Metrohm 861 Advanced Compact IC User Manual
Page 85
4.2 Maintenance and servicing
861 Advanced Compact IC / Instructions for Use 8.861.1033
75
the upper opening in the valve housing. The individual com-
ponents are rinsed with dist. water and/or acetone, and the
sapphire sphere cleaned with a paper towel. The valve is then
reassembled in accordance with Figure 21. The components
of the inlet and outlet valves are identical, they are distin-
guished only by the positioning of the sapphire sleeve 107
and the ceramic holder 109 (see Figure 21).
•
Valves that fail to function faultlessly after such cleaning must
be replaced.
•
In the reinstallation of the inlet valve 99 or the outlet valve 100
on no account must the two outwardly identical valves be in-
terchanged. To determine which valve is which, note that the
liquid flows through the pump head from the bottom up. The
flow direction of the valves can be checked simply by blowing
through the clean valve. Both valves are installed with the
black face in the direction of the pump head (see Figure 19).
is installed instead of the outlet valve
, an extreme pressure buildup occurs within the working cylinder,
which is not detected by the pressure transducer and will destroy the
6 Mounting the pump head
•
Reassemble the components of the pump head 40 as shown
in Figure 19. Tighten the screw 90 by hand. First screw in pis-
ton cartridge 94 manually until the stop is reached and then
use a wrench to turn it through a furt
her 15°. Firmly tighten the
two valve screw holders 101 with a wrench.
•
Reattach pump head 40 to the pump with the help of the 4
fixing screws. Firmly tighten them with the 6.2621.030 Allen
key.
To ensure that the pump head is not positioned wrongly, the
holes at the rear for the clamping bolts have different depths,
i.e. 1 clamping bolt is longer than the rest. The deepest hole
must naturally accommodate the longest bolt. If this is not the
case, the pump will not function properly.
•
Screw connection capillary 39 to pump head 40 (see
Figure 3 / Figure 4 / Figure 5).
•
Connect aspirating tubing 63 to aspirating capillary 38 at
the pump head 40.