This Information Applies To: All Agilent G7129x Vialsampler modules
- The needle is visibly damaged.
- 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.
- The needle needs to be replaced as part of yearly maintenance.
- G7129-87200 - Needle assembly, 1260 Vialsampler for G7129-87017 needle seat,
- G7129-87201 - Needle assembly, 1290 Vialsampler for G7129-87012 needle seat,
- G7129-87202 - Needle assembly, slotted, for high injection volumes
See also: Needle & Needle Seats for HPLC
Steps to follow:
This procedure risks exposure to hazardous, toxic or flammable solvents and reagents. When working with these substances observe safety procedures (for example by wearing protective googles, suitable safety gloves and protective clothing) as described in the material handling and safety data sheet supplied by the chemical vendor, and always follow good laboratory practice.
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.
It is recommended to always exchange the needle assembly and the needle seat at the same time to prevent premature leakage.
- Finish any pending or running acquisition job.
- Stop the flow at the pump and remove the solvent lines from the eluent bottles to avoid spilling solvent.
- Close the shutoff valves at the pump if available on your pump module.
- In the Agilent Lab Advisor Software connect to your LC system then select Service and Diagnostics>Maintenance Positions>Change Needle, Loop and Seat.
- Click Start to start the maintenance task. Double check 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 Vialsampler. See Figure 1
Figure 1 - Running the Change Needle, Loop and Seat maintenance task in Agilent Lab Advisor
6. If using the handheld local controller then start the maintenance mode on the controller and select Change Needle, Loop and Seat function.
7. Open the doors of the Vialsampler
Figure 2 - Remove the safety cover
It is important to move the wash port up and then rotate it to the left until it locks in the service position before servicing the needle and needle seat. Failure to do this may lead to alignment issues, and bent needles and wash port damage if the needle hits the top of the wash port during movement to the needle seat after servicing.
Always unsure the following step is performed before moving on with needle and needle seat damage.
9. Move the wash port into the service position by slightly lifting it up and then rotating it to the left until it locks in place.. See Figure 3.
Figure 3 - Moving the wash port into the service position
10. In Lab Advisor select Next to move the needle in the down position (ca. 2 mm above the seat). If using the handheld local controller, move the needle down until the needle tip is approx. 2 to 4 mm above the seat. This will allow access to the needle assembly to remove the sample loop.
11. Disconnect the sample loop from the needle, and, if needed, also from the top of the Analytical Head (Metering Device). See Figure 4.
Figure 4 - Removing the sample loop from the needle assembly and the analytical head (Metering Device)
12. Loosen the fixing screw holding the needle assembly in place, then gently lift out the needle assembly sliding it up off the alignment pin.
15. Mount and align the new replacement needle assembly (see Parts Required) onto the alignment pin so that it is directly over the needle seat, then tighten the fixing screw firmly to secure the needle in place over the needle seat.
In the following step take care when adjusting the needle to avoid any hand injuries with the sharp needle tip.
16. Align the needle tip with the seat and ensure that they are concentric. I needed, carefully bend the needle into the right position with your fingers, see Figure 7.
Figure 7 - Aligning the needle tip with the center of the needle seat
Do not overtighten the loop capillary fitting in the next step. Incorrect positioning and installation of the needle/loop connection can result in damaging or breaking the sample loop.
17. Re-connect the sample loop to the needle and to the metering head if removed. Make sure of the correct position of the loop capillary - the uncoated part of the capillary must be horizontal. See the beginning of Figure 4 for the correct installation orientation of the needle assembly. Do not over tighten this fitting.
18. In Lab Advisor select Next to lift the needle slowly into the up position. If using the local controller, move the needle up to the upper-most position.
19. Move the wash port back down into its original starting position over the needle seat by turning it right and down. See Figure 8.
Figure 8 - Moving the wash port back to the original position.
20. Reinstall the safety cover removed in step 8, and tighten the Torx T-10 screw to hold the safety cover in place.
21. In Lab Advisor select Next to move the needle in to the needle seat, and then select Back to finish the maintenance procedure. If using the local controller, select Continue to move the needle into the needle seat and then Exit to finish the maintenance procedure.
It is recommended to always exchange the needle assembly and the needle seat at the same time to prevent premature leakage. For the next set of instructions on changing the needle seat assembly please see: How to change the needle seat in an Agilent G7129x Vialsampler module
22. Close the doors of the Vialsampler.
If possible, run a system pressure test with the port 6 of the injection valve blanked using the appropriate blanking nut to ensure the Vialsampler flow path is pressure tight to a pressure higher than your application require.
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 causes damage to both assemblies, requiring replacement.