Stainless Steel Coil Tube for Anti-SARS Antibacterial Dry-Operation Fan Coil Unit Air Conditioning Systems
Product Overview
The Stainless Steel Coil Tube (Product No. 1227) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered coil tube component specifically designed for integration into anti-SARS antibacterial dry-operation fan coil unit (FCU) air conditioning systems. This product represents a specialized application of stainless steel coil tube technology in HVAC (Heating, Ventilation, and Air Conditioning) systems where hygienic performance, corrosion resistance, and thermal efficiency are critical requirements. The coil tube serves as the primary heat exchange element within the fan coil unit, enabling dry-condition air circulation while providing inherent antibacterial surface properties that inhibit the proliferation of pathogenic microorganisms, including SARS-CoV and related respiratory pathogens.
Unlike conventional copper or aluminum coil tubes used in standard fan coil units, this stainless steel coil tube offers superior resistance to condensation-induced microbial growth, chemical degradation, and long-term structural fatigue—making it an ideal material choice for healthcare facilities, cleanrooms, public institutions, and any environment where air quality and hygiene are paramount.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its exceptional combination of mechanical strength, corrosion resistance, and sanitary compatibility. The material properties are engineered to meet the demanding operational conditions of dry-mode fan coil units where condensation is minimized but not entirely eliminated.
- Base Material: Austenitic Stainless Steel (Type 304 / 316L available upon specification)
- Composition (304 Grade): Chromium (Cr) 18–20%, Nickel (Ni) 8–10.5%, Manganese (Mn) ≤2.0%, Carbon (C) ≤0.08%
- Composition (316L Grade): Chromium (Cr) 16–18%, Nickel (Ni) 10–14%, Molybdenum (Mo) 2–3%, Carbon (C) ≤0.03%
- Surface Treatment: Electropolished finish (Ra ≤ 0.4 μm) for enhanced antibacterial performance and reduced biofilm adhesion
- Corrosion Resistance: Superior resistance to chlorides, condensation moisture, and common HVAC refrigerant fluids
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 20°C
- Operating Temperature Range: −196°C to +870°C
- Magnetic Property: Non-magnetic (austenitic structure)
The electropolished surface treatment is a critical differentiator, as it creates a smooth, microscopically uniform surface that discourages bacterial colonization and biofilm formation—directly contributing to the anti-SARS antibacterial functionality of the integrated fan coil unit system.
Specifications
| Parameter | Specification | Unit |
|---|---|---|
| Product No. | 1227 | — |
| Product Name | Coil Tube (盘管) | — |
| Outer Diameter (OD) | 7.0 / 9.52 / 12.0 / 15.88 | mm |
| Wall Thickness | 0.5 / 0.6 / 0.8 / 1.0 | mm |
| Coil Diameter | 50 – 500 (customizable) | mm |
| Coil Length | Up to 12,000 (continuous coil) | mm |
| Material Grade | SUS 304 / SUS 316L / Custom Alloy | — |
| Surface Finish | Electropolished (Ra ≤ 0.4 μm) | — |
| Tolerance (OD) | ±0.05 | mm |
| Tolerance (Wall Thickness) | ±0.03 | mm |
| Maximum Operating Pressure | 1.6 – 4.0 (depending on grade & dimensions) | MPa |
| Refrigerant Compatibility | R-134a, R-410A, R-32, Water/Glycol Mixtures | — |
| Applicable Standards | GB/T 12771, ASTM A269, EN 10217-7 | — |
| Coating (Optional) | Food-grade PTFE (Polytetrafluoroethylene) anti-adhesion layer | — |
Manufacturing Process
The production of this stainless steel coil tube follows a rigorous multi-stage manufacturing process to ensure dimensional precision, surface integrity, and functional performance:
- Raw Material Procurement & Inspection: Stainless steel strip or seamless tube blanks are sourced from certified mills and subjected to spectroscopic analysis (OES — Optical Emission Spectroscopy) to verify chemical composition compliance with the specified grade.
- Precision Forming & Coiling: The tube is cold-formed into the required coil geometry using CNC (Computer Numerical Control) coiling equipment with real-time dimensional monitoring. The coiling process maintains a consistent bend radius to prevent stress concentration and micro-cracking.
- Welding (if applicable): Butt joints are welded using TIG (Tungsten Inert Gas) welding under argon shielding to ensure penetration integrity and minimize oxidation. Weld seams are mechanically polished to match the base tube surface finish.
