When

  • Switching valve is leaking due to damaged valve stator and/or rotor seal

  • Rotor seal is clogged

Parts required

  • Replacement valve stator and/or rotor seal

  • Viper fitting or plastic fitting plugs

Tools required

Hexagon wrench, size 9/64’’

Preparations

  1. Turn off the pump flow.

  2. Disconnect all liquid lines connected to the VICI switching valve.

  3. To remove the installed valve pod from the valve flange, screw a Viper fitting into the valve pod or use plastic fitting plugs.

  4. Pull out the valve pod firmly using the Viper fitting or the plastic fitting plugs.

Follow these steps

  1. Remove the 2 stator screws using the hexagon wrench. Alternately, loosen the screws in turn until you can remove them.

  2. Figure: Stator screws
  3. Remove the stator from the valve body. To avoid damage to the sealing surface, turn the stator so that it rests on its outer surface.

  4. 12
    Figure: VICI switching valve

    No.

    Description

    1

    Stator

    2

    Valve body

  5. Carefully remove the rotor seal with your hand.

  6. NOTICE

    To avoid scratches on the sealing surfaces, do not use pointed or sharp-edged tools to remove or install a seal. Even small scratches may result in poor sealing performances of the valve.

  7. Inspect the sealing surfaces of the rotor seal and stator for scratches. If scratches are visible, replace the rotor seal and/or stator.

  8. Insert the replacement rotor seal:

    • Observe the orientation of the seal. The sealing surface with the engraved flow passages must be facing out. The pattern is asymmetrical to prevent improper placement of the rotor seal.

    • Be careful to avoid contamination of the valve parts. Even minor particles may cause damage to the valve and result in poor sealing performance.

  9. Reinstall the stator and tighten both stator screws alternately, each time approximately one-quarter turn, until they are tightened.

  10. TIP

    Avoid overtightening. The screws hold the assembly together and do not affect the sealing force which is automatically set as the screws close the stator against the valve body.

  11. Reinstall the valve pod as described in the respective section in Replacing the VICI Switching Valve.

  1. Inspect the valves visually for leakage.

  2. Run the script: D02 - Test System Tightness (What Should Be Tested = Sampler). This script also tests the column switching valves for leakage.

  1. If leakage is still observed, replace the valve. See Replacing the VICI Switching Valve.