Stainless Steel Coil Tube (盘管) — Technical Specification
1. Product Overview
Stainless steel coil tubes (盘管, Coiltube), as supplied by Wenzhou Jixing Metal Materials Co., Ltd., are precision-engineered tubular products formed through continuous coiling of stainless steel tubing into planar or helical configurations. These products are primarily designed for thermal exchange applications, where the extended surface area provided by the coiled geometry significantly enhances heat transfer efficiency compared to straight tubular configurations.
Coil tubes find extensive use in heat exchangers, air conditioning systems, refrigeration coils, condensers, evaporators, and industrial process cooling/heating systems. The geometric arrangement of the coil—whether planar (flat spiral), helical, or serpentine—directly influences the fluid dynamics, pressure drop, and thermal performance of the system in which it is deployed.
Wenzhou Jixing Metal Materials Co., Ltd. specializes in the manufacturing and supply of high-quality stainless steel coil tubes conforming to international standards, offering a wide range of diameters, wall thicknesses, and coiling configurations tailored to specific application requirements.
2. Material & Properties
Coil tubes are manufactured from austenitic and duplex stainless steel grades, selected based on the specific environmental, mechanical, and corrosion-resistance demands of the application.
2.1 Commonly Available Grades
- SUS 304 / ASTM A213 TP304 — General-purpose corrosion resistance; suitable for food processing, chemical, and pharmaceutical applications.
- SUS 316 / ASTM A213 TP316 — Enhanced resistance to chlorides and pitting corrosion; ideal for marine, chemical, and high-purity environments.
- SUS 316L / ASTM A213 TP316L — Low-carbon variant of 316L; superior weldability and resistance to sensitization during welding operations.
- SUS 321 / ASTM A213 TP321 — Stabilized with titanium; excellent resistance to intergranular corrosion at elevated temperatures (up to 870°C).
- SUS 310S / ASTM A213 TP310S — High-temperature grade with exceptional oxidation resistance; suitable for furnace and kiln applications.
- SUS 304L / ASTM A213 TP304L — Low-carbon austenitic grade; preferred for welded assemblies requiring resistance to sensitization.
2.2 Key Physical and Mechanical Properties (Typical for SUS 304)
- Density (密度): 8.0 g/cm³
- Melting Point (熔点): 1400–1450°C
- Thermal Conductivity (热导率): 16.3 W/(m·K) at 100°C
- Specific Heat (比热容): 0.50 J/(g·K) at 100°C
- Tensile Strength (抗拉强度): ≥ 520 MPa
- Yield Strength (屈服强度): ≥ 205 MPa
- Elongation (延伸率): ≥ 40%
- Modulus of Elasticity (弹性模量): 193 GPa
- Maximum Service Temperature (最高使用温度): 870°C (continuous), 1093°C (intermittent)
3. Specifications
The following table presents the typical specification ranges for stainless steel coil tubes manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Custom dimensions are available upon request.
| Parameter (参数) | Specification Range (规格范围) | Standard Reference (标准参考) |
|---|---|---|
| Outer Diameter (OD, 外径) | 3.0 mm – 50.8 mm (1/8" – 2") | ASTM A213, EN 10216-5 |
| Wall Thickness (壁厚) | 0.30 mm – 3.00 mm | ASTM A213, GB/T 12771 |
| Coil Diameter (盘管直径) | 50 mm – 600 mm (customizable) | Customer-specific |
| Coil Height / Pitch (盘管高度/节距) | 10 mm – 200 mm (customizable) | Customer-specific |
| Tube Length (管长) | 1 m – 30 m (or as required) | ASTM A213 |
| Surface Finish (表面光洁度) | Ra 0.4 – 1.6 μm (polished); Ra 1.6 – 3.2 μm (pickled) | ASTM A269, EN 10217 |
| OD Tolerance (外径公差) | ±0.05 mm – ±0.10 mm | ASTM A213 |
| Wall Thickness Tolerance (壁厚公差) | ±10% of nominal | ASTM A213 |
| End Condition (端部状态) | Flat cut, beveled, threaded, or flanged | Customer-specific |
| Coiling Configuration (盘绕方式) | Planar (平面盘绕), Helical (螺旋盘绕), Serpentine (蛇形盘绕) | Customer-specific |
| Material Grades (材质牌号) | SUS 304, 304L, 316, 316L, 321, 310S, 2205 | ASTM A213, EN 10216-5, GB/T 12771 |
| Heat Treatment (热处理) | Solution annealed (固溶退火), pickled and passivated (酸洗钝化) | ASTM A213 |
4. Manufacturing Process
The production of stainless steel coil tubes involves a multi-stage manufacturing process designed to ensure dimensional accuracy, material integrity, and optimal surface quality:
- Raw Material Selection (原材料选择): Hot-rolled stainless steel coils or seamless tubes are procured from certified mills, with full chemical composition and mechanical property verification.
- Tube Forming (管材成型): Raw material is cold-drawn or cold-rolled into seamless tubing of the required outer diameter and wall thickness. For larger diameters, welded tube processes may be employed with full-penetration welds.
- Heat Treatment (热处理): Tubes undergo solution annealing at temperatures between 1010°C and 1150°C, followed by rapid water quenching to restore full austenitic structure and mechanical properties.
- Pickling and Passivation (酸洗钝化): Tubes are treated with nitric/hydrofluoric acid solutions to remove surface oxides and scale, followed by passivation to establish a protective chromium oxide layer.
- Coiling / Forming (盘绕成型): Using CNC-controlled coiling machines, tubes are precisely wound into the specified geometry—planar, helical, or serpentine. The coiling process is carefully controlled to avoid work hardening, cracking, or excessive springback. The coiling radius must exceed the minimum bend radius (typically 3× OD for seamless tubes) to prevent ovalization or wall thinning.
