Stainless Steel Coil Tube — Ultra-Pure Water (UPW) Final Rinse Process
Product Overview
The Stainless Steel Coil Tube with Ultra-Pure Water Final Rinse is a high-purity tubing product manufactured by Wenzhou Jixing Metal Materials Co., Ltd, specifically engineered for the most demanding semiconductor and biopharmaceutical applications. This product represents the culmination of a rigorous multi-stage manufacturing process, with the final internal surface treatment employing 18.2 MΩ·cm resistivity Ultra-Pure Water (UPW) rinsing followed by nitrogen (N₂) drying. This terminal processing step ensures the internal bore achieves contamination levels below 0.1 ppb, making it suitable for critical fluid transfer in environments where even trace particulate or ionic contamination is unacceptable.
The coil tube form factor offers significant advantages in terms of material utilization, transportation efficiency, and downstream forming flexibility. Delivered in coil configuration, the tubing can be cut, bent, or formed to precise specifications at the end-user facility, minimizing waste and enabling customized assembly integration.
Material & Properties
The base material for this coil tube is premium-grade austenitic stainless steel, typically selected from the following alloys depending on the specific application requirements:
- 316L (UNS S31603) — General-purpose high-purity tubing with excellent corrosion resistance
- 316LMO (UNS S31603 + Mo) — Enhanced molybdenum content for superior resistance in chloride environments
- EP-Grade 316L (Electro-Polished) — Ultra-low roughness variant for semiconductor gas delivery
- 304L (UNS S30403) — Economical option for less aggressive media
Key Material Properties
- Internal Surface Roughness (Ra): ≤ 0.25 μm (electro-polished grade); ≤ 0.5 μm (passivated grade)
- Internal Contamination Level: ≤ 0.1 ppb (parts per billion) after UPW final rinse
- Residual Water Resistivity: 18.2 MΩ·cm (MilliOhm·cm), the theoretical maximum for deionized water
- Tensile Strength: 515–750 MPa (depending on alloy and heat treatment)
- Operating Temperature Range: −196°C to +870°C (cryogenic to elevated)
- Maximum Operating Pressure: Up to 4000 psi (276 bar), depending on wall thickness
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Form | Coil Tube (盘管 / Coiltube) | — |
| Material Grade | 316L / 316LMO / 304L (EP-grade available) | ASTM A269 / ASTM A270 |
| Outer Diameter (OD) | 1/8" to 2" (3.18 mm – 50.8 mm) | ASME B36.19M |
| Wall Thickness | 0.010" to 0.120" (0.25 mm – 3.05 mm) | ASME B36.19M |
| Coil Length | Up to 500 m per coil (customizable) | — |
| Final Rinse Water Resistivity | 18.2 MΩ·cm (Ultra-Pure Water) | ASTM D1128 |
| Drying Method | High-purity Nitrogen (N₂) blow-dry, ≥ 99.999% purity | — |
| Internal Surface Finish | Electro-polished Ra ≤ 0.25 μm / Passivated Ra ≤ 0.5 μm | ASTM A380 |
| Internal Contamination | ≤ 0.1 ppb total dissolved solids | — |
| Passivation Treatment | Citric acid or nitric acid passivation (per ASTM A380) | ASTM A380 |
| Helicoid (Helix) Weld | Available with orbital TIG welded helix, Ra ≤ 0.4 μm | ASME B31.3 |
| End Condition | Sealed ends / Cap-sealed for shipping | — |
| Coating / Packaging | Anti-static wrap + VCI paper + protective end caps | — |
Manufacturing Process
The production of this Ultra-Pure Water final-rinsed coil tube follows a meticulously controlled multi-stage process to ensure the highest purity standards. The process flow is described below:
- Hot Rolling & Annealing: Stainless steel strip is hot-rolled and subsequently annealed to achieve the desired grain structure and mechanical properties.
- Cold Forming (Tube Milling): The strip is cold-formed into a seamless coil tube using precision rolls, achieving tight dimensional tolerances (±0.02 mm for OD).
- Helix Welding (if applicable): For welded coil tube, a high-frequency helical weld is performed with orbital TIG welding, followed by mechanical grinding and chemical cleaning of the weld seam.
- Heat Treatment (Solution Annealing): The coil tube is solution-annealed at 1050–1150°C in a controlled atmosphere to ensure full austenitic transformation and optimal corrosion resistance.
- Pickle & Passivation: The tube undergoes pickling to remove oxide scales, followed by passivation treatment (ASTM A380 compliant) to establish a protective chromium oxide layer on the surface.
- Electro-Polishing (EP) / Internal Cleaning: For semiconductor-grade tubing, electro-polishing is performed to achieve Ra ≤ 0.25 μm internal surface roughness, removing up to 0.025 mm of surface material to eliminate inclusion-induced pits.
- Multi-Stage Purified Water Rinse: The internal bore is sequentially rinsed with progressively higher purity water (DI water → 1 MΩ·cm → 10 MΩ·cm → 18.2 MΩ·cm UPW) to eliminate any residual contaminants from prior processing steps.
