Stainless Steel Coil Tube (Coiltube) — High-Performance Pump Delivery Grade
Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered continuous-length tubing product supplied by Wenzhou Jixing Metal Materials Co., Ltd. This product is specifically designed and qualified for demanding applications including super high-rise concrete pump delivery systems, where tubing must withstand extreme internal pressures, repeated flexing, and abrasive material flow over extended service cycles. The coil tube is delivered in a continuous coiled configuration, enabling efficient storage, transport, and on-site fabrication without the need for joint welding, thereby minimizing potential failure points in critical structural and fluid conveyance systems.
Notably, coil tubes of this grade have been validated in 600-meter super high-rise pump delivery experiments conducted by China Construction Western Construction (中建西部建设), achieving results recognized as world advanced level in the construction and materials engineering sector. This validates the product's suitability for the most demanding vertical pumping applications globally.
Material & Properties
The coil tube is manufactured from high-grade austenitic stainless steel, selected for its exceptional combination of strength, ductility, corrosion resistance, and fatigue performance. The material composition and mechanical properties are engineered to meet or exceed international standards for pressure-containing and structural tubing applications.
- Base Material: Austenitic Stainless Steel (grades including 304 / 304L, 316 / 316L, 321, and custom alloy compositions per project specification)
- Corrosion Resistance: Superior resistance to oxidation, acid rain, and aggressive chemical environments; passive chromium oxide film provides self-healing protection
- Mechanical Strength: High tensile strength and yield strength ensuring structural integrity under cyclic loading conditions
- Flexibility & Fatigue Life: Excellent elongation properties allowing repeated bending without crack initiation; critical for pump delivery line routing
- Temperature Tolerance: Maintains mechanical properties across a wide temperature range from cryogenic to elevated service temperatures
- Non-magnetic Properties: Inherent non-magnetic characteristics beneficial for specialized industrial and medical applications
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Form | Continuous Coiled Tubing (Coiltube) | — |
| Outer Diameter (OD) | 6.0 mm – 325.0 mm (custom sizes available) | ASTM A213 / A269 / GB/T 12771 |
| Wall Thickness | 0.5 mm – 12.0 mm | ASTM A213 / A269 / GB/T 12771 |
| Coil Diameter | 1.0 m – 4.0 m (customizable) | Manufacturer Specification |
| Coil Length | 100 m – 5,000 m per coil (continuous) | — |
| Surface Finish | 2B, BA (Bright Annealed), No. 4 Brushed, Mirror Polish (Ra ≤ 0.4 μm) | ASTM A480 / GB/T 4237 |
| End Condition | Plain, Beveled, or Threaded (per specification) | ASME B1.20.1 |
| Tolerance on OD | ±0.05 mm – ±0.50 mm (per diameter range) | ASTM A213 |
| Tolerance on Wall Thickness | ±10% (standard); ±5% (precision grade) | ASTM A213 / GB/T 12771 |
| Maximum Working Pressure | Up to 35 MPa (350 bar) — validated for 600 m pump delivery | Project-Specific Validation |
| Minimum Bend Radius | 3D – 5D (depending on material grade and wall thickness) | Manufacturer Specification |
| Packaging | Steel band strapped coil with moisture-proof wrapping and export-grade palletization | ISO 4180 |
Manufacturing Process
The coil tube is produced through a tightly controlled multi-stage manufacturing process designed to ensure dimensional accuracy, metallurgical homogeneity, and surface integrity:
- Strip Preparation: Cold-rolled stainless steel strip is procured from certified mills, undergoing incoming inspection for chemical composition (via optical emission spectrometry), mechanical properties, and surface quality.
- Coiling & Forming: The strip is precisely formed around a mandrel using a continuous roll-forming process, with real-time diameter monitoring via laser measurement systems to ensure dimensional consistency throughout the coil length.
- Welding (if applicable): Longitudinal seam welding is performed using TIG (Tungsten Inert Gas) or laser welding techniques, followed by back-bevel grinding and internal wire brushing to achieve a smooth, crevice-free weld root.
- Heat Treatment & Annealing: Continuous annealing in a controlled atmosphere (nitrogen or vacuum) eliminates residual stresses, restores full austenitic microstructure, and enhances corrosion resistance and ductility.
- Pickling & Passivation: The coil undergoes acid pickling to remove oxide scale and subsequent passivation treatment to establish a uniform chromium-rich passive film on the surface.
- Surface Finishing: Final surface treatment (BA, mechanical polishing, or electrolytic polishing) is applied per customer specification to achieve the required finish grade.
- Non-Destructive Testing (NDT): 100% inline eddy current testing (ECT) and/or ultrasonic testing (UT) detects subsurface and surface defects. Hydrostatic pressure testing is performed at 1.5× the maximum service pressure to validate weld integrity.
- Coiling & Packaging: The finished tubing is wound onto a precision coil winder with controlled tension to prevent deformation, then packaged for export or domestic distribution.
Applications
The Stainless Steel Coil Tube is engineered for a broad spectrum of high-performance applications:
- Super High-Rise Construction: Concrete pump delivery lines for structures exceeding 600 meters in height, where the tubing must endure extreme hydrostatic pressure, abrasive slurry flow, and dynamic flexing during vertical pumping operations.
- Petroleum & Chemical Industry: Process piping, heat exchanger tubes, and fluid conveyance lines in corrosive environments (acid, alkali, chlorinated media).
- Food & Pharmaceutical Processing: Sanitary-grade tubing for milk, beverage, and pharmaceutical product transfer requiring hygienic surface finishes and compliance with FDA / 3-A standards.
- Automotive & Aerospace: Fuel lines, brake lines, exhaust system components, and structural tubing in vehicle and aircraft manufacturing.
- Medical Equipment: Endoscope tubing, dialysis equipment components, and surgical instrument shafts requiring mirror-polish finishes and biocompatibility.
- Mechanical Engineering: Hydraulic cylinders, pneumatic systems, and structural frames requiring high fatigue resistance and dimensional precision.
- Energy & Power Generation: Boiler tubes, heat exchangers, and supercritical power plant components operating under extreme thermal and pressure conditions.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring product conformance to international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO 45001:2018 — Occupational Health and Safety Management System Certification
- ASTM / ASME — Material and product compliance with American Society for Testing and Materials / American Society of Mechanical Engineers standards
- EN 10204 3.1 — Material Test Certificates issued per European standard for each shipment
- CE Marking — Conformity with European Union directives where applicable
- Mill Test Reports (MTR): Provided for every coil, documenting chemical analysis, mechanical test results, and heat treatment records
- Third-Party Inspection: Available upon request through SGS, BV, or TÜV for independent verification
Unique Selling Points
Validated for Extreme-Height Pump Delivery: The coil tube product has been experimentally proven in 600-meter super high-rise concrete pump delivery applications, achieving results recognized as world advanced level. This represents a significant engineering milestone, demonstrating the tubing's capability to withstand the most extreme pressure and abrasion conditions encountered in modern megastructure construction.
- Continuous Length Advantage: Elimination of longitudinal joints reduces leak risk, stress concentration points, and maintenance requirements in critical applications.
- Custom Engineering Capability: Full customization of dimensions, material grades, surface finishes, and coil configurations to meet project-specific requirements.
- Integrated Quality Assurance: From raw material sourcing through final packaging, every stage is monitored with in-line testing and traceable documentation.
- Global Supply Readiness: Export-grade packaging, international standard compliance, and flexible logistics support for worldwide project delivery.
- Technical Support & Application Engineering: Dedicated engineering team provides consultation on material selection, design optimization, and installation guidance for complex projects.