Stainless Steel Coil Tube — Wenzhou Jixing Metal Materials Co., Ltd.
Product Overview
The Stainless Steel Coil Tube (Product Code: 1473) is a precision-engineered, continuous-length tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Designed for high-performance industrial applications, this coil tube is produced through advanced cold-drawing and cold-rolling processes, delivering exceptional dimensional accuracy, surface finish, and mechanical integrity. The product is available in a wide range of standard and custom configurations, catering to demanding requirements in heat exchangers, refrigeration systems, automotive components, and chemical processing equipment.
A key differentiator in the manufacturing of this coil tube is the proprietary integration of an oil-based cleaning agent system developed specifically for the production line. This cleaning technology ensures superior surface purity and corrosion resistance, particularly critical for seamless coil tube applications where internal and external contamination must be eliminated to the highest standards.
Material & Properties
The coil tube is fabricated from premium-grade stainless steel alloys, selected to meet or exceed international standards for chemical composition and mechanical performance. The primary alloy grades include:
- AISI 304 / UNS S30400 — General-purpose austenitic stainless steel with excellent corrosion resistance and formability.
- AISI 316 / UNS S31600 — Enhanced molybdenum-bearing grade offering superior resistance to pitting and crevice corrosion in aggressive environments.
- AISI 321 / UNS S32100 — Titanium-stabilized grade suitable for elevated-temperature applications up to 870 °C.
- AISI 316L / UNS S31603 — Low-carbon variant providing improved weldability and resistance to intergranular corrosion.
Mechanical Properties (Typical Values)
- Tensile Strength (UTS): 515–730 MPa
- Yield Strength (0.2% Proof Stress): 205–310 MPa
- Elongation at Break: ≥ 35%
- Hardness (HB): 120–220 (depending on grade and temper condition)
- Density: 7.90–8.03 g/cm³
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 25 °C
- Thermal Expansion Coefficient: 16–18 × 10⁻⁶ /°C (20–100 °C)
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6.0 mm – 114.3 mm (1/4" – 4") | ASTM A269 / EN 10216-5 |
| Wall Thickness | 0.30 mm – 6.0 mm | ASTM A269 / GB/T 12771 |
| Coil Length | 15 m – 500 m (continuous) | Manufacturer specification |
| Coil Weight | 200 kg – 5,000 kg | Manufacturer specification |
| Surface Finish | Bright Annealed (BA), No. 4 Brushed, Polished, Pickled & Passivated | ASTM A403 / GB/T 4237 |
| Dimensional Tolerance (OD) | ±0.05 mm – ±0.15 mm (per grade) | ASTM A269 |
| Dimensional Tolerance (Wall) | ±0.03 mm – ±0.10 mm | ASTM A269 |
| Roundness | ≤ 0.05 mm | ISO 1130 |
| End Condition | Plain, Beveled, or Perforated | Custom / Customer drawing |
| Temperature Range | −196 °C to +870 °C (grade-dependent) | ASME BPVC Section VIII |
Manufacturing Process
The production of Wenzhou Jixing Metal Materials' Stainless Steel Coil Tube follows a rigorous multi-stage manufacturing workflow designed to ensure dimensional precision, metallurgical integrity, and surface excellence:
- Raw Material Selection & Inspection: Hot-rolled stainless steel strip or seamless tube blanks are sourced from certified suppliers and subjected to spectroscopic analysis (OES), mechanical testing, and visual inspection to verify chemical composition and base material quality.
- Coil Winding & Pay-Off: Raw strip or tube stock is precisely wound onto the production line coil pay-off system, ensuring uniform tension control throughout the forming process.
- Forming & Cold Drawing: The tube blank is cold-drawn through precision-die sets to achieve the target outer diameter and wall thickness. Multi-pass drawing ensures uniform grain structure and eliminates residual stresses.
- Heat Treatment (Annealing): Formed tubes undergo bright annealing in a controlled-atmosphere furnace (H₂ or vacuum environment) to relieve cold-work hardening, restore ductility, and achieve the desired microstructure without oxide scale formation.
- Oil-Based Cleaning & Degreasing: A proprietary oil-based cleaning agent — developed specifically for coil tube production lines — is applied to remove residual lubricants, oils, and particulate contaminants from both the internal bore and external surface. This cleaning process utilizes a combination of chemical dissolution and mechanical action to achieve surface cleanliness levels exceeding ISO 8573-1 Class 1. The oil-based formulation is engineered to provide excellent wetting characteristics, rapid evaporation rates, and non-corrosive action on stainless steel surfaces, ensuring no residual film remains after processing.
