Replacing Pump Check Valves - Thermo Scientific Dionex Easion Operator's Manual

Dionex Easion Operator's Manual
4. Install the new sample loop between the two ports.
5. Make sure the loop is tightly coiled, so that the door can close securely.
6. Click the pump On button on the Chromeleon ePanel.
7. Check for leaking fittings and tighten if required.
8. Close the Dionex Easion front door.
5.6

Replacing Pump Check Valves

A dirty check valve causes erratic flow rates and pressures. In addition, it may
cause the pump to lose prime and/or be difficult to reprime.
Thermo Fisher Scientific recommends replacing both check valves at the same
time. If new check valves are not available, clean the check valves and reinstall
them (see Section
To remove the old check valves:
1. Turn off the Dionex Easion power switch.
2. Disconnect the power cord.
3. Put on standard disposable laboratory rubber gloves (powder-free, particle-
free, and oil-free) before disassembling the pump head.
Never disassemble the pump head with bare hands. Even minute
particles of dust or dirt on the check valves or piston can contaminate
the inside of the pump head and result in poor pump performance.
4. Disconnect the tube fittings from the inlet and outlet check valve assemblies
on the primary pump head (see
5. Use a 1/2-inch wrench to loosen both check valve assemblies. Remove the
check valve assemblies from the pump head.
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5.7).
Figure 5-4).
Doc. 155028-01 08/20