Stainless Steel Coil Tube — Coiled Pipe for Series Conveyor Systems
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered continuous pipe product formed into a coiled configuration for efficient storage, transportation, and deployment in industrial conveying systems. This product is specifically designed for use in series coil pipe conveyor applications, where a traction wire rope system pulls the coiled pipe through a serpentine or linear transport path. The coil tube eliminates the need for field welding and joining, providing a seamless, leak-resistant conduit ideal for fluid transfer, pneumatic conveying, and material handling in mining, chemical, and infrastructure sectors.
The dynamic analysis of traction wire ropes in series coil pipe conveyor systems (as referenced in Dynamic Analysis of Traction Wire Rope for Series Coil Pipe Conveyor) informs the mechanical design parameters of this product, ensuring that the coil tube's wall thickness, outer diameter, and coil geometry are optimized to withstand cyclic tensile, compressive, and bending loads imposed by the traction-driven transport mechanism.
Material & Properties
The coil tube is fabricated from high-grade austenitic and duplex stainless steel grades, selected for superior corrosion resistance, mechanical strength, and formability during the cold-coiling process.
- Primary Grades: AISI 304 (UNS S30400), AISI 316L (UNS S31603), AISI 321 (UNS S32100), and Duplex 2205 (UNS S32205)
- Corrosion Resistance: Exceptional resistance to pitting, crevice corrosion, and intergranular corrosion in acidic, alkaline, and chloride-rich environments
- Mechanical Properties: Tensile strength ranging from 515 MPa (304) to 620 MPa (2205); elongation ≥ 40% at break, ensuring ductility during coiling without work-hardening failure
- Temperature Range: Continuous service from −196 °C (cryogenic) to 870 °C (oxidation limit for 304/316L)
- Non-magnetic: Austenitic grades exhibit negligible magnetic permeability, suitable for electromagnetic-sensitive installations
- Hygienic Surface: Passivated surface with surface roughness Ra ≤ 0.4 μm available for food-grade and pharmaceutical applications
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6.0 mm – 219.0 mm (1/4" – 8-5/8") | ASTM A269 / EN 10217-7 |
| Wall Thickness | 0.5 mm – 6.0 mm | ASTM A269 |
| Coil Inner Diameter (CID) | 200 mm – 1200 mm | Supplier-specific |
| Coil Length per Roll | 100 m – 1000 m (customizable) | Supplier-specific | Surface Finish | No. 1 (Hot Rolled), 2B, BA (Bright Annealed), Electropolished (Ra ≤ 0.25 μm) | ASTM A480 |
| End Condition | Plain cut, beveled (37.5°/45°), threaded (BSP/NPT), or flanged | ISO 14284 / ASME B1.20.1 |
| Maximum Working Pressure | Up to 25 MPa (design-dependent) | PV = 2 × t × S × E / D |
| Tolerance (OD) | ±0.05 mm (precision) / ±0.10 mm (standard) | EN 10217-7 |
| Tolerance (Wall) | ±10% of nominal | ASTM A269 |
| Heat Treatment | Solution Annealed (1010–1150 °C) + Water Quenched | ASTM A269 |
| Coil Forming Method | Cold Coiling / Induction-Helical Coiling | Supplier-specific |
| Packaging | Wooden reel or steel drum with VCI (Vapor Corrosion Inhibitor) wrapping | ISO 17292 |
Manufacturing Process
- Raw Material Procurement: High-purity stainless steel strip or hot-rolled coil sourced from certified mills (e.g., Outokumpu, ThyssenKrupp, POSCO) with full mill test certificates (MTC) compliant with EN 10204 3.1.
- Surface Preparation: Strip is degreased, descaled, and passivated to remove mill scale and organic contaminants prior to forming.
- Forming (Cold Drawing / Roll Forming): The strip is drawn through precision-die tooling or roll-formed into the target OD and wall thickness. Multi-pass forming ensures dimensional accuracy and minimizes residual stress.
