Stainless Steel Coil Tube (Coiltube) for Clean Room & Purification Systems
Product Code: 356 | Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered continuous stainless steel tube wound into a compact coil configuration, specifically designed for integration into clean room engineering systems, air purification units, and HVAC ductwork assemblies. This product is engineered to meet the rigorous demands of ultra-clean environments where particle control, corrosion resistance, and hygienic performance are paramount.
Coiltube products from Wenzhou Jixing Metal Materials Co., Ltd. are manufactured in accordance with international standards governing clean room construction and pharmaceutical/semiconductor-grade air handling systems. The coil configuration enables efficient storage, transportation, and on-site deployment, significantly reducing installation time and labor costs compared to straight-length tube segments.
Key Distinction: Unlike conventional straight stainless steel tubing, coil tubes are manufactured through a continuous forming process that ensures uniform wall thickness, superior mechanical consistency, and reduced material waste—resulting in enhanced structural integrity for critical purification applications.
2. Material & Properties
2.1 Base Materials
Coiltube products are fabricated from high-grade austenitic stainless steel grades, selected to optimize corrosion resistance, thermal stability, and surface finish quality:
- SAE 304 (UNS S30400): General-purpose austenitic stainless steel with excellent corrosion resistance, suitable for most clean room and food-grade applications. Contains 18% Chromium (Cr) and 8% Nickel (Ni).
- SAE 316 (UNS S31600): Enhanced austenitic stainless steel with 2–3% Molybdenum (Mo) addition, providing superior resistance to pitting and crevice corrosion in aggressive chemical environments. Ideal for pharmaceutical and semiconductor clean room applications.
- SAE 321 (UNS S32100): Stabilized austenitic stainless steel with Titanium (Ti) stabilization, offering improved resistance to intergranular corrosion at elevated temperatures.
- SAE 316L (UNS S31603): Low-carbon variant of SAE 316 (Carbon ≤ 0.03%), providing enhanced weldability and resistance to sensitization in high-temperature service conditions.
2.2 Mechanical Properties
| Property | SAE 304 | SAE 316 | SAE 316L |
|---|---|---|---|
| Tensile Strength (MPa) | ≥ 515 | ≥ 515 | ≥ 485 |
| Yield Strength (0.2% offset, MPa) | ≥ 205 | ≥ 205 | ≥ 170 |
| Elongation (% in 50 mm) | ≥ 40 | ≥ 40 | ≥ 45 |
| Hardness (HB) | ≤ 217 | ≤ 217 | ≤ 217 |
| Density (g/cm³) | 8.0 | 8.0 | 8.0 |
2.3 Surface Finish Options
- No. 4 Finish: Brushed finish with visible grain lines; suitable for general clean room ductwork and visible piping.
- Mirror Polish (8K): High-lustre reflective finish; recommended for pharmaceutical-grade purification coil tubes where visual inspection and cleaning are critical.
- Electropolished (EP): Electrochemically polished surface with Ra ≤ 0.25 μm; eliminates micro-crevices and provides optimal sanitary performance for GMP-regulated environments.
- Pickled & Passivated: Chemical cleaning and passive film restoration; standard for industrial-grade coil tubes.
3. Specifications
| Parameter | Specification / Range | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | Φ6 mm – Φ108 mm | ASTM A554 / ASTM A269 |
| Wall Thickness | 0.3 mm – 3.0 mm | ASTM A554 / ASTM A269 |
| Coil Length (per coil) | 5 m – 50 m (customizable) | Manufacturer Specification |
| Coil Diameter (outer) | Φ300 mm – Φ1200 mm | Manufacturer Specification |
| Dimensional Tolerance (OD) | ± 0.1 mm to ± 0.5 mm (per request) | ASTM A554 |
| Dimensional Tolerance (Wall Thickness) | ± 0.05 mm to ± 0.15 mm | ASTM A269 |
| Surface Roughness (Ra) | 0.25 μm – 1.6 μm (depending on finish) | ASTM A269 / EN 10305 |
| Operating Temperature Range | −196 °C to +870 °C | Material-dependent |
| Pressure Rating | Up to 2.5 MPa (depending on OD & wall thickness) | ASME B31.3 |
| Welding Compatibility | TIG (GTAW), Orbital, Laser Welding | ASME B31.3 / EN 12164 |
3.1 Standard Dimensions — Common Coil Tube Sizes
| Designation | OD (mm) | Wall Thickness (mm) | Material Grade | Typical Application |
|---|---|---|---|---|
| CT-06x0.5 | 6.0 | 0.50 | 304 / 316L | Micro-filter housings, capillary tubes |
| CT-08x0.6 | 8.0 | 0.60 | 304 / 316L | HEPA pre-filter supports |
| CT-10x0.8 | 10.0 | 0.80 | 304 / 316 | Purification coil windings |
| CT-12x1.0 | 12.0 | 1.00 | 304 / 316 | Medium-pressure duct connectors |
| CT-16x1.2 | 16.0 | 1.20 | 304 / 316 | Clean room HVAC ductwork |
| CT-20x1.5 | 20.0 | 1.50 | 304 / 316 | Process piping, fluid transfer |
| CT-25x1.5 | 25.0 | 1.50 | 304 / 316L | Pharmaceutical process lines |
| CT-32x2.0 | 32.0 | 2.00 | 304 / 316 | Large-scale purification systems |
| CT-50x2.0 | 50.0 | 2.00 | 304 / 316 | Main ductwork, high-flow applications |
| CT-76x2.5 | 76.0 | 2.50 | 304 / 316 | Industrial ventilation systems |
4. Manufacturing Process
4.1 Production Workflow
- Raw Material Procurement: Certified stainless steel strip/coil sourced from approved mills with full mill test certificates (MTC) compliant with EN 10204 3.1 or equivalent.
