Ultra-Long Coil Tube (500 m – 2000 m+ per Coil)
1. Product Overview
The Ultra-Long Coil Tube (ULCT) is a premium-grade stainless steel coil tube product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Engineered to deliver coil lengths ranging from 500 meters to over 2000 meters per coil, this product represents a significant advancement in stainless steel coil tube technology. By dramatically increasing coil length, the ULCT eliminates the need for frequent butt-weld joints in long-run installations, thereby enhancing system integrity, reducing maintenance requirements, and improving overall reliability in demanding industrial and marine applications.
Conventional stainless steel coil tubes are typically limited to coil lengths of 200–500 meters. The ULCT breaks through this industry constraint, offering coil lengths up to four times the standard, making it an ideal solution for applications where joint minimization is critical.
2. Material & Properties
2.1 Available Grades
- Austenitic Grades: AISI 304 (UNS S30400), AISI 316L (UNS S31603), AISI 321 (UNS S32100)
- Super-Austenitic Grades: 904L (UNS N08904), 254 SMO (UNS S31803)
- Duplex Grades: 2205 (UNS S31803), 2507 (UNS S32750)
- Custom Alloys: Available upon request per customer specifications
2.2 Key Material Properties
- Corrosion Resistance: Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride-containing environments
- Mechanical Strength: Tensile strength ranging from 520 MPa (304) to 880 MPa (2507), depending on grade selection
- Temperature Range: Serviceable from cryogenic temperatures (−196 °C) to elevated temperatures up to 870 °C (grade-dependent)
- Surface Finish: Available in BA (Bright Annealed), 2B, No. 4, or custom polished finishes
- Formability: Superior cold-forming characteristics enabling complex geometries without cracking
3. Technical Specifications
| Parameter | Specification | Notes |
|---|---|---|
| Coil Length | 500 m – 2000 m+ per coil | Custom lengths available upon request |
| Outer Diameter (OD) | 3.0 mm – 50.8 mm | Welded and seamless options |
| Wall Thickness | 0.3 mm – 3.0 mm | ±10% tolerance |
| Coil Inner Diameter | 150 mm – 400 mm | Configurable to shipping requirements |
| Coil Outer Diameter | 600 mm – 1500 mm | Depends on coil length and tube dimensions |
| Coil Weight | Up to 8,000 kg per coil | Subject to transport and handling limits |
| Joint Requirement | Single continuous coil — zero intermediate joints | Key differentiator vs. standard coils |
| Applicable Standards | ASTM A269, ASTM A270, EN 10216-5, ISO 13679 | Additional standards upon request |
| Surface Treatment | BA, 2B, No. 4, Mirror Polished, PTFE Coated | PTFE coating available for anti-scaling service |
| Packaging | Wooden crate, steel frame, or custom marine-grade packaging | Protective end caps and moisture barriers included |
4. Manufacturing Process
Producing ultra-long stainless steel coil tubes demands exceptional process control, advanced metallurgical expertise, and specialized equipment. The manufacturing workflow at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous multi-stage process:
- Raw Material Selection: Virgin stainless steel strip is sourced from certified mills with strict chemical composition control. Incoming material undergoes spectroscopic verification to confirm alloy grade compliance.
- Precision Slitting: The master coil is slit to exact tube blank width with laser-guided edge trimming, ensuring dimensional accuracy within ±0.05 mm tolerance.
- Forming & Welding: The strip is fed through high-precision roll forming stations to achieve the target tube geometry. For welded tubes, a high-purity TIG (Tungsten Inert Gas) or laser welding process is employed under inert gas shielding to produce a clean, oxide-free weld seam.
- Continuous Annealing: The formed tube passes through a continuous annealing furnace under controlled atmosphere (vacuum or dew-point-controlled hydrogen-nitrogen mix). This step relieves forming stresses, restores full austenitic microstructure, and achieves the required mechanical properties and surface finish.
- Pickling & Passivation: The annealed tube is treated with citric acid or nitric acid-based solutions to remove oxide scale and form a protective chromium oxide passive layer, ensuring maximum corrosion resistance.
