Stainless Steel Planar Coil Tube (Coiltube) — Wenzhou Jixing Metal Materials Co., Ltd
1. Product Overview
The Stainless Steel Planar Coil Tube (hereinafter referred to as "Coiltube") is a precision-engineered heat exchanger component manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is designed in a planar (flat) coil configuration, which distinguishes it from conventional helical or spiral coil tubes. The planar geometry enables superior heat transfer efficiency per unit surface area, compact installation footprint, and enhanced fluid distribution uniformity — characteristics extensively validated in experimental research on heat transfer characteristics of planar coil tubes under varying coiling configurations.
Coiltubes are widely deployed in industrial heat exchange systems where efficient thermal management is critical. The product leverages the inherent corrosion resistance, mechanical strength, and hygienic surface properties of stainless steel, making it suitable for demanding applications across chemical processing, pharmaceutical manufacturing, food and beverage production, HVAC systems, and energy sector operations.
2. Material & Properties
Coiltubes are fabricated from high-grade austenitic stainless steel, ensuring exceptional resistance to oxidation, pitting, and crevice corrosion under aggressive thermal and chemical environments.
- Primary Grades: AISI 304 (UNS S30400), AISI 316L (UNS S31603), AISI 321 (UNS S32100), and custom alloy compositions available upon request.
- Key Mechanical Properties: Tensile strength ≥ 520 MPa (0.2% proof stress ≥ 205 MPa for 304 grade); elongation ≥ 40%; excellent cold-formability and weldability.
- Thermal Properties: Thermal conductivity 14–16 W/(m·K) at 25°C; coefficient of thermal expansion approximately 17.3 × 10⁻⁶ /°C.
- Corrosion Resistance: Chromium content ≥ 18%, providing a stable passive oxide film; 316L grade additionally contains Ni ≥ 10% and Mo ≥ 2% for superior chloride resistance.
- Surface Finish: Electropolished (Ra ≤ 0.5 μm), passivated, or available in 2B / BA finish per customer specification.
3. Technical Specifications
| Parameter | Specification |
|---|---|
| Product Type | Planar Coil Tube (Flat Coil / Meander Coil) |
| Material Grade | SUS304, SUS316L, SUS321, 310S, Custom |
| Tube Outer Diameter (OD) | Φ3.0 mm – Φ50.8 mm (1/8" – 2") |
| Tube Wall Thickness | 0.3 mm – 3.0 mm |
| Coil Pitch (Center-to-Center Spacing) | 5 mm – 50 mm (configurable) |
| Coil Width / Planar Dimensions | Custom; typical range 100 mm – 2000 mm per axis |
| Number of Turns / Passes | 2 – 200+ (application-dependent) |
| Operating Temperature Range | −196°C to +870°C (grade-dependent) |
| Operating Pressure | Up to 4.0 MPa (design pressure, custom up to 10 MPa) |
| Connection Type | Flanged, Threaded (BSPP/BSPT/NPT), Welded, Tri-Clamp, Quick-Disconnect |
| Surface Treatment | Electropolishing, Passivation, Pickling, PVD Coating |
| Applicable Standards | ASTM A269/A270, GB/T 12771, EN 10217-7, JIS G3459 |
4. Manufacturing Process
The manufacturing of planar Coiltubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous multi-stage process to ensure dimensional accuracy, mechanical integrity, and surface quality:
- Material Selection & Inspection: Stainless steel seamless or welded tube stock is procured from certified mills, subjected to spectral analysis (PMI), hydrostatic testing, and dimensional verification.
- Tube Straightening & Cutting: Incoming tube is straightened to eliminate residual curvature and cut to required coil lengths with precision shearing or cold sawing.
- Planar Coiling / Forming: Tubes are cold-formed into planar (meander) configurations using CNC-controlled bending machinery. The bending radius is carefully controlled (typically R ≥ 3D) to prevent wall thinning, ovality distortion, and stress concentration. Different coiling patterns (serpentine, parallel-pass, multi-layer) are selected based on thermal performance requirements.
- Heat Treatment (Stress Relief): Annealing at 1050°C – 1150°C with controlled cooling to relieve cold-work stresses, restore full grain structure, and maximize corrosion resistance and ductility.
- Surface Finishing: Electropolishing removes surface contamination and creates a smooth, hygienic surface; chemical passivation forms a uniform chromium oxide layer for enhanced corrosion protection.
- End Processing & Connection Fabrication: Flanges are welded, threaded fittings are machined, or sanitary fittings are assembled at inlet/outlet ports.
- Quality Inspection & Testing: Dimensional verification (CMM or laser scanning), pressure testing (hydrostatic at 1.5× design pressure), leak testing (helium or bubble), and visual inspection per ASME/ISO standards.
5. Applications
Planar Coiltubes find extensive application in industries requiring compact, high-efficiency heat exchange solutions:
- Chemical Processing: Reactor cooling jackets, heat exchangers for corrosive media, distillation column internals.
- Pharmaceutical & Biotech: Sterile heat exchangers for CIP/SIP systems, bioreactor temperature control, UHT processing equipment.
- Food & Beverage: Pasteurizers, condensers, evaporators, and hygienic fluid heating/cooling systems.
- HVAC & Refrigeration: Compact air-to-fluid heat exchangers, evaporator coils, condenser assemblies.
- Energy Sector: Solar thermal collectors, geothermal heat exchangers, hydrogen fuel cell cooling plates.
- Petrochemical & Oil/Gas: Crude oil preheating, refinery heat recovery systems, offshore platform fluid management.
- Power Generation: Boiler economizers, condensers, waste heat recovery units.
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system ensuring product traceability and regulatory compliance:
- ISO 9001:2015 — Quality Management System certification.
- ISO 14001:2015 — Environmental Management System.
- ASME "B" Stamp — Boiler and Pressure Vessel Code certification (where applicable).
- PED 2014/68/EU — European Pressure Equipment Directive compliance.
- CE Marking — Conformity with European health, safety, and environmental protection standards.
- 3-A Sanitary Standards — For food-grade applications.
- EHEDG — European Hygienic Engineering Design Group compliance for hygienic systems.
- NACE MR0175 — Resistance to sulfide stress cracking for oil and gas applications.
7. Unique Selling Points
Superior Planar Geometry: Unlike conventional helical coils, the planar (flat) configuration provides uniform fluid distribution across the heat transfer surface, minimizing flow maldistribution losses and maximizing the effective heat transfer coefficient. Experimental research has demonstrated that optimized planar coiling patterns can achieve heat transfer rates 15–30% higher than equivalent helical configurations under turbulent flow conditions.
Customizable Coiling Patterns: Multiple planar coiling configurations (single-pass serpentine, multi-pass parallel, double-layer offset, and hybrid designs) are available, allowing thermal engineers to tailor performance to specific process requirements.
Compact Footprint: The flat geometry enables installation in space-constrained environments, reducing overall equipment footprint by up to 40% compared to volumetric spiral coils of equivalent heat transfer capacity.
End-to-End Engineering Support: From thermal simulation and CFD modeling to custom fabrication and on-site commissioning, the company provides integrated engineering solutions.
8. Conclusion
The Stainless Steel Planar Coil Tube (Coiltube) from Wenzhou Jixing Metal Materials Co., Ltd represents a state-of-the-art heat exchange component combining advanced metallurgical properties with precision manufacturing. Its planar architecture, validated through rigorous experimental research on heat transfer characteristics under varying coiling methods, delivers superior thermal performance, corrosion resistance, and installation flexibility — making it an ideal solution for demanding industrial heat management applications worldwide.