WA-V-102C3L30 Stainless Steel Coil Tube for Fan Coil Units
1. Product Overview
The WA-V-102C3L30 Stainless Steel Coil Tube is a precision-engineered coiled piping product manufactured by Wenzhou Jixing Metal Materials Co., Ltd., specifically designed for integration into fan coil units (FCU) within commercial and industrial HVAC (Heating, Ventilation, and Air Conditioning) systems. This product represents the culmination of advanced metallurgical processing and precision forming techniques, delivering superior thermal conductivity, mechanical integrity, and long-term corrosion resistance in demanding hydronic applications.
The coil tube functions as the primary heat exchange conduit within fan coil units, facilitating the transfer of thermal energy between circulating water/coolant and the ambient air stream. Its helical geometry maximizes surface area within a compact volumetric footprint, thereby optimizing the heat exchange efficiency of the overall system.
2. Material & Properties
2.1 Base Material Composition
The WA-V-102C3L30 coil tube is fabricated from austenitic stainless steel, conforming to the standard designation AISI 304 (UNS S30400) or its European equivalent EN 1.4301 (X5CrNi18-10). The chemical composition adheres to the following specifications:
- Carbon (C): ≤ 0.08 wt%
- Chromium (Cr): 18.0–20.0 wt%
- Nickel (Ni): 8.0–10.5 wt%
- Manganese (Mn): ≤ 2.0 wt%
- Silicon (Si): ≤ 1.0 wt%
- Phosphorus (P): ≤ 0.045 wt%
- Sulfur (S): ≤ 0.030 wt%
2.2 Mechanical Properties
- Tensile Strength (Rm): 520–720 MPa
- Yield Strength (Rp0.2): ≥ 205 MPa
- Elongation (A50): ≥ 40%
- Hardness (HV30): ≤ 210 HV
- Density: 7.93 g/cm³
2.3 Physical & Thermal Properties
- Thermal Conductivity (at 20°C): 16.3 W/(m·K)
- Thermal Conductivity (at 100°C): 21.6 W/(m·K)
- Specific Heat Capacity: 0.50 J/(g·K)
- Thermal Expansion Coefficient (20–100°C): 16.0 × 10⁻⁶ /K
- Electrical Resistivity: 0.72 Ω·mm²/m
2.4 Corrosion Resistance
The high chromium and nickel content provides exceptional resistance to atmospheric corrosion, water-based media, and dilute aqueous solutions. The passive chromium oxide film (Cr₂O₃) self-heals under aerobic conditions, ensuring long-term protection against pitting, crevice corrosion, and intergranular attack within the operating temperature range of −196°C to +870°C.
3. Technical Specifications
| Parameter | Specification | Standard/Reference |
|---|---|---|
| Product Model | WA-V-102C3L30 | — |
| Outer Diameter (OD) | 9.52 mm (3/8") | ASME B36.19M |
| Wall Thickness | 1.00 mm | ± 0.10 mm tolerance |
| Inner Diameter (ID) | 7.52 mm | Calculated |
| Coil Length | Up to 300 m (continuous) | Customizable |
| Coil Diameter | 610 mm (24") | Industry standard |
| Surface Finish | Mirror polish / 2B finish (Ra ≤ 0.4 μm) | ASTM A967 |
| End Condition | Plain end / Beveled end | Per customer requirement |
| Heat Treatment | Solution annealed (1050–1100°C) + Water quench | ASTM A240 |
| Maximum Operating Pressure | 1.6 MPa (232 psi) | ASME B31.5 |
| Operating Temperature Range | −40°C to +200°C | Material-dependent |
| Manufacturing Standard | ASTM A554 / EN 10217-7 / GB/T 14976 | Multi-standard compliance |
| Welding Suitability | TIG (GTAW) / Orbital / Resistance | ASME IX |
| Package Format | Wooden pallet / Steel drum / Stretch-wrapped coil | ISO 4180 |
4. Manufacturing Process
The production of the WA-V-102C3L30 coil tube follows a rigorous multi-stage manufacturing sequence designed to ensure dimensional accuracy, metallurgical homogeneity, and surface integrity:
- Raw Material Preparation: Hot-rolled stainless steel strip (HRS) is procured from certified mill suppliers and subjected to incoming inspection for chemical composition (via XRF or wet chemistry) and mechanical properties.
- Acid Pickling & Descaling: The strip undergoes chemical pickling using a mixture of nitric acid (HNO₃) and hydrofluoric acid (HF) or citric acid to remove mill scale and restore the passive chromium oxide layer.
- Cold Rolling: The strip is cold-rolled to the target wall thickness through multiple passes, inducing controlled work hardening while maintaining ductility within specification limits.
- Solution Annealing: The cold-rolled coil is heat-treated at 1050–1100°C followed by rapid water quenching to dissolve carbides, eliminate residual stresses, and restore full austenitic ductility.
