Stainless Steel Coil Tube — Model 1501
Product Overview
The Model 1501 Stainless Steel Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd., is a precision-engineered coiled tubular product designed for demanding industrial and marine applications. The coil tube (Coiltube) is formed by continuously bending seamless or welded stainless steel tubing into a helical or spiral configuration, delivering a compact, flexible, and structurally robust solution for fluid conveyance, heat exchange, structural support, and specialized marine engineering.
This product is particularly valued in offshore aquaculture systems, where its corrosion resistance and mechanical integrity ensure long service life under harsh marine environments. The coil geometry provides inherent spring-back properties, enabling easy deployment, installation, and retrieval in dynamic aquatic conditions.
Material & Properties
The Model 1501 Coil Tube is fabricated from high-grade austenitic stainless steel, selected for superior resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride-rich environments.
- Base Alloy Grade: AISI 316L / ASTM A312 TP316L (preferred for marine and aquaculture applications)
- Alternative Grades: AISI 304L, AISI 321, Duplex 2205 (UNS S32205) available upon request
- Chromium (Cr) Content: 16.0–18.0 wt% — provides passive oxide layer formation
- Nickel (Ni) Content: 10.0–14.0 wt% — stabilizes austenitic structure
- Molybdenum (Mo) Content: 2.0–3.0 wt% — enhances pitting and crevice corrosion resistance
- Carbon (C) Maximum: ≤ 0.03 wt% (low-carbon variant to prevent sensitization)
- Tensile Strength: ≥ 515 MPa (75 ksi)
- Yield Strength (0.2% offset): ≥ 205 MPa (30 ksi)
- Elongation: ≥ 40% (minimum, in 50 mm gauge length)
- Hardness: ≤ 92 HRB (annealed condition)
- Operating Temperature Range: −196 °C to +870 °C (non-oxidizing atmosphere)
- Surface Finish: 2B (cold-rolled and annealed), No. 4 brushed, or electropolished (Ra ≤ 0.4 μm)
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) | — |
| Model / Catalog No. | 1501 | Internal designation |
| Outer Diameter (OD) | 3.0 mm – 25.4 mm (customizable up to 100 mm) | ASTM A312 / A213 |
| Wall Thickness | 0.3 mm – 3.0 mm | ASTM A312 |
| Coil Mean Diameter | 50 mm – 500 mm (configurable) | Customer specification |
| Coil Length (uncoiled) | 3 m – 30 m per coil (standard); up to 100 m (continuous) | — |
| Coil Pitch | 5 mm – 25 mm (adjustable) | — |
| Number of Turns | 10 – 200 turns per coil | — |
| Tolerance on OD | ± 0.05 mm (precision grade) | ISO 4287 |
| Tolerance on Wall Thickness | ± 10% of nominal | ASTM A312 |
| End Condition | Plain, beveled, or custom-formed ends | — |
| Material Grade | 316L (standard); 304L, 321, 2205 Duplex (optional) | ASTM A312 / EN 10217 |
| Heat Treatment | Solution annealed (1050–1150 °C, water quench) | ASTM A312 |
| Packaging | Wooden crate / export-grade pallet, desiccant sealed | ISO 11607 |
Manufacturing Process
The production of the Model 1501 Coil Tube follows a rigorous multi-stage manufacturing protocol to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Procurement: Hot-rolled stainless steel coil strip is sourced from certified mills with full traceability (mill certificates, heat number tracking).
- Slitting & Cold Forming: The strip is slit to precise width and cold-rolled into seamless tubing via roll-forming or drawn and welded (DW) processes, depending on OD and wall specifications.
- Welding & Seam Finishing (where applicable): Argon-Tungsten Arc Welding (AWT / TIG) is employed for seam closure, followed by internal grinding and electropolishing to achieve weld integrity equivalent to the base material.
- Solution Annealing: Tubing is heated to 1050–1150 °C in a protective atmosphere (argon or vacuum) and rapidly quenched to dissolve carbides, restore full austenitic structure, and maximize corrosion resistance.
