Stainless Steel Coil Tube (盘管) — Ultra-Long Length Pumping-Grade Product
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd (Product No. 407) is a precision-engineered continuous stainless steel tube supplied in coiled configuration. This product is specifically designed for applications requiring ultra-long length delivery without joints or weld seams, including pump delivery systems for Lightweight Ultra-High Performance Concrete (LWU-HPC) and other industrial fluid transport scenarios. The coil format eliminates the need for intermediate couplings, thereby reducing pressure drop, minimizing leak risk, and enabling continuous uninterrupted flow over extended distances.
This product line represents a significant advancement in metallurgical engineering for continuous tube supply, combining the corrosion resistance of austenitic stainless steel with the logistical advantages of coiled delivery. The coil tube is particularly suited for applications where traditional straight-length pipe would require excessive welding, threading, or mechanical jointing.
Material Composition & Mechanical Properties
The coil tube is fabricated from high-grade austenitic stainless steel, conforming to the chemical and mechanical requirements of internationally recognized standards. The material selection ensures excellent formability during the coiling process while maintaining structural integrity under operational stress.
- Base Material: Austenitic Stainless Steel (e.g., AISI 304, AISI 316L, or equivalent Chinese standard grades such as 06Cr19Ni10 / 022Cr17Ni12Mo2)
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and intergranular corrosion due to chromium (Cr ≥ 18%) and molybdenum (Mo ≥ 2%) alloying elements
- Formability: High ductility enabling tight coil bending radii without cracking or material thinning
- Temperature Range: Operational temperature range from cryogenic (-196°C) to elevated temperatures (up to 870°C for 304 grade)
- Non-Magnetic Properties: Essentially non-magnetic in annealed condition, suitable for electromagnetic sensitive environments
- Hygienic Surface: Available in electropolished or passivated surface finish for food-grade and pharmaceutical applications
Technical Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Outer Diameter (OD) | 6 mm – 120 mm (custom sizes available) | ASTM A554 / GB/T 12771 |
| Wall Thickness | 0.5 mm – 6.0 mm | ASTM A554 / GB/T 12771 |
| Coil Length | Up to 500 m per coil (ultra-long configuration) | Manufacturer standard |
| Coil Inner Diameter | 200 mm – 600 mm (configurable) | Customer requirement |
| Tensile Strength | ≥ 520 MPa (304); ≥ 515 MPa (316L) | ASTM A554 |
| Yield Strength (0.2% offset) | ≥ 205 MPa | ASTM A554 |
| Elongation (after fracture) | ≥ 40% (in annealed condition) | ASTM A554 |
| Surface Finish | Mirror polished / Electropolished / Passivated / 2B / BA | Ra ≤ 0.1 μm (mirror); Ra ≤ 0.4 μm (electropolished) |
| Dimensional Tolerance | ±0.05 mm (OD); ±0.05 mm (wall thickness) | ISO 4427 / GB/T 12771 |
| End Condition | Plain end / Beveled / Flanged / Threaded (on request) | Customer specification |
| Packaging | Wooden coil cradle with moisture-proof wrapping; export-grade packaging available | ISO 13250 |
Manufacturing Process
The production of high-quality stainless steel coil tubes involves a multi-stage metallurgical and mechanical process designed to maintain material homogeneity and dimensional precision throughout the entire coil length.
- Hot Rolling (热轧): Stainless steel slabs are hot-rolled into seamless tube blanks at temperatures exceeding 1200°C, establishing initial wall geometry and grain structure.
- Piercing & Elongation: The solid billet is pierced using rotary piercing mills to create a hollow tube, followed by controlled elongation to achieve desired OD and wall thickness ratios.
- Intermediate Annealing (中间退火): Periodic solution annealing is performed during cold working to relieve accumulated strain, restore ductility, and prevent cracking during subsequent forming operations.
- Cold Drawing & Sizing (冷拔与定径): The tube is cold-drawn through precision dies to achieve final dimensional tolerances (±0.05 mm) and surface finish requirements. Multiple passes may be employed for high-precision specifications.
