Operating Instructions for EDI Equipment

An EDI equipment operation manual is an essential resource provided by our company to guide the operation and maintenance of EDI ultra-pure water equipment. This manual serves as a comprehensive reference covering crucial details, including EDI equipment parameters and operational maintenance procedures.

Understanding the Importance of EDI Operation and Maintenance

The seamless and long-term operation of EDI equipment depends not only on the initial system design but also on correct operation and maintenance practices. This encompasses the startup and shutdown processes during the system’s operation. To ensure the long-term performance of the system, it’s essential to regularly record operational data for future reference and daily maintenance tasks. Daily operational data plays a vital role in diagnosing equipment issues and making informed decisions.

1. Pre-Startup Inspection

Before starting the EDI equipment, ensure that the reverse osmosis (RO) unit is operating in a recirculation mode. Verify the action of flow switches and related interlocking actions (if necessary, test the RO interlocking actions as well). Set alarm control values.

2. Initial Start-Up

A proper start-up of the EDI equipment is crucial for preparing it for normal operation and preventing damage due to excessive flow, water hammer, or electrical overload. Adhering to the following procedure also helps ensure that the system operates within the designed parameters, delivering water that meets the specified requirements.

3. EDI Start-Up Procedure

Before connecting the pipelines to the CEDI (Continuous Electrodeionization) unit, ensure that all upstream pretreatment equipment and pipelines meet cleanliness requirements. Confirm correct pipeline connections to the CEDI module and check that they meet cleanliness standards. Inspect all relevant manual valves for correct positions and open/close status, including inlet valves, product water valves, ultra-pure water tank inlet valves, and concentrate flow control valves.

During the flushing process, check all pipeline connections and valves for leaks. If necessary, tighten the connections. Confirm the correct wiring from the CEDI module to the power supply module.

Start the RO product water transfer pump. Adjust valve openings to achieve the designed flow rate and pressure. Verify the designed recovery rate and actual recovery rate. Continuously monitor system pressure and ensure it does not exceed the maximum operating pressure limit of the module.

At the designed flow rate, adjust the valves until the product water pressure is 2-5 psig higher than the concentrate discharge pressure. Repeat these steps until the system operation aligns with the designed product water output and concentrate flow rate. Calculate the system recovery rate and compare it to the design value.

Turn on the module power switch and slowly adjust the direct current power supply on the display panel to the required value. Observe the outlet water quality. Record all operational data.

Test all flow limit switches and related interlocking actions. Ensure that the EDI power supply module cuts off power when the concentrate recirculation flow rate is insufficient.

Continue circulating the CEDI unit until the product water quality meets the requirements. Once the EDI water quality meets standards, open the EDI product water valve (to the downstream water tank) and close the EDI product water recirculation valve (to the RO water tank). Reconfirm that the product water pressure is 2-5 psig higher than the concentrate discharge pressure. Compare system operating values to design values. Once the system operates stably (both in terms of water quality and flow rate), record operational data in the daily running data sheet and select the automatic mode for operation.

In the first week of system operation, regularly check the system’s performance to ensure its reliable and consistent operation.

4. Routine Operation

Once the EDI system is up and running (inevitably, the EDI system will experience periodic shutdowns and restarts), each shutdown and restart involves pressure and flow variations, as well as mechanical impacts on the EDI module. Therefore, it’s crucial to minimize the frequency of system shutdowns and restarts to ensure the smooth operation of the EDI system.

Checks before and during system startup should be routine tasks, and thorough records of these tasks should be maintained. Calibration of instruments, alarm systems, safety equipment, and pipeline leak checks should also be part of your daily routine.

5. Shutdown

Reduce current and voltage to 0, and turn off the power supply for the EDI module. Shut down the RO product water transfer pump. Close the inlet valves of each EDI module. Close the isolation valves of the EDI modules.

6. Restart After System Shutdown

Ensure that EDI system valve operation is in the EDI recirculation state. Start the RO product water transfer pump. Follow the EDI startup procedure step by step. If necessary, refer to the EDI supplier’s documentation for sterilization and disinfection procedures.

7. Running Records

To effectively monitor the operation of the EDI system, it’s crucial to collect relevant data and record it in daily operation sheets. Operational data not only helps track the system’s performance but also plays a significant role in diagnosing and addressing EDI equipment issues.


Incorporating these operating instructions and best practices into your routine operation and maintenance procedures will help ensure the efficient and reliable operation of your EDI equipment.

Xi’an CHIWATEC Water Treatment Technology is a high-tech enterprise specialized in various water processing devices. Aside from these individual products, which cover a number of types and series, we can also help with related comprehensive engineering projects. Thanks to our hard work and dedication upon our founding, we are now one of the fastest-developing water treatment equipment manufacturers in Western China.

Further reading

EDI equipment

Do you have a water treatment project we can help with

Designing,machining,installing,commissioning, customize and one-stop service

    We will answer your email shortly!