Polytetrafluoroethylene (PTFE) Stainless Steel Coil Tube — Condenser Application Series
Product Overview
The PTFE-coated stainless steel coil tube is a high-performance heat exchange component manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product combines the mechanical strength and structural integrity of austenitic stainless steel with the exceptional chemical inertness and thermal stability of Polytetrafluoroethylene (PTFE, also known as Teflon). Designed primarily for condenser applications in chemical processing, pharmaceutical manufacturing, and food-grade fluid handling systems, this coil tube delivers superior resistance to corrosion, thermal cycling, and aggressive media environments where conventional heat exchangers fail prematurely.
The coil tube geometry maximizes surface-area-to-volume ratio, enabling efficient heat transfer in compact installations. The PTFE lining provides a non-stick, non-reactive inner surface that prevents fouling and product contamination, making it particularly suitable for processing viscous, corrosive, or thermally sensitive fluids.
Material & Properties
Base Material — Stainless Steel
- Grade: SUS304 / SUS316L (ASTM A270 / ASTM A269)
- Carbon Equivalent (CE): ≤ 0.04% (SUS316L) / ≤ 0.08% (SUS304)
- Chromium (Cr): 18–20% (SUS304) / 16–18% (SUS316L)
- Nickel (Ni): 8–10.5% (SUS304) / 10–14% (SUS316L)
- Molybdenum (Mo): 2–3% (SUS316L only)
- Tensile Strength: ≥ 515 MPa (SUS304) / ≥ 485 MPa (SUS316L)
- Elongation: ≥ 40% (minimum)
- Operating Temperature Range: −196°C to +870°C (base steel)
PTFE Lining Layer
- Material: Virgin Polytetrafluoroethylene (PTFE)
- Coating Thickness: 0.2 mm – 0.8 mm (adjustable per application)
- Service Temperature: −200°C to +260°C
- Chemical Resistance: Resistant to all known chemicals including concentrated sulfuric acid, hydrochloric acid, hydrofluoric acid, aqua regia, and organic solvents
- Friction Coefficient: 0.04 – 0.10 (lowest among engineering materials)
- Dielectric Strength: 20 – 60 kV/mm
- Water Absorption: < 0.01% (non-hygroscopic)
- Thermal Conductivity: 0.25 W/(m·K)
Specifications
| Parameter | Specification |
|---|---|
| Inner Diameter (ID) | Φ6 mm – Φ50 mm (standard); custom sizes available |
| Outer Diameter (OD) | Φ8 mm – Φ63.5 mm |
| Wall Thickness | 0.5 mm – 3.0 mm |
| Coil Diameter | Φ100 mm – Φ1500 mm |
| Coil Length (per coil) | 1 m – 50 m (customizable) |
| PTFE Coating Thickness | 0.2 mm – 0.8 mm |
| Surface Finish (base steel) | 2B / BA / No.4 brushed / Custom Ra ≤ 0.8 μm |
| Surface Finish (PTFE) | Glossy smooth, Ra ≤ 0.4 μm |
| Pressure Rating | Up to 2.5 MPa (design dependent) |
| End Treatment | Plain end / Threaded (BSP, NPT) / Flanged |
| Manufacturing Standard | ASTM A270 / ASTM A269 / GB/T 14976 / EN 10217 |
| PTFE Coating Standard | ASTM D1486 / ISO 15000 |
Manufacturing Process
- Material Selection & Inspection: Cold-rolled stainless steel strip (SUS304/SUS316L) is sourced from certified mills and subjected to spectroscopic analysis (OES) and mechanical testing to verify chemical composition and tensile properties.
- Pipe Forming: High-precision spiral or straight-seam welding is performed using TIG (Tungsten Inert Gas) welding with 99.99% argon shielding gas to ensure a clean, defect-free weld seam. Alternatively, seamless pipe is used for higher-pressure applications.
