Stainless Steel Coil Tube (Coil Tube) — Product No. 798
Product Overview
The Stainless Steel Coil Tube (hereinafter referred to as "Coil Tube"), designated as Product No. 798, is a precision-engineered seamless or welded stainless steel tubing supplied in continuous coil form. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd, this product is designed for applications requiring high corrosion resistance, mechanical integrity, and the ability to be drawn, formed, or cut into custom lengths without the need for additional straightening operations. The coil configuration offers significant advantages in downstream processing efficiency, material utilization, and inventory management compared to straight-length pipe deliveries.
Material & Properties
Coil Tubes are fabricated from austenitic and duplex stainless steel grades conforming to international standards including AISI (American Iron and Steel Institute), EN (European Norms), and JIS (Japanese Industrial Standards). The following materials are typically available:
- 304 / 304L (AISI 304 / EN 1.4301 / JIS SUS304) — General-purpose austenitic grade with excellent corrosion resistance and formability
- 316 / 316L (AISI 316 / EN 1.4401 / JIS SUS316) — Molybdenum-enhanced grade offering superior resistance to pitting and crevice corrosion
- 321 (AISI 321 / EN 1.4541) — Stabilized with titanium, suitable for elevated-temperature service
- 310S (AISI 310S / EN 1.4845) — High-temperature oxidation-resistant grade
- 2205 Duplex (EN 1.4462) — Duplex austenitic-ferritic grade with high yield strength and enhanced chloride resistance
Key Mechanical Properties (Typical for Grade 316L)
- Tensile Strength (UTS): ≥ 515 MPa (74,700 psi)
- Yield Strength (0.2% Proof): ≥ 205 MPa (29,700 psi)
- Elongation: ≥ 40%
- Hardness (HBW): ≤ 217
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | 1/8" – 6" (3.18 mm – 152.4 mm) |
| Wall Thickness | 0.10 mm – 6.0 mm (0.004" – 0.236") |
| Coil Length | 10 m – 50 m (33 ft – 164 ft), customizable |
| Coil ID (Inner Diameter) | 150 mm – 500 mm (6" – 20") |
| Surface Finish | Pickle & Passivate (PP), Brushed, Mirror (No. 4 / 8K), Matte |
| End Condition | Open ends, capped, or cut-to-length (CTL) upon request |
| Tolerance (OD) | ±0.05 mm (±0.002") |
| Tolerance (Wall) | ±10% of nominal |
| Applicable Standards | ASTM A269, ASTM A213, EN 10216-5, GB/T 12771 |
| Packaging | Steel band strapping, VCI paper wrapping, wooden pallet or crate |
Manufacturing Process
The production of Coil Tubes follows a rigorous multi-stage process to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Hot Rolling / Casting: Continuous casting ingots are hot-rolled into seamless tube blanks or welded strip for ERW (Electric Resistance Welding) or TIG (Tungsten Inert Gas) welded tubing.
- Piercing & Mandrel Drawing: For seamless variants, the billet is pierced and cold-drawn over a mandrel to achieve precise OD and wall thickness.
- Coiling: The finished tube is wound onto a coil mandrel under controlled tension to maintain roundness and prevent kinking or deformation.
- Pickling & Passivation: Chemical treatment using citric or nitric acid solutions removes scale and forms a protective chromium oxide passive film on the surface.
- Heat Treatment (Solution Annealing): Where required, tubes are solution-annealed at 1010–1150°C followed by rapid water quenching to restore full austenitic structure and maximize corrosion resistance.
- Non-Destructive Testing (NDT): Eddy current inspection and ultrasonic testing verify wall integrity, weld quality (for welded variants), and absence of defects.
- Dimensional Inspection: Automated gauging confirms OD, wall thickness, and roundness within specified tolerances.
Applications
Coil Tubes find extensive use across multiple industries due to their corrosion resistance, formability, and hygienic surface characteristics:
- Oil & Gas Industry: Downhole tubing, casing, subsea pipelines, and chemical processing lines
- Food & Beverage Processing: Sanitary-grade tubing for dairy, brewing, and pharmaceutical equipment (BA finish available)
- Chemical Processing: Heat exchangers, condensers, evaporators, and reactor internals
- Automotive & Aerospace: Exhaust systems, fuel lines, hydraulic lines, and structural components
- Construction & Architecture: Handrails, structural supports, decorative cladding
- Marine & Offshore: Ballast systems, ballast water treatment, desalination equipment
- Power Generation: Boiler tubes, superheater tubes, and turbine components
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system with the following certifications and compliance:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System
- EN 10204 3.1 — Third-party material test certificates available upon request
- ASME Section IX — Welding procedure qualification (for welded coil tube variants)
- API 5L / API 5CT — Compliance for oil & gas sector applications
- CE Marking — Conformity with European directives
- NACE MR0175 / ISO 15156 — Resistance to sulfide stress cracking for sour service environments
Unique Selling Points
- Coil Delivery Advantage: Eliminates the need for downstream straightening, reduces material waste through optimized nesting, and streamlines inventory management for end users.
- Precision Dimensional Control: Tolerances held to ±0.05 mm on OD, ensuring seamless integration into automated forming and welding systems.
- Multi-Grade Availability: Stock of over 20 stainless steel grades, including custom-mixed alloys upon request.
- Custom Surface Finishes: From industrial PP finish to food-grade electropolished and mirror surfaces (Ra ≤ 0.4 μm).
- Full Traceability: Each coil is accompanied by a heat-number-linked certificate of analysis (CoA) with full chemical and mechanical test data.
- Direct-from-Manufacturer Pricing: Eliminates intermediary markups, offering competitive pricing without compromising quality.
Conclusion
The Coil Tube (Product No. 798) from Wenzhou Jixing Metal Materials Co., Ltd represents a premium-grade stainless steel tubing solution engineered for demanding industrial applications. With rigorous manufacturing controls, international standard compliance, and flexible delivery configurations, this product delivers exceptional value in terms of material performance, processing efficiency, and total cost of ownership.