Ultra-Pure Water Final Wash Stainless Steel Coil Tube — Semiconductor & Biopharmaceutical Grade
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. presents a precision-engineered stainless steel coil tube featuring a proprietary Ultra-Pure Water (UPW) Final Wash internal surface treatment process. This advanced finishing technique employs 18.2 MΩ·cm resistivity ultra-pure water rinse followed by high-purity nitrogen blow-drying as the terminal manufacturing step, ensuring contamination-free internal surfaces suitable for the most demanding semiconductor fabrication and biopharmaceutical applications.
The coil tube format provides consistent geometry, superior dimensional accuracy, and efficient downstream processing through continuous feed capability. The ultra-pure water final wash eliminates residual particulates, ionic contaminants, and organic residues that conventional cleaning methods cannot address, delivering a surface integrity that meets ISO Class 1 cleanliness standards.
Material & Properties
Base Material
- Primary Grade: SUS316L / AISI 316L (ASTM A213 Type 316L)
- Alternative Grades: SUS304L, SUS310S, Custom Alloy Compositions
- Chemical Composition: Cr 16.0–18.0%, Ni 10.0–14.0%, Mo 2.0–3.0%, C ≤ 0.03%
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and chemical attack in aggressive process environments
- Temperature Range: −196 °C to +870 °C (−320 °F to +1,600 °F) continuous service
Internal Surface Properties (Post UPW Final Wash)
- Surface Resistivity: ≥ 18.2 MΩ·cm (equivalent to ultrapure water rinse standard)
- Internal Surface Roughness: Ra ≤ 0.1 μm (electropolished finish)
- Particulate Contamination: < 1 particle ≥ 0.5 μm per 100 cm²
- Extractable Ions: Na⁺, K⁺, Ca²⁺, Cl⁻ below detection limits (ICP-MS verified)
- Endotoxin Level: < 0.25 EU/mL (LAL test compliant)
- Organic Residue: < 1 ppb total organic carbon (TOC)
Specifications
| Parameter | Specification |
|---|---|
| OD Range | 1.5 mm – 25.0 mm (0.059 in – 0.984 in) |
| Wall Thickness | 0.20 mm – 2.0 mm (0.008 in – 0.079 in) |
| Coil Inner Diameter | 150 mm – 500 mm (5.9 in – 19.7 in) |
| Coil Length per Spool | 50 m – 500 m (164 ft – 1,640 ft) |
| OD Tolerance | ±0.02 mm (±0.0008 in) |
| Wall Thickness Tolerance | ±0.01 mm (±0.0004 in) |
| Roundness | ≤ 1% of nominal OD |
| Internal Surface Finish | Ra ≤ 0.1 μm (Electropolished + UPW Final Wash) |
| External Surface Finish | Bright Annealed / Mirror Polished / Passivated |
| Final Wash Process | 18.2 MΩ·cm UPW Rinse + N₂ (99.999%) Blow Dry |
| Protective Packaging | Vacuum-sealed polyethylene bags + desiccant + nitrogen atmosphere |
| Maximum Operating Pressure | Up to 150 bar (2,175 psi) depending on OD/WT |
Manufacturing Process
Step-by-Step Production Workflow
- Wire Rod Selection: Vacuum Arc Remelted (VAR) or ESR certified mill rod stock with certified chemical composition and ultrasonic flaw detection.
- Piercing & Cross Rolling: Hot piercing followed by cold cross-rolling to achieve target blank dimensions with controlled grain flow.
- Cold Drawing (Coil Form): Progressive multi-die cold drawing on continuous coil drawing equipment to achieve final OD and wall thickness tolerances.
- Solution Annealing: Furnace annealing at 1050 °C – 1100 °C in inert atmosphere to relieve cold-work stresses and restore full austenitic microstructure.
- Pickling & Passivation: Acid pickling to remove oxide scale followed by controlled passivation to form protective chromium oxide layer.
- Electropolishing (Internal): Controlled DC electropolishing at optimized current density to achieve Ra ≤ 0.1 μm internal surface with controlled material removal.
- Intermediate Cleaning: Multi-stage degreasing with industrial-grade water and controlled solvent rinse.