- Pickling & Passivation: Tubes are immersed in a nitric-hydrofluoric acid pickling bath to remove any residual scale or discoloration, followed by passivation with a dilute nitric acid solution to restore and enhance the passive chromium oxide layer.
- Final Coil Winding: Finished tubes are wound onto precision steel cores with controlled tension to prevent deformation, kinking, or surface marring during storage and transport.
- Quality Control & Testing: Each coil undergoes comprehensive inspection including dimensional verification (OD, wall thickness, roundness), surface quality assessment, hydrostatic pressure testing (up to 10× working pressure), and chemical composition verification.
Cleaning Agent Technology
The oil-based cleaning agent integrated into the production line represents a proprietary advancement in coil tube surface preparation. Unlike conventional aqueous-based cleaners, this formulation delivers superior penetration into micro-crevices and internal bore surfaces, achieving cleaning efficiencies of >99.5% while maintaining environmental compliance. The formulation incorporates high-purity mineral oil base stocks with specialized surfactants and anti-corrosion additives, ensuring that the final product surface is free of contaminants that could compromise downstream welding, brazing, or corrosion resistance performance.
Applications
The Stainless Steel Coil Tube is engineered for a broad spectrum of high-performance industrial applications:
- Heat Exchangers & Condensers: Precision-diameter coil tubes are ideal for compact heat exchanger assemblies in HVAC, refrigeration, and industrial process cooling systems.
- Refrigeration & Air Conditioning: Used as capillary tubes and evaporator coils in domestic and commercial refrigeration units, where dimensional accuracy and leak-tight integrity are paramount.
- Automotive Industry: Employed in fuel lines, brake lines, turbocharger coolant circuits, and exhaust aftertreatment systems requiring high-temperature resistance and corrosion durability.
- Chemical & Petrochemical Processing: Suitable for fluid transport, reactor internals, and distillation column components where resistance to aggressive chemical media is required.
- Medical & Pharmaceutical Equipment: Used in sterilizable fluid lines, autoclave components, and medical device manufacturing where biocompatibility and cleanability are critical.
- Food & Beverage Processing: Compliant with sanitary standards (3-A, FDA) for use in food-grade fluid transfer, pasteurization, and brewing equipment.
- Power Generation: Applied in boiler feedwater systems, superheater tubes, and nuclear-grade applications requiring proven long-term reliability.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management infrastructure ensuring full traceability and compliance with international standards:
- ISO 9001:2015 — Quality Management System certification for consistent production quality and continuous improvement.
- ISO 14001:2015 — Environmental Management System, covering the oil-based cleaning agent lifecycle and waste management protocols.
- ISO 45001:2018 — Occupational Health and Safety Management System.
- CE Marking — Conformity with European directives for pressure equipment (PED 2014/68/EU).
- EN 10204 3.1 — Full material certification with third-party inspection available upon request.
- ASME / NB Stamp — Available for pressure vessel and piping applications requiring National Board registration.
- ASTM A269 / A270 — Compliance with American Society for Testing and Materials standards for seamless and welded austenitic stainless steel tubing.
- GB/T 12771 — Chinese national standard for seamless stainless steel tubes for fluid transport.
- GB/T 4237 — Chinese national standard for cold-rolled stainless steel strips and plates.
- RoHS / REACH Compliance — Restriction of hazardous substances in all product materials and processing chemicals.
Unique Selling Points
- Proprietary Cleaning Technology: The integration of a purpose-developed oil-based cleaning agent ensures unmatched surface cleanliness, directly translating to superior corrosion resistance and weldability in end-use applications.
- Precision Dimensional Control: Advanced multi-pass cold-drawing with in-line metrology delivers tolerance compliance exceeding standard requirements, critical for heat exchanger and refrigeration applications.
- Full Traceability: Every coil is traceable from raw material mill certificate through final inspection, supporting regulatory compliance in aerospace, medical, and nuclear sectors.
- Customization Capability: Flexible production parameters accommodate non-standard diameters, wall thicknesses, surface finishes, and coil configurations to meet bespoke customer requirements.
- Environmental Consciousness: The oil-based cleaning agent formulation is engineered for minimal VOC emissions and full recyclability, aligning with global sustainability mandates.