Stainless Steel Spiral Coil Tube for Reel Irrigation Systems
Product Overview
The Stainless Steel Spiral Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered tubular product designed for high-performance applications in agricultural irrigation, particularly for center-pivot and lateral-move reel irrigation systems. The coil tube is formed from seamless or welded stainless steel pipe through a controlled bending process that produces a continuous helical spiral configuration, offering superior hydraulic performance, mechanical durability, and corrosion resistance compared to conventional straight-pipe alternatives.
This product category (Item No. 898) represents an advanced solution in fluid transport and agricultural engineering, where parameter-optimized spiral geometry ensures uniform flow distribution, reduced pressure drop, and extended service life under demanding field conditions.
Material & Properties
The coil tube is fabricated from austenitic stainless steel grades selected for their exceptional balance of mechanical strength, corrosion resistance, and formability:
- Grade 304 (UNS S30400): Chromium-Nickel austenitic stainless steel with excellent general corrosion resistance, suitable for most irrigation water chemistries.
- Grade 316 (UNS S31600): Molybdenum-enhanced austenitic stainless steel providing superior resistance to chlorides, sulfides, and aggressive agricultural chemicals.
- Grade 321 (UNS S32100): Titanium-stabilized austenitic stainless steel offering enhanced resistance to intergranular corrosion in high-temperature service environments.
Mechanical Properties (typical for Grade 304):
- Tensile Strength (UTS): ≥ 515 MPa (74,700 psi)
- Yield Strength (0.2% offset): ≥ 205 MPa (29,700 psi)
- Elongation: ≥ 40%
- Hardness: ≤ 92 HRB
- Modulus of Elasticity: ~193 GPa
Corrosion Resistance:
- Pitting Resistance Number (PREN): 19–26 depending on grade
- Resistance to atmospheric, freshwater, and mildly corrosive agricultural solutions
- Non-toxic and non-contaminating for potable water and food-grade applications
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Outer Diameter (OD) | 19.05 mm – 168.28 mm (¾" – 6") | ASTM A554 / ASME B36.19M |
| Wall Thickness | 0.8 mm – 6.35 mm (Schedule 5S – 40S) | ASTM A554 / ASME B36.19M |
| Coil Diameter (Helix) | 200 mm – 5000 mm (customizable) | Project-specific |
| Pitch (Helix Spacing) | 50 mm – 500 mm | Optimized per hydraulic design |
| Number of Turns | 2 – 150 turns | Project-specific |
| Tube Length (Uncoiled) | Up to 200 m per continuous coil | Manufacturer capacity |
| Surface Finish | Mirror polished (Ra ≤ 0.4 μm) / Brushed (Ra ≤ 1.6 μm) / Mill finish | ASTM A240 |
| Bend Radius | ≥ 5× OD (minimum) | ISO 11071 |
| Operating Temperature | −196 °C to +870 °C (Grade 304) | Material-dependent |
| Operating Pressure | Up to 1.6 MPa (232 psi) typical; higher available | ASME B31.3 |
| End Preparation | Plain / Beveled / Threaded / Flanged | ASME B1.20.1 / B16.5 |
| Material Certification | EN 10204 Type 3.1 mill test certificates | ISO 9001:2015 |
Manufacturing Process
The production of parameter-optimized spiral coil tubes follows a rigorous multi-stage process to ensure dimensional accuracy, mechanical integrity, and surface quality:
- Raw Material Selection & Inspection: Stainless steel seamless tubes or ERW (Electric Resistance Welded) pipes conforming to ASTM A269 / A554 are received and subjected to incoming quality inspection including chemical composition analysis (OES), dimensional verification, and visual surface examination.
- Pre-Forming & Stress Relief: Tubes undergo pre-conditioning to eliminate residual stresses from prior manufacturing operations, ensuring uniform plastic deformation during coiling.
- Parametric Coiling (Helical Bending): Using CNC-controlled coil forming machines, the straight tube is bent into a precise helical spiral. The bending parameters—including coil diameter, pitch, number of turns, and bend radius—are optimized through finite element analysis (FEA) to minimize ovality, residual stress, and springback. This parameter optimization is critical for achieving uniform hydraulic performance in irrigation applications.
