Stainless Steel Coil Tube — Coiltube Series (Ref. No. 856)

1. Product Overview

The Stainless Steel Coil Tube (Coiltube) series, manufactured by Wenzhou Jixing Metal Materials Co., Ltd, represents a high-performance tubular product engineered for heat transfer applications in chemically aggressive and thermally demanding environments. These coil tubes are specifically designed for integration into exothermic reactor systems, where spatial arrangement optimization—validated through Computational Fluid Dynamics (CFD) simulation—ensures maximum thermal exchange efficiency and uniform temperature distribution.

Unlike conventional straight tubular heat exchangers, coil tubes leverage their helical geometry to enhance turbulent flow characteristics, thereby improving the Nusselt number (Nu) and overall heat transfer coefficient. This product line is particularly suited for applications involving strong exothermic reactions where precise thermal management is critical to process safety and product quality.

2. Material & Properties

2.1 Material Grades

2.2 Key Mechanical Properties (Annealed Condition)

Property 304 / 304L 316 / 316L 310S 2205 Duplex
Tensile Strength (MPa) ≥ 515 ≥ 515 ≥ 515 ≥ 450
Yield Strength (0.2% Offset, MPa) ≥ 205 ≥ 205 ≥ 205 ≥ 220
Elongation (%) ≥ 40 ≥ 40 ≥ 40 ≥ 25
Corrosion Resistance (Pitting, ASTM G48) Mild Good Excellent Excellent
Maximum Service Temperature (°C) 870 870 1150 320

2.3 Surface Finish Options

3. Technical Specifications

Parameter Specification Range Standard / Reference
Outer Diameter (OD) 6 mm – 159 mm (¼" – 6") ASTM A554 / GB/T 14976
Wall Thickness 0.5 mm – 12 mm (0.020" – 0.472") ASME B36.19M
Coil Winding Diameter 150 mm – 2000 mm Custom per application
Coil Length (per Spool) 5 m – 500 m As specified
Number of Coils / Turns 2 – 500 turns Per design requirement
Coil Pitch 1.5 × OD – 3.0 × OD CFD-optimized spacing
Tolerance on OD ±0.10 mm (OD < 25 mm); ±0.15 mm (OD ≥ 25 mm) ASTM A554
Tolerance on Wall Thickness ±10% of nominal ASTM A554
End Form Plain, Beveled (37°), Threaded (NPT/BSP) Per customer specification
Welding Quality 100% Helium Leak Test (≤ 1×10⁻⁷ Pa·m³/s) ISO 15497

3.1 Design Considerations — CFD-Optimized Spatial Arrangement

A distinguishing feature of this Coiltube product line is its integration with CFD-based reactor design optimization. Through numerical simulation of conjugate heat transfer (CHT) within exothermic reactor vessels, the spatial arrangement of coil bundles is optimized to achieve:

4. Manufacturing Process

4.1 Production Workflow

  1. Material Procurement: Seamless stainless steel tubes sourced from certified mills (e.g., Outokumpu, Sandvik, Taiyuan Steel), with full material traceability via Heat Number documentation.
  2. Dimensional Inspection: Incoming tubes verified for OD, wall thickness, and roundness using ultrasonic (UT) and laser profilometry systems.
  3. Tube Straightening & Cut-to-Length: Precision straightening followed by laser or saw cutting to specified coil loop lengths.
  4. Coil Winding: Automated CNC coil winding machines form the helical geometry with controlled pitch and winding diameter, ensuring consistent curvature without wall-thickness reduction below acceptable limits.
  5. Welding (if multi-loop coils): Orbital TIG (Tungsten Inert Gas) welding or automatic plasma welding with full-penetration butt joints; internal purge gas (Argon) maintained at ≥ 0.5 bar to prevent oxidation.
  6. Heat Treatment: Solution annealing at 1050°C – 1150°C followed by rapid water quench to restore full austenitic structure and maximize corrosion resistance.
  7. Pickling & Passivation: Immersion in nitric/hydrofluoric acid bath to remove mill scale and form a stable chromium oxide passive layer (≥ 1000 Å thickness).
  8. Final Inspection & Testing: Visual inspection, dimensional verification, hydrostatic pressure testing (1.5× working pressure), and optional eddy current (ET) or ultrasonic testing for weld integrity.
  9. Packaging: Coils secured with stainless steel bands, wrapped in VCI (Vapor Corrosion Inhibitor) film, and crated for transport.

4.2 Process Controls

5. Applications

5.1 Primary Application Domains

Industry Application Key Requirement
Chemical Processing Exothermic reactor cooling coils, distillation column condensers High heat transfer efficiency, corrosion resistance
Pharmaceutical Manufacturing Reactor jacket coils, crystallization vessel cooling Electropolished surface, GMP compliance
Petrochemical & Refining Crude oil heat exchangers, polymerization reactor coils High-temperature resistance, fouling resistance
Food & Beverage Milk pasteurization coils, juice heat exchangers Sanitary design, 3A/EHEDG compliance
Pulp & Paper Black liquor evaporator coils, digester heating Resistance to sulfuric acid and lignin fouling
Power Generation Nuclear-grade steam generator tubes, waste heat recovery High purity, nuclear qualification
Automotive & Aerospace Hydraulic system coils, fuel cooler tubes Precision tolerances, fatigue resistance

5.2 CFD-Optimized Reactor Coil Systems

In strongly exothermic chemical reactors—such as those used in polymerization, nitration, and hydrogenation processes—the Coiltube product is deployed as an integral heat removal system. CFD simulations guide the determination of optimal:

6. Quality Certifications & Compliance

6.1 Product Certifications

6.2 Testing & Inspection Certificates

6.3 Traceability & Documentation

Each Coiltube product is accompanied by a comprehensive Product Data Sheet (PDS) including: material certification, dimensional drawings, heat treatment records, welding logs, NDT reports, and dimensional inspection certificates. Full material traceability is maintained from raw steel coil through to finished product, ensuring complete supply chain accountability.

7. Unique Selling Points

  1. CFD-Validated Design: Spatial arrangement optimized through Computational Fluid Dynamics simulation, ensuring superior thermal performance in exothermic reactor applications compared to empirically designed alternatives.
  2. Wide Material Spectrum: Availability in standard austenitic, super-austenitic, and duplex grades accommodates the most aggressive chemical environments.
  3. Precision Manufacturing: CNC-controlled winding and orbital welding deliver geometric accuracy and joint integrity exceeding industry benchmarks.
  4. Full Traceability: End-to-end material and process documentation ensures compliance with the most stringent regulatory requirements (FDA, GMP, PED, ASME).
  5. Custom Engineering Support: Wenzhou Jixing Metal Materials provides integrated CFD-based design consultation, enabling customers to optimize reactor-coil systems prior to fabrication.

8. Ordering Information

To initiate an order or request a technical consultation, please provide the following parameters:

Wenzhou Jixing Metal Materials Co., Ltd — Precision Stainless Steel Tubular Solutions for Demanding Process Industries