Stainless Steel & White Copper Coil Tube (盘管) — Technical Specification
1. Product Overview
The Coil Tube (盘管), designated as product No. 329 in the catalog of Wenzhou Jixing Metal Materials Co., Ltd., is a precision-formed tubular product manufactured from high-grade stainless steel and white copper (Cupro-Nickel Alloy) materials. The coil tube is produced through a continuous drawing and coiling process, resulting in a long-length, tightly wound tubular configuration that is optimized for downstream processing, heat exchanger fabrication, and specialized industrial applications.
Coil tubes are distinguished from straight seamless tubes by their continuous winding geometry, which eliminates the need for end-to-end welding in many applications, thereby enhancing structural integrity, reducing joint failure points, and improving thermal and pressure performance. Wenzhou Jixing Metal Materials Co., Ltd. applies rigorous process control methodologies—drawing upon advanced metallurgical research and production engineering—to ensure superior dimensional accuracy, surface finish quality, and mechanical properties in every coil tube batch.
2. Material & Properties
The coil tube product line encompasses multiple alloy grades, with primary materials including austenitic stainless steels and white copper (Cupro-Nickel) alloys:
2.1 Stainless Steel Grades
- 304 (UNS S30400 / 1.4301) — General-purpose austenitic stainless steel offering excellent corrosion resistance, formability, and weldability. Widely used in food processing, chemical, and pharmaceutical applications.
- 316 (UNS S31600 / 1.4401) — Enhanced molybdenum-containing grade providing superior resistance to pitting and crevice corrosion, particularly in chloride-rich environments.
- 316L (UNS S31603 / 1.4404) — Low-carbon variant of 316, ideal for welded applications where intergranular corrosion resistance is critical.
- 321 (UNS S32100 / 1.4541) — Titanium-stabilized grade offering excellent resistance to sensitization and high-temperature oxidation.
- 310S (UNS S31008 / 1.4845) — High-temperature grade with exceptional oxidation resistance up to 1150°C, suitable for furnace components and heat treatment equipment.
2.2 White Copper (Cupro-Nickel Alloy) Grades
- C70600 (B10, 10% Ni) — Good corrosion resistance in seawater, moderate strength, excellent formability.
- C72500 (B30, 30% Ni) — High-strength cupro-nickel alloy with superior resistance to cavitation erosion and biofouling, commonly used in marine and power generation applications.
2.3 Typical Mechanical Properties (Stainless Steel 304 Coil Tube)
| Property | Specification | Test Standard |
|---|---|---|
| Tensile Strength (抗拉强度) | ≥ 520 MPa | ASTM A213 / GB/T 249 |
| Yield Strength (屈服强度) | ≥ 205 MPa | ASTM A213 / GB/T 249 |
| Elongation (伸长率) | ≥ 35% | ASTM A213 / GB/T 249 |
| Hardness (硬度) | ≤ 92 HRB (Annealed Condition) | ASTM A213 |
| Grain Size (晶粒度) | ≥ ASTM No. 5 | ASTM E112 |
2.4 Typical Mechanical Properties (White Copper C72500 Coil Tube)
| Property | Specification | Test Standard |
|---|---|---|
| Tensile Strength (抗拉强度) | ≥ 520 MPa | ASTM B751 / ASTM B318 |
| Yield Strength (屈服强度) | ≥ 310 MPa | ASTM B751 |
| Elongation (伸长率) | ≥ 20% | ASTM B751 |
| Corrosion Rate in Seawater (海水腐蚀速率) | < 0.02 mm/year | ASTM G101 |
3. Specifications
| Parameter (参数) | Specification Range (规格范围) | Notes |
|---|---|---|
| Outer Diameter (外径) | Φ 1.5 mm – Φ 50.8 mm (0.059" – 2.0") | Custom diameters available upon request |
| Wall Thickness (壁厚) | 0.1 mm – 3.0 mm (0.004" – 0.118") | Tolerance: ± 0.05 mm or ± 10% (whichever is greater) |
| Coil Length (盘管长度) | 30 m – 500 m per coil (continuous) | Configurable based on customer requirement |
| Coil Diameter (盘径) | Φ 300 mm – Φ 1500 mm | Standard: Φ 600 mm / Φ 800 mm |
| Surface Finish (表面状态) | Annealed Bright (BA), Pickled & Passivated (2B), Polished | Ra ≤ 0.8 μm for BA finish |
| End Condition (端部状态) | Plain, Beveled, or Threaded | Custom end preparation available |
| Material Grades (材质牌号) | 304, 304L, 316, 316L, 321, 310S, C70600, C72500 | Additional grades upon inquiry |
| Applicable Standards (适用标准) | ASTM A213, ASTM B751, GB/T 249, GB/T 17897, EN 10216-5, JIS G3459 | Multi-standard compliance |
| Packaging (包装) | Wooden crate, steel frame, or export-standard packaging | VCI (Volatile Corrosion Inhibitor) protection available |
4. Manufacturing Process
The production of high-quality coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorously controlled multi-stage process designed to maximize material integrity while minimizing production costs. The following process flow represents the standard manufacturing sequence:
- Raw Material Selection (原材料选择) — Ingot sourcing from certified mills with full traceability documentation. Incoming materials undergo spectroscopic analysis (OES — Optical Emission Spectroscopy) to verify chemical composition compliance with specified alloy grades.
- Hot Rolling & Annealing (热轧与退火) — Billet or rod stock is hot-rolled to near-final dimensions and subsequently annealed to relieve residual stresses, refine grain structure, and restore ductility for subsequent cold working operations.
