Stainless Steel Coil Tube — Micro-Channel Condenser Coil for Heat Pump Systems
Product Overview
The Stainless Steel Coil Tube (Coil Tube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered tubular component designed specifically for micro-channel condenser applications in heat pump water heaters and refrigeration systems. This product, catalogued under item number 484, represents an advanced solution for external winding micro-channel condenser configurations, where the coil structure plays a critical role in determining the overall thermodynamic performance of the heat pump system.
Based on extensive research and experimental validation regarding the influence of external winding micro-channel condenser coil structure on heat pump water heater performance, this coil tube is optimized for maximum heat transfer efficiency, compact integration, and long-term durability under demanding thermal cycling conditions.
Material & Properties
- Base Material: Stainless steel (grades including AISI 304 / SUS 304, AISI 316L / SUS 316L, and AISI 430 / SUS 430) selected for optimal corrosion resistance, thermal conductivity, and mechanical strength.
- Corrosion Resistance: Excellent resistance to chloride-induced pitting and general atmospheric corrosion, ensuring service life exceeding 20 years in aggressive environments.
- Mechanical Properties: High tensile strength (minimum 520 MPa for 304 grade), yield strength ≥205 MPa, and elongation ≥40% at room temperature, providing structural integrity under vibration and thermal expansion loads.
- Thermal Conductivity: Approximately 16.3 W/(m·K) for 304 grade stainless steel, balancing heat transfer capability with corrosion performance.
- Operating Temperature Range: -196 °C to +870 °C (grade-dependent), accommodating extreme cold-start and high-temperature discharge conditions in heat pump cycles.
- Surface Finish: Electropolished or passivated inner and outer surfaces (Ra ≤ 0.4 μm) to minimize flow resistance and prevent biofilm accumulation.
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Category | Coil Tube (盘管) | Internal Catalog No. 484 |
| Outer Diameter (OD) | 6.35 mm (1/4"), 8.00 mm, 9.52 mm (3/8"), 12.70 mm (1/2") | ASTM A269 / ASTM A213 |
| Wall Thickness | 0.50 mm – 1.50 mm (customizable) | ISO 3506 |
| Coil Diameter | 50 mm – 300 mm (configurable per system design) | Manufacturer Specification |
| Coil Length | Up to 50 m continuous length per coil | — |
| Material Grade | 304, 316L, 430, or custom alloy | ASTM A240 / JIS G4304 |
| Surface Treatment | Passivated, electropolished, or passivated + PTFE-coated | AMS 2700 |
| Pressure Rating | Up to 3.0 MPa working pressure | ASME B31.3 |
| Tolerance (OD) | ±0.05 mm | ISO 3506 |
| Tolerance (Wall Thickness) | ±10% of nominal | ISO 3506 |
| Helix Pitch | 15 mm – 60 mm (adjustable) | Design-Specific |
Manufacturing Process
- Material Selection & Inspection: Virgin stainless steel strip or seamless tube stock is procured with full material traceability (Mill Test Certificate, MTC). Incoming material undergoes spectral analysis (PMI) and mechanical testing to verify grade conformance.
- Coil Forming: Precision roll-forming equipment shapes the tube into the specified helical geometry. The forming process is controlled to avoid excessive cold work that could reduce ductility or induce residual stresses detrimental to fatigue performance.
- Heat Treatment (if applicable): Annealing at 1050–1150 °C followed by controlled cooling restores full solution-treated microstructure, ensuring maximum corrosion resistance and dimensional stability.
- Surface Treatment: Chemical passivation (nitric acid or citric acid solution) or electrolytic polishing is applied to remove surface contaminants and form a stable chromium oxide passive film.
- Quality Control: Each batch undergoes dimensional verification (CMM or laser measurement), hydrostatic pressure testing (at 1.5× working pressure for 30 minutes), and visual inspection for surface defects.
- Packaging & Labeling: Coils are individually wrapped in protective film, packaged in moisture-barrier containers, and labeled with batch traceability information.
Applications
- Heat Pump Water Heaters: Serves as the core condenser coil in external winding micro-channel condenser configurations, directly influencing COP (Coefficient of Performance) and overall system efficiency.
- Industrial Refrigeration: Used in evaporator and condenser assemblies for food processing, cold storage, and HVAC systems requiring corrosion-resistant components.
- Automotive Heat Exchangers: Integrated into vehicle thermal management systems including air conditioning condensers and battery cooling loops.
- Medical & Pharmaceutical Equipment: Employed in sterilization systems and process heat exchangers where biocompatibility and cleanliness are critical.
- Marine & Offshore Systems: Utilized in seawater-cooled condensers and heat recovery units where resistance to chloride corrosion is paramount.
Unique Selling Points
Performance-Optimized Coil Geometry: Leveraging research findings on external winding micro-channel condenser coil structure effects on heat pump water heater performance, this product delivers superior heat transfer coefficients and reduced pressure drop compared to conventional coil designs.
- Extended Service Life: Stainless steel construction eliminates the need for internal coatings, reducing lifecycle costs by up to 40% versus copper or aluminum alternatives in corrosive environments.
- Customizable Geometry: Flexible manufacturing capability allows coil diameter, pitch, and tube dimensions to be tailored to specific system design requirements.
- Full Traceability: Every coil is traceable to its raw material mill certificate, ensuring compliance with international quality management systems.
- Thermal Cycling Durability: Proven performance through thousands of thermal cycles without fatigue cracking or dimensional drift.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System certification for manufacturing processes.
- ISO 14001:2015 — Environmental Management System certification.
- ASTM A269 / ASTM A213 — Compliance with American standards for welded austenitic stainless steel tubing and seamless austenitic stainless steel tubing.
- EN 10216-5 — European standard for welded austenitic stainless steel tubes for general purposes.
- JIS G3459 / JIS G3446 — Japanese Industrial Standards for stainless steel tubes.
- ASME B31.3 — Compliance with pressure piping code requirements.
- RoHS & REACH — Compliant with European hazardous substance and chemical registration regulations.
- Mill Test Certificate (MTC / EN 10204 3.1) — Provided with every shipment for full material traceability.
Conclusion
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. represents a state-of-the-art solution for micro-channel condenser applications in heat pump systems. By integrating advanced material science, precision manufacturing, and performance-driven design optimization, this product delivers exceptional thermal performance, corrosion resistance, and long-term reliability — making it the preferred choice for engineers and OEMs demanding uncompromising quality in thermal management applications.