Stainless Steel Refrigeration Coil Tube — For Fluorine Refrigerant Cooling Systems & Air Coolers
Product Overview
The stainless steel coil tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered tubular product specifically designed for fluorine refrigerant (Freon) cooling coil assemblies and air-cooled heat exchanger systems. These coil tubes serve as critical heat transfer elements in industrial and commercial refrigeration applications, where reliable hydraulic performance, corrosion resistance, and long-term operational integrity are paramount.
Based on extensive hydraulic calculation studies and field-proven design principles for fluorine refrigerant cooling coils and air coolers, Wenzhou Jixing Metal Materials delivers coil tubes that meet rigorous international standards for dimensional accuracy, wall uniformity, and mechanical performance under cryogenic and high-pressure conditions.
Material & Properties
The coil tubes are fabricated from high-purity austenitic stainless steel grades, selected for their exceptional resistance to fluorine-based refrigerants (R-134a, R-410A, R-22, R-407C, and other HCFC/HFC refrigerants) and their compatibility with the wide temperature ranges encountered in refrigeration cycles.
- Primary Alloy Grades: AISI 304 (UNS S30400), AISI 316L (UNS S31603), and AISI 321 (UNS S32100)
- Chromium Content: 17.5%–26% (provides primary corrosion resistance)
- Nickel Content: 8.0%–12% (stabilizes austenitic microstructure)
- Molybdenum Content (316L): 2.0%–3.0% (enhanced pitting and crevice corrosion resistance)
- Titanium Stabilization (321): 0.5%–1.0% Ti (prevents intergranular corrosion during welding)
- Operating Temperature Range: −196°C to +450°C (depending on grade)
- Maximum Operating Pressure: Up to 3.5 MPa (subject to wall thickness and geometry)
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 20°C
- Surface Finish: Bright annealed, electropolished (Ra ≤ 0.4 μm), or passivated
- Hygienic Compliance: ASTM A270 / A269, suitable for food-grade and pharmaceutical applications
Specifications
| Parameter | Specification | Tolerance / Standard |
|---|---|---|
| Outer Diameter (OD) | Φ6.0 mm – Φ32.0 mm | ±0.05 mm (custom ranges available) |
| Wall Thickness | 0.3 mm – 2.5 mm | ±5% of nominal |
| Coil Length per Spool | 5 m – 500 m (continuous coil) | Configurable per customer requirement |
| Coiling Diameter | Φ100 mm – Φ500 mm | Dependent on tube OD and wall thickness |
| Minimum Bend Radius | ≥ 3× OD (cold forming) | No cracking, no wall thinning > 15% |
| Hydraulic Pressure Test | 1.5× Working Pressure (sustained 30 min) | No leakage, no permanent deformation |
| Refrigerant Compatibility | R-134a, R-410A, R-22, R-407C, R-507, R-1234yf | No material degradation at design conditions |
| Applicable Standards | ASTM A269, ASTM A270, EN 10217-7, GB/T 12771 | Full compliance with all listed standards |
| End Condition | Plain end, beveled, or threaded | Customizable per application |
| Coil Packaging | Wooden reel with moisture-proof wrapping | Export-grade packaging available |
Manufacturing Process
The production of Wenzhou Jixing Metal Materials' stainless steel coil tubes follows a meticulously controlled multi-stage manufacturing process to ensure consistent quality, dimensional accuracy, and metallurgical integrity:
- Raw Material Selection: Virgin stainless steel strip or seamless tube blanks sourced from certified mills, with full material traceability and chemical composition verification via spectroscopic analysis (OES/XRF).
- Coil Winding / Tube Drawing: Precision winding of stainless steel strip into tubular form using hydraulic or mechanical coiling equipment. Alternatively, seamless tubes are cold-drawn through precision dies to achieve target OD and wall thickness. The coil winding process ensures uniform curvature and eliminates stress concentrations.
- Welding (if applicable): TIG (Tungsten Inert Gas) welding with high-purity argon shielding (≥ 99.995% Ar) for welded coil tube configurations. Weld quality is verified via helium leak testing at 1×10⁻⁹ mbar·L/s.
- Heat Treatment: Solution annealing at 1050°C–1150°C followed by controlled cooling (air or water quench depending on grade) to achieve a fully austenitic microstructure with optimal mechanical properties and maximum corrosion resistance.
- Pickling & Passivation: Acid pickling (nitric/hydrofluoric acid blend) to remove oxide scale, followed by passivation treatment to form a stable chromium oxide (Cr₂O₃) protective film on the surface.
- Surface Finishing: Electropolishing or mechanical polishing to achieve required surface roughness (Ra ≤ 0.4 μm for hygienic applications). Final passivation to restore corrosion resistance post-finishing.