- Hydrostatic Testing: Each coil undergoes 100% hydrostatic pressure testing at 1.5× the maximum operating pressure (MOP) to verify weld integrity and wall thickness uniformity.
- Coil Winding & Stabilization: The tested tube is wound onto precision-controlled coil reels with tension regulation systems that prevent coil set, kinking, or inter-coil contact damage. The coil is stabilized with banding and protective wrapping.
- Final Inspection & Certification: Comprehensive dimensional inspection, surface quality assessment, and mechanical property verification are performed. Full material traceability documentation and mill test certificates (MTC) are issued per EN 10204 Type 3.1.
5. Applications
5.1 Subsea Umbilical Systems
Ultra-long coil tubes are the preferred choice for subsea umbilical cables used in offshore oil and gas production. By providing continuous tube runs of 500–2000+ meters, the ULCT eliminates the need for multiple butt-weld joints in the umbilical's hydraulic, electrical, and chemical injection lines. This significantly reduces the risk of subsea leak points, lowers installation time, and decreases long-term maintenance costs in harsh marine environments.
5.2 Long-Distance Pipeline Systems
In onshore and offshore long-distance pipeline applications — including chemical transport, district heating, and process fluid distribution — ultra-long coils minimize the number of field welds required. Each eliminated weld represents a reduction in potential failure points, inspection burden, and hydrostatic testing requirements.
5.3 Marine & Offshore Installations
- Platform cooling water systems and fire water piping
- Ballast water management systems (BWMS) where biofouling resistance is critical
- Desalination plant feed and brine lines
- Subsea production tree manifolds and flowlines
5.4 Industrial Process Applications
- Chemical processing plant heat exchanger tubing (eliminating joints in long tube bundles)
- Pharmaceutical and food-grade sanitary piping systems
- Power generation condensate and feedwater systems
- Hydrogen energy infrastructure — high-pressure hydrogen transport lines
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system ensuring that every Ultra-Long Coil Tube product meets international standards and industry-specific requirements:
| Certification / Standard | Description |
|---|---|
| ISO 9001:2015 | Quality Management System certification covering all manufacturing processes |
| ISO 14001:2015 | Environmental Management System ensuring sustainable production practices |
| ISO 45001:2018 | Occupational Health and Safety Management System |
| EN 10204 Type 3.1 | Inspection certificate issued by a designated responsible person, with full traceability |
| ASTM / ASME | Compliance with ASTM A269, A270, A312 and ASME B31.3 piping code requirements |
| NORSOK M-650 | Compliance for subsea umbilical and riser applications (where applicable) |
| DNV-GL / ABS / LR | Classification society approvals for marine and offshore applications |
| PED 2014/68/EU | European Pressure Equipment Directive compliance for pressure-containing applications |
7. Unique Selling Points
- Industry-Leading Coil Length: Offering 500 m to 2000 m+ per coil — up to 4× the industry standard — the ULCT sets a new benchmark in stainless steel coil tube production.
- Zero Intermediate Joints: A single continuous coil eliminates butt-weld joints, dramatically reducing the risk of corrosion-induced failures and leak points.
- Reduced Installation Cost & Time: Fewer joints mean fewer field welds, fewer NDT inspections, and significantly shorter installation timelines — especially critical in subsea and offshore environments where mobilization costs are extremely high.
- Full Material Traceability: Every coil is traceable from raw material mill to final delivery, with complete chemical composition, mechanical property, and test data documentation.
- Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd offers tailored solutions for coil length, tube dimensions, alloy grade, surface finish, and packaging to meet specific project requirements.
- Comprehensive Testing: 100% hydrostatic testing, dimensional inspection, surface quality assessment, and mechanical property verification on every coil.
Note: The Ultra-Long Coil Tube product line is designed for specialized industrial and marine applications where joint minimization is paramount. For projects requiring coil lengths exceeding 2000 meters, custom solutions are available upon consultation with Wenzhou Jixing Metal Materials Co., Ltd engineering team.