Stainless Steel Coil Tube (盘管 Coiltube) — Technical Product Specification
Product Overview
The Stainless Steel Coil Tube (盘管 Coiltube) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. (Item No. 1086). This product is supplied in coiled form, offering superior flexibility in downstream processing and installation. Coil tubes are widely utilized in HVAC (Heating, Ventilation, and Air Conditioning) systems, particularly in fan coil units (风机盘管), heat exchangers, refrigeration circuits, and industrial process piping where continuous, joint-free tubing is required.
Coil tubes are produced through cold drawing or cold forming processes, which impart superior mechanical properties and dimensional accuracy compared to hot-finished alternatives. The coiled configuration enables efficient storage, transportation, and rapid deployment on-site, minimizing welding joints and reducing potential leakage points.
Material & Properties
Material Grades
- Austenitic Stainless Steel (奥氏体不锈钢): AISI 304 (UNS S30408), AISI 316 (UNS S31608), AISI 321 (UNS S32108)
- Super-Austenitic Grades (超级奥氏体钢): AISI 316L (UNS S31603), AISI 904L (UNS N08904)
- Stabilized Austenitic (稳定化奥氏体钢): AISI 321, AISI 347 (UNS S34700)
Mechanical Properties (Typical, Cold-Drawn Condition)
- Tensile Strength (抗拉强度): 520–750 MPa (75,000–109,000 psi), depending on grade and wall thickness
- Yield Strength (屈服强度): 205–450 MPa (29,700–65,300 psi)
- Elongation (伸长率): ≥30% (A5T)
- Hardness (硬度): 95–130 HRB (annealed condition)
Corrosion Resistance (耐腐蚀性)
- Excellent resistance to atmospheric corrosion, acidic environments, and chlorinated solutions
- Grade 316/316L provides superior pitting and crevice corrosion resistance (耐点蚀和缝隙腐蚀) due to molybdenum (Mo) addition (2.0–3.0%)
- Stable chromium oxide passive film (Cr₂O₃) ensures long-term durability in aggressive media
Specifications
| Parameter (参数) | Specification (规格) |
|---|---|
| Product Name (产品名称) | Stainless Steel Coil Tube (盘管 Coiltube) |
| Item Number (序号) | 1086 |
| Outer Diameter (外径, OD) | 6.0 mm – 35.0 mm (customizable) |
| Wall Thickness (壁厚, WT) | 0.4 mm – 2.5 mm (customizable) |
| Coil Length (盘管长度) | 50 m – 500 m per coil (customizable) |
| Coil Inner Diameter (盘管内径) | 100 mm – 300 mm |
| Surface Finish (表面光洁度) | 2B, No. 4 (Brushed), BA (Bright Annealed), Mirror (Ra ≤ 0.1 μm) |
| Applicable Standards (适用标准) | ASTM A269, ASTM A270, GB/T 14976, EN 10217-7, JIS G3459 |
| Manufacturing Method (制造方法) | Cold Drawing (冷拔) / Cold Forming (冷成型) |
| Heat Treatment (热处理) | Solution Annealing (固溶退火) at 1010–1120°C, followed by water quenching |
| Delivery Condition (交货状态) | Coiled, annealed, pickled, and passivated (盘状、退火、酸洗、钝化) |
| Minimum Order Quantity (最小起订量) | 1 coil (per specification) |
| Package (包装) | Export-standard wooden pallet with moisture-proof wrapping |
Manufacturing Process (制造工艺)
- Raw Material Selection (原材料选择): Virgin stainless steel strip (冷轧带钢) of certified mill origin, with strict chemical composition verification (Spectrometer Analysis, 光谱分析).
- Cold Forming / Cold Drawing (冷成型/冷拔): Strip is fed through a series of progressively reducing dies or roll-forming stations to achieve target OD and wall thickness with tight dimensional tolerances (±0.05 mm).
- Intermediate Annealing (中间退火): Periodic solution annealing (固溶退火) at 1050°C is performed during multi-pass drawing to relieve accumulated cold work and maintain ductility.
- Pickling & Passivation (酸洗钝化): Pickling in mixed HNO₃/HF solution removes oxide scale; subsequent passivation (钝化) in dilute HNO₃ (20–30%) restores the protective Cr₂O₃ passive film.
- Coiling (盘绕): The finished tube is wound onto precision mandrels at controlled tension to maintain uniform coil geometry and prevent kinking or deformation.
- Non-Destructive Testing (无损检测, NDT): 100% inline eddy current testing (涡流检测, ECT) for wall thickness uniformity and defect detection; hydrostatic pressure testing (水压试验) at 2× working pressure for leak integrity.
