Replacing the Rotor Seal in the MS Selection Valve

Answer

This Information Applies To: Agilent LC/MS Systems

Issue

The MS solvent selection valve (SSV) rotor seal is replaced annually as part of the Preventive Maintenance. It can also be replaced as part of troubleshooting a leak, a flow blockage, or when there are issues with the calibrant flow.

Items Required

• 9/64 inch hex key
• MS selection valve rotor seal, PEEK (p/n 0101-1409)
• MS selection valve rotor seal, Tefzel 400 Bar (p/n 0100-1854) (optional)
• MS selection valve rotor seal, Vespel 400 Bar (p/n 0100-1855) (optional)

Steps to Follow

1. Stop the LC and calibrant flow.
2. Open the front panel and disengage the latch.
3. Before completely removing the front panel, unclip the grey display cable attached to the top-right side of the panel.
4. Remove the top panel by lifting the panel and pulling forward.

   Tips: The top panel hinges at the back and will come free from the slots once lifted and pulled forward.

5. Remove the waste, nebulizer, and peak tubing connections from the SSV.

   Tips: Take a photo to help remember which port each tubing connects to.

6. Remove the hex screws from the stator face with the hex key.

   
   Figure 1: Removing the hex screws on a 6400 series LC/MS
   

7. Check the stator face for any damage or scratches. Carefully place the stator face down, polished side up.

   Tips: Take note of the rotor seal orientation before removing.

8. Remove the old rotor seal and replace with the new part.
9. Reinstall the stator face and tighten hex screws to fingertight. Then tighten each screw ¼ turn to secure the stator face.

   Caution: Do not overtighten the screws.

10. Reconnect the tubing to the SSV.
11. Start the LC flow and ensure that no leaks are seen from the valve and fittings.
12. Replace the top and front panels.

    Tips: Remember to plug the grey display cable back into the front panel.