Stainless Steel Coil Tube — HVAC Fan Coil & Air Cooler Application Series
Manufactured by Wenzhou Jixing Metal Materials Co., Ltd., this product line comprises precision-engineered stainless steel coil tubes designed for use in air cooler coils and fan coil units (FCUs) within heating, ventilation, and air conditioning (HVAC) systems. The product is classified under the technical literature and application study category, reflecting its role in advanced thermal management research and industrial deployment.
Product Overview
The stainless steel coil tube is a core heat exchange component in closed-loop cooling systems, particularly within fan coil units and air coolers. Its primary function is to facilitate efficient thermal transfer between circulating chilled water and ambient air. This product series is specifically engineered to address the critical challenge of large cold water temperature differences — a condition where the supply and return water temperature differential significantly exceeds standard design parameters. Under such conditions, conventional coil tubes may suffer from reduced heat transfer efficiency, accelerated corrosion, and premature thermal fatigue. The stainless steel coil tube from Wenzhou Jixing is formulated to maintain optimal performance and structural integrity under these demanding operational scenarios.
The coil tube is wound into helical configurations that maximize surface area within a compact footprint, enabling high-density heat exchange. The material selection and manufacturing tolerances are optimized to minimize thermal stress during rapid temperature cycling and to resist scaling, biofilm formation, and chemical degradation from treated cooling water.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its superior corrosion resistance, mechanical strength, and thermal conductivity balance. Key material characteristics include:
- Base Material: Austenitic stainless steel (typically Grade 304 or 316, depending on application-specific corrosion requirements)
- Corrosion Resistance: Excellent resistance to pitting, crevice corrosion, and intergranular corrosion in chloride-containing cooling water environments
- Thermal Conductivity: Optimized for efficient heat transfer under large temperature differential conditions
- Mechanical Strength: High tensile strength and elongation to withstand thermal expansion and contraction cycles
- Surface Finish: Precision-polished interior surface to minimize fluid resistance and reduce scale adhesion
- Temperature Range: Suitable for continuous operation across a wide temperature spectrum, accommodating large ΔT (temperature difference) scenarios without material degradation
- Non-toxicity: Compliant with potable water and food-grade contact standards where applicable
Specifications
| Parameter | Specification |
|---|---|
| Product Name | Stainless Steel Coil Tube (盘管 / Coil Tube) |
| Product Code | 1216 |
| Material Grade | ASTM A270 / A269 — Stainless Steel (Grade 304 / 316) |
| Tube Diameter | Customizable (commonly φ6.35 mm to φ12.7 mm outer diameter) |
| Wall Thickness | 0.5 mm – 1.2 mm (application-dependent) |
| Coil Configuration | Helical winding with optimized pitch and winding density |
| Maximum Operating Pressure | 1.6 MPa – 2.5 MPa (standard); higher pressure variants available |
| Temperature Differential Tolerance | Designed for large ΔT operation (supply-return differential up to 15–20 °C) |
| Surface Treatment | Passivation treatment; optional electropolishing for enhanced corrosion resistance |
| Welding Quality | Seamless or welded with full penetration; radiographic inspection available |
| Standards Compliance | GB/T 14976, ASTM A270, EN 10217, ISO 683 |
| Customization | Dimensions, coil pitch, material grade, and surface finish available per customer specification |
Manufacturing Process
The production of the stainless steel coil tube follows a rigorous multi-stage manufacturing process designed to ensure dimensional accuracy, material homogeneity, and long-term performance reliability:
- Raw Material Selection & Inspection: Stainless steel strip or seamless tube stock is sourced from certified mills and subjected to spectrographic analysis to verify alloy composition and mechanical properties.
- Cold Drawing / Forming: The tube is cold-drawn or formed to achieve precise outer diameter, wall thickness, and roundness tolerances. This process also introduces beneficial work hardening that enhances fatigue resistance.
- Coil Winding: The formed tube is wound into helical coil configurations using precision CNC-controlled winding equipment. Winding parameters — including pitch, diameter, and number of turns — are tailored to the thermal load requirements of the target application.