- Ultra-Pure Water (UPW) Final Rinse: The terminal rinse employs water with a resistivity of 18.2 MΩ·cm (the maximum achievable for ultrapure water at 25°C per ASTM D1128), ensuring that no ionic species are deposited on the internal surface. This is the defining final processing step for this product grade.
- Nitrogen (N₂) Blow-Dry: Immediately following the UPW rinse, high-purity nitrogen gas (≥ 99.999%, 5N grade) is blown through the internal bore under controlled pressure to displace residual moisture without introducing hydrocarbon or particulate contamination. This eliminates the risk of water spotting or re-deposition of dissolved species upon drying.
- Inspection & Testing: Each coil undergoes eddy current testing, hydrostatic pressure testing, dimensional verification, and internal surface cleanliness verification (via TOC analysis or ICP-MS sampling).
- Packaging & Shipping: The coil is end-sealed with protective caps, wrapped in anti-static and VCI (Volatile Corrosion Inhibitor) material, and packed in a protective container for shipment.
Critical Process Note: The UPW final rinse and nitrogen drying must be performed in a controlled cleanroom environment (minimum ISO Class 7 / Class 10,000) to prevent post-rinse contamination. The entire sequence from UPW rinse through nitrogen drying to end-sealing must be completed within a defined time window (typically < 30 minutes) to maintain the achieved purity level.
Applications
This Ultra-Pure Water final-rinsed stainless steel coil tube is purpose-built for applications where internal surface purity is a critical process parameter:
Semiconductor Manufacturing
- Ultra-pure chemical delivery lines (HF, H₂SO₄, HNO₃, H₂O₂, etc.)
- High-purity gas distribution systems (H₂, N₂, NF₃, SiH₄, WF₆)
- Wet bench fluid transfer in photolithography and etching areas
- Chemical Mechanical Polishing (CMP) slurry delivery
Biopharmaceutical Industry
- Water for Injection (WFI) distribution systems
- Pure Steam (PS) and Condensate return lines
- Bioreactor feed and harvest lines
- Parenteral drug filling circuits
- Cell culture media delivery systems
Additional Applications
- Fuel cell hydrogen delivery systems
- Photovoltaic (solar cell) manufacturing fluid lines
- Food and beverage processing (high-purity water)
- Electroplating and coating fluid circuits
- Research-grade analytical instrument fluid paths
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system ensuring that all products meet or exceed international standards:
| Certification / Standard | Scope |
|---|---|
| ISO 9001:2015 | Quality Management System |
| ISO 14001:2015 | Environmental Management System |
| ISO/IEC 17025 | Testing & Calibration Laboratory Competence |
| ASTM A269 / A270 | Welded and Seamless Stainless Steel Tubing |
| ASTM A312 | Welded Austenitic Stainless Steel Tubing |
| ASTM A380 | Passivation of Stainless Steel Parts |
| ASTM D1128 | Water Resistivity Measurement (UPW verification) |
| ASME B31.3 | Process Piping (applicable for system integration) |
| ASME B36.19M | Instrument, Condenser, and Heat Exchanger Tubing Dimensions |
| SEMI F57 / F58 | Semiconductor Equipment Materials (cleanliness & outgassing) |
| 3-A Sanitary Standards | Food/Biopharmaceutical Equipment (where applicable) |
| CE Marking | European Conformity |
| Mill Test Reports (MTR) | Full chemical and mechanical property documentation per coil |
Unique Selling Points
- Industry-Leading Purity: The 18.2 MΩ·cm UPW final rinse represents the highest achievable water purity standard, ensuring residual contamination below 0.1 ppb — critical for advanced semiconductor node manufacturing (≤ 7nm) and GMP-compliant biopharmaceutical production.
- Contamination-Free Drying: The proprietary nitrogen blow-dry process eliminates water spotting and prevents re-deposition of dissolved ions, a common failure mode in conventional air-drying or heat-drying methods.
- Coil Form Factor Advantage: Delivered as continuous coil tubing, this product enables on-site cutting and forming, reducing lead time, minimizing inventory requirements, and eliminating butt-weld joints that could introduce contamination points.
- Full Traceability: Each coil is accompanied by a complete Mill Test Report (MTR) including chemical analysis, mechanical test results, and process documentation, enabling full lot traceability from raw material to finished product.
- Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd offers customizable OD, wall thickness, coil length, alloy grade, and surface finish specifications to match specific application requirements.
- Integrated Cleanroom Processing: The final rinse and drying steps are performed in a controlled cleanroom environment, ensuring that the achieved purity level is maintained through to packaging.
Summary
The Stainless Steel Coil Tube with Ultra-Pure Water Final Rinse by Wenzhou Jixing Metal Materials Co., Ltd represents a benchmark product in the high-purity tubing market. The combination of precision manufacturing, rigorous electro-polishing, 18.2 MΩ·cm UPW terminal rinsing, and nitrogen drying creates a product that meets the exacting standards of the semiconductor and biopharmaceutical industries. With full traceability, comprehensive certifications, and customizable specifications, this product is an ideal solution for engineers and procurement professionals seeking contamination-free fluid and gas delivery systems.