CHIWATEC Provides a Complete Guide to Reverse Osmosis (RO) System Operation and Maintenance

During the operation of a reverse osmosis (RO) system, you may encounter performance issues such as reduced water output, pressure fluctuations, or declining desalination rate. This guide — based on CHIWATEC’s operation and maintenance standards — provides detailed explanations of RO system commissioning, operation, troubleshooting, and chemical cleaning to ensure optimal system performance and long-term reliability.

(1) Startup Procedure

1. Open the precision filter drain valve and start the pretreatment system to produce normal feed water.
2. Open the raw water inlet valve, start the booster pump, and close the drain valve once the filter outlet water is clear.
3. Open the concentrate control valve and adjust the throttling valve on the booster pump to a moderate level.
4. When the filtered water pressure reaches about 30 PSI, turn on the main power switch.
5. Gradually open the throttling valve after the main pump starts. Adjust the concentrate valve until the permeate-to-concentrate ratio reaches the design parameters.
6. The system includes raw water pressure protection — if inlet pressure drops below the preset limit, the RO system will automatically stop to protect the high-pressure pump. After the pressure is restored, press the reset button to resume operation.
7. Never close the concentrate valve completely — sudden pressure spikes may cause damage to the membrane or endanger operator safety.
8. Record operational parameters in a daily logbook to track performance.
9. When using the system for the first time, discharge permeate for at least one hour before collecting it.

(2) Shutdown Procedure

1. Stop the RO high-pressure pump and close the inlet valve.
2. Turn off the main power switch.
3. Stop the raw water booster pump and close all valves.
4. Shut down the main power supply.
5. Verify that all gauges and meters return to zero.

The RO unit operates automatically with programmed cycles for water production and protective flushing. Operational parameters such as pressure and flow rate should be adjusted based on on-site conditions.

• Water Production:
  The high-pressure pump’s initial inlet pressure is set to 0.05 MPa and adjusted during operation as required.
• Protective Flushing:
  When the RO unit stops, perform a 5-minute flush to completely discharge the concentrated water and prevent scaling or fouling.

The RO system is mostly automated; operators only need to monitor system parameters. If feed water quality deteriorates, water output decreases, or pressure drop exceeds 0.1 MPa, the cause must be investigated immediately.

Key indicators of system performance include:

• Desalination rate
• Recovery rate
• Pressure differential

Common causes of abnormal operation include changes in feed water quality, equipment wear, or membrane fouling. The operator should follow a systematic troubleshooting approach to identify and resolve problems efficiently.

When the following conditions appear, immediate limpeza química is required:

1. Total pressure drop increases by 0.15–0.20 MPa.
2. Desalination rate decreases by 3% or more.
3. Total permeate flow decreases by 10% or more.
4. Even without these symptoms, clean the system every 5–6 months.

Key Cleaning Guidelines

• Select the cleaning agent based on the type of contamination.
• Use NH₄OH e H₂SO₄ to adjust pH (accurate pH measurement is essential).
• Wear protective gear (goggles, gloves, and safety shoes).
• Ensure all cleaning chemicals are fully dissolved before use.
• Cleaning pressure: 0.15–0.3 MPa; time: ~2 hours; temperature ≤ 35°C.
• After cleaning, rinse thoroughly until permeate meets quality standards.

Recommended Cleaning Formulas

• Acidic Cleaning: 0.3% HCl solution
• Alkaline Cleaning: 0.3% NaOH (pH adjusted to 12)
• Preservation Solution: 0.5–1% sodium bisulfite or formaldehyde solution

• Run the system for at least 2 hours daily; for shutdowns over 72 hours, fill with sodium bisulfite solution for protection.
• After each stop, rinse the system with low-pressure water for 15 minutes to avoid scaling.
• During startup, increase pressure gradually; rinse thoroughly if formaldehyde preservation was used.
• In winter, prevent freezing by filling with 5% glycerol + 0.5% sodium bisulfite solution.

The proper operation and maintenance of RO systems are essential for ensuring high-quality permeate, maximizing membrane lifespan, and minimizing downtime.
CHIWATEC’s comprehensive operating procedures — from startup and flushing to chemical cleaning and preservation — provide industrial operators with a reliable framework to maintain peak RO performance and reduce maintenance costs.

By following these standardized methods, users can ensure safe, stable, and efficient operation of their reverse osmosis systems for years to come.

Typically every 5–6 months, or sooner if pressure drop increases by 0.15–0.20 MPa or permeate flow drops by more than 10%.

Between 0.15–0.3 MPa, using a low-pressure, high-flow circulation to prevent membrane damage.

No. Always flush the RO system thoroughly with clean water until all cleaning residues are removed.

Wear full protective equipment — gloves, goggles, and acid/alkali-resistant clothing — and ensure all cleaning agents are fully dissolved.

CHIWATEC provides complete RO operation, maintenance, and training support, ensuring system stability, extending membrane life, and reducing total operation costs.

Xi'an CHIWATEC A Water Treatment Technology é uma empresa de alta tecnologia especializada em vários dispositivos de processamento de água. Além desses produtos individuais, que abrangem vários tipos e séries, também podemos ajudar com projetos de engenharia abrangentes relacionados. Graças ao nosso trabalho árduo e dedicação desde a nossa fundação, somos agora um dos fabricantes de equipamentos de tratamento de água com desenvolvimento mais rápido na China Ocidental.

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