with international standards:
6.1 Certifications & Standards
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ASME Certificate of Compliance — Section IX (Welding) and Section VIII (Pressure Vessels)
- EN 10204 3.1 — Material test certificates per European standard
- EN 10204 3.2 — Third-party inspection certificates (available upon request)
- CE Marking — Conformity with European directives (PED 2014/68/EU)
- TÜV / Lloyd's Register — Third-party inspection and approval (available)
- SGS Testing — Independent material and dimensional verification
6.2 Inspection & Testing Protocol
- 100% hydrostatic pressure testing (水压试验) per ASTM A213
- Radiographic testing (RT) or ultrasonic testing (UT) for weld integrity
- Spectroscopic chemical composition analysis (光谱成分分析)
- Hardness testing (硬度测试) — Rockwell B or Vickers
- Intergranular corrosion testing (晶间腐蚀测试) — ASTM A262 Practice E
- Dimensional measurement verification (尺寸检测)
- Visual surface inspection (表面目视检查) — 100% coverage
6.3 Traceability
Every coil tube product is accompanied by a complete quality documentation package including mill test certificates (MTC), heat number traceability, dimensional inspection reports, pressure test records, and non-destructive testing (NDT) results. Full batch traceability from raw material to finished product is maintained in accordance with ISO 9001 requirements.
7. Unique Selling Points
- Flow Distribution Optimized Geometry: Coil dimensions engineered based on empirical flow distribution data from heat screen heat exchanger experiments, ensuring uniform flow allocation and superior thermal performance
- Wide Material Selection: Multiple stainless steel grades available to match specific operating conditions and corrosion environments
- Precision Manufacturing: CNC-controlled coil winding with ±0.05 mm dimensional accuracy for consistent performance
- Custom Configuration: Flexible customization of coil diameter, pitch, tube dimensions, and end conditions to meet project-specific requirements
- Comprehensive Quality Assurance: Multi-stage inspection protocol with full traceability documentation
- International Standard Compliance: Products manufactured to ASTM, ASME, and EN standards with CE marking available
8. Ordering Information
For technical consultation, custom quotations, and sample requests, please contact Wenzhou Jixing Metal Materials Co., Ltd. directly. Technical support is available for application-specific design optimization, including flow distribution analysis and thermal performance simulation.
Note: All specifications are subject to verification based on actual order requirements. Custom configurations may require extended lead times. Material availability and pricing are subject to change without prior notice.