- Electropolishing: The coil tube undergoes electropolishing in a controlled electrolytic bath (typically H₃PO₄-based), which removes surface micro-roughness, eliminates residual metal particles, and creates a passivated chromium oxide layer. This step is critical for achieving the antibacterial surface performance.
- Passivation Treatment: A post-polishing passivation step using nitric acid or citric acid solution further enhances the passive chromium oxide film, improving long-term corrosion resistance.
- Quality Inspection: Each batch undergoes comprehensive inspection including dimensional measurement (OD, wall thickness, coil diameter), hydrostatic pressure testing, surface roughness profiling (Ra measurement), and visual examination under magnification.
- Packaging & Delivery: Finished coil tubes are individually wrapped in protective film, packaged in moisture-barrier containers, and labeled with full traceability documentation including heat numbers, test certificates, and material certifications.
Applications
This stainless steel coil tube is purpose-engineered for use in anti-SARS antibacterial dry-operation fan coil unit air conditioning systems, where the following application scenarios are primary:
- Healthcare Facilities: Hospitals, clinics, operating rooms, and intensive care units (ICUs) where airborne pathogen control is essential. The antibacterial surface properties of the electropolished stainless steel coil tube reduce the risk of HVAC-mediated cross-contamination.
- Public Institutions: Schools, government buildings, transportation hubs (airports, train stations), and large commercial complexes where high foot traffic increases the risk of respiratory pathogen transmission.
- Pharmaceutical & Biotechnology Cleanrooms: Environments requiring controlled air quality in compliance with GMP (Good Manufacturing Practice) standards, where the coil tube's resistance to microbial growth and chemical corrosion ensures long-term operational reliability.
- Food Processing Facilities: Where hygienic air handling systems are mandated, the stainless steel coil tube's compliance with food-grade material standards ensures safe and sanitary operation.
- Residential & Commercial HVAC: Premium residential buildings and commercial spaces where occupants prioritize indoor air quality (IAQ) and long-term system hygiene.
In the dry-operation mode of the fan coil unit system, the coil tube operates with minimal or no condensation on its surface. This is achieved through precise temperature control of the refrigerant or water loop flowing through the coil tube, keeping the surface temperature above the dew point. The stainless steel material's inherent resistance to corrosion under these conditions ensures that the coil tube maintains its structural and functional integrity over extended service life cycles without degradation.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and product certifications to assure customers of the highest standards of manufacturing excellence:
- ISO 9001:2015 — Quality Management System certification, demonstrating consistent capability to provide products and services that meet customer and regulatory requirements.
- ISO 14001:2015 — Environmental Management System certification, reflecting commitment to environmentally responsible manufacturing practices.
- ISO 45001:2018 — Occupational Health and Safety Management System certification.
- GB/T 12771 — Chinese National Standard for welded stainless steel tubes for general purposes.
- ASTM A269 / A270 — American Society for Testing and Materials standards for seamless and welded austenitic stainless steel tubes.
- EN 10217-7 — European Standard for stainless steel tubes for general purposes.
- NSF/ANSI 61 — Drinking Water System Components certification (applicable for water-loop applications in fan coil units).
- Material Certificates (MTC): Full EN 10204 Type 3.1 test certificates provided with each shipment, including chemical analysis, mechanical test results, and dimensional verification.
Unique Selling Points
1. Integrated Anti-SARS Antibacterial Capability: The electropolished stainless steel surface provides inherent resistance to bacterial adhesion and biofilm formation, directly contributing to the anti-SARS antibacterial performance of the fan coil unit system. This eliminates the need for chemical antimicrobial coatings that may degrade over time.
2. Dry-Operation Compatibility: Specifically engineered for dry-condition fan coil unit operation, the coil tube maintains dimensional stability and surface integrity even under repeated thermal cycling without condensation-induced stress.
3. Superior Long-Term Durability: Stainless steel's exceptional fatigue resistance and corrosion resistance ensure a service life significantly exceeding that of copper or aluminum alternatives, reducing lifecycle maintenance costs and system downtime.
4. Full Traceability: Every coil tube is accompanied by complete material traceability documentation, enabling compliance with stringent regulatory requirements in healthcare, pharmaceutical, and food industries.
5. Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd. offers flexible customization of coil diameter, tube dimensions, material grade, and surface finish to meet specific project requirements and OEM (Original Equipment Manufacturer) integration needs.