Stainless Steel Coil Tube (盘管 / Coiltube) — Technical Product Specification
Product Overview
The Stainless Steel Coil Tube (Chinese: 盘管, English: Coiltube / Coil Tube) is a continuous, helically wound tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. (Product Catalog No. 1664). Unlike conventional straight-length stainless steel tubes, coil tubes are produced in a continuous wound form, which offers significant advantages in material utilization, storage efficiency, and downstream processing flexibility. The coil tube geometry—characterized by a consistent helical pitch and uniform cross-sectional profile—enables precise thermal transfer, fluid conveyance, and structural applications across multiple industrial sectors.
This product line is engineered to meet the stringent requirements of modern manufacturing, combining the corrosion resistance and mechanical integrity of austenitic stainless steel with the logistical and economic benefits of coil delivery formats.
Material & Properties
The coil tubes are fabricated from high-grade austenitic stainless steel grades, selected based on application-specific performance requirements. The primary material grades include:
- AISI 304 / EN 1.4301 — General-purpose austenitic stainless steel with excellent corrosion resistance and formability.
- AISI 316 / EN 1.4401 — Enhanced corrosion resistance with molybdenum addition, suitable for harsh chemical and marine environments.
- AISI 316L / EN 1.4404 — Low-carbon variant of 316, ideal for welding-intensive applications and high-purity environments.
- AISI 321 / EN 1.4541 — Titanium-stabilized grade resistant to intergranular corrosion at elevated temperatures.
Key Material Properties (Typical Values for Grade 304)
- Tensile Strength: ≥ 520 MPa (75,000 psi)
- Yield Strength (0.2% Offset): ≥ 205 MPa (29,700 psi)
- Elongation at Break: ≥ 40%
- Maximum Service Temperature: 870°C (1,598°F)
- Corrosion Resistance: Superior resistance to atmospheric corrosion, weak acids, and alkaline solutions
- Surface Finish: 2B (Cold Rolled and Annealed), BA (Bright Annealed), or No. 4 Brushed finish available
Specifications
| Parameter | Specification Range | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6.0 mm – 50.0 mm (0.24" – 2.0") | ASTM A213 / EN 10217 |
| Wall Thickness | 0.5 mm – 3.0 mm (0.020" – 0.118") | ASTM A269 / GB/T 12771 |
| Coil Pitch (Helix Spacing) | Adjustable: 10 mm – 50 mm | Custom / Customer-Specified |
| Coil Inner Diameter | 100 mm – 500 mm (4" – 20") | Industry Standard |
| Coil Length (Continuous) | Up to 500 m (1,640 ft) per coil | — |
| Dimensional Tolerance (OD) | ±0.1 mm or ±0.05% of nominal | ASTM A511 |
| Dimensional Tolerance (Wall) | ±10% of nominal thickness | ASTM A213 |
| Roundness | ≤ 0.1 mm | EN 10217 |
| End Condition | Plain end, beveled, or threaded | Customer-Specified |
| Delivery Condition | Annealed and Pickled (A&P), or Solution Annealed | ASTM A213 |
| Maximum Weight per Coil | Up to 5,000 kg (11,000 lbs) | Logistics Constraint |
Manufacturing Process
The production of the stainless steel coil tube follows a rigorous multi-stage manufacturing workflow designed to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection: Cold-rolled stainless steel strip of certified chemical composition is sourced from accredited mills. Incoming material undergoes spectrographic verification (OES) and mechanical testing to confirm conformance to the specified grade.
- Forming & Welding: The strip is precision-formed into a tubular configuration using high-precision roll-forming equipment. Seaming is achieved through automatic argon-protected TIG welding (Gas Tungsten Arc Welding, GTAW) or high-frequency induction welding (HFW), depending on the target diameter and wall thickness. The welding process is continuously monitored for seam integrity.
- Heat Treatment (Solution Annealing): The formed tube is subjected to solution annealing at 1010°C – 1150°C followed by rapid quenching. This process relieves residual stresses, restores full austenitic microstructure, and maximizes corrosion resistance.
- Pickling & Passivation: The annealed tube undergoes acid pickling (HNO₃/HF blend) to remove surface scale and impurities, followed by passivation to establish a stable chromium oxide film on the surface.
- Coil Winding: The continuous tube is wound onto a precision-driven coil winder with controlled tension and pitch to produce the final helical coil geometry. Winding parameters are calibrated to prevent deformation, kinking, or inter-coil contact damage.