- Final Inspection & Packaging (终检与包装): Dimensional verification (OD, WT, straightness), surface quality audit, and protective packaging prior to dispatch.
Applications (应用领域)
- HVAC Fan Coil Units (风机盘管): Primary application — coil tubes serve as the heat exchange medium in fan coil units, transferring thermal energy between refrigerant and air stream with high efficiency.
- Refrigeration & Air Conditioning (制冷与空调): Evaporator and condenser tubing for commercial and industrial refrigeration systems.
- Automotive Heat Exchangers (汽车换热器): Intercooler tubes, condenser coils for automotive HVAC systems.
- Food & Beverage Industry (食品饮料行业): Sanitary process piping, heat exchangers, and condensers where hygienic requirements (FDA-compliant, 3-A Sanitary) are critical.
- Pharmaceutical & Medical (医药行业): Clean-room process piping, sterilization loops, and pharmaceutical equipment tubing.
- Petrochemical & Chemical Processing (石油化工): Corrosion-resistant process tubing for aggressive chemical environments.
- Power Generation (发电): Superheater tubes, economizer coils, and condensate recovery piping.
- Heat Recovery Systems (余热回收系统): Thermal energy recovery coils for industrial waste heat utilization.
Quality Certifications & Control (质量认证与控制)
Wenzhou Jixing Metal Materials Co., Ltd. maintains a rigorous Quality Management System (质量管理体系) aligned with international standards to ensure consistent product performance and compliance:
- ISO 9001:2015 — Quality Management Systems (质量管理体系)
- ISO 14001:2015 — Environmental Management Systems (环境管理体系)
- CE Marking — Conformity with European directives (EN 10217-7)
- Mill Test Certificates (MTC) — EN 10204 Type 3.1 certificates provided with each batch, including full chemical analysis and mechanical test results
- Third-Party Inspection (第三方检验) — Available upon request (SGS, BV, TÜV)
Quality Control Measures (质量控制措施)
Based on industry best practices in fan coil unit quality control (风机盘管质量控制), the following critical control points are enforced throughout the manufacturing lifecycle:
- Incoming Inspection (来料检验): 100% chemical composition verification via OES (Optical Emission Spectroscopy, 光学发射光谱) on all raw material lots.
- In-Process Monitoring (过程监控): Real-time dimensional measurement at each cold-drawing station; automated rejection of out-of-tolerance segments.
- Heat Exchanger Performance Testing (换热器性能测试): Thermal efficiency verification ensuring minimum overall heat transfer coefficient (U-value) of ≥ 250 W/(m²·K) for standard configurations.
- Leak Testing (密封性测试): 100% hydrostatic pressure test at 2× maximum operating pressure for 15 minutes; zero-defect acceptance criterion.
- Corrosion Testing (耐蚀性测试): Salt spray testing (盐雾试验) per ASTM B117 — Grade 316L achieves ≥ 500 hours without red rust; Grade 304 achieves ≥ 200 hours.
- Traceability (可追溯性): Full heat-number traceability from raw material to finished coil, enabling root-cause analysis and recall management.
Unique Selling Points (独特优势)
- Joint-Free Continuous Length (无焊缝连续长度): Elimination of longitudinal weld seams ensures superior pressure containment and eliminates stress-corrosion cracking (应力腐蚀开裂, SCC) susceptibility.
- Precision Dimensional Tolerance (精密尺寸公差): ±0.05 mm tolerance on OD and wall thickness ensures optimal heat transfer efficiency and compatibility with fin-tube assemblies.
- Custom Coil Configuration (定制化盘管配置): Flexible customization of coil length, OD, wall thickness, and surface finish to match specific HVAC equipment designs.
- Superior Surface Integrity (优异表面完整性): BA and Mirror finishes reduce fouling resistance and improve heat transfer coefficients by minimizing boundary layer turbulence.
- Full Traceability & Certification (完整可追溯性与认证): Comprehensive quality documentation supporting regulatory compliance in global markets.
Conclusion (总结)
The Stainless Steel Coil Tube (Item No. 1086) from Wenzhou Jixing Metal Materials Co., Ltd. represents a high-performance, precision-manufactured tubular solution designed for demanding thermal management applications. With adherence to international manufacturing standards, rigorous quality control protocols, and comprehensive material traceability, this product delivers exceptional reliability, corrosion resistance, and thermal efficiency — meeting the exacting requirements of the global HVAC, refrigeration, and industrial process engineering sectors.