Operation and Maintenance of Milli Q Water System

Standard Operating Procedure (SOP) for Milli Q Water purification system for its operation, and general maintenance procedure.

SOP for Milli Q Water System

1.0   PURPOSE:

    • The purpose of this Standard Operating Procedure (SOP) is to describe the operation and maintenance procedure of the Milli Q Water System.

2.0   SCOPE – SOP for Milli Q Water System:

    • This SOP is applicable to the following Milli Q Water system at the Quality control department at the pharmaceutical drug manufacturing plant.
      • Model: Elix 10 / Academic

3.0   REFERENCES – SOP for Milli Q Water System:

    • Instruction Manual of the instrument


    • QC-Officer shall be responsible for :
    • To operate the Milli Q water system instrument as per the SOP.
    • Quality Control Head or Designee shall be responsible for :
    • To provide training to all concerned persons before the implementation of the SOP.
    • Quality Assurance shall be responsible for:
    • To ensure the implementation of the system as per SOP
    • Quality Head and Plant Head shall be responsible for:
    • To review and approve the SOP.


    • LED: Light-emitting display
    • NA: Not Applicable
    • QA: Quality Assurance
    • QC: Quality Control
    • SOP: Standard Operating Procedure


    • Open the Feed water-isolating valve.
    • Switch “ON” the power to the system by moving the switch to position “I” located at the rear of the system.
    • The system displays the version and serial number for 10 seconds.
    • Then it will show the display of operating mode.
    • Press “OPERATE/STANDBY” for 2 seconds, the system goes to PREOPERATIVE mode.
    • Now the system is ready for use.
    • Moving the point of use, the trigger forward will initiate and start to dispense water.
    • The system will dispense water from the point of use of the gun.
    • When the dispensing is over move the trigger back to the vertical position to go to PREOPERATIVE mode.
    • When the point of use trigger is brought slightly forward, the Milli Q system goes into a RECIRCULATION mode.
    • The green LED will flash when the water quality is not optimal.
    • Once the green LED is lit steadily, the trigger can be brought forward to dispense water from the point of use of the gun.
    • If the resistivity is below the setpoint, the green LED will blink continuously.
    • Alarm System 

    • During the process, if the ALARM light is lit and display shows the following message “LOW PRESSURE” then restart the system as follows.
      • Press 2 seconds on OPERATE/STANDBY. Repeat this action if the unit goes back into the “LOW PRESSURE” mode.
    • If the message continuously persists contact Engineer for Technical service.
      • In PREOPERATIVE mode, press MEASURE to display temperature.
    • The CLEANING function is used for cleaning and sanitizing the ultrafiltration module.
    • To program a dispensing time period, in PRE OPERATE mode, press MENU for at least 2 seconds.
    • Select or change the volume of water you want to dispense from the Milli Q water system by pressing the MEASURE or CLEANING keypad under the PRESET VOLUME.
    • Press the OPERATE/STANDBY button to validate your volume selection.
    • Press the dispenser trigger forward and allow the water to dispense.
    • After dispensing the LCD will prompt you to ‘CLOSE THE VALVE’.
    • Bring the Dispenser trigger to the upright position.
    • To display the age of the purification cartridge, in PREOPERATIVE mode press MENU for at least 2 seconds. Press MENU twice, the age of the cartridge is shown.
    • Press MENU for at least 2 seconds, display returns back to initial operating mode.
    • Language Selection:

    • To choose display language, in PRE OPERATE mode press MENU for 2 seconds.
    • Now Press MENU four times.
    • Press the arrow keys to change between different languages.
    • Press MENU again to return to PREOPERATIVE mode.
    • This is a default setting for the English language.
    • To choose the unit of measurement for conductivity, in PRE OPERATE mode press MENU for 2 seconds.
    • Press MENU four times.
    • Press on OPERATE/STANDBY.
    • The arrow keys allow the choice of MWcm or m Siemens/cm as units.
    • Press MENU again for 2 seconds to return to the initial operating mode.
    • This is a default setting for MW
    • To choose the measurement unit for Pressure, press MENU for 2 seconds.
    • Press the MENU button the second time.
    • Press twice on OPERATE/STANDBY button.
    • One press on the MEASURE or CLEANING button allows the choice of the display unit.
    • Press 2 seconds on the MENU to validate units and to return to start.
    • The bar is programmed as a default position.

7.0   Routine Maintenance:

    • Replacing the QUANTUM Ultra-pure cartridge
    • Sanitization of the Ultrafiltration module
    • Replacing the Q-Gard Purification Pack
    • Replacing the MILLIPAK 40.
    • Cleaning the screen filter in the feedwater line.



  1. SOP for pH meter
  2. SOP for Conductivity Meter


Janki Singh is experienced in Pharmaceuticals, author and founder of Pharma Beginners, an ultimate pharmaceutical blogging platform. Email: [email protected]

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