When
Damage of a metering device head
Parts required
Replacement metering device head
Tools required
Screwdriver, Torx T30
Tweezers (optional)
Preparations
Run the script: C22 - Replace Metering Head to undock the metering device head.
Prepare the autosampler for maintenance:
Turn off the pump flow. Wait until the system pressure is down to zero before you continue the shutdown of the autosampler.
To empty the drain pump, leave the drain pump turned on until no condensing water is present in the waste tubing. After that, turn off the drain pump and remove the peristaltic tubing from the drain pump. Any liquid that is present in the drain pump tubing flows off to waste.
Move the needle into service position and secure the needle unit. See Securing the Needle Unit.
Empty the seal wash system:
- Unscrew the cap of the seal wash reservoir.
- Together with the cap, remove the seal wash line from the seal wash reservoir.
- To empty the seal wash line, lift up the lever of the seal wash pump. Release the lever when the line is empty.
Disconnect the capillaries from the metering device head. See Disconnecting and Connecting Metering Device Head Capillaries.
Disconnect the seal wash lines from the metering device head. To facilitate the removal, disconnect the tubing connectors with the lines connected from the metering device head and use tweezers.
Removing the Metering Device Head
Loosen the two screws that attach the metering device head to the autosampler with the screwdriver.
Remove the metering device head:
- Take the metering device head by its front. Carefully move the metering device head to the left and the right a few times to detach the piston from the metering device.
- Check that the metering device head stands out by approximately 5 mm from the front panel of the autosampler.
- Carefully push the front of the metering device head downward and pull the metering device head away from the front panel.
- Check that the metering device head is removed with the piston.
No. | Description |
---|---|
1 | Piston |
2 | Metering device head |
TIP
If the piston is stuck in the metering device, remove the piston first before you continue with the replacement procedure. See section Removing a Stuck Piston from the Metering Device.
Installing the Metering Device Head
Unpack the replacement metering device head. Leave the fitting plugs installed and the seal wash lines interconnected on the replacement metering device head.
Insert the metering device head in the opening in the front panel.
Tighten the two screws on the metering device head with the screwdriver (Torx T30) until they cannot be turned further.
Remove the fitting plugs from the metering device head.
Disconnect the interconnected seal wash lines from the interconnecting tubing connector. The seal wash lines can remain connected to the metering device head.
Connect the seal wash lines of the new metering device head in the seal wash system. Follow the corresponding installation steps for the seal wash lines to install in Replacing the Seal Wash Lines
Connect the capillaries on the metering device head. See Disconnecting and Connecting Metering Device Head Capillaries.
Complete the autosampler maintenance:
Unlock the needle unit. See Unlocking the Needle Unit.
Restart the autosampler.
Prepare the autosampler for operation. See Preparing the System for Operation.
Run the script: C22 - Replace Metering Head. The autosampler prepares the metering device head for operation.
Test the seal wash system for leakage. See Testing the Seal Wash System for Leakage.
Flush the seal wash system. Run the script: B01 - Change Liquids / Solvents (with: Rear Seal Wash Liquid and Refresh Only = Off.)