- Forming & Coiling: The annealed strip is fed through precision mandrel dies and formed into the target circular cross-section using a continuous bending and welding process. The coil is wound onto a 610 mm diameter spool with controlled tension to prevent deformation.
- Welding: A longitudinal or spiral TIG (Gas Tungsten Arc Welding) seam is formed with argon shielding (99.99% Ar) to prevent oxidation. Weld parameters are controlled to achieve a penetration ratio of ≥ 95% with minimal heat-affected zone (HAZ) distortion.
- Surface Finishing: The welded coil tube undergoes internal and external polishing (mechanical or electrolytic) to achieve the specified surface roughness (Ra ≤ 0.4 μm for mirror finish), critical for minimizing fluid friction losses and preventing biofilm accumulation.
- Quality Inspection: Each coil is subjected to hydrostatic pressure testing (1.5× working pressure), eddy current testing for wall thickness verification, and dimensional measurement per ASTM E127 (OD) and ASTM E165 (wall thickness).
- Packaging & Dispatch: The inspected coil is wrapped in protective plastic film, secured with steel strapping, and palletized for export-grade shipping.
5. Applications
The WA-V-102C3L30 stainless steel coil tube finds extensive application across multiple industries:
- HVAC Systems: Primary application in fan coil units for commercial buildings, hospitals, data centers, and clean rooms, where the coil tube serves as the heat exchange element for chilled water or hot water circuits.
- Food & Beverage Processing: Used in hygienic heat exchangers, pasteurization systems, and CIP (Clean-in-Place) compatible piping where corrosion resistance and surface smoothness are critical (FDA 21 CFR compliant).
- Pharmaceutical Manufacturing: Employed in GMP (Good Manufacturing Practice) environments for process piping, condensers, and thermal control systems requiring high purity and traceability.
- Marine & Offshore: Utilized in desalination plants, shipboard HVAC systems, and marine cooling circuits exposed to saltwater environments.
- Geothermal & Solar Thermal: Integrated into closed-loop heat transfer systems where long-term durability under cyclic thermal loading is essential.
- Industrial Process Cooling: Applied in chemical processing, electronics cooling, and semiconductor manufacturing where precise temperature control and material compatibility are paramount.
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring product conformity to international standards:
- ISO 9001:2015 — Quality Management System certification for manufacturing and supply processes.
- ISO 14001:2015 — Environmental Management System certification.
- EN 10204 — Type 3.1 Mill Test Certificates (MTC) provided for every shipment, issued by an independent third-party inspection body.
- CE Marking — Compliance with European Pressure Equipment Directive (PED) 2014/68/EU where applicable.
- ASTM Compliance — Full conformance with ASTM A554 (welded austenitic stainless steel tubing), ASTM A269 (welded austenitic tubing for chemical and allied industries), and ASTM A967 (passivation practice).
- NACE MR0175 / ISO 15156 — Resistance to sulfide stress cracking for sour service applications (where applicable).
- Third-Party Inspection: Products available for inspection by SGS, Bureau Veritas, or TÜV upon customer request.
7. Unique Selling Points
- Extended Service Life: The austenitic 304 stainless steel matrix provides 3–5× longer service life compared to carbon steel alternatives in aqueous HVAC environments, significantly reducing maintenance intervals and total cost of ownership (TCO).
- Superior Thermal Performance: The mirror-polished internal surface minimizes fouling resistance (fouling factor ≤ 0.0001 m²·K/W), maintaining heat exchange efficiency over extended operational cycles.
- Hygienic Design: Ra ≤ 0.4 μm surface finish eliminates dead zones and microbial harborage, meeting 3-A Sanitary Standards and EHEDG (European Hygienic Engineering Design Group) guidelines.
- Customization Flexibility: Coil length, surface finish grade, and end preparation can be tailored to specific project requirements, supporting both OEM integration and field installation.
- Traceability: Full heat-number traceability from mill certificate to finished product ensures material pedigree and facilitates compliance audits in regulated industries.
- Cost Efficiency: Continuous coil format reduces field welding joints by up to 90% compared to straight pipe assemblies, lowering installation labor costs and potential leak points.
8. Storage & Handling Recommendations
- Store in a dry, well-ventilated warehouse with ambient temperature between 5°C and 40°C.
- Avoid stacking coils vertically; maintain horizontal orientation on wooden pallets with proper load distribution.
- Protect from contact with carbon steel tools and materials to prevent galvanic corrosion and iron contamination.
- Do not remove protective wrapping prior to installation; ensure all cutting and fabrication tools are dedicated to stainless steel service.
Note: This technical specification is provided for informational purposes. Actual product dimensions and properties may vary based on order-specific requirements. Customers are advised to consult Wenzhou Jixing Metal Materials Co., Ltd. directly for project-specific engineering support, sample testing, and custom quotation.