How to change the needle seat on a G7167x Multisampler

This Information Applies To: All Agilent G7167x Multisampler modules

Issue:

Required when:

• The needle seat is visibly damaged, blocked, or is leaking.
• Leaks or blockages in the Vialsampler are observed, especially between the needle and needle seat.
• The limit for the needle interaction EMF counter is exceeded.
• Replace the needle as part of  the yearly maintenance procedures.

Steps to follow

Tools Required:

• 8710–0510 - Open-end wrench 1/4 - 5/16 inch

• Flathead screwdriver

 Parts Required:

• G4267-87012 - High Pressure Needle Seat, 0.12 mm (PEEK)

  OR

  G4267-87020 - High Pressure Seat Assembly 0.075 mm (PEEK)
  

  See also: Needle & Needle Seats for HPLC

Warning: This procedure risks exposure to hazardous, toxic, or flammable solvents and reagents. Wear appropriate PPE as described in the material handling and safety data sheet supplied by the chemical vendor, and always follow good laboratory practice.

Warning: Risk of injury by uncovered needle. Do not open the safety cover of the needle station during normal operation. Wear safety goggles and safety gloves when removing the needle assembly

Caution: It is recommended to always exchange the needle assembly and the needle seat at the same time to prevent premature leakage. See: How to change the needle on a G7167x Multisampler

1. Finish any pending or running acquisition job.

2. Stop the flow at the pump and remove the solvent lines from the eluent bottles to avoid spilling solvent.

3. Close the shutoff valves at the pump if available on your pump module.

4. Close any online sessions you have connected to the LC system. Open Agilent Lab Advisor Software, connect to your LC system then select Service and Diagnostics>Maintenance Positions>Change Needle, Loop, and Seat.

5. Select Change Seat. If changing the needle assembly, then also select Change Needle. Click Start to start the maintenance task. Confirm the part number for the needle and needle seat listed in the pop-up configuration window match the new needle and needle seat being installed in the Multisampler (Figure 1).

Figure 1. Running the change needle maintenance task in Lab Advisor.

 6. Open the Multisampler front door.

 7. Disconnect the seat capillary from the injection valve (Figure 2).

Figure 2. Disconnect the seat capillary from the Multisampler injection valve.

 8. Slightly pull (1) the front clip that holds the needle seat assembly in position. Then carefully lift (2) the complete assembly from the holder (Figure 3).

 Figure 3. Removing the needle seat assembly from the Multisampler.

 9. Insert the new needle seat (1). Press it firmly into position (2) (Figure 4).

Figure 4: Installing the new needle seat assembly into the Multisampler.

 10. Reconnect the seat capillary to the injection valve (Figure 5).

Figure 5: Reconnecting the seat capillary from the Multisampler injection valve.

 11. It is also recommended to change the needle assembly to ensure a good needle/needle seat seal. See: How to change the needle on a G7167x Multisampler.

 12. Close the Multisampler front door.

 13. In Agilent Lab Advisor software close the Change needle/loop>End, click End, and wait until the needle assembly is in the needle park station. If using the local controller (Instant Pilot) close Change needle/seat.

 If possible, run a system pressure test with the outlet of the Multisampler injection valve blanked using the appropriate blanking nut. This checks that the Vialsampler flow path is pressure tight to a pressure higher than your application requires.

 Cause: Over time deposits can block the needle and the needle seat causing pressure issues and leaks. Also, wear and tear of the needle against the seat during normal operation eventually damages both assemblies, requiring replacement.