Stainless Steel Coil Tube with Rotary & Cantilever Pay-Off System
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. (Product No. 215) delivers high-grade stainless steel coil tube engineered for seamless deployment in industrial piping systems, heat exchangers, and process engineering applications. The coil tube is supplied in a continuous spiral wound configuration, designed to be loaded onto a purpose-built rotary or cantilever pay-off reel system for controlled, kink-free unspooling during installation and maintenance operations.
The core value proposition of this product lies in its compatibility with a dedicated axial-rotation pay-off mechanism. The coil tube rests flat on a precision-engineered turntable, allowing the entire assembly to rotate about its longitudinal axis as the tube is drawn off. This method eliminates the lateral bending stresses, ground abrasion, and torsional distortion that plague conventional pay-out methods, thereby preserving the geometric integrity and mechanical properties of the tube throughout its service life.
Unique Selling Points
- Zero-Kink Deployment: The rotary pay-off system ensures the coil tube is released under pure axial tension, fundamentally preventing kinking — the single most common cause of coil tube rejection in the field.
- Surface Integrity Preservation: By eliminating ground contact during unspooling, the outer surface of the tube remains free from scratches, gouges, and abrasive wear, maintaining corrosion resistance and aesthetic finish.
- Continuous Length Advantage: Coil tube is supplied in continuous spools, reducing field weld count by up to 70% compared to straight-length tube, which translates to lower installation labor, fewer potential leak points, and reduced overall project cost.
- Dual Configuration Flexibility: Available for use with both rotary turntable and cantilever arm pay-off reels, accommodating varied site conditions from tight indoor plant rooms to open-air construction yards.
- Engineered for Maintenance: The pay-off system is specifically categorized under installation and maintenance operations, making it ideal for retrofit projects, repair campaigns, and shutdown interventions where rapid tube replacement is critical.
Material & Properties
The coil tube is manufactured from austenitic stainless steel grades selected for their combination of corrosion resistance, formability, and weldability. The primary material specification is Grade 304 (UNS S30400 / 1.4301), with Grade 304L (UNS S30403 / 1.4307) available for low-carbon, high-corrosion-resistance requirements. Grade 316L (UNS S31603 / 1.4404) is offered for applications involving chlorides, acidic media, or marine environments.
Key Material Properties (Grade 304 Reference)
- Tensile Strength: ≥ 520 MPa (≥ 75,400 psi)
- Yield Strength (0.2% Offset): ≥ 205 MPa (≥ 29,735 psi)
- Elongation at Rupture: ≥ 40% (minimum)
- Hardness: ≤ 200 HB (Brinell)
- Density: 7.93 g/cm³ (0.286 lb/in³)
- Thermal Conductivity (20°C): 16.3 W/(m·K) (9.36 BTU/(hr·ft·°F))
- Modulus of Elasticity: 193 GPa (28,000,000 psi)
- Maximum Service Temperature: 870°C (1,598°F) in air; 425°C (797°F) in continuous aqueous service
- Corrosion Resistance: Excellent resistance to atmospheric, organic, and mild inorganic acids; pitting resistance equivalent number (PREN) of 18–20 for Grade 304
Specifications
| Parameter | Specification | Notes |
|---|---|---|
| Product Code | 215 | Wenzhou Jixing internal catalog number |
| Product Name | Stainless Steel Coil Tube | Continuous spiral-wound configuration |
| Material Grade | 304 / 304L / 316L | Other grades available on request |
| Outside Diameter (OD) | 6.0 – 108.0 mm (0.236 – 4.252 in) | Custom diameters available |
| Wall Thickness | 0.5 – 6.0 mm (0.020 – 0.236 in) | Tolerance ±10% per ASTM A213 |
| Coil Diameter (OD of Spool) | 600 – 2,400 mm (23.6 – 94.5 in) | Selected per pay-off reel capacity |
| Coil Length (Continuous) | 500 – 5,000 m (1,640 – 16,404 ft) | Dependent on tube size and spool diameter |
| Surface Finish | Pickled & Passivated (P&P) | 2B, No.4, or mirror finish available |
| End Condition | Plain cut / Beveled / Threaded | Bevel angle 37.5° ± 1° for butt weld prep |
| Applicable Standards | ASTM A213 / A269, ASME SA-213 / SA-269, EN 10216-5, ISO 13924 | Mutually exclusive per order specification |
| Pay-Off System Type | Rotary Turntable or Cantilever Arm | Axial rotation deployment |
| Coil Orientation on Reel | Flat (horizontal axis) | Coil plane parallel to turntable surface |
| Maximum Deployment Speed | 15 – 30 m/min (49 – 98 ft/min) | Speed dependent on tube OD and wall thickness |
| Minimum Bending Radius | ≥ 5 × OD | Exceeding this causes kinking — immediate scrap |
| Packaging | Wooden pallet, VCI wrap, moisture-absorbent desiccant | Sealed against atmospheric corrosion during transit |
Manufacturing Process
The production of Wenzhou Jixing stainless steel coil tube follows a tightly controlled multi-stage process designed to ensure dimensional accuracy, metallurgical consistency, and surface quality suitable for demanding process applications.
