Exchange the Needle Seat Assembly

When

The seat is visibly damaged.
Leaks or blockages are observed.
The limit for the seat interaction EMF counter is exceeded.
The needle seat needs to be replaced as part of the yearly maintenance.

Tools required

Qty.	p/n	Description
1	8710-0510	Open-end wrench 1/4-5/16 inch
1	5182-3466	Torx screwdriver T10
1	5023-3138	Reversible Screwdriver + Blade 1,0 x 5,5

Parts required

Qty.	p/n	Description
1	G7129-87017	Seat Assembly, PEEK, 0.17 mm, 1260 Vialsampler OR
1	G7129-87012	Seat Assembly, PEEK, 0.12 mm, 1290 Vialsampler OR
1	G7129-87117	Seat Assembly, Vespel, 0.17 mm, 1260 Vialsampler OR
1	G7129-87112	Seat Assembly, Vespel, 0.12 mm, 1290 Vialsampler

Prerequisites

Finish any pending 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.

WARNING

Risk of injury by uncovered needle

An uncovered needle is a risk of harm to the operator.

Do not open the safety cover of the needle station during normal operation.
Wear safety goggles and safety gloves when removing the needle assembly.

NOTE

When the instrument setup has changed, configure the new setup in the online view of the Chromatographic Data System. See The Vialsampler User Interface.

NOTE

When the instrument setup has changed, configure the new setup in the online view of the Chromatographic Data System. See The Vialsampler user interface.

NOTE

It is recommended to always exchange the needle assembly and the needle seat at the same time to prevent premature leakage.

NOTE

The use of a Vespel needle seat (G7129-87112 and G7129-87117) limits the maximum system pressure to 600 bar.

In the Agilent Lab Advisor software select Service & Diagnostics > Maintenance Positions > Change Needle, Loop and Seat , click Start and wait until the needle assembly is in maintenance position.

OR: In the Local Controller start the maintenance mode and select Change Needle, Loop and Seat function.
In Lab Advisor use Next to move the needle in the down position.
Disconnect the seat capillary fitting from the injection valve (port 5) and ease out the needle seat from the leak tray with the help of a flathead screwdriver.
Insert the new needle seat and press it firmly into position. Then, connect the seat capillary fitting to port 5 of the injection valve.
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.
In Lab Advisor use Next to lift the needle slowly into the up position.
In Lab Advisor, select Next to move the needle into the needle seat and then Back to finish the maintenance procedure.

OR: In the Local Controller, select Continue to move the needle into the needle seat and then Exit to finish the maintenance procedure.
Perform a System Pressure Test.

21-Jun-2025