Finned Stainless Steel Coil Tube (Water-Cooled Heat Exchanger)
Product Overview
The Finned Stainless Steel Coil Tube (Product No. 1648) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a high-performance water-cooled heat exchange component designed for efficient thermal transfer in industrial and commercial applications. This product integrates precision-engineered stainless steel tubing with helical or spiral fins to maximize the effective heat transfer surface area, enabling superior thermal performance in compact configurations. The coil tube is supplied in a coiled (盘管, Coil Tube) format, facilitating easy installation, routing, and integration into diverse heat exchange systems including air coolers, condensers, evaporators, and refrigeration circuits.
This product line represents a significant advancement in thermal engineering, incorporating the New Method for Thermal Calculation of Finned Coil Tubes (Water-Cooled) — a proprietary thermal calculation methodology that enables precise prediction of heat transfer coefficients, pressure drops, and overall thermal efficiency under varying operating conditions. This computational approach ensures that each coil tube is engineered to meet exact thermal load requirements, minimizing over-design while guaranteeing operational reliability.
Material & Properties
The finned coil tube is constructed from premium-grade stainless steel, selected for its exceptional corrosion resistance, mechanical strength, and thermal conductivity. The following material specifications define the baseline properties:
- Base Tube Material: Austenitic stainless steel conforming to ASTM A213 / ASME SA-213 standards. Commonly available grades include 304 (UNS S30400), 316 (UNS S31600), and 321 (UNS S32100).
- Fin Material: Matching stainless steel grade or aluminum (per customer specification), bonded via high-frequency induction brazing or mechanical crimping.
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, acidic and alkaline solutions, and chlorinated environments — particularly with 316 grade.
- Thermal Conductivity: Approximately 16.3 W/(m·K) for Grade 304 at 20°C, providing reliable heat transfer performance.
- Mechanical Properties: Minimum yield strength of 205 MPa (Grade 304), with elongation ≥ 40% ensuring excellent formability during coil winding and fin attachment.
- Operating Temperature Range: −196°C to +870°C (depending on grade), accommodating cryogenic to high-temperature applications.
- Operating Pressure: Designed for working pressures up to 2.5 MPa (363 psi), with hydrostatic test pressure of 1.5× working pressure.
Specifications
| Parameter | Specification | Unit |
|---|---|---|
| Product Code | 1648 | — |
| Tube Outer Diameter (OD) | 6.35 / 8.0 / 9.53 / 10.0 / 12.7 / 15.88 | mm |
| Tube Wall Thickness | 0.5 – 1.5 | mm |
| Coil Diameter (Center-to-Center) | 100 – 1500 (customizable) | mm |
| Coil Length | 1 – 200 (customizable) | m |
| Fin Type | Spiral-wound / Helical / Plate fins | — |
| Fin Height | 3 – 12 | mm |
| Fin Pitch (Spacing) | 2.0 – 6.0 | mm |
| Fin Material | Stainless Steel 304/316 or Aluminum | — |
| Fin Bonding Method | High-Frequency Induction Brazing / Mechanical Crimping | — |
| Heat Transfer Surface Area | Up to 500 m² per coil (finned) | m² |
| Coolant Flow Rate (Water) | 0.5 – 50 | L/min |
| Thermal Efficiency (η) | ≥ 85% (typical, water-to-air) | % |
| End Connections | Welded / Threaded (NPT/BSP) / Flanged (ANSI/EN) | — |
| Surface Treatment | Pickling & Passivation / Electropolishing (optional) | — |
| Maximum Working Pressure | 2.5 | MPa |
| Hydrostatic Test Pressure | 3.75 | MPa |
| Weight (Typical, 10 m coil) | 5 – 25 | kg |
Manufacturing Process
The production of the finned stainless steel coil tube follows a rigorously controlled multi-stage manufacturing process, adhering to international quality standards:
- Raw Material Inspection & Incoming Quality Control: Stainless steel tubes are sourced from certified mills and subjected to full chemical composition analysis (spectroscopic testing), mechanical property verification, and dimensional inspection prior to acceptance.
- Tube Straightening & Cutting: Coiled stainless steel tubing is straightened using hydraulic straightening equipment and cut to specified lengths with laser or plasma cutting to ensure precise dimensional accuracy (±0.5 mm tolerance).
- Surface Preparation: Tubes undergo thorough degreasing, pickling, and passivation treatment to remove mill scale, oxidation, and contaminants, ensuring optimal fin adhesion and long-term corrosion resistance.
- Fin Attachment (Finning): Fins are attached to the prepared tubes using one of the following methods:
- High-Frequency Induction Brazing: Continuous spiral fin stock is bonded to the tube surface using a high-frequency induction heating process, achieving metallurgical bonding with minimal heat-affected zone (HAZ) distortion.
- Mechanical Crimping (Roll Finning): Pre-formed fin strips are mechanically crimped onto the tube surface using precision roll-fin machines, creating a tight mechanical interlock suitable for non-ferrous fin materials.
