Stainless Steel Coil Tube — Model JT-274 Series
Product Overview
The JT-274 Series Stainless Steel Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd., is a precision-engineered coiled tubular product designed for advanced thermal management and heat recovery applications. Drawing upon rigorous experimental and numerical research methodologies—specifically informed by three-coil liquid circulation heat recovery system studies—this product line delivers exceptional thermal efficiency, mechanical durability, and long-term operational reliability in demanding industrial environments.
Coil tubes (Coiltube) represent a critical component class in heat exchanger design, where the helical geometry provides a high surface-area-to-volume ratio, compact footprint, and enhanced convective heat transfer characteristics. The JT-274 series is engineered to leverage these geometric advantages while incorporating premium austenitic stainless steel grades to withstand aggressive chemical environments, high operating temperatures, and cyclic thermal loading.
Material & Properties
The JT-274 coil tubes are fabricated from high-grade austenitic stainless steel, selected for superior corrosion resistance, thermal conductivity, and mechanical strength across a wide temperature range. The primary material grades include:
- SUS304 (AISI 304 / 1.4301): General-purpose austenitic stainless steel with excellent corrosion resistance, weldability, and formability. Suitable for most industrial and food-grade applications.
- SUS316L (AISI 316L / 1.4404): Enhanced molybdenum-bearing grade offering superior resistance to pitting and crevice corrosion, particularly in chlorinated and acidic environments.
- SUS321 (AISI 321 / 1.4541): Titanium-stabilized grade providing excellent resistance to intergranular corrosion at elevated temperatures (up to 870°C).
- SUS310S (AISI 310S / 1.4845): High-temperature grade suitable for sustained operation up to 1150°C, ideal for furnace and high-heat-recovery applications.
Key material properties include:
- Density: 7.90–8.00 g/cm³
- Thermal Conductivity: 14–16 W/(m·K) at 20°C
- Thermal Expansion Coefficient: 16–18 × 10⁻⁶ /°C (20–100°C)
- Yield Strength: 205–310 MPa (annealed condition)
- Tensile Strength: 515–720 MPa
- Operating Temperature Range: −196°C to 1150°C (grade-dependent)
Specifications
| Parameter | Specification | Unit |
|---|---|---|
| Product Model | JT-274 Series | — |
| Tube Outer Diameter (OD) | 6.0 – 32.0 (customizable) | mm |
| Wall Thickness | 0.5 – 3.0 (customizable) | mm |
| Coil Diameter (Helical) | 50 – 500 | mm |
| Coil Pitch | 10 – 80 | mm |
| Number of Coils | 1 – 10 (configurable) | — |
| Total Tube Length | 1 – 100 | m |
| Surface Finish | Ba & Pe (Bright Annealed & Pickled) / No. 4 / Mirror | — |
| End Treatment | Beveled / Plain / Threaded / Fitted | — |
| Tolerance (OD) | ±0.05 – ±0.20 | mm |
| Tolerance (Wall) | ±10% of nominal | — |
| Material Grade | SUS304 / SUS316L / SUS321 / SUS310S | — |
| Standard Reference | ASTM A269 / ASTM A270 / GB/T 12771 / EN 10217 | — |
Manufacturing Process
The production of JT-274 coil tubes follows a multi-stage, precision-controlled manufacturing workflow to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection & Inspection: Certified stainless steel seamless or welded pipe stock is sourced from approved mills. Incoming material undergoes spectroscopic analysis (PMI — Positive Material Identification), dimensional verification, and visual inspection for surface defects.
- Tube Straightening & Cutting: Pipe stock is precision-straightened and cut to specified lengths using CNC-controlled saws to achieve tight dimensional tolerances.
- Coiling / Forming: The straight tubes are fed into a hydraulic or mechanical coil-forming machine, which bends the tube into the designated helical geometry. The forming process is carefully controlled to prevent wall thinning, ovality, or stress concentration at the bends. Minimum bend radius is maintained at 3× the tube OD to preserve structural integrity.
- Heat Treatment (if required): For applications requiring stress relief or solution annealing, coil tubes may undergo controlled furnace treatment at temperatures between 1010–1150°C, followed by controlled cooling to optimize microstructure and relieve residual forming stresses.
- Pickling & Passivation: The formed coil tubes undergo acid pickling (typically HNO₃/HF blend) to remove oxide scale, followed by passivation treatment to restore the passive chromium oxide layer, ensuring optimal corrosion resistance.
- Surface Finishing: Depending on the application, the surface may be polished to a No. 4 finish, mirror finish (Ra ≤ 0.1 μm), or left in a BA&P condition. Electropolishing is available for ultra-clean, low-particulate applications.
