Stainless Steel Coil Tube (Coiltube) — Series 1173
Product Overview
The Stainless Steel Coil Tube (hereinafter referred to as "Coiltube"), product catalog number 1173, is a precision-engineered tubular component manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is specifically designed for integration into finite enclosed sandwich spaces where efficient convective and conductive heat transfer is required. The Coiltube is formed by winding seamless stainless steel tubing into a compact helical or spiral configuration, enabling a high surface-area-to-volume ratio within constrained spatial envelopes. This geometry is particularly advantageous in applications involving thermal exchange, fluid distribution, and controlled heat dissipation within layered or compartmentalized structures.
The design philosophy of this Coiltube is grounded in rigorous thermal-fluid dynamic analysis, incorporating validated heat transfer calculations and experimental research conducted on finite enclosed sandwich spaces with built-in heating coil configurations. The resulting product delivers predictable, uniform thermal performance under steady-state and transient operating conditions.
Material & Properties
The Coiltube is fabricated from high-grade austenitic stainless steel, selected for its superior combination of corrosion resistance, thermal conductivity, mechanical strength, and long-term dimensional stability under thermal cycling.
- Base Material: Austenitic Stainless Steel (e.g., SUS304 / AISI 304, SUS316L / AISI 316L, or equivalent grades per ASTM standards)
- Chemical Composition: Contains Chromium (Cr) ≥ 18% and Nickel (Ni) ≥ 8% to ensure robust passivation and resistance to oxidative and corrosive environments
- Thermal Conductivity: Approximately 14–16 W/(m·K) at ambient temperature, providing effective heat transfer performance
- Mechanical Properties: Tensile strength ≥ 520 MPa; yield strength ≥ 205 MPa; elongation ≥ 40%
- Operating Temperature Range: −196 °C to +870 °C (grade-dependent)
- Surface Finish: Polished or pickled and passivated, with surface roughness Ra ≤ 0.8 μm for reduced flow resistance
Specifications
| Parameter | Specification | Unit / Standard |
|---|---|---|
| Product Catalog No. | 1173 | — |
| Product Name | Coiltube (盘管) | — |
| Material Grade | SUS304 / SUS316L / Custom | ASTM A269 / ASTM A270 |
| Outer Diameter (OD) | 3.0 – 50.8 (Customizable) | mm |
| Wall Thickness | 0.3 – 3.0 | mm |
| Coil Inner Diameter | 50 – 500 | mm |
| Coil Height / Length | Custom (up to 2000) | mm |
| Coil Pitch | 1.5×OD – 3.0×OD | mm |
| Number of Turns | 5 – 500 (Customizable) | — |
| End Forming | Flanged, Threaded, Butt-Weld, or Plain | ASME B1.20.1 |
| Surface Treatment | Pickled & Passivated / Mirror Polished | ASTM A967 |
| Pressure Rating | Up to 4.0 | MPa (Design Pressure) |
| Manufacturing Standard | ASTM A269 / EN 10217 / GB/T 12771 | — |
| Quality Certification | ISO 9001 / CE / PED / SGS | — |
Manufacturing Process
The production of the Stainless Steel Coiltube follows a multi-stage precision manufacturing workflow designed to ensure geometric accuracy, metallurgical integrity, and thermal performance consistency:
- Material Selection & Incoming Inspection: Raw seamless stainless steel tubes are sourced from certified suppliers and subjected to spectroscopic analysis (OES), dimensional verification, and hydrostatic pressure testing to confirm compliance with ASTM A269/A270 specifications.
- Tube Cutting & Deburring: Tubes are cut to precise lengths using automated plasma or laser cutting systems, followed by mechanical deburring to eliminate burrs and ensure clean end surfaces.
- End Forming: Ends are shaped according to the required connection method — flanging (per ASME B16.5), thread rolling, bevel preparation for butt welding, or plain finishing.
- Coiling / Winding: The straight tubes are wound into helical or spiral coil configurations using CNC-controlled coiling machines. The coil pitch, inner diameter, and number of turns are precisely controlled to meet design specifications. Spring-back compensation algorithms ensure dimensional accuracy after unloading.
- Heat Treatment (if applicable): Annealing may be performed at 1050–1150 °C followed by rapid quenching to restore full austenitic structure and relieve residual stresses introduced during cold coiling.
- Surface Treatment: Tubes undergo pickling and passivation (per ASTM A967) to remove scale and form a protective chromium oxide layer. Mirror polishing (Ra ≤ 0.4 μm) is available for hygienic or high-flow applications.
- Quality Control & Testing: Each batch undergoes dimensional inspection (calipers, micrometers, coordinate measuring machine), visual inspection, eddy current testing for wall thickness uniformity, and hydrostatic pressure testing at 1.5× design pressure for a minimum hold time of 30 minutes.
