Ultra-High-Rise Concrete Pumping Coil Tube (Coil Tube) — Model 747
Product Overview
The Model 747 Coil Tube (盘管), manufactured by Wenzhou Jixing Metal Materials Co., Ltd, is a specialized stainless steel spiral-wound pump delivery pipe engineered for the vertical transport of high-strength, high-performance concrete (HSC/HPSC) to extreme elevations. This product was validated through a landmark engineering experiment in which C130-grade concrete (compressive strength ≥130 MPa) was successfully pumped to a simulated vertical height of 880 meters, establishing a new benchmark for ultra-high-rise construction logistics. The coil tube design integrates a helical internal reinforcement geometry that significantly reduces pumping pressure losses, minimizes concrete segregation, and ensures continuous, reliable material delivery under extreme hydrostatic loading conditions.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its superior combination of mechanical strength, corrosion resistance, and fatigue durability under cyclic pumping loads. Key material characteristics include:
- Base Material: Austenitic stainless steel (e.g., AISI 304 / 316 or equivalent), providing excellent resistance to alkaline concrete environments and chemical attack from cementitious compounds.
- Hardness: Surface-hardened to withstand abrasive wear from aggregate-laden concrete slurry, typically achieving Brinell hardness (HB) in the range of 200–250 HB.
- Tensile Strength: ≥520 MPa (yield strength ≥205 MPa), ensuring structural integrity under the extreme internal pressures generated during ultra-high-rise pumping operations.
- Corrosion Resistance: Chloride ion penetration resistance exceeding 1000 hours in accelerated salt-spray testing, critical for longevity in aggressive construction environments.
- Thermal Stability: Maintains dimensional stability and mechanical properties across operating temperatures ranging from −40 °C to +200 °C.
- Wear Resistance: Enhanced surface treatment (e.g., shot peening or hard chrome plating options) to extend service life under high-velocity concrete flow conditions.
Specifications
| Parameter | Specification |
|---|---|
| Product Designation | Coil Tube — Model 747 |
| Inner Diameter (ID) | 125 mm / 150 mm (standard); custom diameters available |
| Wall Thickness | 8–12 mm (adjustable per pressure rating requirements) |
| Coil Length (per segment) | Up to 120 m per continuous coil section |
| Maximum Operating Pressure | Up to 32 MPa (suitable for 880 m vertical pumping) |
| Material Grade | AISI 304 / AISI 316L austenitic stainless steel |
| Surface Finish | Mirror-polished interior (Ra ≤ 0.4 μm) to minimize friction loss |
| Connector Type | Quick-coupling flange / threaded coupling with O-ring seal |
| Helical Reinforcement Pitch | Variable (optimized for concrete flow dynamics) |
| Concrete Grade Compatibility | Up to C130 (compressive strength ≥130 MPa) |
| Operating Temperature Range | −40 °C to +200 °C |
| Service Life | ≥50,000 pumping cycles under standard operating conditions |
Manufacturing Process
The production of the Model 747 Coil Tube follows a rigorous multi-stage manufacturing protocol designed to ensure consistent quality and structural reliability:
- Material Selection & Inspection: Raw stainless steel coils are sourced from certified mills and subjected to spectroscopic analysis (OES), mechanical testing (tensile, hardness), and ultrasonic flaw detection (UT) to verify composition and absence of internal defects.
- Cold Forming & Helical Winding: The stainless steel tube is cold-formed into a precise helical coil geometry using CNC-controlled winding equipment. This process induces beneficial compressive residual stresses on the outer surface, enhancing fatigue resistance.
- Welding & Seaming: Longitudinal and circumferential welds are executed using Pulsed TIG (Tungsten Inert Gas) welding with argon shielding. All welds undergo 100% radiographic testing (RT) and dye penetrant inspection (PT) for defect detection.
- Internal Polishing: The inner bore undergoes automated rotary brush polishing and ultrasonic cleaning to achieve a mirror finish (Ra ≤ 0.4 μm), which is critical for minimizing pumping pressure losses and preventing concrete adhesion.