- Quality Inspection: Each coil undergoes 100% visual inspection, dimensional verification (OD, wall thickness, roundness), and sampling for hydrostatic pressure testing (typically 5 MPa for 30 seconds). Radiographic testing (RT) or eddy current testing (ET) is performed on weld seams per customer requirement.
- Packaging & Dispatch: Finished coils are wrapped in moisture-proof protective film, strapped with steel bands, and secured on wooden pallets or steel cradles for safe transport.
Applications
The stainless steel coil tube finds extensive application across multiple industries due to its combination of corrosion resistance, mechanical strength, and the processing advantages inherent to coil form:
- Heat Exchangers & Thermal Systems: The helical coil geometry provides high surface-area-to-volume ratio, making it ideal for condensers, evaporators, radiators, and heat recovery systems in HVAC and process engineering.
- Automotive Industry: Used in radiator coils, condenser tubes, fuel lines, and exhaust heat exchangers where corrosion resistance and thermal cycling durability are critical.
- Food & Beverage Processing: Compliant with sanitary requirements for conveying food-grade liquids, pasteurization coils, and cleaning-in-place (CIP) systems.
- Pharmaceutical & Biotechnology: Employed in sterile fluid transfer lines, bioreactor heat exchange coils, and cleanroom-compatible piping systems.
- Chemical Processing: Resistant to aggressive chemical media; used in reactor cooling coils, distillation columns, and chemical transfer lines.
- Marine & Offshore: Grade 316/316L coil tubes utilized in ballast water systems, seawater cooling circuits, and offshore platform infrastructure.
- Medical Equipment: Sanitary-grade coil tubes for medical gas delivery, sterilization equipment, and diagnostic instrument fluid lines.
- Aerospace: Lightweight, corrosion-resistant coil tubes for fuel systems, hydraulic lines, and thermal management in aerospace applications.
Unique Selling Points
1. Superior Material Utilization: The continuous coil form eliminates cut-off waste inherent in straight-length tube delivery, reducing material consumption by up to 15–20% and lowering the overall carbon footprint of downstream fabrication.
2. Enhanced Processing Efficiency: Coil tubes can be directly fed into automated cutting, bending, and welding machines, enabling high-speed, labor-efficient production lines with minimal manual intervention.
3. Consistent Quality Throughout Length: Continuous manufacturing and automated inspection ensure uniform dimensional and metallurgical properties along the entire coil length, minimizing batch-to-batch variability.
4. Customizable Geometry: Coil pitch, diameter, and length can be precisely tailored to customer specifications, enabling optimized integration into bespoke thermal, fluid, or structural designs.
5. Wenzhou Jixing Metal Materials Co., Ltd. — Integrated Supply Chain: As a vertically integrated manufacturer, the company controls the entire production chain from strip procurement through final coil winding, ensuring traceability, quality consistency, and competitive pricing.
Quality Certifications & Compliance
The product and manufacturing processes of Wenzhou Jixing Metal Materials Co., Ltd. are certified and compliant with the following international and national standards:
- ISO 9001:2015 — Quality Management System certification, demonstrating commitment to consistent product quality and continuous improvement.
- ISO 14001:2015 — Environmental Management System certification, ensuring environmentally responsible manufacturing practices.
- EN 10204 3.1 — Third-party inspection certificate for material compliance with European standards.
- ASTM A213 / A269 / A511 — Conformance to American Society for Testing and Materials (ASTM) standards for stainless steel tubes.
- GB/T 12771 / GB/T 21832 — Compliance with Chinese National Standards for stainless steel seamless and welded tubes.
- EN 10217-7 — European standard for austenitic stainless steel tubes for pressure purposes.
- PED 2014/68/EU — European Pressure Equipment Directive compliance for pressure-rated applications (where applicable).
- Mill Test Certificates (MTC): Each shipment is accompanied by a comprehensive MTC detailing chemical composition, mechanical properties, heat treatment records, and non-destructive testing results.
Summary
The Stainless Steel Coil Tube (Product No. 1664) from Wenzhou Jixing Metal Materials Co., Ltd. represents a high-performance, cost-effective tubular solution that leverages the inherent advantages of austenitic stainless steel combined with the logistical and manufacturing benefits of coil form. Whether deployed in thermal exchange systems, fluid conveyance networks, or structural applications, this product delivers exceptional corrosion resistance, mechanical reliability, and processing efficiency. With full traceability, international certifications, and customizable specifications, it serves as a versatile foundation for advanced industrial engineering solutions.