4.6 Servicing the high-pressure pump
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60
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883 Basic IC plus
■ Ensure that no precipitates can form when changing the eluent. Salt
crystals between the piston and seal cause abrasive particles that can
find their way into the eluent. These particles lead to contaminated
valves, an increase in pressure and, in extreme cases, scratched pistons
and thus to leakages in the high-pressure pump.
Immediately successive solutions must always be miscible. If the system
must be rinsed with organic solvents, use several solvents with rising or
falling lipophilicity.
■ In order to protect the pump seals, ensure that the pump is never oper-
ated dry. Therefore ensure that the eluent supply is correctly connected
and that there is enough eluent in the eluent bottle each time before
turning on the pump.
4.6 Servicing the high-pressure pump
NOTICE
You can find a video sequence for this task in the Multimedia Guide IC
Maintenance or on the Internet at http://ic-help.metrohm.com/.
Figure 18
High-pressure pump – Parts
1
Pressure screw, short (6.2744.070)
Fastened to the outlet valve holder.
2
Outlet valve holder
3
Fastening screw
4
Pump head