Stainless Steel Coil Tube — Calorimeter & Heat Exchange Grade
Product Code: JX-CT-252 | Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The JX-CT-252 Stainless Steel Coil Tube is a precision-engineered continuous-coiled tubular product designed for high-performance heat exchange, refrigeration, and calorimetric applications. Manufactured in a continuous coil configuration, this product offers superior flexibility in downstream processing — including straightening, cutting, bending, and welding — while maintaining excellent mechanical integrity and thermal conductivity throughout the coil length.
This coil tube is specifically optimized for use in refrigeration systems employing R134a (1,1,1,2-Tetrafluoroethane) refrigerant, where it serves as the primary working medium conduit within evaporators, condensers, and calorimeters. The product has been developed with reference to advanced literature on the flow characteristics of R134a within coil geometries, incorporating structural optimizations that enhance heat transfer efficiency and reduce pressure drop under two-phase flow conditions.
2. Material & Properties
2.1 Base Alloy
- Primary Grade: AISI 304 / SUS 304 (18-8 Austenitic Stainless Steel)
- Alternative Grades Available: AISI 316L / SUS 316L, AISI 321 / SUS 321, Custom Alloy Compositions
- Chemical Composition (AISI 304): Cr 18.0–20.0%, Ni 8.0–10.5%, Mn ≤ 2.0%, Si ≤ 0.75%, S ≤ 0.030%, C ≤ 0.080%
2.2 Key Physical & Mechanical Properties
- Thermal Conductivity: 16.3 W/(m·K) at 20°C
- Density: 7,930 kg/m³
- Tensile Strength: ≥ 515 MPa (Annealed Condition)
- Yield Strength: ≥ 205 MPa
- Corrosion Resistance: Excellent resistance to pitting, crevice, and intergranular corrosion; suitable for chlorinated environments (316L grade)
- Operating Temperature Range: −196°C to +450°C
- Surface Finish: 2B, BA (Bright Annealed), or Custom Polish (Ra ≤ 0.4 μm available)
3. Technical Specifications
| Parameter | Specification | Tolerance | Standard Reference |
|---|---|---|---|
| Outer Diameter (OD) | 6.0 – 32.0 mm | ±0.10 mm | ASTM A213 / EN 10216-5 |
| Wall Thickness | 0.4 – 1.5 mm | ±0.05 mm | ASTM A213 / EN 10216-5 |
| Coil Inner Diameter (CID) | 300 – 1,000 mm | ±5 mm | Manufacturer Spec. |
| Coil Length (per spool) | 50 – 500 m (continuous) | — | Custom Order |
| End Condition | Plain / Beveled / Welded Cap | — | Customer Spec. |
| Pressure Rating (Test) | Up to 1.5 MPa (hydrostatic) | — | ASTM A213 |
| Maximum Working Pressure | 1.0 MPa (R134a service) | — | EN 1273 |
| Helix Diameter (if pre-coiled) | 15 – 100 mm | ±0.5 mm | Custom Order |
| Helix Pitch | 5 – 25 mm | ±0.3 mm | Custom Order |
| Surface Treatment | Pickled & Passivated / Electropolished | — | ASTM A967 |
| Refrigerant Compatibility | R134a, R410A, R22, R404A, Ammonia (NH₃) | — | ASHRAE 15 |
4. Manufacturing Process
The production of the JX-CT-252 Coil Tube follows a rigorous multi-stage manufacturing sequence designed to ensure dimensional precision, metallurgical homogeneity, and surface integrity:
- Hot-Rolled Strip Production: Stainless steel slabs are reheated to 1,150–1,200°C and hot-rolled into precision strip stock with controlled thickness and width tolerances.
- Pickle & Passivate: The hot-rolled strip undergoes acid pickling (HNO₃/HF blend) to remove scale and oxidation, followed by passivation to restore the protective chromium oxide layer.
- Cold Rolling & Annealing: The strip is cold-rolled to final thickness specifications, then solution-annealed at 1,050–1,100°C in a controlled-atmosphere furnace to relieve internal stresses and achieve the desired mechanical properties.
-
Tube Forming (Seamless or Welded):
- Seamless method: Strip is rolled into a tube via rotary piercing or capillary drawing.