- Piercing & Hot Extrusion (穿孔与热挤压) — The annealed rod is pierced to form a hollow tube blank, followed by hot extrusion to achieve the target outer diameter and wall thickness with high dimensional consistency.
- Pickling & Descaling (酸洗除鳞) — Hot-formed oxide scale is removed through controlled acid pickling (typically HNO₃/HF mixed acid for stainless steels; H₂SO₄/HNO₃ for white copper alloys). The pickling parameters (concentration, temperature, immersion time) are precisely calibrated to prevent surface etching or intergranular attack.
- Cold Drawing (冷拔) — The tube blank is cold-drawn through precision-die tooling to achieve the final dimensional tolerances. Multiple drawing passes may be employed for tight-tolerance or thin-wall applications. Drawing lubricants are selected based on material grade to ensure optimal formability and surface quality.
- Intermediate Annealing (中间退火) — For multi-pass cold drawing processes, intermediate annealing is performed at controlled temperatures (typically 1050°C – 1150°C for stainless steels; 850°C – 950°C for white copper alloys) to recover ductility and prevent work-hardening failures.
- Final Annealing & Pickling (最终退火与酸洗) — A final solution anneal followed by pickling and passivation (for stainless steels) ensures the desired metallurgical condition, surface cleanliness, and corrosion resistance.
- Coiling (盘管成型) — The straight tube is continuously coiled onto a precision mandrel using a controlled winding speed and tension system. Tension parameters are optimized to prevent ovality, kinking, or spring-back effects that could compromise dimensional accuracy.
- Quality Inspection (质量检验) — Comprehensive inspection including dimensional measurement, hydrostatic testing, visual inspection, surface roughness verification, and chemical composition analysis.
4.1 Key Quality Improvement Methodologies
Based on advanced production engineering research (as documented in industry technical literature on white copper coil tube quality enhancement), the following methodologies are implemented to elevate product quality while reducing production costs:
- Optimized Pickling Parameters — Precise control of acid concentration, temperature, and immersion duration minimizes over-etching and reduces material waste, while ensuring complete oxide removal.
- Controlled Coiling Tension — Real-time tension monitoring systems prevent geometric defects (ovality, flat spots) that would otherwise necessitate rework or scrap.
- Grain Size Control — Annealing cycle optimization (soaking time and cooling rate) ensures consistent grain structure, which directly correlates to mechanical property uniformity.
- Die Wear Management — Predictive maintenance scheduling for drawing dies based on production volume and material hardness reduces dimensional drift and extends die service life, lowering per-unit tooling costs.
- Process Integration — Continuous production line configuration (hot extrusion → pickling → cold drawing → coiling) minimizes inter-stage handling, reduces oxidation risk, and improves throughput efficiency.
5. Applications
Coil tubes manufactured by Wenzhou Jixing Metal Materials Co., Ltd. serve a broad spectrum of industrial applications, leveraging the unique advantages of continuous coil geometry and high-performance alloy materials:
5.1 Heat Exchanger Manufacturing (换热器制造)
- Shell-and-tube heat exchangers for power generation, petrochemical, and HVAC systems
- Plate-fin and air-cooled heat exchanger tubes
- Condensers and evaporators in refrigeration systems
5.2 Marine & Offshore Industry (海洋与离岸工业)
- Seawater cooling systems in naval vessels and offshore platforms
- Cupro-nickel alloy (C72500) coil tubes for marine heat exchangers, offering superior cavitation resistance and biofouling protection
- Ballast water system tubing
5.3 Chemical & Petrochemical Processing (化工与石化)
- Process piping and reactor internals requiring corrosion-resistant tubing
- Distillation column internals
- Acid handling systems (316L grade)
5.4 Food & Pharmaceutical Industry (食品与制药)
- Sanitary-grade tubing for dairy, beverage, and food processing equipment (304/316L, electropolished finish)
- Pharmaceutical CIP (Clean-In-Place) systems
- Whey protein separator and UHT (Ultra-High Temperature) sterilization equipment
5.5 Medical Device Manufacturing (医疗器械制造)
- Surgical instrument tubing (needle tubes, catheter precursor tubing)
- Orthopedic implant precursor components
5.6 Automotive & Aerospace (汽车与航空航天)
- Catalytic converter substrate tubing
- Fuel injection system components
- High-temperature exhaust system tubing (310S grade)
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management infrastructure ensuring full regulatory and industry-standard compliance:
| Certification / Standard (认证/标准) | Description |
|---|---|
| ISO 9001:2015 | Quality Management System certification ensuring consistent product quality and process control |
| ISO 14001:2015 | Environmental Management System certification for sustainable manufacturing practices |
| ISO/TS 22163 | Automotive industry quality management standard (where applicable for automotive-grade tubing) |
| EN 10204 3.1 | Inspection document (test report) issued by authorized inspection personnel, providing full traceability |
| EN 10204 3.2 | Inspection certificate issued by authorized inspection personnel, certifying full compliance with specified requirements |
| CE Marking | European Conformity marking for products intended for the European Economic Area |
| Mill Test Certificate (MTC) | Provided with each shipment, documenting chemical composition, mechanical properties, heat number, and dimensional verification |
| NACE MR0175 / ISO 15156 | Compliance for sour service applications (sulfide stress cracking resistance) |
7. Unique Selling Points
7.1 Superior Coiling Quality Control — Advanced tension-controlled coiling systems with real-time monitoring ensure geometric precision (ovality < 2% of OD), surface integrity, and consistent coil tension throughout the entire length, minimizing downstream processing defects.
7.2 Integrated Cost