Stainless Steel Coil Tube (Fan Coil Unit Application Series)
Product Overview
The Stainless Steel Coil Tube is a precision-engineered, continuous-length tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Designed primarily for integration into Fan Coil Units (FCU) and HVAC (Heating, Ventilation, and Air Conditioning) systems, this coil tube delivers superior thermal transfer efficiency, corrosion resistance, and hygienic performance. The product line has been validated through rigorous experimental research referenced in the development of the Chinese National Standard GB/T — Technical Standard for Hospital Clean Care and Isolation Units, establishing its suitability for critical healthcare environments requiring stringent air purification and contamination control.
Unlike conventional copper or aluminum coil tubes, the stainless steel variant offers a closed-loop, non-leaching surface that eliminates microbial colonization pathways, making it an ideal choice for hospital wards, operating theaters, intensive care units (ICUs), and pharmaceutical cleanrooms.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its exceptional combination of mechanical strength, corrosion resistance, and thermal conductivity in HVAC service conditions.
- Primary Alloys: SUS304 (UNS S30400) and SUS316L (UNS S31603)
- Corrosion Resistance: Superior resistance to chlorides, moisture, and antimicrobial cleaning agents commonly used in hospital environments
- Surface Finish: Electropolished or passivated inner surface with roughness Ra ≤ 0.8 μm to minimize biofilm adhesion
- Temperature Range: Operational from −40 °C to +150 °C
- Hygienic Compliance: Non-toxic, non-odoriferous, and compliant with food-grade and medical-grade surface standards
- Mechanical Properties: Yield strength ≥ 205 MPa (SUS304); tensile strength ≥ 520 MPa
Technical Specifications
| Parameter | Specification |
|---|---|
| Product Name | Stainless Steel Coil Tube (盘管) |
| Product Catalog No. | 595 |
| Material Grade | SUS304 / SUS316L |
| Outer Diameter (OD) | 6.35 mm (⅛") / 9.52 mm (⅜") / 12.7 mm (½") |
| Wall Thickness | 0.5 mm – 1.2 mm |
| Coil Diameter | 100 mm – 500 mm (customizable) |
| Coil Length | 3 m – 50 m (per continuous coil) |
| Surface Treatment | Electropolished / Passivated / Mirror Polished |
| Operating Pressure | Up to 1.6 MPa (232 psi) |
| Thermal Conductivity | 16.3 W/(m·K) (SUS304) |
| Application Standard | GB/T Hospital Clean Care & Isolation Unit Technical Standard |
| Manufacturer | Wenzhou Jixing Metal Materials Co., Ltd |
Manufacturing Process
- Coil Forming: Continuous stainless steel strip is precision-fed through calibrated roll-forming dies to achieve the target outer diameter and wall thickness with tolerance ±0.05 mm.
- Welding & Seam Closure: High-frequency induction welding or orbital TIG (Tungsten Inert Gas) welding is applied to create hermetic longitudinal seams with full penetration and minimal heat-affected zone (HAZ).
- Heat Treatment: Solution annealing at 1050–1100 °C followed by rapid water quenching to restore full austenitic microstructure and maximize corrosion resistance.
- Coil Winding: The formed tube is wound into a helical coil geometry using CNC-controlled winding machines, ensuring consistent pitch and uniform curvature without work-hardening.
- Surface Finishing: Electropolishing removes the HAZ and creates a chromium-enriched passive oxide layer; optional mirror polishing (Ra ≤ 0.4 μm) is available for high-cleanliness applications.
- Pressure Testing & Inspection: Each coil is hydrostatically tested at 2.0 MPa for 30 minutes to verify weld integrity; 100% visual and dimensional inspection is performed.
Applications
Hospital & Medical Facilities
- Integration into Fan Coil Units (FCU) for hospital wards, where experimental research has demonstrated that stainless steel coil tubes with added filtration systems significantly enhance airborne particulate and microbial removal efficiency in existing hospital buildings.
- Application in ICU (Intensive Care Unit) and operating room HVAC systems requiring Grade 5–7 cleanroom compliance per GB/T standards for hospital clean care and isolation units.
- Use in pharmaceutical manufacturing facilities (GMP Class A/B) for controlled air distribution and temperature regulation.
General HVAC & Industrial Applications
- Chilled water and hot water coil assemblies in commercial buildings, hotels, and laboratories.
- Food processing and dairy industry heat exchangers requiring CIP (Clean-in-Place) compatibility.
- Marine and coastal HVAC systems where chloride-induced corrosion of conventional copper coils is a concern.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System certification for manufacturing processes
- ISO 14001:2015 — Environmental Management System
- GB/T Hospital Clean Care & Isolation Unit Technical Standard — Product performance validated through experimental research referenced in the standard's compilation
- Material Compliance: ASTM A269 / ASTM A270 for wrought austenitic stainless steel tubing
- Hygienic Design: Compliant with 3-A Sanitary Standards and EHEDG (European Hygienic Engineering & Design Group) guidelines for medical-grade applications
- Traceability: Full batch-level material certification (Mill Test Reports) with chemical composition and mechanical property verification
Unique Selling Points
1. Hygienic Superiority: The electropolished stainless steel surface eliminates the micro-porosity and galvanic corrosion pathways inherent to copper coil tubes, reducing the risk of Legionella and biofilm formation — a critical advantage validated in hospital air purification research.
2. Research-Backed Performance: Product specifications are informed by experimental studies on fan coil unit air purification in existing hospital buildings, ensuring real-world efficacy in healthcare environments governed by the GB/T Hospital Clean Care & Isolation Unit Technical Standard.
3. Corrosion Longevity: SUS316L grade offers extended service life in aggressive environments (chlorinated water, humid hospital air) without degradation of thermal performance or surface integrity.
4. Customizable Geometry: Flexible coil diameter, pitch, and length configurations allow seamless integration into both retrofit and new-build Fan Coil Unit assemblies.
5. Sustainable Material: Stainless steel is 100% recyclable, non-toxic, and free of lead or heavy metal leaching — aligning with green building and LEED certification requirements.