Bio-Rad BioLogic Signal Import Module (SIM) - Manual (Page 197)

Figure 11-2. Piston Assembly and Access to the Piston Seal
(view showing the back of the Pumphead Module)
f. Using your finger, press each new piston seal into its recess. Use the piston guide to press the
seal completely into its recess.
g. Wipe the pistons with a dampened cloth before returning them to the piston wells. This ensures
that no crystallized salt residues are present which could damage the new seals.
When returning each piston assembly to its piston well, make sure that the seals in the piston
wells on the pumphead assembly are securely mounted in place. The piston assemblies should
be oriented so that the flat faces on the piston guides are in the vertical position.
h. Using the four long mounting screws removed earlier, remount the pumphead module to the
Workstation so that it is secure. Insert and tighten the mounting screws. Do not over tighten.
i. Condition the seal by pumping 100 ml of 100% methanol through each pumphead with the 40
psi backpressure regulator in place.
l. Flush the system with water, and then fill and flush with the buffers to be used for the
separation.
2. Cleaning and replacing a check valve.
a. Soak the new check valves in 50% methanol to wet them. Sonicate in 50% methanol, if
possible.
b. Remove the two short screws at the top of the pumphead assembly and the two long screws at
the bottom of the pumphead assembly. Each pump separates into three blocks, revealing four
check valves and two O-rings.
c. Replace the check valves. It is not necessary to replace the O-rings, as they are not subjected
to high pressure.
d. Reassemble the pumphead. (Refer to Figure 11-3.) Check valves fit into the pumphead module
in one direction only.
e. Wipe the pistons with lab tissue before returning them to the piston wells, and rinse the piston
guides in running water.
The piston assemblies should be oriented so that the flat faces on the piston guides are in the
vertical position.
PISTON
SPRING
SPRING GUIDE
BACK OF PUMP
HEAD ASSEMBLY
FLAT FACE
(VERTICAL POSITION)
PISTON GUIDE
PISTON SEAL
O-RING
MAINTENANCE MAINTENANCE AND TROUBLESHOOTING
11-4