Stainless Steel Coil Tube (Coiltube) — Product Technical Specification
1. Product Overview
The Stainless Steel Coil Tube, also referred to as Coiltube or Continuous Coil Pipe, is a precision-engineered tubular product manufactured in a continuous coil form, enabling efficient downstream processing, forming, and cutting operations. This product is specifically designed for applications requiring seamless or welded tubular stock that can be fed through automated machinery without the need for individual straight-length handling. The coil configuration facilitates high-throughput production environments where material continuity and processing efficiency are critical.
Wenzhou Jixing Metal Materials Co., Ltd. specializes in the production and supply of stainless steel coil tubes conforming to international standards, with particular expertise in the processing and handling of spliced coil tube assemblies. The company's dedicated machine tools for spliced coil tube processing enable the production of coil tubes with consistent quality throughout the entire coil length, even where weld seams or splice joints are present.
2. Material & Properties
2.1 Material Grades
- Austenitic Grades: AISI 304, AISI 304L, AISI 316, AISI 316L, AISI 321, AISI 310S
- Ferritic Grades: AISI 430, AISI 441, AISI 444
- Duplex Grades: UNS S31803 (2205), UNS S32750 (2507)
- Custom Grades: Available upon request for specialized alloy compositions
2.2 Mechanical Properties (Typical — Grade 304)
| Property | Specification | Test Standard |
|---|---|---|
| Tensile Strength (Ultimate) | ≥ 515 MPa | ASTM A213 / ASTM A554 |
| Yield Strength (0.2% Offset) | ≥ 205 MPa | ASTM A213 / ASTM A554 |
| Elongation at Break | ≥ 40% | ASTM A213 / ASTM A554 |
| Hardness | ≤ 92 HRB | ASTM A262 |
| Density | 8.0 g/cm³ | — |
| Thermal Conductivity (20°C) | 16.3 W/(m·K) | — |
| Corrosion Resistance | Excellent in most environments; superior in oxidizing acids | ASTM A262 |
2.3 Surface Finish Options
- Pickled & Annealed (2B): Standard matte finish, suitable for general fabrication
- Polished (No. 4 / Mirror): For aesthetic and hygienic applications
- Pickled & Passivated: Enhanced corrosion resistance for chemical processing
- Heat-Resistant Annealed: For high-temperature service applications
3. Specifications
| Parameter | Specification Range | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | Φ6 mm – Φ108 mm | ASTM A554 / GB/T 12770 |
| Wall Thickness (WT) | 0.3 mm – 6.0 mm | ASTM A554 / GB/T 12770 | Coil Width (for flat tube/strip) | 6 mm – 200 mm | Internal Standard |
| Coil Length (Continuous) | Up to 1,000 m per coil (typical) | Customer Specification |
| Coil Weight | 500 kg – 3,000 kg (depending on dimensions) | — |
| OD Tolerance | ±0.10 mm (standard); ±0.05 mm (precision) | ASTM A554 |
| WT Tolerance | ±10% (standard); ±5% (precision) | ASTM A554 |
| Straightness | ≤ 1.0 mm/m | Internal Standard |
| End Condition | Open ends, capped, or custom | Customer Specification |
| Applicable Standards | ASTM A554, ASTM A213, ASME SA-213, GB/T 12770, EN 10216-5, JIS G3459 | — |
4. Manufacturing Process
4.1 Production Workflow
- Raw Material Selection: High-quality stainless steel strip or round bar sourced from certified mills, with full material traceability and mill test certificates (MTC).
- Coiling & Forming: Strip material is fed through precision roll-forming equipment to create the desired tube cross-section in continuous coil form. For round tubes, the strip is formed into a circular profile with a longitudinal seam.
- Welding (for Welded Coil Tube): The formed strip is welded along the longitudinal seam using TIG (Tungsten Inert Gas) welding or laser welding, with argon gas backing to prevent internal oxidation.
- Splice Joint Processing: When coil lengths require extension, spliced joints are created using a specialized machine tool designed for coil tube splicing. This dedicated equipment ensures that splice joints maintain mechanical continuity, dimensional accuracy, and corrosion resistance equivalent to the parent tube material.
- Heat Treatment / Annealing: Solution annealing is performed in a protective atmosphere (hydrogen, nitrogen, or vacuum) to restore full austenitic properties, relieve residual stresses, and ensure maximum corrosion resistance.