- Solution Annealing (固溶退火): The tube is heated to 1050°C – 1150°C and rapidly quenched to dissolve carbide precipitates, ensuring maximum corrosion resistance and mechanical properties.
- Coiling (盘绕): The continuous tube is wound onto a precision coiling mandrel at controlled tension to achieve uniform coil geometry without residual stress or distortion. The coiling process employs tension-controlled rollers to prevent ovality and kinking.
- Surface Treatment: Final surface preparation includes pickling, passivation (chemical or electrolytic), and optional electropolishing to achieve Ra ≤ 0.1 μm for hygienic applications.
- Quality Inspection: Each coil undergoes ultrasonic testing (UT), hydrostatic pressure testing, dimensional verification, and chemical composition analysis (OES/SEM) prior to dispatch.
Applications
The ultra-long stainless steel coil tube finds extensive application across multiple industrial sectors:
- Concrete Pumping Systems (混凝土泵送系统): As studied in the context of Lightweight Ultra-High Performance Concrete (LWU-HPC), coil tubes serve as continuous pump delivery lines for concrete transport over extended distances without joint-induced pressure losses or blockage risks.
- Food & Beverage Industry: Hygienic-grade coil tubing for CIP (Clean-In-Place) compatible fluid transfer in dairy, brewery, and pharmaceutical processing.
- Chemical & Petrochemical Processing: Corrosion-resistant coil tubing for acid, alkali, and solvent transport in continuous processing lines.
- Medical & Pharmaceutical Equipment: Biocompatible tubing for sterilization circuits, dialysis systems, and cleanroom fluid distribution.
- Oil & Gas Industry: Subsea umbilical cables, wellhead tubing, and chemical injection lines requiring long continuous runs.
- Automotive & Aerospace: Fuel lines, hydraulic circuits, and exhaust system components requiring high-temperature resistance and fatigue durability.
- Construction & Infrastructure: Structural reinforcement, curtain wall systems, and architectural decorative elements.
- Energy & Power Generation: Solar thermal collectors, heat exchanger tubes, and nuclear-grade coolant loops.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system ensuring product conformity to international and national standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System
- EN 10204 3.1 — Material Inspection Certificate (third-party verified)
- ASTM A554 — Standard Specification for Seamless and Welded Austenitic Stainless Steel Tube
- ASTM A269 — Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing
- GB/T 12771 — Chinese National Standard for Stainless Steel Seamless Tubes for Fluid Transport
- GB/T 14976 — Chinese National Standard for Cold-Rolled Stainless Steel Seamless Tubes
- EN 10216-5 — European Standard for Heat Exchanger Tubes
- PED 2014/68/EU — Pressure Equipment Directive compliance (where applicable)
- NACE MR0175 — Resistance to sulfide stress cracking (for oil & gas applications)
Unique Selling Points
- Ultra-Long Continuous Length: Coils of up to 500 meters eliminate the need for field welding or mechanical joining, reducing installation time and eliminating potential failure points.
- Precision Coiling Technology: Proprietary tension-controlled coiling ensures zero ovality, uniform spring-back characteristics, and predictable uncoiling behavior for downstream processing.
- Multi-Grade Material Availability: Comprehensive range from 304 to 316L, 321, 347, duplex (2205), and super-austenitic grades to meet specific corrosion and mechanical requirements.
- Integrated R&D for Specialized Applications: Technical expertise in ultra-long coil tube pumping performance, including studies on Lightweight Ultra-High Performance Concrete (LWU-HPC) delivery optimization.
- Custom Engineering: Capability to produce non-standard OD, wall thickness, coil configuration, and surface finish specifications tailored to project requirements.
- Full Traceability: Every coil is accompanied by mill test certificates with heat number traceability, chemical analysis, mechanical test results, and dimensional inspection reports.
Note: This product specification is based on the technical research and manufacturing capabilities documented under Product No. 407 (盘管 Coiltube) by Wenzhou Jixing Metal Materials Co., Ltd. The application context referenced includes advanced pumping performance studies for Lightweight Ultra-High Performance Concrete (轻质超高性能混凝土), demonstrating the versatility of stainless steel coil tubes in demanding construction and engineering applications.