Stainless Steel Coil Tube — Industrial-Grade Coiltube for HVAC & Thermal Systems
Product Overview
The stainless steel coil tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered tubular product designed for demanding thermal management applications. Supplied in continuous coil form, this product serves as a critical heat-exchange medium in dry fan coil units, radiant ceiling panels, and other hydronic heating and cooling systems. The coiled configuration enables efficient storage, transport, and on-site installation with minimal waste, while the stainless steel construction ensures long-term resistance to corrosion, thermal cycling, and mechanical stress.
Developed with reference to energy efficiency optimization principles for hydronic radiant systems, this coil tube integrates high thermal conductivity with exceptional durability, contributing to the overall system COP (Coefficient of Performance) improvement in modern HVAC installations.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its optimal balance of thermal performance, corrosion resistance, and formability.
- Material Grade: SUS304 / SUS316L (ASTM A269 / ASTM B423 compliant)
- Composition (SUS304): Cr ≥ 18.0%, Ni ≥ 8.0%, C ≤ 0.08%, Mn ≤ 2.0%, Si ≤ 1.0%
- Composition (SUS316L): Cr ≥ 16.5%, Ni ≥ 10.0%, Mo ≥ 2.0%, C ≤ 0.03%
- Thermal Conductivity: 16.3 W/(m·K) at 20°C
- Operating Temperature Range: −196°C to +870°C
- Corrosion Resistance: Superior resistance to oxidation, pitting, and intergranular corrosion
- Mechanical Strength: Yield strength ≥ 205 MPa; Tensile strength ≥ 515 MPa
- Surface Finish: 2B / BA / No.4 polished / Custom per requirement
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | Φ6.0 mm – Φ50.8 mm (customizable) |
| Wall Thickness | 0.5 mm – 3.0 mm |
| Coil Length | 50 m – 200 m per coil (standard); up to 500 m upon request |
| Coil Inner Diameter | Φ200 mm – Φ600 mm |
| Tolerance (OD) | ±0.1 mm (precision grade) |
| Tolerance (Wall Thickness) | ±10% of nominal |
| End Condition | Plain end / Beveled / Flared / Threaded (optional) |
| Surface Treatment | Pickled & passivated; optional electropolishing |
| Applicable Standards | GB/T 14976, ASTM A269, ASTM B423, EN 10216-5 |
| Testing Methods | Hydrostatic test, Eddy current inspection, Spectroscopic analysis |
Manufacturing Process
- Hot Rolling: Stainless steel billets are hot-rolled into seamless tube blanks with controlled grain structure.
- Piercing & Elongation: Tubes are pierced and elongated to achieve precise dimensional tolerances.
- Cold Drawing: Tubes are cold-drawn through precision dies to attain final OD and wall thickness specifications with superior surface finish.
- Heat Treatment: Solution annealing at 1050°C – 1150°C followed by controlled cooling to eliminate residual stresses and restore full austenitic phase stability.
- Pickling & Passivation: Acid pickling removes oxide scale; passivation forms a protective chromium oxide layer.
- Coiling: Tubes are wound into uniform coils using computer-controlled winding equipment to ensure consistent coil diameter and layer stacking.
- Quality Inspection: Each coil undergoes dimensional measurement, spectroscopic composition verification, hydrostatic pressure testing, and eddy current flaw detection.
Applications
The stainless steel coil tube from Wenzhou Jixing Metal Materials Co., Ltd is specifically engineered for thermal system applications, including but not limited to:
- Dry Fan Coil Units (DFCU): Used as refrigerant or water circuit tubing within air-coil assemblies for commercial HVAC systems, contributing to improved energy efficiency through optimized heat transfer surface area.
- Radiant Ceiling Panels: Serves as embedded heating/cooling tubing in hydronic radiant systems, providing uniform temperature distribution with minimal thermal stratification.
- Industrial Heat Exchangers: Suitable for shell-and-tube and plate-fin heat exchanger manufacturing.
- Refrigeration & Air Conditioning Systems: Employed in condenser and evaporator coil fabrication.
- Food & Pharmaceutical Processing: Utilized where hygienic, corrosion-resistant tubing is mandated.
- Automotive & Aerospace Thermal Management: Applied in compact heat exchange assemblies requiring high reliability.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- CE Marking — Conformity with European health, safety, and environmental protection standards
- EN 10204 3.1 — Material test certificates per European standard
- Mill Test Reports (MTR) — Provided for each production lot, including chemical composition, mechanical properties, and dimensional verification
- NACE / NORSOK — Compliance for oil and gas applications (where applicable)
Unique Selling Points
- Energy Efficiency Optimization: Designed with reference to thermodynamic analysis of dry fan coil and radiant panel systems, enabling up to 15% improvement in seasonal energy efficiency ratio (SEER) through superior thermal conductivity and minimal thermal resistance.
- Seamless Construction: Eliminates weld seams that could act as corrosion initiation points or thermal bottlenecks, ensuring uniform heat transfer along the entire tube length.
- Extended Service Life: Stainless steel construction provides a design life exceeding 25 years in aggressive environments where carbon steel alternatives would fail within 5–8 years.
- Hygienic Surface Finish: Achieves Ra ≤ 0.4 μm surface roughness, suitable for potable water and food-grade applications without additional treatment.
- Coil Supply Advantage: Continuous coil format reduces installation time by up to 40% compared to straight-length tubing, minimizing field splices and associated failure points.
- Full Traceability: Each coil is individually tagged with heat number, production date, and test data, enabling complete supply chain traceability.
Note: Wenzhou Jixing Metal Materials Co., Ltd maintains a research-driven approach to product development, incorporating findings from energy efficiency studies on hydronic thermal systems to continuously improve coil tube performance specifications. Custom engineering support is available for specialized applications requiring non-standard dimensions or material grades.