Stainless Steel Coil Tube — High-Efficiency Continuous Forming Product
1. Product Overview
The Stainless Steel Coil Tube (产品编号: 279) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is produced via a high-speed continuous coil forming process, achieving an exceptional production cycle time of approximately 20 seconds per unit — a benchmark figure that reflects the integration of advanced automation, optimized die design, and high-performance stainless steel feedstock. The coil tube is supplied in continuous coil form, enabling downstream customers to achieve seamless integration into their own fabrication lines with minimal material waste and maximum throughput.
"A single fan coil tube comes off the production line in as little as 20 seconds" — this operational metric underscores the manufacturing excellence and process maturity of Wenzhou Jixing's coil tube production system.
2. Material & Properties
2.1 Base Material
The coil tube is fabricated from high-quality austenitic stainless steel strip, conforming to internationally recognized material standards. The primary alloy grades employed include:
- 304 (UNS S30408) — General-purpose austenitic grade with excellent corrosion resistance and formability
- 304L (UNS S30403) — Low-carbon variant suitable for welding applications
- 316 (UNS S31608) — Molybdenum-enhanced grade for superior resistance to chlorides and chemical environments
- 316L (UNS S31603) — Low-carbon 316 variant for enhanced weldability and pitting resistance
2.2 Key Mechanical & Physical Properties
| Property | Grade 304 / 304L | Grade 316 / 316L | Test Standard |
|---|---|---|---|
| Tensile Strength (Rm) | ≥ 520 MPa | ≥ 515 MPa | ASTM A270 / GB/T 12771 |
| Yield Strength (Rp0.2) | ≥ 205 MPa | ≥ 170 MPa | ASTM A270 / GB/T 12771 |
| Elongation (A50) | ≥ 40% | ≥ 35% | ASTM A270 |
| Density | 7.93 g/cm³ | 8.00 g/cm³ | — |
| Operating Temperature Range | −196 °C to +870 °C | −196 °C to +870 °C | ASTM A270 |
| Corrosion Resistance (Pitting, PREN) | PREN ≈ 18–20 | PREN ≈ 24–26 | ASTM G48 |
2.3 Surface Finish Options
- 2B (Cold Rolled, Annealed & Pickled) — Standard mill finish with moderate luster
- No. 4 Brushed — Uniform unidirectional grain for aesthetic and functional applications
- Mirror (8K) — High-polish finish with Ra ≤ 0.4 μm
- Satin / Hairline — Intermediate finish suitable for architectural and decorative uses
3. Specifications
| Parameter | Specification |
|---|---|
| Product Code | 279 |
| Product Name | Coil Tube (盘管) |
| Manufacturer | Wenzhou Jixing Metal Materials Co., Ltd. |
| Outer Diameter (OD) | 3.0 mm – 25.0 mm (custom sizes available upon request) |
| Wall Thickness | 0.3 mm – 1.5 mm |
| Coil Diameter | Up to 1,200 mm (standard); larger diameters on request |
| Coil Length per Unit | 10 m – 50 m (configurable) |
| Production Cycle Time | ≈ 20 seconds per standard-length unit |
| Tolerance on OD | ± 0.05 mm (precision grade) |
| Tolerance on Wall Thickness | ± 10% of nominal |
| Manufacturing Standard | GB/T 12771, ASTM A270, EN 10217-7 |
| End Treatment | Flat-cut, chamfered, or crimped (per customer specification) |
| Packaging | Wooden pallet with protective wrapping; export-grade packaging available |
4. Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorously controlled, multi-stage process designed to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Inspection & Incoming Quality Control
Stainless steel strip is received from certified mills and subjected to spectroscopic analysis (OES), mechanical testing, and visual inspection to verify chemical composition and mechanical properties prior to processing.
- Strip Uncoiling & Leveling
The coiled strip is unrolled and passed through a precision leveling line to eliminate residual curvature and ensure flatness within ± 0.1 mm/m, which is critical for uniform tube wall thickness.
