Stainless Steel Coil Tube for Ultra-High-Rise Concrete Pumping Systems
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. (Product No. 747) presents a premium-grade stainless steel coil tube (Coil Tube) engineered specifically for demanding concrete pumping applications in super high-rise construction. This product was validated through the landmark High-Strength High-Performance C130 Concrete Simulated Vertical Height 880m Super High-Rise Pumping Coil Tube Experiment, which demonstrated the tube's exceptional capability to withstand extreme hydrostatic pressures, high shear forces, and prolonged abrasive wear conditions encountered during ultra-tall building construction.
Unlike conventional straight-length piping systems, the coil tube design offers superior flexibility, compact storage, and ease of deployment at construction sites. The stainless steel construction provides outstanding corrosion resistance against aggressive concrete alkaline environments (pH 12–14), ensuring extended service life even under continuous exposure to wet cement slurries and chemical admixtures.
Material & Properties
The coil tube is manufactured from high-performance austenitic stainless steel, selected for its superior mechanical properties and resistance to pitting, crevice corrosion, and stress corrosion cracking in concrete pumping environments.
- Base Material: Austenitic stainless steel (304/316 grade or equivalent), providing excellent ductility and formability for coil winding operations
- Corrosion Resistance: Superior resistance to concrete alkaline environment (pH 12–14), chloride-induced pitting (CIC), and sulfuric acid attack from cement hydration byproducts
- Mechanical Strength: High tensile strength and yield strength to resist internal hydraulic pressures exceeding 30 MPa during 880m vertical pumping operations
- Abrasion Resistance: Hardened inner surface or protective lining to withstand continuous passage of aggregate-laden concrete mixtures (C130 grade and above)
- Thermal Stability: Maintains dimensional integrity and mechanical properties across operating temperature ranges from -20°C to +150°C
- Non-Magnetic Properties: Essential for compatibility with magnetic pumping systems and non-destructive testing protocols
- Hygienic Surface: Smooth inner surface (Ra ≤ 0.8 μm) minimizes concrete adhesion and reduces pump pressure drop
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Designation | Stainless Steel Coil Tube (Coiltube) | — |
| Product No. | 747 | — |
| Outer Diameter (OD) | 60 mm – 150 mm (configurable) | ASTM A213 / GB/T 14976 |
| Wall Thickness | 3.0 mm – 8.0 mm | ASTM A269 |
| Coil Length | Up to 12,000 mm per coil | Manufacturer specification |
| Coil Diameter | 800 mm – 1,500 mm | — |
| Minimum Bend Radius | ≥ 5 × OD | ASTM A213 |
| Maximum Working Pressure | ≥ 40 MPa (tested to 880m equivalent head) | Internal test protocol |
| Surface Finish (Inner) | Electropolished, Ra ≤ 0.8 μm | ASTM A270 / GB/T 13116 |
| Surface Finish (Outer) | Mirror polished / 2B finish | — |
| Tensile Strength | ≥ 520 MPa | ASTM A240 |
| Yield Strength | ≥ 205 MPa | ASTM A240 |
| Elongation | ≥ 40% | ASTM A240 |
| Corrosion Resistance (Pitting) | PITV ≥ 25 mV in 3.5% NaCl solution | ASTM G150 |
| Operating Temperature Range | -20°C to +150°C | — |
| Concrete Grade Compatibility | Up to C130 (Ultra-High Performance Concrete) | EN 206 / GB/T 50164 |
Manufacturing Process
The production of this coil tube follows a rigorous multi-stage manufacturing process to ensure consistent quality and mechanical performance:
- Raw Material Selection & Ingot Casting: High-purity stainless steel billets are sourced from certified mills, with chemical composition verified to ASTM A240 specifications. Ingot casting employs vacuum induction melting (VIM) or argon oxygen decarburization (AOD) to minimize impurities.
- Hot Rolling & Annealing: Billets are hot-rolled into seamless tube blanks, followed by solution annealing at 1050°C – 1150°C to achieve a uniform austenitic microstructure free of carbide precipitation.
- Precision Cold Drawing: The tube blanks undergo multi-pass cold drawing through tungsten carbide (WC) dies to achieve tight dimensional tolerances (±0.05 mm) and enhanced mechanical properties through work hardening.
- Intermediate Annealing: Periodic solution heat treatment (1050°C, water quench) is performed between cold drawing passes to restore ductility and prevent cracking.
