Replacing The Check Valve Cartridge - Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual

UltiMate 3000 Series:
LPG-3400XRS Pump

7.3.4 Replacing the Check Valve Cartridge

Two check valve cartridges are installed in the pump head: one inlet check valve cartridge
between proportioning valve and displacement chamber, and one outlet check valve cartridge
between the two displacement chambers.
The two check valve cartridges and the displacement chambers are identical, respectively.
Description
Check valve cartridge (identical for inlet and outlet valve nut)
1. Remove and disassemble the pump head (→ page 110).
2. Disassemble the stack of purge unit, displacement chambers and valve cartridges.
3. Remove the cartridges from the displacement chamber bores.
4. Clean the replacement cartridges and the other pump head components (→ page 127).
5. Install the check valve cartridges in the respective bores in the displacement chambers.
Mind the correct orientation of the valve cartridges and the displacement chambers.
Verify that the valve cartridges are installed in the direction of flow. A flow direction
sign on the check valve cartridges shows the correct orientation (→ Fig. 61). The
displacement chambers should be positioned such that the small notches point upward
and the bores for the guide bushings are on the same side as the pump outlet on the purge
unit (→ Fig. 62).
6. Form a stack out of the purge unit, displacement chambers and valve cartridges
(→ Fig. 62). The bores for the pistons and piston guide bushings should be on the
same side as the pump outlet.
Fig. 62: Stack of displacement chambers (notches pointing upward),
7. Reassemble the pump head with the new valve cartridges and re-install it to the
interior front panel (→ page 113).
Page 124
Fig. 61: Flow direction sign on check valve cartridge
valve cartridges, and purge unit
Part No.
6043.0145
Operating Instructions