- Coil Winding: The formed pipe is wound into a precise helical coil using CNC-controlled winding machinery, ensuring uniform pitch and consistent coil diameter with tolerances within ±0.5 mm.
- Surface Preparation: The exterior surface undergoes mechanical cleaning (shot blasting or polishing), followed by chemical degreasing and acid pickling to remove mill scale and contaminants, achieving a clean substrate for PTFE adhesion.
- PTFE Coating Application: A suspension-grade PTFE slurry is applied via fluidized bed coating or electrostatic spray method. The coated coil tube is then sintered in a controlled atmosphere furnace at 380°C – 420°C for 30 – 90 minutes, transforming the PTFE from a powder/suspension into a continuous, bonded film.
- Quality Inspection: Each unit undergoes 100% visual inspection, coating thickness measurement (eddy current or magnetic induction method), hydrostatic pressure testing, and adhesion testing (cross-cut method per ASTM D3359).
- Final Assembly & Packaging: End fittings are installed, dimensional verification is performed, and the product is packaged in protective wrapping with accompanying material test certificates.
Applications
- Chemical Processing: Condensers for handling fluorinated compounds, chlorinated solvents, and strong mineral acids where conventional heat exchangers suffer rapid corrosion.
- Pharmaceutical Manufacturing: Closed-loop condensation systems for solvent recovery and distillation of active pharmaceutical ingredients (APIs) requiring GMP-compliant, non-contaminating surfaces.
- Food & Beverage Industry: Pasteurization condensers, juice concentration systems, and alcohol distillation equipment requiring hygienic-grade, non-adhesive surfaces.
- Petrochemical Sector: Refinery overhead condensers and distillation column reflux systems exposed to hydrogen sulfide and chloride environments.
- Electronics & Semiconductor: Ultra-pure chemical delivery systems and wafer cleaning condensers requiring zero-metallic-ion contamination.
- Laboratory & Pilot Plants: Custom coil condensers for research reactors, pilot-scale distillation, and specialty chemical synthesis.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System
- ISO 22000 / HACCP — Food Safety Management (for food-grade applications)
- CE Marking — European Conformity for pressure equipment (PED 2014/68/EU)
- ASME Stamp — Available for pressure vessel components
- Material Test Report (MTR): Mill certificate (EN 10204 3.1) provided with every shipment, including chemical analysis, mechanical test results, and heat number traceability
- PTFE Coating Certification: Compliance with FDA 21 CFR 177.1550 (food contact) and EC 1935/2004 (EU food contact materials)
- NACE No. 0287 / ISO 9712 — Welding and NDT personnel certification
Unique Selling Points
1. Dual-Layer Protection Architecture: The combination of stainless steel structural backbone with PTFE functional lining provides a synergistic solution — mechanical durability from the steel substrate and chemical/thermal immunity from the PTFE layer.
2. Elimination of Fouling: The ultra-low surface energy of PTFE (18 mN/m) prevents deposition of polymers, salts, and organic residues, significantly reducing cleaning frequency and unplanned shutdowns.
3. Extended Service Life: In aggressive chemical environments, PTFE-lined coil condensers demonstrate 5–10× longer service life compared to unlined stainless steel equivalents, reducing total cost of ownership (TCO).
4. Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd. offers fully customizable coil geometry, diameter, length, coating thickness, and end configurations to match specific process requirements.
5. Regulatory Compliance: Full traceability from raw material to finished product with complete documentation packages meeting international regulatory and audit standards.
Technical Notes
During installation, care must be taken to avoid mechanical abrasion of the PTFE coating. Sharp-edged flanges, excessive bending, or impact loading can compromise coating integrity. Recommended support spacing for coil tubes is 1.0 – 1.5 m, with soft-material gaskets (PTFE or graphite) used at all flange connections. For thermal cycling applications exceeding 200 cycles between −50°C and +250°C, periodic adhesion testing is recommended to ensure long-term coating performance.