- Raw Material Sourcing: Virgin stainless steel strip is procured from certified mill sources. Each batch undergoes incoming inspection for chemical composition (via optical emission spectrometry, OES) and mechanical properties verification before release into production.
- Slitting & Leveling: The coil strip is slit to precise width using a servo-controlled slitting line. The strip is then passed through a leveling unit to eliminate coil set and ensure flatness within ±0.1 mm/m, a prerequisite for uniform tube forming.
- Coil Forming (Roll Forming): The leveled strip enters a multi-station roll-forming line where it is progressively shaped into a circular cross-section. For larger diameters, a U-O (U-shape to O-shape) forming process is employed. The forming process is carefully calibrated to avoid thinning of the wall beyond specification limits.
- Longitudinal Welding: Where applicable, the formed tube undergoes automatic argon arc (TIG) or laser welding along the longitudinal seam. The welding parameters are continuously monitored and recorded to ensure a consistent, defect-free weld bead. Post-weld, the seam is ground flush to achieve uniform wall thickness around the circumference.
- Heat Treatment (Solution Annealing): The welded tube is passed through a continuous annealing furnace at temperatures between 1,050°C and 1,150°C (1,922°F – 2,092°F) under a protective atmosphere (endothermic gas or vacuum) to dissolve carbides, restore full austenitic microstructure, and relieve residual forming stresses.
- Pickling & Passivation: The annealed tube is immersed in a mixed acid bath (typically nitric + hydrofluoric acid) to remove the oxide scale formed during annealing. This is followed by a passivation step using a citric or nitric acid solution to restore the chromium oxide passive layer, ensuring optimal corrosion resistance.
- Coiling: The finished tube is wound into coils of the specified diameter. The coiling tension is precisely controlled to prevent inter-coil compression, which could lead to flattening or ovality. Each coil is labeled with a unique heat traceability tag.
- Non-Destructive Testing (NDT): Every coil undergoes 100% eddy current inspection to detect internal and surface defects including laminations, cracks, and weld seam discontinuities. Hydrostatic pressure testing is performed at 2 × the maximum design pressure to verify seam integrity.
- Dimensional Inspection: Sample lengths from each coil are measured for OD, wall thickness, roundness, and straightness using calibrated instruments. Results are documented in a certificate of conformity.
- Packaging & Dispatch: Coils are wrapped in VCI (Volatile Corrosion Inhibitor) film, strapped to wooden pallets, and enclosed in protective packaging for safe transportation.
Pay-Off System: Rotary & Cantilever Configuration
The coil tube is designed for deployment using a specialized rotary turntable or cantilever arm pay-off reel system. This system is integral to the product's performance and must be understood as a mandatory component of the installation process.
