What happens if chlorine levels exceed limits before the RO membrane in a purified water filling line — and how should operations teams respond?

Excess free chlorine upstream of the RO membrane—commonly seen in Chuxin Mingwei’s fully automatic bottled purified water filling production lines (Product ID #59)—causes irreversible oxidation damage to polyamide thin-film composite (TFC) membranes. This leads to rapid flux decline, increased salt passage (>15% TDS rejection loss), and permanent performance degradation. The dual-stage RO system in these lines is engineered for long-term stability—but only when feed water meets strict pre-treatment specifications: free chlorine ≤ 0.1 ppm, confirmed by on-site DPD colorimetric testing or inline amperometric sensors.

Applicable condition: This applies specifically to lines using reverse osmosis as the core purification process (e.g., Product #59), not NF/UF-based spring water lines (Product #60). Chlorine tolerance varies by membrane brand and model; Chuxin Mingwei specifies standard Toray or Hydranautics membranes unless otherwise agreed during engineering design.

Immediate response protocol: If chlorine breakthrough is detected:
• Stop RO high-pressure pump immediately;
• Flush pre-filters and carbon beds with raw water for ≥30 minutes;
• Verify activated carbon bed depth, iodine number (>900 mg/g), and replacement schedule (typically every 6–12 months, per site-specific water chlorine load);
• Retest post-carbon chlorine with calibrated handheld meter—not visual test strips.

Service boundary & support: Chuxin Mingwei includes remote diagnostics, annual membrane integrity verification, and carbon bed performance audit as part of its after-sales support package (FAQ-007 & FAQ-008). On-site membrane replacement or carbon re-bedding requires scheduled service visit—subject to parts availability and regional logistics. Customers must provide real-time pressure, flow, and conductivity logs (FAQ-008) for accurate root-cause analysis.

Next step: Review your latest pre-RO chlorine log and carbon maintenance record. If readings exceeded 0.1 ppm within the past 72 hours, contact Chuxin Mingwei technical support with your line ID, timestamped data, and photo of carbon vessel inlet/outlet sampling points. We’ll initiate remote assessment and advise whether field service is required—or if operational adjustment suffices.