- Coil Winding: The finished tube is wound into coil form using CNC-controlled winding equipment with precise tension control to prevent deformation, kinking, or ovality exceeding 1% of OD.
- Surface Treatment: Inner surfaces are electropolished to achieve mirror finish (Ra ≤ 0.8 μm), reducing concrete adhesion and minimizing pumping pressure losses. Outer surfaces receive 2B or mirror polishing.
- Non-Destructive Testing (NDT): 100% eddy current testing (ECT) and ultrasonic testing (UT) are performed to detect internal defects, wall thickness variations, and surface imperfections.
- Hydrostatic Pressure Testing: Each coil is pressure-tested to 1.5× the maximum working pressure (≥ 60 MPa) to verify structural integrity.
- Dimensional Inspection & Certification: Final dimensional verification, chemical composition analysis, and mechanical property testing are documented in a full mill test certificate (MTC) per EN 10204 Type 3.1.
Applications
This stainless steel coil tube is purpose-engineered for the following critical applications:
- Super High-Rise Concrete Pumping: Primary application — transporting ultra-high-performance concrete (UHPC, C130 grade) to vertical heights of 880 meters and beyond, as validated by the landmark pumping experiment. The coil tube's flexibility allows easy routing through complex building structures.
- Long-Distance Horizontal Concrete Transfer: Efficient conveyance of concrete mixtures over distances exceeding 200 meters in large-scale infrastructure projects (bridges, dams, tunnels).
- Marine & Offshore Construction: Concrete pumping operations in aggressive chloride-rich marine environments where carbon steel alternatives would suffer rapid corrosion.
- Nuclear & Energy Infrastructure: Concrete placement in radiation environments and high-purity containment structures requiring corrosion-resistant, non-magnetic piping.
- Chemical & Pharmaceutical Plants: Transfer of caustic slurries, alkaline solutions, and aggressive chemical mixtures in process piping systems.
- Food & Beverage Processing: Hygienic-grade fluid transfer where the electropolished inner surface prevents bacterial colonization and ensures easy CIP (Clean-in-Place) sanitation.
- Oil & Gas Industry: Downhole tubing and well completion systems requiring resistance to H₂S (hydrogen sulfide) and CO₂ corrosion.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and holds the following certifications to ensure product conformity and traceability:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO 45001:2018 — Occupational Health & Safety Management System
- EN 10204 Type 3.1 — Full Mill Test Certificate (MTC) for every production lot
- ASTM / ASME Compliance — Materials conform to ASTM A213, A269, A270, and A240 specifications
- CE Marking — European Conformity for pressure equipment (PED 2014/68/EU)
- Pressure Vessel & Piping Inspection — Third-party inspection by NACE-certified inspectors
- Material Traceability — Full heat-number traceability from ingot to finished coil, enabling complete supply chain accountability
Unique Selling Points
Validated for 880m Vertical Pumping: The only stainless steel coil tube product validated through full-scale experimental simulation of C130 concrete pumping at 880m vertical height — setting an industry benchmark for ultra-high-rise construction applications.
- Superior Corrosion Resistance: Austenitic stainless steel construction eliminates the need for protective coatings or cathodic protection, reducing total cost of ownership (TCO) over the product lifecycle compared to carbon steel alternatives with linings.
- Coil Form Factor Advantage: Flexible deployment, compact storage, and reduced on-site welding — minimizing installation time, labor costs, and leak points compared to straight-pipe systems requiring extensive field fabrication.
- Electropolished Inner Surface: Ra ≤ 0.8 μm finish significantly reduces concrete adhesion, pumping pressure drop, and maintenance frequency — critical for continuous operation in high-rise projects.
- Full Traceability & Certification: EN 10204 Type 3.1 MTC with complete heat-number traceability ensures compliance with international project specifications and regulatory requirements.
- Customization Capability: Flexible sizing (OD, wall thickness, coil dimensions) to meet specific project requirements, supported by a dedicated engineering team for application-specific design consultation.
Technical Reference
This product description is informed by the research and experimental validation documented in the study: "High-Strength High-Performance C130 Concrete Simulated Vertical Height 880m Super High-Rise Pumping Coil Tube Experiment" (Learning Reference Document No. 747, Wenzhou Jixing Metal Materials Co., Ltd.). The experimental results confirm the structural integrity, pressure resistance, and long-term durability of stainless steel coil tubes under the most demanding concrete pumping conditions encountered in modern mega-project construction.