Rotary Turntable Pay-Off System
In the rotary configuration, the coil tube is placed flat on a large-diameter turntable such that the plane of the coil lies parallel to the turntable surface. The turntable rotates about its central vertical axis, causing the coil tube to unspool axially. A tension control device and guide roller assembly at the exit point ensures consistent pulling force and prevents lateral displacement of the tube during deployment.
Cantilever Arm Pay-Off System
The cantilever configuration employs an extended arm that supports the coil tube at one end while the tube is drawn off from the opposite end. The arm rotates about a vertical pivot, allowing the coil to unwind under gravity-assisted axial rotation. This configuration is particularly suited for larger coil diameters (exceeding 1,500 mm / 59 in) and heavier tube weights where turntable load capacity may be limiting.
Critical Handling Warning: Under no circumstances shall the coil tube be dragged across the ground, rolled along a surface, or deployed by lifting the coil and pulling the tube from a stationary position. Any kinking — defined as a permanent plastic deformation of the tube cross-section exceeding 5% of the nominal OD — renders the affected section irreparable and requires immediate scrapping. Kinked tube must never be cut out and re-welded, as the metallurgical integrity of the affected zone is compromised beyond safe repair limits.
Deployment Best Practices
- Install the coil tube on the pay-off reel with the coil axis horizontal and the turntable surface level (±0.5° from horizontal).
- Ensure the tube exit guide rollers are aligned with the tube centerline to prevent lateral bending during unspooling.
- Maintain a minimum deployment speed of 5 m/min (16.4 ft/min) to allow the tube to relax its residual coil set before entering the routing path.
- Provide a minimum of 3 × OD of free, unsupported tube length between the pay-off reel and the first fixed support or bend to prevent stress concentration at the reel exit.
- Use a calibrated spring-loaded or hydraulic tensioner at the reel exit to maintain a constant pulling force of 50–200 N (11–45 lbf), depending on tube size.
- Inspect the tube continuously during deployment for any signs of ovality, flattening, or surface damage. Stop immediately and assess if anomalies are observed.
Applications
The stainless steel coil tube with rotary/cantilever pay-off system is deployed across a wide range of industrial and commercial applications where continuous-length tubing, corrosion resistance, and rapid installation are paramount.
Process Engineering & Chemical Processing
- Piping systems for chemical processing plants handling acids, alkalis, and organic solvents
- Pharmaceutical and bioprocess plant piping requiring hygienic, cleanable surfaces
- Food and beverage processing lines subject to CIP (Clean-in-Place) and SIP (Sterilize-in-Place) protocols
- Water treatment and desalination plant internal piping
Heat Transfer & Energy
- Heat exchanger tubes for shell-and-tube and plate-fin configurations
- Condenser and evaporator tube bundles in HVAC and refrigeration systems
- Heat tracing and trace heating systems for pipeline freeze protection
- Solar thermal collector tubing
Oil, Gas & Petrochemical
- Wellhead and Christmas tree tubing connections
- Refinery process piping for high-temperature and high-pressure service
- Offshore platform internal piping systems
- Natural gas processing plant instrumentation tubing
Installation & Maintenance Operations
- Retrofit and replacement of corroded or failed piping in operating plants during shutdown windows
- Emergency repair campaigns requiring rapid tube deployment in confined or elevated spaces
- Modular skid-mounted equipment fabrication where coil tube reduces field welding requirements
- Turnaround and maintenance activities in power generation, petrochemical, and pulp & paper facilities
Specialty Applications
- Nuclear power plant instrumentation and control piping
- Medical device manufacturing and laboratory equipment tubing
- Automotive exhaust system components and fuel system lines
- Aerospace hydraulic and pneumatic tubing
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and holds the following certifications and complies with the following international standards:
Management System Certifications
- ISO 9001:2015 — Quality Management Systems
- ISO 14001:2015 — Environmental Management Systems
- ISO 45001:2018 — Occupational Health and Safety Management Systems
- ISO/TS 22163 — Automotive Quality Management (where applicable)
Product & Process Certifications
- ASME Certificate of Compliance — for production to ASME SA-213 and SA-269 specifications
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