Stainless Steel Coil Tube (盘管 / Coiltube) — Technical Specification
Product No.: 804 | Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd. (温州吉星金属材料有限公司)
1. Product Overview
The Stainless Steel Coil Tube (盘管) is a precision-engineered tubular product formed by cold-rolling or drawing stainless steel strip into a continuous helical coil configuration. Unlike straight seamless or welded pipes, coil tubes are manufactured in continuous lengths wound into coils, offering superior material utilization, reduced waste, and enhanced flexibility for downstream processing. This product line encompasses a wide range of diameters, wall thicknesses, and coil configurations tailored for demanding industrial applications in the energy, chemical processing, food and beverage, pharmaceutical, and nuclear industries.
The technical foundation of this product line is underpinned by rigorous structural dynamics research, specifically the methodology documented in "Layered Testing to Determine Dynamic Boundary Conditions and Sensitivity Analysis of Spiked Coil Tubes" (《分层试验确定刺片式盘管动力学边界条件及灵敏度分析》). This research establishes the mechanical boundary conditions, dynamic response characteristics, and sensitivity parameters governing the structural integrity of coil tubes under operational loading — ensuring that every coil tube produced meets the highest standards of dimensional accuracy, mechanical reliability, and service performance.
2. Material Composition and Properties
2.1 Available Grades
- Austenitic Grades: AISI 304 (UNS S30408), AISI 316 (UNS S31608), AISI 316L (UNS S31603), AISI 321 (UNS S32108), AISI 347 (UNS S34708)
- Duplex Grades: AISI 2205 (UNS S31803), AISI 2507 (UNS S32750)
- Super Duplex Grades: Alloy 2507, Alloy 630
- Custom / Special Grades: Available upon request per ASTM, EN, JIS, GB, or customer-specific specifications
2.2 Mechanical Properties (Typical Values for Grade 316L)
| Property | Symbol | Typical Value | Standard |
|---|---|---|---|
| Tensile Strength (抗拉强度) | σb | ≥ 515 MPa (75 ksi) | ASTM A213 |
| Yield Strength (屈服强度) | σ0.2 | ≥ 205 MPa (30 ksi) | ASTM A213 |
| Elongation (延伸率) | A50 | ≥ 40% | ASTM A213 |
| Density (密度) | ρ | 8.0 g/cm³ | — |
| Thermal Conductivity (热导率) | λ | 16.3 W/(m·K) @ 100°C | — |
| Thermal Expansion Coefficient (热膨胀系数) | α | 16.0 × 10⁻⁶ /K (20–100°C) | — |
2.3 Chemical Composition (Grade 316L — Typical)
| C | Si | Mn | P | S | Cr | Ni | Mo | N |
|---|---|---|---|---|---|---|---|---|
| ≤ 0.030 | ≤ 1.00 | ≤ 2.00 | ≤ 0.045 | ≤ 0.030 | 16.00–18.00 | 10.00–14.00 | 2.00–3.00 | ≤ 0.10 |
3. Dimensional Specifications
| Parameter | Specification | Tolerance |
|---|---|---|
| Outer Diameter (OD) (外径) | Φ 3.0 mm – Φ 200.0 mm | ± 0.05 mm (small OD); ± 0.15% OD (large OD) |
| Wall Thickness (壁厚) | 0.3 mm – 12.0 mm | ± 10% of nominal |
| Coil Inner Diameter (CD) (盘管内径) | 100 mm – 600 mm | ± 10 mm |
| Coil Outer Diameter (最大外径) | 200 mm – 1200 mm | ± 15 mm |
| Coil Length per Spool (每盘长度) | Up to 500 m (continuous) | As specified |
| Coil Weight per Spool (每盘重量) | Up to 5,000 kg | As specified |
| End Condition (端部状态) | Clean cut / Beveled / Threaded / Flanged | Per drawing |
| Surface Finish (表面光洁度) | 2B / BA / Pickled & Passivated / Custom | Ra ≤ 0.8 μm (BA finish) |
4. Manufacturing Process
4.1 Production Flow
- Raw Material Inspection (原材料检验): Incoming stainless steel strip or wire rod is inspected for chemical composition (spectrographic analysis), mechanical properties, and surface quality per ASTM A240 / A269 / GB/T 14976 standards.
- Strip Preparation (带材预处理): The strip undergoes annealing (退火) and pickling (酸洗) to achieve the required solution-treated microstructure, followed by passivation (钝化) to form a protective chromium oxide film.
- Cold Forming / Coiling (冷成型/盘卷): The strip is cold-rolled and wound into coil configuration using precision CNC-controlled forming equipment. Critical process parameters include:
- Forming speed control to prevent work hardening (加工硬化) beyond acceptable limits
- Helical pitch (螺旋节距) accuracy maintained within ± 0.1 mm
- Residual stress (残余应力) management through controlled springback compensation
- Intermediate Annealing (中间退火): For multi-pass forming sequences, intermediate annealing at 1050°C–1150°C restores ductility and eliminates accumulated strain, ensuring uniform mechanical properties throughout the coil.
- Final Heat Treatment (最终热处理): Solution annealing (固溶处理) followed by controlled air or water quenching to achieve full austenitic microstructure with optimal corrosion resistance and mechanical performance.
