Replacing the Inlet Septum for Split/Spitless and Multimode Inlets

Answer

This Information Applies To: Agilent Intuvo 9000, 8860, 8890, 7890A/B, 7820A, 6890, 6850 GC Systems with Split/Splitless, or Multimode Inlets.

Issue:

This article describes how to replace the inlet septum for Split/Splitless and multimode inlets for all Agilent GC Systems. Regular replacement of the septum can reduce small leaks in the inlet, allow for more reproducible chromatography, and protect the column from degradation. Replacement intervals should be every 100 to 400 injections depending on the septum part number and can be replaced sooner if experiencing symptoms of a leak. 

Steps To Follow:

Tools Required:

• Replacement septum
• Tweezers
• Gloves

Warning: The oven and/or inlet may be hot enough to cause burns. If the inlet is hot, wear heat-resistant gloves. If possible, set the temperatures to cooler values during maintenance activities

1. For 8890, 8860, Intuvo 9000 GC systems, in the touchpad, or browser interface, go to  Maintenance > Front (or Back) Inlet > Perform Maintenance. From the checklist, select the Replace Septum check box, then click/press Start Maintenance. Follow the instructions on screen.
   For all other Agilent GC systems, manually reduce the inlet and oven temperatures to below 50 °C. After temperatures are below 50 °C, depressurize the inlet by setting the inlet pressure to zero, then turning off the inlet pressure. This way the inlet will be depressurized safely before turning off the inlet pressure. 
2. Remove the ALS tower if installed and place it on a mounting pin on the back of the instrument.
3. Remove the septum retainer nut. (See Figure 1 for full replacement in steps 3 to 8)
4. Use tweezers to remove the septum from the insert assembly. Do not gouge or scratch the interior of the insert assembly
5. If septum has needle guide recess in one side, ensure that side is facing up.
6. Press new septum firmly into insert assembly.
7. Replace septum retainer nut.
8. Finger-tighten the septum retainer nut until the C-ring is about 1 mm above the nut. (see Figure 2)

   
   Figure 1: Complete replacement procedure for septum in steps 3 to 8

      
   

   
   Figure 2: Proper distance between the septum retainer and the C-ring
   
   

   Tips: Steps 9 to 11 of this procedure are executed automatically in the Intuvo 9000, 8890 and 8860 GC systems if the septum replacement was performed from the Maintenance section of the touchpad, or browser interface.

9. Turn on the inlet pressure, and set the pressure value of the analytical method.
10. Allow the inlet and the column to purge with carrier gas for 15 minutes before heating the inlet or the column.
11.  Restore the conditions of the analytical method

Learn how to effectively maintain your Split/Splitless and Multimode Inlet: GC-7890-2240s - Agilent 7890 Series GC: Preparing for Maintenance and Maintenance Utilities GC-7890-2245s - Agilent 7890 Series GC: Split/splitless inlet Troubleshooting GC-8890-2200s - Agilent 8890 GC Maintenance and Troubleshooting e-learning available from Agilent education. Replacing your septum, liner and O-ring Video on Agilent.com