Stainless Steel Coil Tube (Coil Tube) — Product Technical Specification
Product Overview
The Stainless Steel Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd, is a precision-engineered tubular product supplied in continuous coil form. This product is designed for applications requiring high structural integrity, corrosion resistance, and thermal efficiency. The coil tube format offers significant advantages in terms of material utilization, welding efficiency, and seamless integration into downstream fabrication processes. As referenced in industry literature regarding High Static Pressure Fan Coil Unit with Fresh Air System applications, these coil tubes serve critical roles in HVAC (Heating, Ventilation, and Air Conditioning) systems, heat exchangers, and fluid transport infrastructure.
Material & Properties
Stainless Steel Coil Tubes are fabricated from austenitic and/or ferritic stainless steel grades, providing an optimal combination of mechanical strength, chemical resistance, and formability. The primary grades utilized include:
- AISI 304 (UNS S30400) — General-purpose austenitic grade with excellent corrosion resistance and weldability
- AISI 316 (UNS S31600) — Enhanced chlorides resistance due to molybdenum (Mo) addition
- AISI 316L (UNS S31603) — Low-carbon variant for superior weld zone corrosion resistance
- AISI 321 (UNS S32100) — Titanium-stabilized grade for elevated temperature applications
- AISI 430 (UNS S43000) — Ferritic grade for cost-effective, moderate corrosion environments
Key material properties include tensile strength exceeding 520 MPa (for 304 grade), elongation of ≥35%, and a non-magnetic (austenitic) or slightly magnetic (ferritic) character. Surface finish options range from 2B mill finish to No. 4 brushed, 8K mirror, and custom matte finishes.
Specifications
| Parameter | Specification Range | Standard / Reference |
|---|---|---|
| Outer Diameter (OD) | 6.0 mm – 108.0 mm | ASTM A269 / GB/T 12771 |
| Wall Thickness (WT) | 0.5 mm – 6.0 mm | ±10% tolerance |
| Coil Length | 20 m – 200 m (customizable) | — |
| Coil Inner Diameter | 300 mm – 600 mm | — |
| End Condition | Open end / Beveled / Cut-to-length | — |
| Surface Finish | 2B / No. 4 / 8K / Matte / Custom | ASTM A480 |
| Heat Treatment | Solution Annealed / Pickled & Passivated | ASTM A269 |
| Manufacturing Method | ERW (Electric Resistance Welding) / Laser Welded / Seamless | — |
| Pressure Rating | Up to 4.0 MPa (grade-dependent) | ASME B31.3 |
| Operating Temperature | −196 °C to +870 °C (grade-dependent) | — |
Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous, multi-stage manufacturing process:
- Raw Material Inspection — Incoming stainless steel strip/coil is verified for chemical composition (via spectroscopic analysis), mechanical properties, and surface quality per ASTM A240 / GB/T 3280.
- Slitting & Leveling — Wide coil stock is slit to precise widths and leveled to eliminate residual stresses, ensuring dimensional accuracy.
- Forming — The flat strip is progressively formed into a tubular shape using high-precision roll-forming stations with CNC-controlled tooling.
- Welding — The tube seam is closed via Electric Resistance Welding (ERW) or high-frequency induction welding, achieving weld integrity equivalent to the base metal.
- Heat Treatment (Solution Annealing) — Tubes undergo solution annealing at 1050 °C – 1150 °C followed by rapid water quenching to restore full austenitic microstructure and maximize corrosion resistance.
- Pickling & Passivation — The surface is chemically cleaned using mixed acid solutions (HNO₃ + HF) to remove oxide scale, followed by passivation to establish a protective chromium oxide film.
- Coiling & Packaging — Finished tubes are wound into coils on mandrels, wrapped with protective film, and packaged for shipment.
Applications
Stainless Steel Coil Tubes from Wenzhou Jixing Metal Materials Co., Ltd find extensive application across multiple industrial sectors:
- HVAC Systems — Fan coil units, air handling units, heat exchanger coils, and refrigerant piping (as referenced in high static pressure fan coil applications replacing hot air curtain systems)
- Chemical Processing — Piping for corrosive fluid transport, reactor internals, and heat transfer systems
- Food & Beverage Industry — Hygienic piping for dairy, brewing, and pharmaceutical processing (3-A sanitary standards)
- Automotive Industry — Exhaust systems, fuel lines, and structural tubing
- Petroleum & Gas — Downhole tubing, wellhead components, and separation systems
- Architectural & Decoration — Handrails, balustrades, structural framing, and decorative elements
- Medical Devices — Surgical instrument tubing and equipment housings
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains comprehensive quality management systems and certifications to ensure product excellence:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ASME Stamp — National Board registration for pressure-containing components
- EN 10204 3.1 — Third-party material testing and certification
- CE Marking — Compliance with European directives for market access
- GB/T Standards — Full compliance with Chinese national standards (GB/T 12771, GB/T 14976, GB/T 13296)
All products undergo non-destructive testing (NDT) including ultrasonic testing (UT), eddy current testing (ECT), and hydrostatic pressure testing prior to shipment. Full traceability is maintained from raw material mill certificates through to final product delivery.
Unique Selling Points
- Continuous Coil Format — Eliminates lap joints, maximizes material utilization (up to 98%), and reduces downstream welding labor and time.
- Grade Flexibility — Wide selection of stainless steel grades accommodates diverse corrosion environments and mechanical requirements.
- Thermal Efficiency — Ideal for heat exchanger coil fabrication, enabling compact designs with superior thermal transfer performance as demonstrated in fan coil unit applications.
- Precision Dimensional Control — CNC-driven forming and welding ensure tight tolerances on OD, wall thickness, and roundness.
- Customization Capability — Flexible specifications for diameter, wall thickness, coil length, and surface finish tailored to customer-specific engineering requirements.
- Full Traceability — Each coil is accompanied by complete documentation including mill test certificates (MTC), heat numbers, and dimensional reports.
Conclusion
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd represents a high-performance, versatile solution for industrial and commercial applications demanding corrosion resistance, structural integrity, and manufacturing efficiency. The coil format, combined with rigorous quality control and adherence to international standards, positions this product as a preferred choice for OEM manufacturers, system integrators, and engineering firms worldwide.