Metrohm 930 Compact IC Flex Oven/SeS/PP - Manual (Page 72)

5.7 Servicing the high-pressure pump
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930 Compact IC Flex Oven/SeS/PP (2.930.2500)
￭ 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 lead to contaminated valves, an
increase in pressure and, in extreme cases, scratched pistons.
Immediately successive solutions must always be miscible. If the system
has to 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
operated dry. Therefore ensure that the eluent supply is correctly con-
nected and that there is enough eluent in the eluent bottle each time
before turning on the pump.
5.7 Servicing the high-pressure pump
Figure 17 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
5 Inlet valve holder 6 Pressure screw, short (6.2744.070)
Fastened to the inlet valve holder.
7 Eluent aspiration tubing connector
Consists of a coupling with a pressure
screw. 8 Pressure screw, short (6.2744.070)
Fastened to the pump output.
Maintenance interval The following parts of the high-pressure pump have to be serviced at least
once per year: