When
Damage of piston
Parts and additional items required
Pistons
Syringe filled with isopropanol
Seal wash seals (and seal-handling tool)
Seal wash liquid
Solvent suitable for your application
NOTICE
All pumps except VC-P21 and VC-P33: Whenever you remove the pump head, you must replace the seal wash seals.
Preparations
Remove the pump head (see Replacing the Pump Head).
Follow these steps
Remove the pistons:
If the seal wash plate was removed together with the pump head: Hold down the seal wash plate onto the pump head and pull out the pistons.
If the seal wash plate was removed separately: Pull out the pistons from the seal wash plate.
When reinstalling a piston that you removed
Clean the piston. Follow the steps in Cleaning the Piston.
Replace the seal wash seals (see Replacing the Seal Wash Seals).
To facilitate piston installation, inject a few drops of isopropanol into the piston cavity in which you want to install the piston.
Place the spacing tool onto the pump head.
No. | Description |
---|---|
1 | Pistons (in the picture, the piston bases are marked) |
2 | Spacing tool |
Grasping the pistons by the piston base, push in the pistons until they contact the tool.
Remove the spacing tool. Be careful not to pull out the pistons any further.
Install the pump head (see Installing the Pump Head).
Flush the seal wash system with seal wash liquid (see Flushing the Seal Wash System).
Purge the pump using the solvent of your application.
Inspect all flow connections on the pump head for indications of leakage. Tighten leaky connections when the system pressure is down to zero.
In the Chromeleon software, consider updating the Predictive Performance information for the pistons.
Test the seal wash system and pump for leakage (see Testing the Seal Wash System for Leakage and Testing the Pump for Leakage (General Test)).
Recommended: From the Chromeleon software, perform performance qualification for the pump:
Run the pump-specific Performance Qualification tests (PQ tests) (= Flow Precision Test and Gradient Accuracy Test). For details, refer to the Operational and Performance Qualifications manual.
When the tests are completed, execute the QualificationDone command.