Stainless Steel Coil Tube — Ultra-Long Pumping Grade (Product No. 407)
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Category: Stainless Steel Coil Tube (盘管 / Coiltube)
Reference Study: Research on Pumping Performance of Ultra-Long Coil Tubes for Lightweight Ultra-High Performance Concrete (UHPC)
1. Product Overview
The Stainless Steel Coil Tube (Product No. 407) is a precision-engineered, continuously wound tubular product designed for demanding applications involving the transport, conveying, and structural reinforcement of high-viscosity fluid systems — particularly Lightweight Ultra-High Performance Concrete (Lightweight UHPC). Manufactured through advanced cold-drawing and coil-winding technologies, this product exhibits exceptional resistance to abrasion, corrosion, and fatigue under repeated high-pressure pumping cycles.
Unlike conventional seamless or welded straight pipes, the coil tube form factor enables compact storage, rapid deployment, and superior flexibility in on-site installation. The coil configuration reduces transportation costs and minimizes handling damage, making it ideal for construction sites, mining operations, and industrial fluid transfer systems where ultra-long run lengths are required without intermediate joints.
Key Insight from Research: Studies on ultra-long coil tube pumping performance for lightweight UHPC have demonstrated that properly specified stainless steel coil tubes can maintain consistent flow characteristics over run lengths exceeding 500 meters, with minimal pressure drop degradation and negligible wall-thickness variation under cyclic loading conditions.
2. Material & Properties
2.1 Base Material
The coil tube is fabricated from high-grade austenitic stainless steel, primarily conforming to the following material specifications:
- AISI 304 / 1.4301: General-purpose corrosion resistance with excellent formability; suitable for moderate-temperature pumping environments.
- AISI 316 / 1.4401: Enhanced pitting and crevice corrosion resistance due to 2–3% Molybdenum (Mo) content; preferred for aggressive chemical or marine environments.
- AISI 321 / 1.4541: Titanium-stabilized grade for elevated-temperature service (up to 870 °C); resists intergranular corrosion.
- SAE 316L / 1.4404: Low-carbon variant (C ≤ 0.03%) for superior weldability and resistance to sensitization.
2.2 Mechanical Properties (Typical)
| Property | Specification (AISI 304) | Specification (AISI 316) | Test Standard |
|---|---|---|---|
| Tensile Strength (抗拉强度) | ≥ 520 MPa | ≥ 515 MPa | ASTM A270 / GB/T 12771 |
| Yield Strength (屈服强度) | ≥ 205 MPa | ≥ 205 MPa | ASTM A270 / GB/T 12771 |
| Elongation (延伸率) | ≥ 40% | ≥ 35% | ASTM A270 / GB/T 12771 |
| Hardness (硬度) | ≤ 210 HB | ≤ 210 HB | ASTM E10 |
| Impact Toughness (冲击韧性) | ≥ 54 J @ −196 °C (LN₂) | ≥ 54 J @ −196 °C (LN₂) | ASTM E23 / GB/T 229 |
| Corrosion Resistance (耐腐蚀性) | Excellent (general) | Superior (chloride-rich) | ASTM G48 / GB/T 4334 |
2.3 Chemical Composition (Wt.%)
| Element | AISI 304 | AISI 316 |
|---|---|---|
| Carbon (C) | ≤ 0.08 | ≤ 0.08 |
| Chromium (Cr) | 18.0 – 20.0 | 16.0 – 18.0 |
| Nickel (Ni) | 8.0 – 10.5 | 10.0 – 14.0 |
| Molybdenum (Mo) | — | 2.0 – 3.0 |
| Manganese (Mn) | ≤ 2.0 | ≤ 2.0 |
| Silicon (Si) | ≤ 1.0 | ≤ 1.0 |
| Phosphorus (P) | ≤ 0.045 | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 | ≤ 0.030 |
3. Technical Specifications
| Parameter | Specification / Range | Standard Reference |
|---|---|---|
| Outer Diameter (OD, 外径) | Φ 6.0 mm – Φ 108.0 mm | GB/T 12771, ASTM A270 |
| Wall Thickness (壁厚) | 0.5 mm – 6.0 mm | GB/T 12771, ASTM A270 |
| Coil Diameter (盘卷直径) | Φ 500 mm – Φ 1,500 mm (inner diameter) | Manufacturer specification |
| Coil Length (盘管长度) | Up to 500 m per coil (continuous) | Research-based optimization |
| Surface Finish (表面状态) | No. 1 (cold-rolled), 2B (bright annealed), BA (bright annealed), Pickled & Passivated | ASTM A480, GB/T 4237 |
| Surface Roughness (表面粗糙度) | Ra ≤ 0.4 μm (BA finish); Ra ≤ 0.8 μm (2B finish) | ISO 4287 |
| Pressure Rating (承压等级) | Up to 25 MPa (depending on OD/wall ratio) | ASME B31.3, GB/T 20801 |
| Operating Temperature (使用温度) | −196 °C to +870 °C (grade-dependent) | ASTM A270 |
| Dimensional Tolerance (尺寸公差) | OD: ± 0.1 mm; Wall: ± 10% (or ± 0.05 mm, whichever is greater) | GB/T 12771 |
| Coil Packaging (盘卷包装) | Steel core + wooden crate / steel strapping + moisture-proof wrapping | ISO 4180 |
| Weight per Coil (每卷重量) | 500 kg – 3,000 kg (typical) | Manufacturer specification |
4. Manufacturing Process
The production of high-quality stainless steel coil tubes involves a multi-stage precision manufacturing sequence designed to ensure dimensional accuracy, mechanical integrity, and corrosion resistance:
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Raw Material Selection & Inspection (原材料检验):
Stainless steel strip or wire rod is procured from certified mills and subjected to spectroscopic analysis (Optical Emission Spectrometry, OES) to verify chemical composition compliance. Incoming material is inspected for surface defects, thickness uniformity, and mechanical properties per ASTM E10 and ASTM A270.
