Stainless Steel Coil Tube (盘管 / Coil Tube) — Product Technical Specification
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd (温州吉兴金属材料有限公司)
Product Catalog No.: 250
Classification: Stainless Steel Coil Tubes for Compressor Exhaust Systems and Heat Exchange Applications
1. Product Overview
The stainless steel coil tube (盘管) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered coiled tubing product designed for high-performance applications in compressor exhaust systems, heat exchangers, refrigeration circuits, and industrial fluid transfer systems. The coil tube is formed into continuous helical or spiral configurations, providing superior surface-area-to-volume ratios essential for efficient thermal management and fluid dynamics performance.
Based on rigorous modal design research applied to compressor exhaust coil tubes (压缩机内排气盘管模态设计研究), this product incorporates advanced finite element analysis (FEA) and vibration mode optimization to ensure structural integrity under dynamic operating conditions. The coil geometry is engineered to minimize stress concentration points, resist fatigue failure, and maintain dimensional stability across extreme temperature and pressure cycles.
2. Material & Properties
2.1 Base Material Grades
- Austenitic Stainless Steel (奥氏体不锈钢): Grades 304 (UNS S30400), 304L (UNS S30403), 316 (UNS S31600), 316L (UNS S31603) — offering excellent corrosion resistance, formability, and weldability
- Duplex Stainless Steel (双相不锈钢): Grades 2205 (UNS S32205), 2507 (UNS S32750) — providing enhanced mechanical strength and resistance to chloride stress corrosion cracking (SCC)
- Super-Austenitic Grades: Grade 904L (UNS N08904) — for extreme corrosion environments
2.2 Mechanical Properties (Typical Values for 304/316 Grades)
| Property | 304 / 304L | 316 / 316L | 2205 Duplex |
|---|---|---|---|
| Tensile Strength (抗拉强度), MPa | ≥ 515 | ≥ 485 | ≥ 450 |
| Yield Strength (屈服强度), MPa | ≥ 205 | ≥ 170 | ≥ 450 |
| Elongation (延伸率), % | ≥ 40 | ≥ 40 | ≥ 15 |
| Hardness (硬度), HB | ≤ 217 | ≤ 217 | ≤ 310 |
| Operating Temperature Range (使用温度范围), °C | −196 to +870 | −196 to +870 | −50 to +350 |
2.3 Corrosion Resistance Characteristics
- Excellent resistance to atmospheric corrosion, organic acids, and nitric acid solutions
- 316L grade provides superior resistance to pitting (点蚀) and crevice corrosion (缝隙腐蚀) in chloride-containing environments
- 2205 Duplex offers PREN (Pitting Resistance Equivalent Number) of 32–38, suitable for marine and chemical processing applications
- Passive film (钝化膜) self-healing capability in oxidizing environments
3. Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (外径, OD) | 3.0 mm – 32.0 mm (custom sizes available) |
| Wall Thickness (壁厚, WT) | 0.3 mm – 3.0 mm |
| Coil Pitch (螺距) | 8 mm – 60 mm (configurable per application) |
| Coil Diameter (盘管直径) | 50 mm – 500 mm |
| Coil Length (盘管长度) | Up to 200 m per coil (continuous) |
| Surface Finish (表面光洁度) | Ra ≤ 0.4 μm (electropolished); Ra ≤ 0.8 μm (brushed); Ra ≤ 1.6 μm (standard annealed) |
| Dimensional Tolerance (尺寸公差) | ±0.05 mm (OD); ±0.02 mm (WT) |
| Coil Roundness (盘管圆度) | ≤ 0.5% of coil diameter |
| Helix Angle Deviation (螺旋角偏差) | ≤ ±1° |
| End Forming (端部成型) | Bevel cut (45°), threaded, flanged, or custom fittings |
| Standard Reference | ASTM A269, ASTM A213, GB/T 14976, EN 10216-5, ISO 3506 |
4. Manufacturing Process
4.1 Process Flow
- Raw Material Selection (原材料选择): Certified stainless steel wire rod or seamless tube stock from approved mill sources, with full chemical composition verification via optical emission spectrometry (OES) and laboratory analysis.
- Hot Rolling & Annealing (热轧与退火): Tubes are hot-rolled to approximate dimensions and subsequently annealed in a controlled atmosphere (argon or vacuum) to achieve solution-treated (固溶处理) condition, ensuring uniform microstructure and optimal corrosion resistance.
- Cold Drawing / Cold Forming (冷拔/冷成型): Tubes are cold-drawn through precision tungsten carbide dies to achieve final OD and wall thickness tolerances, improving surface finish and mechanical properties through work hardening (加工硬化).
- Intermediate Annealing (中间退火): Periodic solution annealing at 1050–1150 °C followed by rapid water quenching to restore ductility for continued cold working.
- Coil Forming (盘管成型): Precision coil winding on CNC-controlled mandrels using a multi-axis forming system. The process incorporates real-time monitoring of bending stress, coil pitch uniformity, and dimensional accuracy. Modal analysis (模态分析) parameters derived from compressor exhaust system design research are applied to optimize coil geometry for vibration resistance.
- Welding & Sealing (焊接与密封): Orbital TIG welding (自动轨道TIG焊) for end-to-end joins with full penetration verification. Helium leak testing ensures zero leakage at rated pressure.