- Solution Annealing: Formed tube is solution annealed at 1010–1150 °C followed by rapid water quenching to restore full austenitic microstructure, eliminate work-hardening, and maximize corrosion resistance.
- Coil Forming: The continuous tube is coiled onto a mandrel or reel using either:
- Cold Coiling: Direct mechanical coiling with controlled winding tension to prevent ovality and kinking.
- Induction-Helical Coiling: Induction heating to a controlled temperature (700–850 °C) followed by helical coiling, reducing springback and achieving tighter coil geometry for large OD applications.
- Surface Finishing: Optional electropolishing (acid electrolytic treatment) to achieve Ra ≤ 0.25 μm for sanitary applications, or pickling and passivation for general industrial use.
- Quality Inspection: Each coil undergoes 100% visual inspection, dimensional verification (OD, wall thickness via ultrasonic measurement), and random sampling for hydrostatic pressure testing and spectrographic chemical analysis.
- Packaging & Dispatch: Coils are secured on wooden reels or steel drums, wrapped with VCI protective film, and labeled with product identification, heat number, and traceability codes.
Applications
- Series Coil Pipe Conveyor Systems: Primary application where the coil tube is transported along a conveyor path via traction wire rope, used in mining (ore slurry transfer), tunneling, and pipeline installation without field joints.
- Chemical Processing: Conveyance of aggressive acids, chlorides, and caustic solutions in continuous flow lines.
- Food & Beverage Industry: Hygienic fluid transfer (dairy, beer, pharmaceuticals) with electropolished sanitary coil tubing.
- Petrochemical & Oil & Gas: Downhole tubing, well completion coiled tubing, and corrosion-resistant flow lines.
- Marine & Offshore: Ballast water systems, fire suppression lines, and desalination plant pipework.
- Heat Exchanger & HVAC: Compact coil tubing for brazed plate heat exchangers and chiller circuits.
- Wire Rope & Cable Industry: Protective conduit for traction wire ropes in hoisting and lifting systems.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System
- ISO 14001:2015 — Environmental Management System
- ISO 45001:2018 — Occupational Health & Safety Management
- EN 10204 Type 3.1 — Material Test Certificate (Mill Test Report)
- ASTM A269 — Standard Specification for Welded Austenitic Stainless Steel Seamless and Wrought Pipe
- EN 10217-7 — Technical Delivery Conditions for Stainless Steel Tubes for Pressure Purposes
- PED (Pressure Equipment Directive) 2014/68/EU — CE Marking for pressure applications
- ASME B&PV Code Section VIII Div. 1 — For pressure vessel and piping components
- NORSOK M-650 — For oil and gas industry applications
- 3-A Sanitary Standards — For food, dairy, and pharmaceutical applications
- CRN (Canadian Registration Number) — Available for Canadian market compliance
Unique Selling Points
- Joint-Free Continuous Length: Eliminates field welding and mechanical couplings, dramatically reducing leak points and maintenance requirements in conveyor and pipeline systems.
- Dynamic Load-Optimized Geometry: Coil tube specifications are engineered with reference to traction wire rope dynamic analysis, ensuring compatibility with series conveyor systems subject to cyclic tension and bending fatigue.
- Full Traceability: Every coil is linked to its heat number, chemical composition report, mechanical test data, and dimensional inspection records for complete supply-chain traceability.
- Wide Grade & Dimensional Range: Capability to supply from micro-bore (6 mm OD) to large-diameter (219 mm OD) coils across austenitic, duplex, and super-duplex grades.
- Custom Coil Configuration: Coil inner diameter, roll length, end preparation, and surface finish are fully customizable to match specific conveyor system design parameters.
- Superior Corrosion Performance: Duplex 2205 coils offer 2× the yield strength of 304/316L with superior chloride pitting resistance (PREN ≥ 35), extending service life in aggressive environments.
Note: All product specifications are subject to final confirmation based on customer application requirements. Wenzhou Jixing Metal Materials Co., Ltd. provides engineering consultation, sample testing, and technical support for custom coil tube solutions tailored to series conveyor and industrial piping applications.