Metrohm 940 Professional IC Vario ONE/SeS/PP/Prep 2 - Manual (Page 88)

5.8 Servicing the high-pressure pump
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940 Professional IC Vario ONE/SeS/PP/Prep 2 (2.940.1520)
￭ Has the pressure dissipated?
￭ Is the instrument switched off?
1 Release the coupling from the pressure screw and seal it with a stop-
per.
2 Unscrew and remove the pressure screw on the pump head's output
(18-8).
3 Unscrew and remove the four fastening screws (18-3) using the hex
key.
4 Remove the pump head (18-4).
Replacing the piston seal
Carry out the following work on both pistons in turn.
Servicing a piston consists of the following tasks:
1. Replace the piston seal.
2. Optional: Clean or replace the zirconium oxide piston.
3. Reinstall the piston.