- Coil Bending / Coiling: The annealed tubing is fed through precision CNC-controlled coiling dies, which impart the helical geometry with controlled pitch, turn count, and spring-back compensation. Tooling is laser-calibrated to maintain dimensional tolerances within ± 0.05 mm.
- Surface Treatment: Post-coiling passivation (nitric acid or citric acid bath) removes free iron and establishes a stable chromium oxide passive layer. Optional electropolishing reduces surface roughness to Ra ≤ 0.4 μm.
- Quality Inspection: Each coil undergoes ultrasonic testing (UT) for wall thickness uniformity, hydraulic pressure testing (1.5× working pressure for 30 seconds), visual inspection of surface and welds, and dimensional verification via coordinate measuring machine (CMM).
- Final Packaging: Coils are individually wrapped in anti-corrosion film, placed in desiccant-sealed containers, and secured in export-grade wooden crates.
Applications
The Model 1501 Stainless Steel Coil Tube is engineered for high-performance applications across multiple industries:
- Marine Aquaculture: Structural framework and mooring components for raft-based abalone farming cages (筏养鲍鱼笼), where resistance to biofouling (tube worm attachment) and galvanic corrosion is critical. The smooth electropolished surface minimizes biological adhesion of marine organisms.
- Heat Exchangers & Condensers: Helical coil configurations maximize heat transfer surface area in compact volumes, ideal for refrigeration, HVAC, and chemical process equipment.
- Automotive & Aerospace: Fluid lines, fuel conduits, and hydraulic hose alternatives requiring flexibility, fatigue resistance, and lightweight construction.
- Food & Pharmaceutical Processing: Hygienic-grade tubing for CIP (Clean-In-Place) and SIP (Sterilize-In-Place) systems, meeting FDA 21 CFR Part 117 and EU Regulation 1935/2004.
- Oil & Gas / Petrochemical: Downhole tubing, well completion coiled tubing, and high-pressure fluid transport in offshore platforms.
- Medical Devices: Endoscope guide tubes, surgical instrument shafts, and implantable components (where 316LVM grade is specified).
- Architectural & Decorative: Handrails, balustrades, and sculptural elements requiring corrosion resistance and aesthetic finish.
Unique Selling Points
- Superior Anti-Fouling Performance: The electropolished surface finish (Ra ≤ 0.4 μm) significantly reduces the adhesion of marine biofouling organisms, including tube worms (Serpulidae / Hydroides spp.), extending maintenance intervals in aquaculture and offshore applications.
- Full Traceability: Each batch is accompanied by a Mill Test Certificate (MTC) per EN 10204 3.1, with heat number, chemical composition, and mechanical property verification.
- Customizable Geometry: Coil pitch, diameter, turn count, and end configurations are tailored to customer-specific engineering drawings, enabling seamless integration into proprietary systems.
- Extended Service Life: The combination of 316L material, solution-annealed microstructure, and passivated surface provides a projected service life exceeding 25 years in seawater immersion.
- Environmental Compliance: Production adheres to ISO 14001 environmental management standards; no hexavalent chromium or lead-based fluxes are used in processing.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework supported by the following certifications:
- ISO 9001:2015 — Quality Management System (QMS)
- ISO 14001:2015 — Environmental Management System (EMS)
- ISO 45001:2018 — Occupational Health and Safety Management System (OHSMS)
- EN 10204 Type 3.1 — Inspection Certificate for Material Testing
- ASTM A312 / A213 — Compliance with American Society for Testing and Materials standards for austenitic stainless steel tubing
- EN 10217-7 — European standard for austenitic stainless steel tubes and pipes for pressure purposes
- NSF/ANSI 61 — Drinking water system components (for food-grade applications)
- PED 2014/68/EU — Pressure Equipment Directive compliance (where applicable)
- CE Marking — Conformity with European health, safety, and environmental protection standards
Note: The Model 1501 Coil Tube is designed and manufactured to meet the stringent requirements of marine aquaculture infrastructure, as demonstrated by its application in raft-based abalone farming systems. The integration of corrosion-resistant 316L stainless steel with precision coil geometry and anti-fouling surface treatment addresses the critical challenge of biological attachment (tube worm colonization) that degrades structural integrity and operational efficiency in long-term submerged deployments.