- Welding & Joining: Header connections and end fittings are welded using argon arc welding (TIG/GTAW) to ensure hermetic seals and minimal heat-affected zone (HAZ) distortion.
- Passivation & Surface Treatment: A chemical passivation process removes free iron contamination from the surface, restoring and enhancing the natural chromium oxide passive film. Optional electropolishing further refines the interior surface for reduced flow resistance.
- Quality Inspection: Each coil tube undergoes dimensional verification, hydrostatic pressure testing, and visual inspection. Select batches are subjected to ultrasonic testing (UT) or radiographic testing (RT) for internal defect detection.
- Packaging & Delivery: Finished coils are protected with moisture-absorbent packaging and delivered in configurations suitable for direct integration into fan coil units or air cooler assemblies.
Applications
The stainless steel coil tube from Wenzhou Jixing Metal Materials Co., Ltd. is deployed across a broad spectrum of HVAC and thermal management applications:
- Fan Coil Units (FCUs): Serves as the primary heat exchange element in commercial and residential fan coil systems, delivering efficient cooling and heating through air-side and water-side thermal transfer.
- Air Coolers & Chilled Water Air Handlers: Integrated into large-capacity air coolers where large cold water temperature differences are common due to system design or operational conditions.
- Commercial HVAC Systems: Used in office buildings, hotels, hospitals, and retail facilities requiring reliable, corrosion-resistant coil solutions for long-term maintenance-free operation.
- Industrial Process Cooling: Applied in manufacturing environments where cooling water may contain chlorides or other corrosive agents that would degrade carbon steel or copper alternatives.
- Food & Pharmaceutical Processing: Suitable for hygienic applications where non-toxic, easily cleanable, and corrosion-resistant materials are mandated by regulatory standards.
- Large ΔT Cooling Systems: Specifically optimized for applications where the chilled water supply and return temperature differential is elevated, ensuring consistent thermal performance without degradation of heat transfer coefficients.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and product certifications to assure customers of consistent performance and regulatory compliance:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing processes
- ISO 14001 — Environmental Management System, ensuring sustainable and environmentally responsible production practices
- GB/T 14976 — Chinese national standard for seamless stainless steel tubes
- ASTM A270 / A269 — American standards for austenitic stainless steel tube and pipe
- EN 10217 — European standard for non-ferrous metallic tubes and pipes
- Hydrostatic Pressure Testing — 100% batch testing to verify structural integrity and weld quality
- Material Traceability — Full traceability from raw material mill certificates through final product delivery
Unique Selling Points
The integration of large cold water temperature difference performance data into the product design philosophy sets this coil tube series apart from conventional offerings. By studying and addressing the specific degradation mechanisms that occur under elevated ΔT conditions — including reduced convective heat transfer coefficients, increased thermal stress, and accelerated fouling — Wenzhou Jixing delivers a coil tube solution that maintains rated capacity and efficiency even in non-ideal operating conditions. This results in longer service life, reduced maintenance intervals, and lower total cost of ownership for system integrators and end users.
- Optimized for Large ΔT Operation: Engineered to sustain high heat transfer performance under large supply-return water temperature differentials, mitigating the performance penalties observed in standard coil designs.
- Premium Stainless Steel Construction: Superior corrosion resistance compared to carbon steel or copper tube alternatives, eliminating the need for chemical water treatment in many applications.
- Precision Manufacturing Tolerances: CNC-controlled winding and forming ensure uniform coil geometry, consistent flow distribution, and predictable thermal performance.
- Customizable Configuration: Flexible adaptation of dimensions, material grade, and coil parameters to match specific system design requirements.
- Full Quality Traceability: End-to-end material and process documentation supporting compliance audits and long-term performance verification.
For detailed technical inquiries, customization requests, or sample evaluation, contact Wenzhou Jixing Metal Materials Co., Ltd. directly for engineering support and quotation services.