Stainless Steel Coil Tube for Wall Radiant Heating Systems
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered continuous coil pipe designed specifically for integration into wall-mounted radiant heating and cooling systems. This product is engineered to facilitate efficient thermal energy transfer through wall-embedded hot water circuits, providing superior thermal comfort with optimized floor-area coverage ratios. The coil tube is particularly suited for localized radiant heating installations where the relationship between pipe layout area and occupant thermal comfort must be precisely controlled and simulated for optimal system performance.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its exceptional combination of thermal conductivity, corrosion resistance, mechanical integrity, and long-term durability under cyclic thermal loading conditions.
- Base Material: Austenitic Stainless Steel (Type 304 / Type 316L)
- Corrosion Resistance: Superior resistance to oxidation, scaling, and chloride-induced pitting under domestic hot water conditions
- Thermal Conductivity: 16.3 W/(m·K) at 20°C, enabling efficient radiant heat transfer to surrounding wall structures
- Operating Temperature Range: −196°C to +425°C, accommodating both heating and cooling applications
- Operating Pressure Rating: Up to 1.6 MPa (232 psi) at 95°C
- Service Life: Exceeds 50 years under normal operating conditions with minimal degradation
- Mechanical Properties: Tensile strength ≥ 520 MPa; elongation ≥ 40%
Specifications
| Parameter | Specification |
|---|---|
| Product Category | Coil Tube (盘管) for Wall Radiant Systems |
| Outer Diameter (OD) | 16 mm, 20 mm, 22 mm (custom sizes available) |
| Wall Thickness | 0.8 mm – 1.5 mm |
| Coil Length (per roll) | Up to 500 m continuous coil |
| Bending Radius (minimum) | 5× OD (without deformation or kinking) |
| Surface Finish | 2B finish or electropolished (Ra ≤ 0.4 μm) |
| Connection Method | Compression fittings, brazed joints, or press-fit connectors |
| Flow Velocity (recommended) | 0.5 – 1.5 m/s |
| Heat Flux Capacity | Up to 45 W/m² per pipe circuit |
| Applicable Standards | ASTM A213, EN 10217-7, GB/T 12771 |
| Manufacturer | Wenzhou Jixing Metal Materials Co., Ltd. (Item No. 806) |
Manufacturing Process
- Raw Material Procurement: High-purity stainless steel strip is sourced from certified mill producers with full traceability documentation and chemical composition verification.
- Cold Rolling & Annealing: The strip undergoes precision cold rolling to achieve exact wall thickness tolerances (±0.05 mm), followed by controlled annealing to relieve residual stresses and restore full austenitic microstructure.
- Precision Forming: The annealed strip is formed into seamless tubes via cold-drawing or cold-rolling processes, maintaining dimensional accuracy and surface integrity throughout the forming cycle.
- Coil Winding: Continuous tubes are wound onto precision-engineered spools to produce coiltube rolls with consistent coil diameters and minimal inter-layer contact stress.
- Hydrostatic Testing: Each coil batch undergoes 100% hydrostatic pressure testing at 1.5× the maximum working pressure to ensure zero leakage points.
- Surface Treatment: Optional electropolishing or passivation treatment is applied to enhance corrosion resistance and reduce internal roughness for improved hydraulic performance.
- Quality Inspection: Final products are inspected via ultrasonic testing (UT), eddy current testing (ECT), and visual examination to confirm compliance with applicable international standards.
Applications
Wall Radiant Heating & Cooling Systems
The primary application of this coil tube is in localized hot water wall radiant systems, where continuous pipe circuits are embedded within or mounted on interior walls to provide uniform radiant heat distribution. Research and simulation studies have demonstrated that the effective laid area of the coil tube circuit significantly influences occupant thermal comfort metrics, including mean radiant temperature (MRT), operative temperature, and predicted mean vote (PMV).
Key Application Scenarios:
- Residential Buildings: Whole-wall or partial-wall radiant heating for living rooms, bedrooms, and bathrooms
- Commercial Facilities: Office spaces, retail environments, and hospitality venues requiring low-profile, silent heating solutions
- Hospital & Healthcare Settings: Corrosion-resistant piping suitable for cleanroom and sterile environments
- Renewable Energy Integration: Compatible with solar thermal collectors, heat pumps, and district heating networks
- Zone-Controlled Systems: Enables localized heating strategies where full-room coverage is not required, optimizing energy consumption based on thermal comfort simulation data
Unique Selling Points
- Optimized for Radiant Comfort Simulation: The product is specifically engineered to perform reliably within the parameters identified in thermal comfort research, ensuring predictable heat flux output for accurate system modeling and design validation.
- Exceptional Formability: The coil tube maintains structural integrity through repeated bending and routing, enabling complex wall layouts without the need for additional fittings or joints.
- Zero-Corrosion Guarantee: Unlike carbon steel or copper alternatives, the stainless steel construction eliminates the risk of internal corrosion, scale buildup, or pipe failure over the system's entire service life.
- Continuous Coil Delivery: Delivered as unbroken coil rolls up to 500 meters, minimizing connection points and associated leak risks in extended wall circuits.
- Energy Efficiency: High thermal conductivity combined with minimal pressure drop enables lower pumping power requirements and reduced overall system energy consumption.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and product certifications to ensure global market compliance:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- CE Marking — European Conformity for pressure equipment (PED 2014/68/EU)
- NSF/ANSI 61 — Drinking Water System Components (where applicable)
- Material Test Reports (MTR) — Full chemical and mechanical property documentation per EN 10204 Type 3.1
- Hydrostatic Test Certificates — Batch-specific pressure test records
- Third-Party Inspection — Available upon request (SGS, Bureau Veritas, TÜV)
Note: This coil tube product has been validated through simulation studies examining the relationship between pipe layout coverage area and thermal comfort performance in wall radiant systems. The findings confirm that optimized coil tube specifications enable precise control over radiant heat output, supporting energy-efficient building envelope heating strategies.