This Information Applies To: Agilent G7129A/B/C Vialsampler
Issue:
Replacing the needle and needle seat of the Vialsampler is required when:
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.
Steps to follow:
Tools Required:
One of the following needle assemblies depending on the Vialsampler configuration:
And one of the following needle seats depending on the Vialsampler configuration:
See also: Needle & Needle Seats for HPLC
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Warning: This procedure risks exposure to hazardous, toxic, or flammable solvents and reagents. When working with these substances observe safety procedures (for example by wearing personal protective equipment) as described in the material handling and safety data sheet supplied by the chemical vendor, and always follow good laboratory practice.
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Tips: It is recommended to always exchange the needle assembly and the needle seat at the same time to prevent premature leakage.
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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 click Service and Diagnostics>Maintenance Positions>Change Needle, Loop and Seat.
Click Start to start the maintenance task. Confirm the part number for the needle and needle seat listed in the pop-up configuration dialog box match the new needle and needle seat being installed in the Vialsampler. (See Figure 1)
If using the handheld local controller then start the maintenance mode on the controller and select the Change Needle, Loop and Seat function.
Open the doors of the Vialsampler
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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.
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Remove the safety cover by loosening the Torx T-10 screw on the side of the safety cover and titling it up and then away from the Vialsampler. (See Figure 2).
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Caution: It is important to move up the wash port and then rotate it to the left until it locks in the service position before servicing the needle and needle seat. Failure to perform this step 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 ensure that the following step is performed before moving on with needle and needle seat exchange.
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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. Lift up the wash port, and then to the right until it locks in place.
In Lab Advisor, click Next to move the needle in the down position (approx. 2 mm above the seat). If using the handheld local controller, move the needle down until the needle tip is approx. 2–4 mm above the seat. This will allow access to the needle assembly to remove the sample loop
Disconnect the sample loop from the needle, and, if needed, also from the top of the Analytical Head. (See Figure 4)
Loosen the fixing screw holding the needle assembly in place, then gently lift out the needle assembly sliding it up off the alignment pin.
Disconnect the seat capillary from the injection valve (port 5) and ease out the needle seat from the leak tray with the help of a flathead screwdriver. (See Figure 5)
Insert the new needle seat and press it firmly into position. Then connect the seat capillary fitting to port 5 of the injection valve. (See Figure 6)
Mount and align the new replacement needle assembly (see Parts Required section) 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.
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Warning: In the following step, take care when adjusting the needle to avoid any hand injuries with the sharp needle tip.
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Align the needle tip with the seat and ensure that they are concentric. If needed, carefully bend the needle into the right position with your fingers. (See Figure 7)
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Caution: 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.
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Reconnect 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.
In Lab Advisor, click Next to lift the needle slowly into the up position. If using the local controller, move the needle up to the uppermost position.
When instructed in Lab Advisor, move the wash port back down into its original starting position over the needle seat by turning it right and down. (See Figure 8)
Reinstall the safety cover removed in step 8, and tighten the Torx T-10 screw to hold the safety cover in place.
In Lab Advisor, click Next to move the needle into the needle seat, and then click 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.
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 that the Vialsampler flow path is pressure tight to a pressure higher than your application require.
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Learn more on how to effectively troubleshoot your Agilent G7129x Vialsampler: |