- Coil Winding & Forming: Continuous cold-forming process using precision roll-forming dies to produce uniform tube geometry. The coiling process is executed at controlled speeds to prevent work hardening and maintain dimensional accuracy.
- Welding (if applicable): For welded coil tubes, longitudinal seams are formed using automatic TIG (Tungsten Inert Gas) welding or laser welding under inert gas shielding (Argon/He mixtures) to prevent oxidation.
- Heat Treatment: Solution annealing at 1050–1100 °C followed by controlled cooling to restore full austenitic microstructure and maximize corrosion resistance.
- Pickling & Passivation: Chemical treatment using nitric acid/hydrofluoric acid blend to remove mill scale and restore the passive chromium oxide film.
- Surface Finishing: Mechanical polishing, electrolytic polishing, or mirror polishing depending on the specified finish grade.
- Quality Inspection: Dimensional verification (OD, wall thickness, coil diameter), surface roughness measurement, hydrostatic pressure testing, and visual inspection.
- Packaging & Shipping: Coils are wrapped in protective film, placed in wooden crates or steel containers with desiccants to prevent moisture damage during transit.
4.2 Key Manufacturing Advantages
- Continuous Production: Eliminates butt welds present in straight-length tubing, reducing potential leak paths and contamination sources in clean room applications.
- Material Efficiency: Coil configuration minimizes cutting waste, with material utilization rates exceeding 95%.
- Uniform Microstructure: The continuous forming process ensures consistent grain structure throughout the coil length, providing reliable mechanical performance.
- Custom Coil Configuration: Coil diameter, length, and winding pattern can be tailored to specific installation requirements and equipment footprint constraints.
5. Applications
5.1 Clean Room & Purification Systems
- DCC (Direct Chemical Cleaning) Purification Coil Tubes: Used in ultra-clean air handling units (AHUs) for semiconductor fabrication facilities, where coil tubes serve as heat exchange elements and air distribution channels.
- HEPA/ULPA Filter Housing Support Structures: Coil tubes form the structural framework for high-efficiency particulate air (HEPA) and ultra-low penetration airborne (ULPA) filters.
- Clean Room Ductwork: Seamless coil tubes for laminar airflow (LAF) systems, maintaining ISO Class 1–7 clean room environments.
5.2 Pharmaceutical & Biotechnology
- Process piping for GMP-regulated pharmaceutical manufacturing facilities
- WFI (Water for Injection) and purified water distribution systems
- CIP (Clean-in-Place) and SIP (Sterilization-in-Place) compatible piping
- Bio-reactor and fermentation vessel connections
5.3 Food & Beverage Industry
- Sanitary process piping for dairy, beverage, and food processing
- Cooling coil tubes for refrigeration and pasteurization systems
- Steam distribution lines in food processing plants
5.4 Semiconductor & Electronics
- Chemical distribution systems (CDS) for wafer processing
- Purge gas and vacuum piping in lithography and etch chambers
- Clean room HVAC and pressure control systems
5.5 Industrial & General Engineering
- HVAC systems in hospitals, laboratories, and precision manufacturing facilities
- Heat exchanger tubing for industrial process applications
- Structural support tubing in corrosive environments
6. Quality Certifications & Standards Compliance
6.1 Applicable Standards
| Standard | Scope |
|---|---|
| ASTM A554 | Specification for Seamless Austenitic Stainless Steel Tube for Chemical and Related Applications |
| ASTM A269 | Specification for Seamless and Welded Austenitic Stainless Steel Tubing |
| EN 10305-2 | Seamless Stainless Steel Tubes for General Purposes — Technical Delivery Conditions |
| ISO 14001:2015 | Environmental Management Systems |
| ISO 9001:2015 | Quality Management Systems |
| ASME B31.3 | Process Piping Code |
| EN 12164 | Hygienic Stainless Steel Tubing for Food, Dairy, Pharmaceutical and Biotechnology |
| 3-A Sanitary Standards | Sanitary Construction Standards for Dairy, Food, and Beverage Processing |
6.2 Quality Assurance Measures
- Mill Test Certificates (MTC): Every batch is accompanied by EN 10204 3.1 type MTC with full chemical composition and mechanical property data.
- Hydrostatic Testing: All coil tubes are pressure-tested to verify structural integrity and absence of internal defects.
- Spectroscopic Analysis