Stainless Steel Coil Tube — Spiral Coil Pipe for Irrigation & Industrial Applications
Product Overview
The Stainless Steel Coil Tube (Product No. 898) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered spiral coil pipe designed for demanding applications in agricultural irrigation systems, industrial fluid transport, and mechanical assemblies. The product is supplied in continuous coil form, enabling efficient downstream processing such as cutting, bending, and forming without the need for additional welding or joining of individual pipe segments.
This coil tube product is specifically optimized for use in hose reel sprinkler systems (卷盘喷灌机), where the geometric parameters of the spiral coil—including coil diameter, pitch, and cross-sectional dimensions—are critically important for achieving balanced hydraulic performance, fatigue resistance, and operational reliability over extended service cycles.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its exceptional combination of corrosion resistance, mechanical strength, and formability. The primary material grades available include:
- 304 (UNS S30400) — General-purpose grade with excellent corrosion resistance in atmospheric, freshwater, and mild chemical environments. Composition: 18% Cr, 8% Ni, ≤0.08% C.
- 316 (UNS S31600) — Enhanced pitting and crevice corrosion resistance due to 2–3% Molybdenum (Mo) addition. Ideal for saline, coastal, and aggressive chemical environments.
- 321 (UNS S32100) — Titanium (Ti) stabilized grade offering superior resistance to intergranular corrosion at elevated temperatures (up to 870 °C).
| Property | 304 Grade | 316 Grade | 321 Grade |
|---|---|---|---|
| Tensile Strength (MPa) | ≥ 515 | ≥ 515 | ≥ 485 |
| Yield Strength (MPa) | ≥ 205 | ≥ 205 | ≥ 170 |
| Elongation (%) | ≥ 40 | ≥ 40 | ≥ 40 |
| Density (g/cm³) | 7.93 | 8.00 | 7.93 |
| Operating Temperature Range (°C) | −196 to +870 | −196 to +870 | −196 to +870 |
| Corrosion Resistance (ASTM A262 Practice E) | Good | Excellent | Good (Ti-stabilized) |
Specifications
| Parameter | Specification / Range |
|---|---|
| Product Code | 898 |
| Product Name | Stainless Steel Coil Tube (盘管 Coil Tube) |
| Outer Diameter (OD) | 6.0 mm – 50.8 mm (customizable) |
| Wall Thickness | 0.5 mm – 3.0 mm |
| Coil Diameter | 300 mm – 2,000 mm |
| Coil Length | 10 m – 100 m per coil (continuous) |
| Surface Finish | 2B (Cold Rolled Annealed), BA (Bright Annealed), or No. 4 Brushed |
| Tolerance (OD) | ±0.05 mm (precision grade); ±0.1 mm (standard grade) |
| Tolerance (Wall Thickness) | ±10% of nominal |
| Manufacturing Standard | ASTM A269 / A270; GB/T 12771; EN 10217 |
| End Condition | Plain end, beveled end, or pre-formed fitting ready |
| Coil Packaging | Woven strap + shrink-wrapped core, moisture-proof outer wrapping |
Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous, multi-stage manufacturing workflow to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection: High-purity stainless steel wire rod or strip, conforming to ASTM A276 or equivalent, is procured from certified mills. Incoming material undergoes spectroscopic analysis (OES) to verify chemical composition.
- Coil Winding (Spiral Forming): The formed tube is wound into a continuous spiral coil using a CNC-controlled coil winding machine. The winding parameters—coil diameter, pitch, and tension—are optimized based on the intended application (e.g., hose reel sprinkler systems require specific coil geometry to minimize fatigue during repeated extension and retraction cycles).
- Heat Treatment & Annealing: Post-forming annealing at 1050–1150 °C in a protective atmosphere furnace relieves residual stresses, restores full austenitic microstructure, and enhances corrosion resistance. The cooling rate is controlled to prevent sensitization (chromium carbide precipitation at grain boundaries).
- Pickling & Passivation: The coil is treated with a mixed acid solution (HNO₃ + HF) to remove oxide scale, followed by passivation to establish a stable chromium oxide (Cr₂O₃) surface film, ensuring long-term corrosion protection.
- Quality Inspection: Each coil undergoes ultrasonic testing (UT) for internal defects, eddy current testing (ECT) for surface cracks, hydrostatic pressure testing (typically 2× working pressure), and dimensional verification using laser micrometry.
- Packaging & Dispatch: Coils are securely strapped, wrapped in moisture-barrier film, and labeled with material certificates (Mill Test Reports, MTR) before shipment.
Applications
The Stainless Steel Coil Tube (Product No. 898) is engineered for versatility across multiple industries:
- Agricultural Irrigation Systems: Primary application in hose reel sprinklers (卷盘喷灌机), where the spiral coil tube serves as the water delivery conduit. The optimized coil geometry ensures uniform water distribution, low flow resistance, and resistance to fatigue from repeated mechanical cycling.
- Food & Beverage Processing: Sanitary-grade 316L coil tubes for CIP (Clean-In-Place) systems, beverage transfer lines, and dairy processing equipment where hygienic surface finishes and non-toxicity are mandatory.
- Chemical & Petrochemical Industry: Corrosion-resistant coil tubing for chemical transfer, acid handling, and process instrumentation lines.
- Pharmaceutical Manufacturing: GMP-compliant tubing for sterile fluid transfer, cleanroom piping, and medical device manufacturing.
- Automotive & Aerospace: Precision coil tubes for fuel lines, brake lines, hydraulic circuits, and exhaust system components.
- Building & Construction: Structural coil tubes for handrails, decorative elements, and architectural railings.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring product conformity with international standards:
- ISO 9001:2015 — Quality Management Systems certification covering all manufacturing and quality assurance processes.
- ISO 14001:2015 — Environmental Management Systems certification demonstrating commitment to sustainable manufacturing practices.
- ASME BPVC (Boiler and Pressure Vessel Code) — Compliance for pressure-containing applications.
- ASTM A269 / A270 — Seamless and welded austenitic stainless steel tubular products for general applications.
- GB/T 12771 — Chinese national standard for welded austenitic stainless steel seamless and welded tubes for general engineering purposes.
- EN 10217 — European standard for austenitic stainless steel tubes for pressure purposes.
- 3.1 Material Certificates — Full chemical and mechanical analysis per EN 10204, traceable to heat number.
Unique Selling Points
1. Optimized Spiral Geometry: The coil tube is designed with parameters specifically optimized for hose reel sprinkler applications, incorporating research-based calculations for coil diameter, pitch, and cross-sectional dimensions to minimize hydraulic losses and maximize fatigue life during repeated deployment cycles.
2. Precision Dimensional Control: Advanced CNC winding and forming equipment ensures tight tolerances (±0.05 mm on OD), guaranteeing seamless integration into downstream assembly processes and consistent hydraulic performance.
3. Superior Corrosion Performance: Available in 304, 316, and 321 grades with passivated surfaces, the coil tube delivers outstanding resistance to pitting, crevice corrosion, and intergranular attack in aggressive environments.
4. Full Traceability: Every coil is accompanied by a Mill Test Report (MTR) with complete chemical composition, mechanical property data, and heat number traceability, ensuring full supply chain transparency.
5. Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd. offers fully customizable coil tube solutions, including tailored OD, wall thickness, coil diameter, length, surface finish, and end conditions to meet specific project requirements.
6. Cost-Effective Continuous Supply: The coil format eliminates the need for butt-welding multiple pipe segments, reducing installation labor, minimizing leak points, and lowering total cost of ownership (TCO) for large-scale projects.