- Dimensional Inspection (尺寸检测): Finished coil tubes are inspected for outer diameter, wall thickness, coil diameter, pitch accuracy, and surface finish using laser measurement systems, ultrasonic thickness gauges, and visual inspection.
- Non-Destructive Testing (无损检测, NDT): Ultrasonic testing (UT) and magnetic particle inspection (MT) are performed to detect internal and surface defects.
- Packaging and Shipping (包装与运输): Finished products are packaged with protective wrapping, wooden crates, or pallets as specified, with full documentation including mill certificates, test reports, and dimensional drawings.
5. Applications
Stainless steel coil tubes are deployed across a broad spectrum of industrial and commercial applications, leveraging their corrosion resistance, thermal performance, and geometric flexibility:
5.1 Heat Exchangers (热交换器)
- Plate-and-frame heat exchangers
- Shell-and-tube heat exchangers (condensers, evaporators, reboilers)
- Air-to-water and water-to-water heat exchangers
5.2 HVAC and Refrigeration (暖通空调与制冷)
- Air conditioning evaporator and condenser coils
- Chiller systems and cold storage units
- Radiators and heating coils
5.3 Chemical and Petrochemical Industry (化工与石油行业)
- Process cooling and heating systems
- Distillation column condensers
- Reactor jacket cooling coils
- Corrosive fluid handling systems
5.4 Food and Pharmaceutical Industry (食品与制药行业)
- Pasteurization and sterilization equipment
- CIP (Clean-in-Place) systems
- Hygienic heat exchangers
5.5 Power Generation (电力发电)
- Boiler economizers and superheaters
- Turbine cooling systems
- Nuclear-grade heat transfer components
5.6 Marine and Offshore (海洋与海上工程)
- Ship engine cooling systems
- Ballast water heat exchangers
- Offshore platform cooling coils
6. Quality Certifications and Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and adheres to the following international and national standards and certifications:
6.1 Quality Management Systems
- ISO 9001:2015 — Quality Management Systems
- ISO 14001:2015 — Environmental Management Systems
- ISO 45001:2018 — Occupational Health and Safety Management Systems
6.2 Product Standards (产品标准)
- ASTM A213 / A213M — Standard Specification for Seamless Austenitic Stainless Steel Tubes for High-temperature Service
- ASTM A269 — Standard Specification for Seamless and Welded Austenitic Stainless Steel Sanitary Tubing
- EN 10216-5 — Thermally formed tubes for pressure purposes; austenitic stainless steel tubes
- EN 10217-7 — Tubes for pressure purposes; austenitic stainless steel tubes
- GB/T 12771 — Stainless steel seamless tubes for general application
- GB/T 13296 — Seamless stainless steel tubes for heat exchangers and heat transfer equipment
6.3 Testing and Inspection Standards
- ASTM E165 — Magnetic Particle Testing
- ASTM E233 — Ultrasonic Testing of Welds
- ASTM A320 — Chemical Analysis Methods for Stainless Steel
- ISO 10474-1 — Determination of surface roughness parameters
6.4 Third-Party Certifications
- EN 10204 3.1 / 3.2 — Inspection and Test Certificates
- NORSOK M-650 — Requirements for materials for the petroleum and natural gas industries (where applicable)
- PED 2014/68/EU — Pressure Equipment Directive compliance (where applicable)
- ASME Stamp — U Stamp or S Stamp certification for pressure vessels and piping (where applicable)
7. Unique Selling Points
- Customized Coiling Geometry (定制盘绕几何): Capable of producing planar, helical, and serpentine coil configurations with precise pitch control, enabling optimized heat transfer performance tailored to specific application requirements.
- Wide Material Range (广泛材质选择): Availability of multiple stainless steel grades including 304, 304L, 316, 316L, 321, 310S, and 2205, accommodating diverse corrosion and temperature environments.
- Precision Manufacturing (精密制造): CNC-controlled coiling processes ensure dimensional accuracy within ±0.10 mm tolerance, minimizing assembly issues and maximizing system performance.
- Comprehensive Quality Assurance (全面质量保证): Full traceability from raw material to finished product, with mill certificates, chemical analysis reports, mechanical test data, and NDT documentation provided with every shipment.
- Surface Quality (表面质量): Options for pickled, polished (Ra 0.4 μm), and sanitary-grade finishes, ensuring both aesthetic and functional requirements are met.
- Scalable Production (可扩展生产): Capable of producing both small-batch custom coils and high-volume production runs, with competitive lead times and pricing.
8. Technical Notes
Note on Coiling Method and Heat Transfer Performance: Research has demonstrated that the coiling configuration—planar versus helical—significantly influences the convective heat transfer coefficient and pressure drop characteristics of coil tubes. Planar coil tubes (平面盘管) generally exhibit higher heat transfer rates due to the induced secondary flow (Dean vortices) in the curved geometry, but at the cost of increased pressure drop. The optimal coiling configuration should be selected based on the specific thermal-hydraulic requirements of the application, balancing heat transfer efficiency against pumping power consumption. Wenzhou Jixing Metal Materials Co., Ltd. can provide engineering support and CFD-based simulation data to assist in the selection of the optimal coil geometry for a given application.
Storage and Handling: Coil tubes should be stored in a dry, well-ventilated environment, protected from moisture and atmospheric contaminants. During handling, avoid dropping or dragging coils to prevent surface damage and geometric distortion. When transporting, ensure adequate support to prevent deformation of the coiled geometry.
For detailed technical inquiries, custom specification requirements, or sample requests, please contact Wenzhou Jixing Metal Materials Co., Ltd. engineering and sales team.