- Precision Sizing & Straightening (精整与矫直): Final dimensional accuracy is achieved through rotary sizing and straightening operations, with online laser measurement systems providing real-time dimensional feedback.
- Surface Finishing (表面处理): Depending on application requirements, the coil tube receives pickling (酸洗), passivation (钝化), bright annealing (BA finish), or electropolishing (电解抛光) treatment.
- Non-Destructive Testing (无损检测): 100% inspection using:
- Eddy Current Testing (ECT, 涡流检测) for internal and external surface defects
- Hydrostatic Pressure Testing (水压试验) at 1.5× working pressure for leak integrity
- Magnetic Particle Inspection (MT, 磁粉检测) for surface-breaking defects (where applicable)
- Final Coiling & Packaging (最终盘卷与包装): Coils are wound onto steel cores, wrapped with moisture-proof protective film, and secured with steel strapping. Each coil is tagged with a unique heat number, mill test report reference, and traceability code.
4.2 Dynamic Boundary Condition Analysis (动力学边界条件分析)
As established in the referenced research ("Layered Testing to Determine Dynamic Boundary Conditions and Sensitivity Analysis of Spiked Coil Tubes"), the structural performance of coil tubes is critically dependent on accurately characterized dynamic boundary conditions. This research employs a layered testing methodology (分层试验法) to isolate and quantify:
- Boundary Constraint Parameters (边界约束参数): The rotational stiffness (转动刚度) and translational restraint (平动约束) at coil tube connection points under dynamic loading.
- Sensitivity Analysis (灵敏度分析): Quantitative assessment of how variations in material properties, geometric parameters, and loading conditions affect the natural frequencies (固有频率) and mode shapes (振型) of the coil tube assembly.
- Vibration Response Characteristics (振动响应特性): The amplitude-frequency response (幅频响应) and phase-frequency response (相频响应) under operational excitation.
This analytical framework ensures that coil tubes are engineered with appropriate safety margins (安全裕度) against fatigue failure (疲劳失效), vibration-induced degradation (振动导致的性能退化), and dynamic overload (动态过载) conditions throughout their service life.
5. Applications
5.1 Primary Application Sectors
- Power Generation (发电): Heat exchanger tubes (热交换器管), boiler coils (锅炉盘管), superheater coils (过热器盘管), economizer coils (省煤器盘管), and steam generator tubes in thermal and nuclear power plants.
- Petrochemical & Refining (石油化工与炼油): Distillation column internals (蒸馏塔内件), reactor coils (反应器盘管), heat transfer coils (传热盘管), and process piping in high-temperature, high-pressure, and corrosive environments.
- Food & Beverage Processing (食品加工): Sanitary-grade coil tubing (卫生级盘管) for dairy processing, brewing, and pharmaceutical-grade fluid handling systems requiring high purity and corrosion resistance.
- Automotive & Aerospace (汽车与航空航天): Exhaust system components (排气系统组件), turbocharger cooling coils (涡轮增压器冷却盘管), fuel system tubing, and cryogenic fluid transfer lines.
- Marine & Offshore (海洋与海上工程): Subsea heat exchanger coils (海底热交换器盘管), desalination system tubing (海水淡化系统管道), and marine propulsion system components.
- Medical & Laboratory (医疗与实验室): Autoclave coils (高压灭菌器盘管), pharmaceutical reactor tubing (制药反应器管道), and laboratory-grade fluid delivery systems.
5.2 Unique Selling Points (独特卖点)
- Dynamic Performance Guarantee: Each coil tube batch is backed by dynamic boundary condition analysis data, providing customers with verified vibration and fatigue performance predictions for their specific installation configurations.
- Full Traceability (全追溯性): Complete material traceability from raw steel mill certificate through every production stage, including heat number, production date, operator ID, and test results.
- Custom Engineering Support (定制工程支持): Dedicated engineering team available for application-specific design calculations, including thermal stress analysis (热应力分析), pressure drop calculations (压降计算), and vibration assessment (振动评估).
- Multi-Standard Compliance (多标准合规): Products certified to ASTM, ASME, EN, ISO, JIS, GB, and customer-specific standards simultaneously.
6. Quality Certifications and Standards Compliance
6.1 Applicable Standards
| Standard | Description | Scope |
|---|---|---|
| ASTM A213 | Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubes for High-Temperature Service | Material & Heat Exchanger Tubes |
| ASTM A269 | Standard Specification for Seamless and Welded Austenitic Stainless Steel Pipes | Piping Applications |
| ASTM A312 | Standard Specification for Seamless, Welded, and Heavy-Walled Austenitic Stainless Steel Pipes and Tubes | General Industrial |
| ASME SA-213 | Boiler and Pressure Vessel Code, Section II, Part D | Pressure Vessels & Boilers |
| EN 10216-5 | Heat-Exchanger and Heat Transfer Tubes — Part 5: Non-Heat-Treated Tubes of Austenitic Stainless Steels | European Heat Exchangers |
| GB/T 14976 | 无缝不锈钢管 (Seamless Stainless Steel Tubes) | Chinese National Standard |
| ISO 15530 | Stainless Steel — Chemical Composition Designation | Material Identification |
6.2 Quality Management Certifications
- ISO 9001:2015 — Quality