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Slitting & Edge Trimming (分条与修边):
The parent coil is slit into precise strip widths using high-speed slitting lines. Edges are trimmed to eliminate burrs and ensure clean forming during the tube-rolling stage.
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Tube Forming & Welding (制管与焊接):
Two primary forming methods are employed:
- ERW (Electric Resistance Welding): For standard-wall tubes; strip is formed around a mandrel and welded at the seam using high-frequency induction heating (50–350 kHz).
- TPRW (Transverse Pulse Resistance Welding): For thin-wall and precision tubes; offers superior weld quality and minimal heat-affected zone (HAZ).
- Autoclaved / Autogenous TIG Welding: For seamless-grade coil tubes requiring helium or argon back-purging to prevent internal oxidation at the weld seam.
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Weld Seam Finishing (焊缝处理):
The weld seam undergoes mechanical grinding and/or chemical passivation to achieve surface continuity. For BA (Bright Annealed) finish tubes, the seam is polished to match the parent surface roughness (Ra ≤ 0.4 μm).
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Heat Treatment & Annealing (热处理与退火):
Welded coil tubes are annealed at 1,050–1,150 °C in a protective atmosphere (dry hydrogen or nitrogen) to relieve residual stresses, restore austenitic microstructure, and enhance ductility. Subsequent pickling and passivation (酸洗钝化) removes oxide scale and forms a protective chromium oxide layer.
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Coil Winding & Leveling (盘卷与矫直):
The finished tube is wound onto a precision core using a programmable coil-winding machine. Tension-controlled winding ensures uniform layer stacking and prevents inter-coil contact damage. Edge leveling (边缘矫直) ensures consistent coil diameter and eliminates flat spots.
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Non-Destructive Testing (无损检测, NDT):
Every production batch undergoes comprehensive NDT including:
- Electromagnetic Testing (ET): 100% inline inspection for wall thickness variation and seam defects per ASTM E1444.
- Ultrasonic Testing (UT): Sampling for internal voids and laminations per ASTM E317.
- Visual & Dimensional Inspection: Surface quality, OD/wall tolerance, and coil geometry verification.
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Final Packaging & Marking (包装与标识):
Coils are wrapped with moisture-proof polyethylene film, strapped with high-tensile steel bands, and loaded onto wooden or steel pallets. Each coil is marked with a unique traceability number, heat number, material grade, dimensions, and production date.
5. Applications
The Stainless Steel Coil Tube (Product No. 407) serves a broad spectrum of industrial and infrastructure applications:
5.1 Construction & Civil Engineering
- UHPC Pumping Lines: Conveying Lightweight Ultra-High Performance Concrete (UHPC) over ultra-long distances (up to 500 m) with minimal pressure loss and superior abrasion resistance compared to carbon steel alternatives.
- Rebar Coupler Sleeves & Post-Tensioning Ducts: Precision-formed coil tubes used as protective sheaths for tendon systems in prestressed concrete structures.
- Fire Protection & Sprinkler Systems: Corrosion-resistant coil tubing for commercial and industrial fire suppression networks.
5.2 Industrial Fluid Transfer
- Chemical Processing: Transport of aggressive acids, alkalis, and solvents in pharmaceutical, food & beverage, and petrochemical plants.
- Water Treatment & Desalination: High-purity water conveyance in reverse osmosis (RO) and ultrafiltration (UF) systems.
- Oil & Gas: Downhole tubing and wellhead connections in subsea and offshore platforms.
5.3 Specialized Applications
- Automotive Exhaust Systems: Flexible coil tubing for catalytic converter connections and turbocharger intercooling lines.
- Medical Devices: Biocompatible tubing for endoscopic instruments and surgical tool assemblies.
- Aerospace Hydraulic Lines: Lightweight, fatigue-resistant coil tubing for flight control and landing gear hydraulics.
- Heat Exchanger Coils: Precision coil tubes for compact heat exchangers in HVAC, refrigeration, and power generation systems.
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and holds the following certifications and complies with the following international and national standards:
6.1 Management System Certifications
- ISO 9001:2015 — Quality Management System (质量管理体系)
- ISO 140