Bio-Rad BioLogic DuoFlow Pathfinder 80 System HR Gradient Pump Maintenance Kit - Manual (Page 2)

the Washout Block onto the pistons and set the pump head module back onto the Washout
Block on the BioLogic Workstation. (The Washout Block guides the pump head module in the
reattachment process and protects the pistons.)
h.
Replace the four screws until the pump head module is secure on the Workstation but do not
overtighten.
Figure 2. Removing the Piston Seals (view showing the back of the Pump Head Module)
2. Cleaning and replacing a check valve.
a. Remove the Pump Head Module from the Workstation. Refer to Figure 1 and the previous
procedure.
b. Remove the two Pump Head Module Assembly screws at the top of the module. See Figure
3.
NOTE: Never remove the top screws without first removing the Pump Head Module from the
Workstation.
The pump head can now be separated into three parts and the two check valves will be
accessible.
c. To clean the check valves, remove them from the assembly and clean by sonication in a bath
of warm water with detergent or in a bath of methanol. After sonication, rinse thoroughly.
Using a syringe, inject filtered, deionised water through the check valve.
d. Reassemble the pump head with either a cleaned check valve or a new check valve.
Because the orientation of the check valve is critical, they are designed to fit into the pump
head module in one direction only.
e. Reassemble the pump head as shown in Figure 3. Replace the two pump head module
assembly screws and tighten firmly.
f. Position the Washout Block over the pistons and set the pump head module back onto the
Washout Block on the BioLogic Workstation. See Figure 1. (The Washout Block guides the
pump head module in the reattachment process and protects the pistons.)
g. Replace the four screws until the pump head module is secure on the Workstation but do not
overtighten.
PISTON SEALS
BACK OF PUMP
HEAD MODULE
GLAND
PISTON SEAL
REMOVAL TOOL