- Hydraulic & Pressure Testing: Every coil spool undergoes 100% hydraulic pressure testing at 1.5× the maximum design working pressure. Non-destructive testing (NDT) via eddy current (ET) or ultrasonic testing (UT) is performed to detect wall thickness variations, cracks, or inclusions.
- Final Inspection & Packaging: Dimensional verification (OD, wall thickness, coil length), visual inspection, and certification documentation. Coils are wound onto protective wooden reels, wrapped in moisture-barrier film, and packed for export or domestic delivery.
Applications
Wenzhou Jixing Metal Materials' stainless steel coil tubes are engineered for demanding refrigeration and thermal management applications where fluorine refrigerant compatibility and long-term reliability are essential:
- Industrial Refrigeration Systems: Evaporator and condenser coil assemblies in cold storage facilities, blast freezers, and walk-in coolers using R-134a, R-410A, and R-407C refrigerants.
- Air-Cooled Heat Exchangers: Finned coil tubes for air-cooled condensers and evaporators in commercial HVAC (Heating, Ventilation, and Air Conditioning) systems, where high surface-area-to-volume ratios enhance heat transfer efficiency.
- Chilled Water Systems: Coil tubes integrated into chiller evaporators and plate-fin heat exchangers for precision temperature control in industrial processes.
- Food & Beverage Processing: Hygienic-grade coil tubes for dairy pasteurization, beer brewing cooling loops, and juice processing systems requiring FDA-compliant materials.
- Pharmaceutical & Biotechnology: GMP-compliant coil tubes for bioreactor cooling jackets, cleanroom HVAC systems, and pharmaceutical freeze-drying equipment.
- Cryogenic Applications: Coil tubes designed for low-temperature service (down to −196°C) in LNG (Liquefied Natural Gas) processing and cryogenic storage systems.
- Marine & Offshore: Corrosion-resistant coil tubes for shipboard refrigeration systems and offshore platform cooling circuits exposed to saline environments.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and holds the following certifications and complies with the following international standards:
- ISO 9001:2015 — Quality Management Systems (QMS) certification ensuring consistent product quality and continuous improvement.
- ISO 14001:2015 — Environmental Management Systems certification for sustainable manufacturing practices.
- ISO 45001:2018 — Occupational Health and Safety Management Systems certification.
- CE Marking — Conformity with European Union directives for products sold within the European Economic Area (EEA).
- EN 10204 3.1 — Material Test Certificates (MTC) issued by authorized technical personnel, providing full traceability of material origin, chemical composition, and mechanical test results.
- ASTM A269 / A270 — Standard specifications for austenitic stainless steel seamless, welded, and heavily cold-worked tubing.
- GB/T 12771 — Chinese national standard for stainless steel seamless tubes for general purposes.
- EN 10217-7 — European standard for stainless steel tubes for pressure purposes.
- ASME SA-213 / SA-249 — American Society of Mechanical Engineers standards for heat exchanger and condenser tubing.
- NSF/ANSI 61 — Drinking water system components certification (for food-grade and potable water applications).
- 3-A Sanitary Standards — Dairy and food processing industry compliance for hygienic design and construction.
Unique Selling Points
Hydraulic Design Expertise: Wenzhou Jixing Metal Materials' coil tubes are engineered with deep knowledge of fluorine refrigerant cooling coil and air cooler hydraulic calculations, ensuring optimal flow distribution, minimized pressure drop, and maximum heat transfer efficiency in every application.
Full Material Traceability: Every coil spool is accompanied by a complete material passport including mill test certificates, chemical analysis reports, mechanical test data, and NDT results — enabling full lifecycle traceability from raw material to end installation.
Custom Engineering Capability: Bespoke coil geometries, special alloy grades, and application-specific surface treatments are available to meet unique customer requirements for refrigeration and thermal management systems worldwide.
Cryogenic Reliability: Proven performance at temperatures as low as −196°C without loss of ductility or risk of brittle fracture, making these coil tubes ideal for cryogenic and ultra-low-temperature refrigeration applications.
Fluorine Refrigerant Compatibility: Extensively validated against all major HFC, HCFC, and HFO refrigerants (R-134a, R-410A, R-22, R-407C, R-507, R-1234yf), with no risk of material degradation, stress corrosion cracking, or refrigerant contamination.
Technical Support & Consultation
Wenzhou Jixing Metal Materials Co., Ltd. provides comprehensive technical support including hydraulic calculation assistance, coil layout design consultation, material selection guidance, and application-specific engineering reviews. Customers are encouraged to engage with the technical team at the earliest stage of project development to ensure optimal coil tube specification and seamless integration into refrigeration and cooling system designs.