- Ultra-Pure Water Final Wash (Critical Step):
- Rinse with 18.2 MΩ·cm ultra-pure water (resistivity monitored in real-time)
- Multi-pass inline circulation to ensure complete displacement of process water
- Final single-pass UPW rinse with flow velocity ≥ 1.0 m/s to prevent particulate redeposition
- Online conductivity monitoring confirming ≤ 0.1 μS/cm at discharge point
- Nitrogen Blow-Dry: High-purity nitrogen (99.999%, Grade 5) blow-drying at controlled flow rate and temperature to achieve zero water residue without thermal degradation of passivation layer.
- Inline Inspection: Automated OD/wall thickness measurement, internal visual inspection via borescope, and resistivity verification.
- Clean Packaging: Immediate transfer to Class 100 cleanroom packaging environment with vacuum sealing and nitrogen atmosphere preservation.
Key Distinction: The 18.2 MΩ·cm UPW final wash represents the terminal processing step — no subsequent handling, transport, or packaging operation introduces contamination. This "last-touch" protocol ensures that the pristine surface condition achieved during electropolishing is preserved through to point of use.
Applications
Semiconductor Manufacturing
- Chemical Mechanical Polishing (CMP) fluid delivery systems
- Ultra-pure water (UPW) distribution piping in fabrication plants
- High-purity gas delivery lines (HF, Cl₂, NH₃, WF₆)
- Wet etch and rinse equipment internals
- Lithography tool fluid circuits
- Thin-film deposition chamber gas lines
Biopharmaceutical Industry
- Water for Injection (WFI) and Purified Water (PW) distribution
- Sterile pharmaceutical processing equipment
- Biosimilar and biologics manufacturing lines
- Cleanroom piping (ISO 5 / Grade A environments)
- Bioreactor and fermentation system connections
- Lyophilization (freeze-drying) system tubing
Additional High-Purity Applications
- Food and beverage processing (high-end)
- Photovoltaic (solar cell) manufacturing
- Optical lens cleaning fluid systems
- Electroplating and surface treatment equipment
- Research and laboratory instrumentation
Quality Certifications & Compliance
Standards Compliance
- Material Standards: ASTM A213/A213M, AMS 5528, EN 10216-5
- Surface Quality: ISO 14288 (Surface Roughness), ASTM A967 (Passivation)
- Cleanliness: ISO 14644-1 Class 5 (US Federal Std 209E Class 100)
- Pharmaceutical: 3-A Sanitary Standards, FDA 21 CFR Part 219/117 compliant
- Semiconductor: SEMI F57 (Chemical Purity), SEMI C33 (Surface Finish)
- Water Quality: ASTM D512 (18.2 MΩ·cm resistivity verified)
Certification System
- ISO 9001:2015 Quality Management System
- ISO 13485 Medical Device Quality Management
- ISO 14001 Environmental Management System
- ASME BPV Code (where applicable for pressure applications)
- CE Marking per EU Pressure Equipment Directive (PED 2014/68/EU)
Testing & Documentation
- Mill Test Certificates (MTC) per EN 10204 3.1
- Positive Material Identification (PMI) via XRF for every heat
- Spectrochemical analysis (OES) for full chemical composition verification
- Particle count testing (ISO 4966 compliant) for internal surface cleanliness
- ICP-MS extractable ion analysis for semiconductor qualification
- LAL (Limulus Amebocyte Lysate) endotoxin testing for pharmaceutical qualification
- Online resistivity logging for every UPW wash cycle
- Full traceability from mill rod heat number through final coil identification
Unique Selling Points
- True 18.2 MΩ·cm UPW Final Rinse: Industry-leading resistivity standard verified with online monitoring — no compromise on water purity at the critical final step.
- Nitrogen Atmosphere Drying: Eliminates water spot formation and re-contamination risk inherent in air-drying or thermal drying methods.
- Single-Source Accountability: Complete process control from raw material to final packaging under one supplier eliminates cross-contamination risk from multi-vendor handoffs.
- Coil Format Advantage: Enables continuous automated cutting, welding, and forming downstream — reducing processing steps and contamination exposure points.
- Full Traceability: Every coil is traceable to its specific mill rod heat, wash cycle log, and inspection records — enabling rapid root-cause analysis in critical applications.
- Custom Specification Capability: Flexible OD, wall thickness, coil diameter, and surface finish options to match exact application requirements.
Technical Support & Consultation
Wenzhou Jixing Metal Materials Co., Ltd. provides comprehensive technical support including application engineering consultation, material selection guidance, cleanliness protocol development, and qualification testing assistance. Custom specifications, sample programs, and on-site technical audits are available to support customer qualification and production ramp-up.