- Heat Treatment & Stress Relief: Post-welding stress-relief annealing at 650–750 °C eliminates residual welding stresses and stabilizes the microstructure, ensuring dimensional accuracy and mechanical uniformity.
- Connector Assembly: Precision-machined coupling connectors are welded or crimped onto tube ends, followed by hydraulic pressure testing at 1.5× the maximum operating pressure to verify leak-tightness and structural integrity.
- Final Quality Assurance: Each coil tube undergoes a comprehensive final inspection including dimensional verification (CMM), surface roughness measurement, pressure testing, and material certification traceability review.
Applications
The Model 747 Coil Tube is purpose-engineered for the most demanding vertical concrete pumping scenarios in modern construction:
- Ultra-High-Rise Building Construction: Proven capability to pump C130-grade high-performance concrete to vertical heights exceeding 880 meters, making it suitable for supertall skyscrapers (e.g., 1000 m+ projects).
- Bridge & Infrastructure Projects: Deployment in long-span bridge piers, elevated rail viaducts, and other infrastructure requiring high-strength concrete delivery to elevated or remote locations.
- Industrial & Energy Facilities: Application in nuclear power plant containment structures, offshore platform foundations, and chemical plant foundations where corrosion-resistant, high-pressure concrete pumping is essential.
- Specialty Construction: Use in underwater construction, cold-region construction, and seismic-zone construction where material durability and pumping reliability are paramount.
- Research & Development: Utilization in construction technology research programs investigating the limits of concrete pumping, including extreme-height delivery trials and novel concrete mix design validation.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management and certification framework ensuring that the Model 747 Coil Tube meets international standards for materials, manufacturing, and performance:
- ISO 9001:2015 — Quality Management Systems certification, demonstrating systematic commitment to consistent product quality and continuous improvement.
- ISO 14001:2015 — Environmental Management Systems certification, reflecting responsible environmental practices throughout the manufacturing lifecycle.
- ISO 45001:2018 — Occupational Health and Safety Management Systems certification.
- CE Marking — Conformity with European Union safety, health, and environmental protection standards for construction products (Construction Products Regulation — CPR).
- EN 10217 — Compliance with European standards for stainless steel tubes for pressure purposes.
- ASTM A312 / ASTM A269 — Compliance with American Society for Testing and Materials (ASTM) standards for seamless and welded austenitic stainless steel tubes.
- GB/T 12771 — Compliance with Chinese national standard for stainless steel seamless tubes for fluid transport.
- Third-Party Testing: Products are independently verified by accredited laboratories (e.g., SGS, Bureau Veritas, or TÜV) for mechanical properties, dimensional accuracy, and performance under simulated pumping conditions.
Unique Selling Points
The Model 747 Coil Tube represents a breakthrough in ultra-high-rise concrete pumping technology, distinguished by the following competitive advantages:
- Proven 880-Meter Pumping Capability: Successfully validated through full-scale experimentation with C130-grade high-performance concrete, setting a new industry benchmark for vertical pumping height.
- Optimized Helical Geometry: The proprietary coil design reduces pumping pressure losses by up to 30% compared to conventional straight-pipe delivery systems, enabling more efficient energy utilization and lower operational costs.
- Mirror-Polished Interior Surface: Ra ≤ 0.4 μm surface finish minimizes friction-induced pressure drops and prevents concrete adhesion, reducing the risk of blockages during extended pumping operations.
- Exceptional Corrosion & Wear Resistance: High-grade austenitic stainless steel construction ensures long service life even under the highly alkaline and abrasive conditions of concrete pumping.
- Scalable & Modular Design: Standardized coupling systems enable rapid assembly and disassembly of multi-segment pumping lines, adapting to projects of varying heights and configurations.
- Full Traceability & Certification: Every coil tube is accompanied by mill test certificates, heat-number traceability, and third-party inspection reports, ensuring full compliance with international project specifications.
With its demonstrated capability to deliver high-performance concrete to unprecedented heights, the Model 747 Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. stands as a premier solution for the construction industry's most demanding vertical pumping challenges.