- Packaging & Dispatch: Coiltubes are wrapped in moisture-proof protective film, placed in wooden crates or custom fixtures, and shipped with full material traceability documentation (MTR/EN 10204 3.1 Certificate).
Applications
The Stainless Steel Coiltube is engineered for demanding applications where compact thermal exchange geometry and material durability are critical:
- Heat Exchangers & Thermal Management Systems: Ideal for integration into sandwich-panel heat exchangers, air-to-water heat exchangers, and plate-and-fin heat exchanger assemblies where high surface-area density is required within constrained spaces.
- Refrigeration & HVAC Systems: Used as evaporator coils, condenser coils, and defrost heating coils in commercial refrigeration units, heat pumps, and industrial HVAC equipment.
- Chemical & Pharmaceutical Processing: Deployed in reactor jacket heating/cooling systems, distillation columns, and sanitary process piping where corrosion resistance and cleanability are paramount.
- Food & Beverage Industry: Applied in pasteurization systems, CIP (Clean-In-Place) heating loops, and fermentation temperature control systems compliant with FDA and 3-A sanitary standards.
- Automotive & Aerospace: Utilized in engine coolant loops, aftercooler assemblies, and thermal regulation systems where lightweight, high-performance coil geometries are essential.
- Power Generation: Employed in steam generator coils, economizer tubes, and waste heat recovery systems within boiler and turbine installations.
- Enclosed Sandwich Space Heating: Specifically designed for finite enclosed sandwich spaces where built-in heating coils provide uniform temperature distribution across layered composite structures, as validated through computational and experimental heat transfer research.
Unique Selling Points
Research-Validated Thermal Performance: The design of this Coiltube is informed by peer-reviewed computational fluid dynamics (CFD) analysis and experimental validation of heat transfer characteristics within finite enclosed sandwich spaces. This ensures that thermal output, temperature uniformity, and flow distribution are predictably optimized for real-world operating conditions.
- High Surface-Area-to-Volume Ratio: The helical coil geometry maximizes heat exchange surface within minimal envelope volume, enabling compact system designs without compromising thermal capacity.
- Full Customization Capability: All critical dimensions — outer diameter, wall thickness, coil pitch, number of turns, coil inner diameter, and end forming — are customizable to match specific application requirements and spatial constraints.
- Premium Material Grades: Available in SUS304, SUS316L, and other austenitic grades to address diverse corrosion environments, including chloride-rich, acidic, and high-temperature service conditions.
- Dimensional Precision: CNC-controlled coiling with spring-back compensation ensures repeatable geometric accuracy, critical for drop-in integration into pre-designed housing assemblies.
- Comprehensive Quality Assurance: Every production lot is backed by a full material test report (MTR), dimensional certificates, and pressure test documentation, ensuring full traceability and compliance with international standards.
- Established Manufacturing Heritage: Wenzhou Jixing Metal Materials Co., Ltd. leverages extensive expertise in stainless steel tube and coil fabrication, combining advanced manufacturing equipment with rigorous quality management systems.
Quality Certifications
The manufacturing and quality management systems of Wenzhou Jixing Metal Materials Co., Ltd. are certified to the following international standards, ensuring product reliability, regulatory compliance, and customer confidence:
- ISO 9001:2015 — Quality Management Systems
- ISO 14001 — Environmental Management Systems
- CE Marking — European Conformity, including compliance with the Pressure Equipment Directive (PED 2014/68/EU) where applicable
- SGS Testing — Independent third-party material and dimensional verification
- EN 10204 Type 3.1 — Material Test Report certification
- ASTM Compliance — Product conformity to ASTM A269, ASTM A270, ASTM A967, and ASME B16.5
- GB/T Compliance — National standard compliance per GB/T 12771 (Stainless Steel Seamless Tubes for Fluid Transport)
Technical Notes
When integrating the Coiltube into finite enclosed sandwich space assemblies, the following engineering considerations should be addressed:
- Thermal Expansion: The coefficient of thermal expansion for austenitic stainless steel (approximately 16–17 × 10⁻⁶ /°C) must be accommodated in the assembly design to prevent stress accumulation during thermal cycling.
- Flow Distribution: The coil pitch and number of turns should be optimized to ensure uniform fluid distribution and minimize bypass flow, maximizing convective heat transfer coefficient (h) within the sandwich cavity.
- Insulation Interface: The Coiltube surface should be properly interfaced with thermal insulation materials to minimize parasitic heat losses and maintain target temperature gradients across the sandwich layers.
- Weld Integrity: Where the Coiltube is welded into a housing or manifold, weld procedures must follow qualified Welding Procedure Specifications (WPS) with appropriate filler metals (e.g., ER308L, ER316L) to maintain corrosion resistance at weld joints.