- Surface Treatment (表面处理): Pickling and passivation (酸洗钝化) to remove oxide scale and establish a stable chromium oxide passive layer. Optional electropolishing (电解抛光) for critical service applications.
- Quality Inspection (质量检验): Multi-stage inspection including dimensional measurement, hydrostatic pressure testing, visual inspection, and non-destructive testing (NDT).
4.2 Modal Design Optimization (模态设计优化)
Informed by research on compressor exhaust coil tube modal design (压缩机内排气盘管模态设计研究), the coil geometry undergoes finite element modal analysis to identify natural frequencies and mode shapes. This ensures that the coil tube's first-order natural frequency (一阶固有频率) is positioned away from operational excitation frequencies, thereby preventing resonance-induced fatigue failure (共振疲劳失效). The design incorporates variable pitch sections and optimized bend radii to distribute dynamic loads uniformly along the coil length.
5. Applications
5.1 Primary Application Areas
- Compressor Exhaust Systems (压缩机排气系统): High-temperature exhaust gas routing in reciprocating, rotary screw, and centrifugal compressors, where modal stability and thermal cycling resistance are critical.
- Industrial Heat Exchangers (工业换热器): Coil-and-tube heat exchangers, air preheaters, and aftercoolers in oil & gas, petrochemical, and power generation industries.
- Refrigeration & HVAC (制冷与暖通空调): Evaporator and condenser coils for industrial refrigeration systems, chiller units, and heat pump applications.
- Chemical Processing (化学加工): Reaction vessel coils, distillation column internals, and corrosive fluid transfer lines in pharmaceutical and chemical manufacturing.
- Food & Beverage Industry (食品饮料行业): Pasteurization coils, CIP (Clean-in-Place) compatible heat transfer systems, and sanitary fluid handling.
- Marine & Offshore (海洋与海上): Seawater heat exchanger coils, ballast system tubing, and offshore platform fluid transfer applications.
- Power Generation (发电): Boiler economizer coils, condenser tube bundles, and steam extraction lines.
- Automotive & Aerospace (汽车与航空航天): Turbocharger intercooler coils, fuel system tubing, and hydraulic circuit components.
5.2 Operating Conditions
| Application Category | Max Operating Pressure | Max Operating Temperature | Medium |
|---|---|---|---|
| Compressor Exhaust | 40 MPa | 600 °C | Hot compressed gas |
| Heat Exchanger | 25 MPa | 450 °C | Steam, process fluids |
| Refrigeration | 16 MPa | −60 to +150 °C | Refrigerants (R134a, R410A, NH₃) |
| Chemical Processing | 20 MPa | 350 °C | Acids, chlorides, solvents |
6. Quality Certifications & Standards
6.1 International Certifications
- ISO 9001:2015 — Quality Management System (质量管理体系)
- ISO 14001:2015 — Environmental Management System (环境管理体系)
- ISO 45001:2018 — Occupational Health & Safety Management (职业健康安全管理体系)
- ASME PE Stamp — Pressure Equipment Manufacturing (压力容器制造认证)
- EN 10204 3.1 — Third-party material certification (第三方材料认证)
- NACE MR0175 / ISO 15156 — Compliance for sour service environments (酸性环境适用性)
- PED 2014/68/EU — Pressure Equipment Directive compliance (压力设备指令合规)
6.2 Testing & Inspection Protocols
- Hydrostatic Pressure Test (水压试验): 1.5× working pressure, minimum 5-minute hold time, zero leakage acceptance criterion
- Helium Leak Detection (氦检漏): Sensitivity ≤ 1×10⁻⁹ mbar·L/s for critical weld joints
- Ultrasonic Testing (UT, 超声波检测): 100% coverage for wall thickness verification and internal defect detection
- Visual & Dimensional Inspection (目视与尺寸检验): Coordinate measuring machine (CMM) verification of coil geometry
- Chemical Analysis (化学成分分析): Spectrometric verification against ASTM/EN grade specifications
- Impact Testing (冲击试验): Charpy V-notch (夏比V型缺口) testing per ASTM E23 at specified temperatures
- Corrosion Testing (腐蚀试验): Salt spray testing (ASTM B117), ferric chloride pitting test (ASTM A967), and intergranular corrosion test (ASTM A240)
7. Unique Selling Points
Modal-Optimized Coil Geometry: Leveraging advanced modal design research (模态设计研究) for compressor exhaust systems, each coil tube is engineered with optimized pitch profiles and bend radii that eliminate resonance-prone configurations, extending service life by up to 40% under dynamic loading conditions.
- Full Customization Capability: Coil diameter, pitch, OD, wall thickness, and end fittings are fully customizable to match specific OEM specifications and installation constraints.
- Multi-Grade Material Availability: From standard 304L to super-duplex 2507 and super-austenitic 904L, accommodating the most demanding corrosion and mechanical environments.
- Precision Manufacturing Tolerances: ±0.05 mm OD tolerance and ±0.02 mm wall thickness tolerance ensure consistent thermal performance and fit-up accuracy in heat exchanger assemblies.
- Comprehensive Traceability: Each coil tube is accompanied by a full material traceability dossier including mill certificates, heat number, chemical analysis, mechanical test reports, and NDT records.
- Surface Finish Excellence: Electropolished finish (Ra ≤ 0.4 μm) eliminates surface roughness that could impair fluid flow efficiency or promote biofilm