- Post-Form Annealing (if required): Tubes subjected to significant cold deformation may undergo solution annealing at 1010–1150 °C followed by rapid quenching to restore full austenitic properties and relieve work-hardening effects.
- Surface Finishing: Mechanical polishing, electrolytic polishing, or chemical passivation is applied to achieve the specified surface roughness and enhance corrosion resistance.
- Dimensional & Performance Verification: Final products undergo dimensional inspection (laser measurement), hydrostatic pressure testing, and visual/magnetic particle testing (where applicable) to confirm conformance to design specifications.
- Coil Packaging & Dispatch: Finished coils are protected with moisture-proof wrapping, secured on wooden or steel pallets, and shipped with complete documentation including mill test certificates and dimensional reports.
Applications
The spiral coil tube is engineered for demanding service environments where reliability, corrosion resistance, and hydraulic efficiency are paramount:
- Center-Pivot & Lateral-Move Reel Irrigation Systems: Spiral coil tubes serve as the main conveyance line in large-scale agricultural irrigation systems, providing uniform water distribution across farmland with minimal pressure loss and superior resistance to UV degradation and chemical fertilizers.
- Greenhouse & Hydroponic Systems: Used in nutrient delivery networks where non-toxic, food-grade materials are essential.
- Fire Suppression Systems: Spiral coil configurations provide compact, space-efficient fire hose storage and distribution.
- Industrial Fluid Transfer: Applicable in chemical processing, food & beverage, pharmaceutical, and semiconductor manufacturing where clean fluid handling is required.
- Heat Exchangers & Condensers: Spiral geometry enhances heat transfer efficiency through increased surface area and turbulent flow promotion.
- Automotive & Aerospace Fuel Lines: Coil tubes used in engine fuel delivery systems where compact routing and high-cycle fatigue resistance are required.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system ensuring traceability and conformance to international standards:
- ISO 9001:2015 — Quality Management System certification
- EN 10204 Type 3.1 — Material Test Certificates for each production batch
- ASTM / ASME Standards Compliance — Products manufactured to ASTM A269, A554, A312, and ASME B36.19M specifications
- CE Marking — European Conformity for pressure equipment and machinery components
- NSF/ANSI 61 — Compliance for water system components (where applicable)
- Pressure Testing: 100% hydrostatic testing at 1.5× working pressure with zero-defect acceptance criteria
- Third-Party Inspection: Available upon request (SGS, BV, TUV, etc.)
Unique Selling Points
Parameter-Optimized Spiral Geometry: Unlike conventional coil tubes produced with fixed parameters, this product incorporates computational optimization of helix diameter, pitch, and bend radius to deliver superior hydraulic performance, reduced pressure drop, and enhanced structural fatigue life—directly translating to lower operating costs and extended maintenance intervals in irrigation and industrial applications.
- Full Customization: Coil diameter, pitch, turn count, and end preparations are tailored to specific project requirements, enabling seamless integration into existing systems.
- Superior Corrosion Performance: Austenitic stainless steel grades provide decades of service life in aggressive agricultural and industrial environments without degradation.
- Hygienic & Food-Grade: Mirror-polished surfaces prevent biofilm formation and contamination, meeting pharmaceutical and food processing standards.
- Compact & Space-Efficient: Spiral configuration reduces installation footprint while maintaining continuous fluid conveyance over extended lengths.
- Complete Traceability: Every coil tube is accompanied by full material traceability documentation from raw material mill to finished product dispatch.
- Engineered for Longevity: Post-form annealing and stress-relief treatments ensure the coil maintains dimensional stability and mechanical properties throughout its service life.
Technical Reference Standards
| Standard | Description |
|---|---|
| ASTM A269 | Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubes for Chemical and Heat-Transfer Applications |
| ASTM A554 | Standard Specification for Heat-Resistant Chromium-Nickel Iron-Chromium-Nickel Stainless Steel Bars, Rods, and Wire |
| ASME B36.19M | Welded and Seamless Wrought Stainless Steel Pipe |
| ISO 11071 | Plastic and Metal Tubes — Bending Test Methods |
| EN 10217-7 | Technical Delivery Conditions for Cold-Drawn Seamless and Welded Tubes of Stainless Steels |
| ASME B31.3 | Process Piping — Design and Installation |