User manual

130 1260 Nanoflow Pump User Manual
9 Maintenance
Overview of Maintenance
Overview of Maintenance
Figure 17 on page 131 shows the main assemblies of the pump. The pump
heads and its parts do require normal maintenance (for example, seal
exchange) and can be accessed from the front (simple repairs). Replacing
internal parts will require to remove the module from its stack and to open the
top cover.
Tabl e 23 Simple Repair Procedures
Procedure Symptom Notes
“Removing the Active Inlet Valve” on
page 138
If internally leaking Pressure ripple unstable, run leak test for
verification
“Exchanging the Outlet Valve Sieve” on
page 142
If internally leaking Pressure ripple unstable, run leak test for
verification
“Exchanging the Solvent Selection Valve” on
page 144
Unstable column flow or
system pressure
“Exchanging the Solvent Selection Valve” on
page 144
Column flow and system
pressure drops from time
to time.
A pressure drop of > 10 bar across the frit
(2.5 mL/min H
2
O with purge open) indicates
blockage
“Exchanging the Pump Seals and Seal
Wear-in Procedure” on page 148
If pump performance
indicates seal wear
Leaks at lower pump head side, unstable
retention times, pressure ripple unstable — run
leak test for verification
“Exchanging the Pistons” on page 151 If scratched Seal life time shorter than normally
expected — check pistons while changing the
seals
“Exchanging the Flow Sensor” on page 153 Extended flow range
(100 ul) needed.
Leak on the flow sensor.
Unstable column flow
Flow sensor blocked