Stainless Steel Coiltube — Liquid Particle Counter (LPC) Cleanliness Inspection Specification
Product Overview
The Stainless Steel Coiltube manufactured by Wenzhou Jixing Metal Materials Co., Ltd. represents a precision-engineered tubing solution designed for applications demanding ultra-high cleanliness standards. The integrity of each coil tube batch is validated through rigorous Liquid Particle Counter (LPC) testing, ensuring that particulate contamination levels remain well within the tolerances required for cleanroom-grade industrial and medical systems. This inspection protocol serves as the definitive batch release criterion, guaranteeing that every delivered coil tube meets the stringent cleanliness specifications expected in high-purity fluid handling environments.
Material & Properties
The coil tube is fabricated from high-purity austenitic stainless steel, selected for its exceptional corrosion resistance, mechanical strength, and compatibility with ultra-clean processing. Key material characteristics include:
- Base Material: 304 / 316L grade austenitic stainless steel (UNS S30400 / UNS S31603)
- Surface Finish: Electropolished or passivated interior surface with Ra ≤ 0.4 μm
- Wall Thickness: Precision-controlled to ±0.025 mm tolerance
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and stress corrosion cracking
- Chemical Compatibility: Suitable for transfer of ultra-pure water (UPW), pharmaceutical fluids, semiconductor-grade chemicals, and bioprocess media
Specifications
| Parameter | Specification | Test Method / Standard |
|---|---|---|
| Product Type | Coiltube (Continuous Coil Form) | — |
| Material Grade | 304 / 316L Stainless Steel | ASTM A270 / ASTM A269 |
| Inspection Category | Cleanliness Detection — Particle Counting | ISO 14644-1 / ASTM F2622 |
| Testing Instrument | Liquid Particle Counter (LPC) | ISO 21501-4 |
| Particle Size Classification | ≥ 0.1 μm / ≥ 0.2 μm / ≥ 0.5 μm | Light Scattering Method |
| Counting Threshold | ≥ 0.1 μm (100 nm) | LPC Optical Detection Limit |
| Sampling Method | Flush-and-collect with deionized water (DI Water, 18.2 MΩ·cm) | In-house validated protocol |
| Batch Release Criterion | All particle counts within cleanroom-grade specification limits | ISO 14644-1 Class 5 equivalent |
| Surface Roughness (ID) | Ra ≤ 0.4 μm (electropolished) | ISO 4287 |
| Dimensional Tolerance | OD ±0.025 mm / Wall ±0.025 mm | ASTM A270 |
| Coil Length | Customizable (typically 10 m – 50 m per coil) | Customer specification |
Manufacturing Process
The production of cleanroom-grade stainless steel coil tube follows a tightly controlled multi-stage process:
- Raw Material Selection: Only certified low-carbon, high-purity stainless steel wire rod or strip is procured, with mill test certificates verifying elemental composition and absence of heavy metal contamination.
- Precision Forming: The tubing is cold-drawn or cold-rolled to precise outer diameter (OD) and wall thickness dimensions, followed by continuous coiling on automated forming lines.
- Heat Treatment & Annealing: Solution annealing in a controlled-atmosphere furnace eliminates residual stresses and ensures uniform microstructure.
- Electropolishing: The interior surface undergoes electrochemical polishing to achieve Ra ≤ 0.4 μm, removing embedded contaminants and creating a passive chromium oxide layer.
- Passivation: A citric acid or nitric acid passivation treatment further stabilizes the surface chemistry, enhancing corrosion resistance.
- Final Cleaning: Multi-stage cleaning with ultra-pure water (UPW) removes residual particulates and ionic contamination.
- Particle Counting Inspection (LPC): Each batch undergoes mandatory liquid particle counting using a certified LPC instrument. The tubing is flushed with DI water, and the effluent is analyzed for particles at three critical thresholds: ≥ 0.1 μm, ≥ 0.2 μm, and ≥ 0.5 μm.
- Batch Release: Only batches meeting all particle count limits are released for shipment. Non-conforming batches are quarantined and subject to root cause analysis.
Applications
The LPC-verified stainless steel coil tube is engineered for the most demanding clean environments, including:
- Semiconductor Manufacturing: Ultra-pure water (UPW) distribution, chemical delivery systems, and wafer processing equipment
- Pharmaceutical & Biotechnology: Bioreactor connections, clean-in-place (CIP) systems, and sterile fluid transfer lines (GMP-compliant)
- Medical Devices: Tubing for dialysis systems, infusion pumps, and implantable device manufacturing
- Food & Beverage: Hygienic processing lines requiring high sanitary standards
- Electroplating & Surface Treatment: Chemical metering and recirculation systems
- Oil & Gas: High-purity gas and liquid sampling lines in refinery and petrochemical plants
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring product conformity and traceability:
- ISO 9001:2015 — Quality Management System certification
- ISO 14644-1 — Cleanroom classification compliance for inspection environments
- ISO 21501-4 — Air particle counters (methodology alignment for liquid systems)
- ASTM F2622 — Standard practice for sampling, handling, and preparation of liquid samples for particle counting
- GMP Compliance — Good Manufacturing Practice alignment for pharmaceutical-grade applications
- Mill Test Certificates (MTC) — EN 10204 Type 3.1 material certification for each production batch
Unique Selling Points
Triple-Threshold Particle Classification: The ≥ 0.1 μm / ≥ 0.2 μm / ≥ 0.5 μm grading system provides granular contamination visibility, enabling customers to set precise acceptance criteria tailored to their specific process requirements.
- Objective Batch Release: LPC-based particle counting eliminates subjective assessment, providing quantifiable, repeatable data for every production batch — ensuring consistent quality from coil to coil.
- End-to-End Traceability: Each coil tube is linked to its raw material lot, processing parameters, and full inspection report, enabling complete supply chain traceability.
- Sub-Micron Detection Capability: The ability to detect particles as small as 0.1 μm (100 nm) ensures that even the finest contamination sources — such as metal oxide fragments or organic residues — are identified and eliminated before delivery.
- Industry-Leading Cleanliness: Products consistently meet or exceed ISO 14644-1 Class 5 cleanroom-equivalent cleanliness, positioning them as a preferred choice for semiconductor and pharmaceutical OEMs.
- Customizable Specifications: Coil dimensions, lengths, and particle count acceptance limits are fully customizable to meet customer-specific design requirements.
Summary
The Stainless Steel Coiltube with LPC-verified cleanliness represents the gold standard in high-purity tubing solutions. By integrating state-of-the-art liquid particle counting technology into the manufacturing quality control workflow, Wenzhou Jixing Metal Materials Co., Ltd. delivers coil tubes that are not only dimensionally precise and mechanically robust but also demonstrably free from particulate contamination — providing engineering teams with the confidence to deploy these products in the most critical fluid handling systems.