Stainless Steel Coil Tube (盘管) — Coiled Heat Exchanger Tube
Product Overview
The Stainless Steel Coil Tube (盘管, Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered coiled tubular product designed for thermal exchange, fluid transfer, and process heating/cooling applications. Unlike conventional straight pipe assemblies, the coil tube configuration maximizes heat transfer surface area within a compact spatial footprint, making it an ideal solution for stirred tank reactors (STR), chemical processing vessels, and industrial heating systems.
Based on advanced numerical analysis of flow and heat transfer characteristics within stirred tanks under varying coil tube geometries, the product has been optimized for enhanced thermal performance, uniform fluid distribution, and mechanical durability under dynamic mixing conditions.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, ensuring superior corrosion resistance, mechanical strength, and long-term operational reliability across a wide range of chemical and thermal environments.
- Primary Grades: SUS304 (ASTM 304), SUS316L (ASTM 316L), SUS321 (ASTM 321), SUS316Ti
- Corrosion Resistance: Excellent resistance to acids, alkalis, chlorides, and organic solvents; pitting resistance equivalent number (PREN) ≥ 24 for 316L grade
- Mechanical Properties: Tensile strength ≥ 520 MPa; yield strength ≥ 205 MPa; elongation ≥ 40%
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 20°C
- Operating Temperature Range: −196°C to +870°C (grade-dependent)
- Surface Finish: Electropolished (Ra ≤ 0.4 µm), BA (Bright Annealed, Ra ≤ 0.8 µm), or 2B mill finish
- Hygienic Compliance: Suitable for pharmaceutical and food-grade applications (FDA 21 CFR compliant)
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | Φ12 mm – Φ89 mm (customizable) |
| Wall Thickness (WT) | 0.5 mm – 3.0 mm |
| Coil Diameter (CD) | Φ100 mm – Φ2000 mm |
| Coil Length | Up to 500 m per coil (continuous) |
| Coil Pitch | 1.2× OD – 3.0× OD (adjustable for flow optimization) |
| End Connection | Welded fittings (TIG welded), flanged, threaded, or sanitary tri-clamp |
| Maximum Working Pressure | Up to 1.6 MPa (standard); 4.0 MPa (reinforced) |
| Dimensional Tolerance | OD: ±0.05 mm; WT: ±10%; Coil diameter: ±1% |
| Welding Quality | 100% radiographic inspection (RT) or dye penetrant testing (PT) |
| Surface Roughness | Ra 0.4 µm (electropolished) / Ra 0.8 µm (BA) |
| Standard References | ASTM A269, ASTM A270, GB/T 12771, EN 10217-7 |
Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous, multi-stage manufacturing workflow to ensure dimensional accuracy, structural integrity, and surface quality:
- Raw Material Selection: Cold-rolled stainless steel strip or seamless tube from certified mills, verified by mill test certificates (MTC) in accordance with EN 10204 3.1.
- Coil Forming: Precision spiral coiling using CNC-controlled rolling equipment with real-time diameter monitoring to maintain tight tolerance (±1% of nominal coil diameter).
- Welding: Continuous longitudinal or spiral seam welding via TIG (Tungsten Inert Gas, ISO 14175) process with argon shielding; weld seams are ground and polished to flush with the tube surface.
- Heat Treatment: Solution annealing at 1050–1150°C followed by controlled air or water quenching to restore full austenitic microstructure and eliminate residual stresses.
- Surface Finishing: Mechanical polishing (600–1200 grit) followed by electrochemical polishing (electropolishing) to achieve Ra ≤ 0.4 µm and remove surface contamination.
- Quality Inspection: Hydrostatic pressure testing (1.5× working pressure, 30-second hold), dimensional gauging, surface roughness measurement, and visual inspection of all welds.
- Final Packaging: Protective end caps, moisture-absorbent packaging, and wooden crate or pallet shipment with desiccant protection.
Applications
Primary Application Domains
- Stirred Tank Reactors (STR): Immersed coil heat exchangers for precise temperature control during chemical reactions, polymerization, and fermentation processes. Numerical studies confirm that optimized coil geometry (pitch, diameter, and winding pattern) significantly improves heat transfer coefficient (h) by 15–30% compared to jacketed designs.
- Chemical Processing: Heating and cooling of corrosive fluids including sulfuric acid, hydrochloric acid, and caustic soda solutions in the petrochemical and fine chemical industries.
- Pharmaceutical Industry: GMP-compliant heat exchange for drug synthesis, sterilization (SIP), and clean-in-place (CIP) systems with electropolished surfaces preventing microbial adhesion.
- Food & Beverage Processing: Pasteurization, pasteurization of milk, juice, and dairy products; compliant with FDA and 3-A Sanitary Standards.
- Oil & Gas: Subsea umbilical coiled tubing, cryogenic process piping for LNG (Liquefied Natural Gas) handling at temperatures as low as −196°C.
- Power Generation: Condenser tubes and economizer coils in thermal power plants; superheater elements in biomass and waste-to-energy systems.
- Heat Pump & HVAC Systems: Evaporator and condenser coils for industrial refrigeration and large-scale air conditioning.
Unique Selling Points
1. Numerically Optimized Geometry: Coil dimensions are informed by CFD (Computational Fluid Dynamics) analysis of flow patterns within stirred tanks, ensuring laminar-to-turbulent transition is managed to maximize heat transfer efficiency while minimizing pressure drop.
2. Seamless & Welded Configurations: Available in both seamless (ASTM A269) and welded (ASTM A270) variants, offering flexibility in cost, pressure rating, and application requirements.
3. Hygienic-Grade Surface Finish: Electropolished surfaces with Ra ≤ 0.4 µm meet the most stringent pharmaceutical and food industry requirements, eliminating dead-leg zones and biofilm formation.
4. Custom Engineering: Full customization of coil diameter, pitch, tube OD/WT, end fittings, and special alloys to meet specific process conditions and vessel geometry.
5. Extended Service Life: Austenitic stainless steel matrix provides fatigue resistance under cyclic thermal loading and mechanical vibration from agitators, with a design life exceeding 20 years.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring traceability, compliance, and product excellence:
| Certification / Standard | Description |
|---|---|
| ISO 9001:2015 | Quality Management System certification covering manufacturing, inspection, and documentation processes |
| ISO 14001:2015 | Environmental Management System ensuring sustainable production practices |
| ASME BPV Code | Pressure vessel and piping component compliance (Section IX for welding qualifications) |
| PED 2014/68/EU | European Pressure Equipment Directive compliance for categories II–IV |
| EN 10204 3.1 | Material Test Certificate (MTC) issued for every production batch with full chemical and mechanical analysis |
| 3-A Sanitary Standards | Food equipment design and construction certification for dairy, beverage, and food processing |
| FDA 21 CFR 184 | Food contact material compliance for stainless steel in food processing applications |
| NORSOK M-650 | Material requirements for offshore oil and gas applications (for relevant grades) |
| CE Marking | Conformity with European health, safety, and environmental protection standards |
Conclusion
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. represents a synergistic integration of metallurgical excellence, precision manufacturing, and process-engineering-driven design optimization. Backed by rigorous numerical analysis of fluid dynamics and heat transfer within stirred tank configurations, this product delivers superior thermal performance, mechanical reliability, and hygienic integrity across the most demanding industrial applications. With full traceability from raw material mill certificates through final product inspection, customers benefit from a certified quality chain that ensures consistent performance and regulatory compliance worldwide.