Stainless Steel Fan Coil Tube — Coiltube for HVAC Heat Exchange Systems
Product Overview
The Stainless Steel Fan Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered tubular product specifically designed for integration into fan coil units (FCUs) within heating, ventilation, and air conditioning (HVAC) systems. These coiltubes serve as the primary heat exchange elements, facilitating efficient thermal transfer between refrigerant or water circuits and ambient air streams. The product is engineered in accordance with rigorous industry standards, ensuring optimal performance in both commercial and industrial air conditioning applications.
Wenzhou Jixing Metal Materials Co., Ltd has established itself as a leading supplier of stainless steel coiltubes, leveraging advanced manufacturing capabilities and deep domain expertise in HVAC component engineering. The coiltube product line is developed with a focus on maximizing heat exchange efficiency, minimizing pressure drop, and ensuring long-term durability under cyclic thermal and mechanical loading conditions.
Material & Properties
The coiltube is fabricated from high-grade stainless steel (AISI 304 / AISI 316L), selected for its superior corrosion resistance, thermal conductivity, and mechanical integrity. The material composition and resulting properties are detailed as follows:
- Base Material: Austenitic stainless steel conforming to ASTM A213 / A269 specifications
- Corrosion Resistance: Excellent resistance to chloride-induced pitting and intergranular corrosion, particularly in 316L grade
- Thermal Conductivity: Approximately 16.3 W/(m·K) at 20°C (AISI 304), providing effective heat transfer capability
- Mechanical Strength: Yield strength ≥ 205 MPa (AISI 304); tensile strength ≥ 515 MPa
- Operating Temperature Range: −196°C to +870°C, accommodating extreme thermal cycling
- Surface Finish: Electropolished or mechanical polished inner surface (Ra ≤ 0.4 μm) to minimize fouling and pressure drop
- Hygienic Compliance: Suitable for applications requiring sanitary-grade surfaces
Specifications
| Parameter | Specification |
|---|---|
| Product Code | 406 — Coiltube |
| Outer Diameter (OD) | 6.35 mm (1/4"), 9.53 mm (3/8"), 12.7 mm (1/2") |
| Wall Thickness | 0.5 mm – 1.2 mm |
| Coil Diameter | 100 mm – 800 mm (customizable) |
| Tube Length (per coil) | 0.5 m – 15 m (configurable) |
| Number of Rows | 1 – 4 rows (adjustable per thermal load) |
| Tube Pitch (Longitudinal) | 19.05 mm (3/4"), 25.4 mm (1") |
| Tube Pitch (Lateral) | 19.05 mm (3/4"), 25.4 mm (1") |
| Fin Type | Aluminum corrugated fin / louvered fin / integral fin |
| Fin Pitch | 2.0 – 2.5 mm |
| Material Grade | AISI 304 / AISI 316L / SUS 304 / SUS 316L |
| Surface Treatment | Passivated / Electropolished / PTFE coated (optional) |
| Connection Type | Brazed / Flared / Threaded / Welded |
| Pressure Rating | ≤ 2.5 MPa (working pressure) |
| Heat Exchange Efficiency | Enhanced by ≥ 15% via optimized coil geometry (model-corrected) |
Manufacturing Process
The production of the stainless steel coiltube follows a multi-stage precision manufacturing workflow:
- Material Preparation: Certified stainless steel tube blanks are inspected for chemical composition, mechanical properties, and dimensional tolerances prior to processing.
- Forming & Bending: High-precision CNC bending machines shape the tubes into the designated coil geometry. The bending process is controlled to prevent wall thinning, ovalization, or micro-cracking at the bend radii.
- Fin Attachment: Aluminum fins are applied through a fin-sleeving (integral fin) process or external fin-winding method. The fin-to-tube bond strength is verified to exceed 100 N/cm to prevent delamination under thermal cycling.
- Heat Sink Assembly: Individual coiltubes are assembled into multi-row heat exchanger bundles with precise pitch control using automated fixtures.
- Connection Fabrication: End connections (headers, manifolds, or U-bends) are formed and brazed under vacuum or inert gas atmosphere to ensure leak-free joints.
- Surface Treatment: The assembly undergoes pickling and passivation to remove scale and contaminants, restoring the protective chromium oxide layer on the stainless steel surface.
- Quality Inspection: Each unit is subjected to pressure testing (1.5× working pressure), leak detection (helium or soap bubble method), and dimensional verification.
Thermal Model Correction: Wenzhou Jixing Metal Materials Co., Ltd has incorporated an advanced heat exchange model correction methodology derived from research on fan coil unit thermal performance. This correction accounts for non-uniform air flow distribution across the coil face, inlet/outlet temperature gradients, and fin efficiency degradation under high humidity conditions. The model-corrected design yields a coefficient of performance (COP) improvement of 8–15% compared to conventional coil geometries.
Applications
The stainless steel coiltube is widely deployed across the following sectors:
- Commercial HVAC: Fan coil units in office buildings, shopping malls, hotels, and hospitals for precise temperature and humidity control.
- Industrial Process Cooling: Heat rejection systems in chemical processing, pharmaceutical manufacturing, and food processing facilities.
- Residential Air Conditioning: Ducted and ductless split-system indoor units requiring compact, high-efficiency heat exchangers.
- Cold Storage & Refrigeration: Evaporator coils in low-temperature storage environments demanding corrosion-resistant tubing.
- Marine & Offshore Applications: HVAC systems in ships and offshore platforms where chloride-rich environments necessitate 316L-grade stainless steel.
- Specialty Cooling: Data center thermal management, laboratory temperature-controlled enclosures, and precision equipment cooling.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework. The coiltube product line is certified and compliant with the following standards:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ASTM A213 / A269 — Seamless and welded austenitic stainless steel tube specifications
- GB/T 12771 — Chinese national standard for welded stainless steel tubes
- EN 10216-5 — European standard for welded stainless steel tubes
- ASME B31.9 — Pressure piping (refrigeration and air-conditioning)
- UL / CE Marking — Safety certification for HVAC components in North American and European markets
- SMS / DHP — Sanitary and hygienic design compliance for food-grade applications
Unique Selling Points: The Wenzhou Jixing Metal Materials Co., Ltd coiltube distinguishes itself through: (1) model-corrected heat exchange geometry yielding superior thermal performance; (2) full-range material options from 304 to 316L for diverse environmental conditions; (3) precision manufacturing with dimensional tolerances within ±0.1 mm; (4) comprehensive certification portfolio enabling global market deployment; and (5) customizable coil configurations tailored to specific thermal load requirements.