- Pickling & Passivation: Surface treatment to remove oxide scale and form a passive chromium oxide layer for enhanced corrosion protection.
- Surface Finishing: Polishing, brushing, or other finishing operations as required by the application.
- Coiling & Packaging: The finished tube is wound onto a core and packaged with protective wrapping, moisture barriers, and wooden or metal pallets for shipment.
4.2 Spliced Coil Tube — Specialized Processing
The dedicated machine tool for processing spliced coil tubes represents a key differentiator in Wenzhou Jixing's manufacturing capability. This specialized equipment addresses the critical challenge of joining two coil tube sections to create a continuous length without compromising:
- Dimensional consistency across the splice joint
- Weld integrity and metallurgical compatibility
- Corrosion resistance at the splice location
- Mechanical strength equivalent to the base material
- Surface finish continuity
The splice processing methodology involves precision alignment, controlled welding under inert gas shielding, post-weld heat treatment, and rigorous inspection to ensure the splice joint meets or exceeds the performance of seamless tube.
5. Applications
- Automotive Industry: Exhaust system components, fuel lines, turbocharger pipes, brake lines
- Food Processing & Beverage: Hygienic piping systems, heat exchangers, beverage dispensing lines (304L/316L grades)
- Medical Equipment: Surgical instrument tubing, dialysis machine components, endoscope channels
- Petrochemical & Oil/Gas: Process piping, heat exchanger tubes, instrumentation tubing
- Construction & Architecture: Structural handrails, decorative elements, furniture components
- Electronics & Electrical: Connector housings, shielding components, heat sinks
- General Fabrication: Continuous feed for automated cutting, bending, and forming operations
6. Quality Certifications & Compliance
| Certification / Standard | Description |
|---|---|
| ISO 9001:2015 | Quality Management System certification for consistent product quality |
| ISO 14001:2015 | Environmental Management System compliance |
| ISO/TS 22163 | Medical devices — Quality management system requirements |
| EN 10204 3.1 | Inspection certificates for material and product conformity |
| PED 2014/68/EU | Pressure Equipment Directive compliance (where applicable) |
| NSF/ANSI 61 | Drinking water system components certification (316L grades) |
6.1 Quality Assurance Measures
- Incoming Inspection: 100% verification of raw material certificates, chemical composition analysis (OES), and dimensional checks
- In-Process Control: Continuous monitoring of forming, welding, and heat treatment parameters with statistical process control (SPC)
- Final Testing: Hydrostatic pressure testing, dimensional verification, surface inspection, and optional spectroscopic analysis
- Traceability: Full batch traceability from raw material mill through to finished coil, with unique heat numbers and production batch identifiers
- Third-Party Inspection: Available upon customer request (SGS, BV, TÜV)
7. Unique Selling Points
- Spliced Coil Capability: Proprietary machine tool technology enables the production of continuous-length coil tubes with splice joints that meet full mechanical and corrosion performance standards — eliminating the limitation of single-coil length constraints.
- Continuous Production Efficiency: The coil form eliminates the need for individual tube handling, reducing labor costs and enabling seamless integration with automated downstream processing lines.
- Dimensional Precision: Tight tolerances maintained throughout the entire coil length, including across splice joints.
- Material Versatility: Availability across a broad range of stainless steel grades, including duplex and super-duplex alloys for demanding service conditions.
- Custom Fabrication: Capability for custom dimensions, surface finishes, and end treatments tailored to specific customer requirements.
- Full Traceability: Complete material provenance documentation from mill to delivery, supporting compliance in regulated industries.
8. Packaging & Delivery
- Coils are wound onto steel or wooden cores with protective edge guards
- Wrapped with VCI (Volatile Corrosion Inhibitor) paper and moisture-proof polyethylene film
- Secured on export-grade wooden pallets or steel skids
- Shrink-wrapped and strapped for transit stability
- Marked with product identification, heat number, dimensions, and weight
9. Technical Support & Consultation
Wenzhou Jixing Metal Materials Co., Ltd. provides comprehensive technical support including:
- Material selection guidance based on application requirements
- Dimensional engineering consultation for downstream processing
- Welding procedure recommendations for coil tube fabrication
- Corrosion resistance assessment for specific service environments
- Sample provision for customer qualification testing
Product Catalog Reference: Item No. 1649 — Stainless Steel Coil Tube (Coiltube)
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.