- Welded method: Strip edges are formed and welded using Automatic Submerged Arc Welding (ASAW) or High-Frequency Resistance Welding (HFW), followed by internal/external wire brushing and re-annealing of the weld zone.
- Precision Sizing & Straightening: The formed tube passes through multi-roller sizing mills to achieve final OD and wall thickness within specified tolerances.
- Coiling: The finished tube is coiled onto a pay-off reel at controlled tension to prevent deformation, kinking, or ovality.
- Final Inspection & Testing: Each coil undergoes hydrostatic pressure testing, dimensional verification (OD, wall thickness, coil diameter), surface inspection, and chemical/spectrometric analysis.
5. Applications
5.1 Primary Applications
- Refrigeration & Air Conditioning Systems: Evaporator and condenser coil tubes for commercial refrigeration units, cold storage facilities, and HVAC systems using R134a or R410A refrigerants.
- Calorimeters & Heat Meters: Precise thermal energy measurement devices where R134a flow characteristics within the coil geometry directly influence measurement accuracy. The coil tube's internal smoothness and dimensional consistency are critical for laminar and transitional flow stability.
- Heat Exchangers: Shell-and-tube heat exchangers, plate-fin coils, and brazed aluminum heat exchangers (BAHX) for industrial process heating and cooling.
5.2 Secondary Applications
- Automotive air conditioning components (evaporator tubes, condenser tubes)
- Food and beverage processing equipment (pasteurization, CIP systems)
- Pharmaceutical and laboratory equipment (distillation coils, condensers)
- Solar thermal energy collectors
- Industrial fluid conveying systems requiring corrosion resistance
- Ornamental and architectural applications (handrails, decorative elements)
6. Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and product certifications to ensure compliance with international standards:
| Certification / Standard | Scope |
|---|---|
| ISO 9001:2015 | Quality Management System |
| ISO 14001:2015 | Environmental Management System |
| ISO/IEC 17025 | Testing & Calibration Laboratory Competence |
| CE Marking | European Conformity (Pressure Equipment Directive 2014/68/EU) |
| EN 10216-5 | Welded Circular Stainless Steel Tubes — Technical Delivery Conditions |
| ASTM A213 / A269 | Seamless & Welded Austenitic Stainless Steel Tubes |
| EN 1273 | Technical Specification for Refrigeration and Heat Pump Equipment |
| EN 10204-3.1 | Material Test Certificates (Inspection Reports) |
| SGS / BV Inspection | Third-Party Verification Available |
7. Unique Selling Points (USPs)
Literature-Driven Structural Optimization: The coil geometry and internal surface characteristics of the JX-CT-252 are informed by rigorous academic research on R134a two-phase flow dynamics within curved tube geometries. This includes optimization of helix diameter, pitch, and curvature ratio to minimize flow maldistribution, reduce pressure drop, and maximize heat transfer coefficients — resulting in measurable improvements in system COP (Coefficient of Performance) and calorimetric accuracy.
- Superior Internal Surface Quality: Electropolished interiors with Ra ≤ 0.4 μm reduce flow resistance and minimize refrigerant film degradation, enhancing heat transfer performance.
- Continuous Coil Supply: Eliminates field welding and joint failure points, reducing installation time by up to 40% compared to cut-length tube assemblies.
- Custom Coil Geometry: Pre-coiled helical configurations available with precise control over helix diameter, pitch, and number of turns to match specific heat exchanger designs.
- Full Traceability: Each coil is marked with heat number, lot code, and mill test report reference for complete supply chain traceability.
- Customization Capability: Wenzhou Jixing Metal Materials offers flexible customization of OD, wall thickness, coil diameter, surface finish, and end conditions to meet exact customer specifications.
8. Ordering Information
Customers are advised to specify the following parameters when placing orders:
- Material grade (e.g., 304, 316L, 321)
- Outer diameter and wall thickness (with tolerance requirements)
- Coil inner diameter and approximate coil length
- Surface finish requirements (2B, BA, electropolished)
- End condition (plain, beveled, capped)
- Intended application and refrigerant type (if applicable)
- Required certifications and inspection reports
For detailed technical data sheets, material certificates, and quotation requests, please contact Wenzhou Jixing Metal Materials Co., Ltd. directly.