- Quality Control & Testing: Every batch undergoes rigorous inspection including:
- Dimensional measurement (OD, wall thickness, coil diameter, pitch) using calipers, micrometers, and coordinate measuring machines (CMM)
- Chemical composition verification via optical emission spectroscopy (OES)
- Pressure testing at 1.5× the design pressure to verify leak-tightness
- Corrosion testing (salt spray test per ASTM B117, acid resistance testing)
- Visual and ultrasonic inspection for internal and external defects
- Packaging & Shipping: Finished coil tubes are packaged in protective wooden crates or export-grade steel containers with moisture-absorbing desiccants to prevent corrosion during transit.
Applications
The JT-274 Series Coil Tubes are designed for a broad spectrum of industrial, commercial, and specialized applications:
- Heat Recovery Systems: Primary application domain. The helical coil geometry enables efficient heat exchange between working fluids in liquid circulation heat recovery systems, recovering waste thermal energy from industrial processes, exhaust gases, and combustion systems. Research on three-coil liquid circulation configurations demonstrates that multi-coil arrangements can achieve thermal efficiency improvements of 15–30% over single-coil designs.
- Heat Exchangers: Air-cooled condensers, evaporators, and shell-and-coil heat exchangers in chemical, petrochemical, and power generation industries.
- Refrigeration & HVAC Systems: Evaporator and condenser coils for industrial refrigeration, chiller units, and commercial air conditioning systems.
- Food & Beverage Processing: Sanitary-grade coil tubes for pasteurization, sterilization, and thermal processing equipment, meeting FDA and 3-A Sanitary Standards.
- Pharmaceutical Equipment: GMP-compliant coil assemblies for reaction vessels, condensers, and heat transfer loops in pharmaceutical manufacturing.
- Geothermal Energy Systems: Heat exchanger coils for geothermal heat pump systems and direct-use geothermal applications.
- Automotive & Aerospace: Fuel lines, hydraulic lines, and thermal management coils requiring high-pressure resistance and fatigue durability.
- Solar Thermal Systems: Heat collection coils for concentrated solar power (CSP) and solar thermal water heating systems.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework to ensure product excellence and regulatory compliance:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ISO 45001:2018 — Occupational Health & Safety Management System
- CE Marking — Conformity with European Union directives for pressure equipment and mechanical products
- EN 10204 3.1 — Material Test Certificate (MTC) provided with each shipment
- ASTM A269 / ASTM A270 — Compliance with American Society for Testing and Materials standards for seamless and welded austenitic stainless steel tubing
- GB/T 12771 — Chinese national standard for welded stainless steel tubes
- ASME B31.3 / B31.5 — Compliance with piping code standards for process and refrigeration piping
- NSF/ANSI 61 — Drinking water system components certification (available upon request)
Unique Selling Points
The JT-274 Series differentiates itself in the competitive stainless steel coil tube market through several key value propositions:
- Research-Driven Design: Informed by experimental and numerical simulation studies of multi-coil liquid circulation heat recovery systems, the JT-274 coil geometry is optimized for maximum thermal performance with minimized pressure drop, validated through computational fluid dynamics (CFD) modeling.
- Customizable Multi-Coil Configurations: From single-coil to triple-coil arrangements, customers can specify the number of coils, coil diameter, pitch, and total length to match exact application requirements. This flexibility enables system-level thermal optimization.
- Wide Material Grade Range: Availability across four primary stainless steel grades (SUS304, SUS316L, SUS321, SUS310S) ensures the correct material selection for any operating environment, from cryogenic to ultra-high-temperature applications.
- Precision Forming Capability: Advanced hydraulic coil-forming equipment ensures tight dimensional tolerances (±0.05 mm on OD), minimal wall thinning at bends (<5%), and consistent helical geometry throughout the coil length.
- End-to-End Quality Assurance: From raw material spectroscopic verification through final pressure testing and corrosion testing, every production stage is documented and traceable, with full material certification (EN 10204 3.1) provided.
- Competitive Lead Times: Standard configurations available with 7–15 day lead times; custom configurations delivered within 20–30 days, supported by an efficient supply chain and flexible production scheduling.
- Cost-Effective Solutions: Direct-from-manufacturer pricing eliminates intermediary markups, providing competitive cost structures without compromising on material quality or manufacturing precision.
Technical Support & Consultation
Wenzhou Jixing Metal Materials Co., Ltd. offers comprehensive technical support services including:
- Application-specific coil geometry design and thermal performance simulation
- Material selection guidance based on operating conditions (temperature, pressure, chemical exposure)
- Custom engineering drawings and dimensional specifications
- On-site installation guidance and system integration support
- Post-sale technical consultation and quality feedback loop
Wenzhou Jixing Metal Materials Co., Ltd. — Delivering precision-engineered stainless steel coil solutions with scientific rigor and industrial reliability.