- High-Speed Coil Forming & Seaming
The leveled strip is fed through a series of precision roller dies that progressively form the strip into a tubular cross-section. The open edge is then closed via a high-frequency resistance welding (HFW) or continuous roll-seaming process, producing a seamless or laser-welded joint.
- Heat Treatment (if applicable)
For grades requiring stress relief or solution annealing, the formed tube passes through a continuous annealing furnace with controlled atmosphere (argon or vacuum) to restore full austenitic microstructure and eliminate forming-induced residual stresses.
- Precision Sizing & Calibration
The formed tube is passed through a sizing station to achieve final dimensional tolerances on OD and wall thickness, ensuring consistency along the entire coil length.
- Surface Treatment & Finishing
Pickling, passivation, and optional polishing or brushing are performed to achieve the specified surface finish and enhance corrosion resistance.
- Non-Destructive Testing (NDT)
Each production run undergoes eddy current testing, hydrostatic pressure testing, and visual inspection of weld seams to verify structural integrity and detect any subsurface or surface defects.
- Coiling, Packaging & Dispatch
The finished tube is re-coiled to the specified coil diameter, wrapped with protective film or paper, and palletized for secure shipment.
5. Applications
The Stainless Steel Coil Tube is engineered for a broad spectrum of industrial, commercial, and consumer applications:
- Heat Exchangers & Cooling Systems — The primary application domain, including fan coil units, air conditioning heat exchangers, and refrigeration condensers, where the 20-second production cycle enables rapid, cost-effective manufacturing of large volumes of coil tube assemblies.
- Automotive Industry — Used in exhaust system components, fuel lines, and turbocharger piping where corrosion resistance and high-temperature tolerance are essential.
- Food Processing & Dairy Equipment — Hygienic-grade tubing for food-grade piping, CIP (Clean-in-Place) systems, and sanitary fittings.
- Medical & Pharmaceutical Equipment — Precision tubing for medical gas delivery systems, sterilization equipment, and pharmaceutical processing lines.
- Architectural & Decorative Applications — Handrails, railings, decorative trim, and structural elements in commercial and residential construction.
- Petrochemical & Chemical Processing — Piping and heat exchange elements in corrosive chemical environments, particularly with 316L grade.
- Solar Thermal & Renewable Energy Systems — Absorber tubes and heat collection circuits in solar water heating and concentrated solar power systems.
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework to ensure that every coil tube product meets or exceeds international standards:
- ISO 9001:2015 — Quality Management System certification, ensuring consistent process control and customer satisfaction
- ISO 14001:2015 — Environmental Management System, demonstrating commitment to sustainable manufacturing practices
- ISO 45001:2018 — Occupational Health & Safety Management System
- CE Marking — Conformity with European Union directives for market access
- RoHS Compliance — Restriction of Hazardous Substances, ensuring environmental safety
- MTC (Material Test Certificate) — EN 10204 Type 3.1 mill certificates provided with each shipment
- Third-Party Inspection — Available upon request (SGS, BV, TÜV, or equivalent)
7. Unique Selling Points
- Industry-Leading Production Speed — The 20-second cycle time per coil tube unit represents a significant efficiency advantage, translating to lower unit costs, faster lead times, and the ability to scale production to meet large-volume orders without compromising quality.
- Precision Dimensional Control — Tight tolerances on OD (± 0.05 mm) and wall thickness ensure consistent performance in downstream applications such as brazing, crimping, and heat exchanger assembly.
- Multi-Grade Material Flexibility — Availability in 304, 304L, 316, and 316L grades allows customers to select the optimal balance of corrosion resistance, mechanical properties, and cost for their specific application.
- End-to-End Quality Assurance — From incoming raw material spectroscopy to final NDT and MTC documentation, every stage of production is auditable and traceable.
- Customization Capability — Wenzhou Jixing supports non-standard OD, wall thickness, surface finish, and coil configuration requests, enabling tailored solutions for specialized engineering projects.
Note: All specifications listed are representative values. For project-specific requirements, customers are encouraged to submit detailed technical drawings and performance criteria to Wenzhou Jixing Metal Materials Co., Ltd. for a customized quotation and engineering review.