- Coil Winding: The finned tube assemblies are wound into the specified coil geometry using CNC-controlled winding machines, ensuring uniform coil pitch, consistent bend radius (minimum 3× tube OD), and absence of kinking or flattening at bend points.
- End Preparation & Connection Fabrication: Coil ends are prepared with welded fittings, threaded connections, or flanges per customer specifications. All welds are performed by certified welders using TIG (GTAW) or orbital welding processes.
- Thermal Performance Testing: Each coil assembly undergoes thermal characterization testing in accordance with the proprietary New Method for Thermal Calculation of Finned Coil Tubes (Water-Cooled), verifying that actual heat transfer coefficients, pressure drops, and thermal efficiencies meet design specifications.
- Hydrostatic & Leak Testing: All coils are subjected to hydrostatic pressure testing at 1.5× the maximum working pressure for a minimum of 5 minutes, with zero tolerance for leakage.
- Final Inspection & Packaging: Completed products undergo final dimensional inspection, visual examination, and surface quality verification before protective packaging (desiccant-sealed, wooden crate or palletized) for shipment.
Applications
The finned stainless steel coil tube is widely deployed across multiple industries where efficient water-cooled heat exchange is critical:
- Refrigeration & Air Conditioning (HVAC): Condensers and evaporators in commercial refrigeration systems, chiller units, and industrial air conditioning installations.
- Process Cooling: Heat exchangers in chemical processing, petrochemical, pharmaceutical, and food & beverage industries for cooling reactors, distillation columns, and process streams.
- Power Generation: Auxiliary cooling systems in thermal power plants, gas turbine exhaust heat recovery, and nuclear facility cooling circuits.
- Marine & Offshore: Seawater-cooled heat exchangers for shipboard systems, offshore platform cooling, and desalination plants.
- Automotive & Transportation: Engine cooling loops, fuel cell thermal management systems, and electric vehicle battery cooling assemblies.
- Pharmaceutical & Biotechnology: GMP-compliant cooling systems for bioreactors, fermentation tanks, and sterile process cooling where material purity is paramount.
- Oil & Gas: Wellhead cooling, natural gas dehydration, and flare gas heat recovery systems.
- Waste Heat Recovery: Industrial waste heat capture systems for energy efficiency optimization and carbon footprint reduction.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring that all finned coil tube products meet or exceed international standards:
- ISO 9001:2015 — Quality Management System certification for consistent manufacturing quality.
- ISO 14001:2015 — Environmental Management System certification for sustainable production practices.
- ISO 45001:2018 — Occupational Health and Safety Management System.
- ASME SA-213 / ASTM A213 — Compliance for austenitic stainless steel tubing materials.
- EN 10216-5 — European standard for seamless steel tubes for heat exchangers.
- GB/T 14976 — Chinese national standard for cold-rolled stainless steel seamless tubes.
- TÜV / SGS Inspection — Third-party verification available upon request.
- Material Traceability: Full mill certification (EN 10204 3.1/3.2) provided for every batch, with lot-number traceability from raw material to finished product.
- Welding Certification: All welding operations performed by personnel certified to ASME Section IX or AWS D1.6 standards.
Unique Selling Points
- Proprietary Thermal Calculation Methodology: The integration of the New Method for Thermal Calculation of Finned Coil Tubes (Water-Cooled) enables precise thermal design optimization, resulting in higher efficiency, lower pressure drop, and reduced material usage compared to conventional design approaches.
- Superior Corrosion Resistance: Full stainless steel construction (tube + fins) eliminates galvanic corrosion risks inherent in mixed-material designs, extending service life in aggressive chemical environments.
- Customizable Geometric Configurations: Flexible coil diameters, lengths, fin geometries, and connection types allow tailored solutions for specific thermal loads and spatial constraints.
- Compact Design with High Surface Area: The finned coil configuration achieves up to 500 m² of heat transfer surface area within a single compact coil, reducing footprint and installation costs.
- Full Traceability & Certification: Every product ships with complete material certification, test reports, and quality documentation, ensuring compliance with regulatory and client audit requirements.
- Scalable Production Capacity: Capable of producing from single prototype units to high-volume production runs, accommodating both R&D projects and large-scale industrial deployments.
Technical Notes
Design Note: The thermal performance of the finned coil tube is calculated using the enhanced methodology that accounts for fin efficiency (ηf), overall heat transfer coefficient (Uo), and convective heat transfer coefficients on both the tube-side (water) and fin-side (air/gas) surfaces. The effective heat transfer area (Ae) incorporates both bare tube and fin surface contributions, adjusted for fin efficiency factors derived from empirical correlations validated through experimental testing.
Installation Note: During installation, maintain a minimum bend radius of 3× the tube outer diameter. Avoid welding directly on the finned section. Ensure proper drainage slope for condensate removal in horizontal installations. Use compatible gaskets and sealants for end connections.
Maintenance Note: Periodic inspection of fin condition (fouling, corrosion, mechanical damage) is recommended. Cleaning may be performed using low-pressure water jet or chemical descaling solutions compatible with stainless steel. Avoid abrasive cleaning methods that may compromise the passivation layer.