I.Overview
Stainless steel is a critical structural material in ultra-pure water (UPW) systems, with its performance directly impacting water purity and system reliability. In industries such as semiconductors and pharmaceuticals, it must simultaneously meet ultra-high cleanliness standards and zero contamination release requirements. Stainless steel in ultra-pure water systems represents the “art of balancing cleanliness and strength.” 316L-EP grade stainless steel, with its ultra-low leaching and extreme surface finish, remains the gold standard for semiconductor/pharmaceutical UPW systems.
II.Process
Raw Water → Raw Water Tank → Booster Pump → Flocculant/Reducer Dosing → Activated Carbon Filter → Ultrafiltration (UF) → Scale Inhibitor Dosing → Security Filter → 1st Stage High-Pressure Pump → 1st Stage RO → pH Adjustment → Intermediate Tank → 2nd Stage High-Pressure Pump → 2nd Stage RO → Purified Water Tank → EDI Booster Pump → UV Sterilizer → Cartridge Filter → EDI System → Ultra-Pure Water Tank → Transfer Pump → TOC Removal Unit → Polishing Resin → Final Filter → Point of Use
III.Core applications of 316 stainless steel
Category | Sub - category | Details | |||||
1. Distribution Pipeline System | Pure Water Conveyance | 316L stainless steel pipelines are used to convey ultra - pure water with 18.2 MΩ·cm, avoiding ion leaching and pollution. | |||||
Circulation System | Maintain a constant flow rate (> 1 m/s) to prevent microbial growth. The pipe wall requires electrolytic polishing (Ra ≤ 0.5 μm). | ||||||
2. Water Storage Tanks and Pressure Vessels | Ammonia - free Water Tank | 316L inner tank + argon - shielded welding to isolate the ingress of CO₂/O₂. | |||||
Membrane Shell and Filter Shell | Pressure - bearing RO/UF membrane shells need to withstand 0.6 - 1.0 MPa without metal ion leaching. | ||||||
3. Process Equipment Contact Components | Pumps, Valves and Sensors | Diaphragm pump bodies, conductivity flow cells all use ultra - low carbon stainless steel (316L). | |||||
Mixed Bed Resin Columns | Directly contact high - purity resin. The material must meet the SEMI F19 standard. |
IV.Parameters
Characteristic | 304 Stainless Steel | 316L Stainless Steel (Recommended) | ||||
Carbon Content | ≤0.08% | ≤0.03% (Ultra - low Carbon) | ||||
Molybdenum Content | None | 2.0% - 2.5% (Core for Corrosion Resistance) | ||||
Iron Ion Leaching | >0.5 ppb | <0.1 ppb (80°C/24h Static Test) | ||||
Intergranular Corrosion Risk | Sensitive in Welded Areas | Ultra - low Carbon Design to Thoroughly Avoid | ||||
Applicable Standard | ASTM A240 | SEMI F19 (Semiconductor - Grade Certification) |
V.Here is a guideline for you to get a proper quotation
Tell us the raw water/source of water(tap water, well water, or sea water, etc)
Provide water analysis report(TDS , conductivity, or resistivity, etc)
Required production capacity( 5m³/H, 50m³/H,or 500m³/H, etc)
What's the pure water used for( industrial,Food and Beverage,or agriculture, etc )