Bio-Rad Profinia™ Protein Purification Instrument - Manual (Page 154)

Cleaning and Replacing Inlet (Bottom) Check Valves
Fig. 13.4. Diagram of the inlet check valve.
To clean or replace the inlet check valve:
1. Remove the two tubing fittings from the bottom of the inlet flow cell.
2. Using your fingers or a 9/16" open-end wrench, unscrew the inlet flow cells from the
pump body.
3. Hold the check valve body with a 9/16" open-end wrench, and loosen the threaded
insert with a ½" open-end wrench.
4. Unscrew the insert (male threaded part) from the valve body (female threaded part).
Note the black rubber disk on the insert, and look into the cavity of the valve body; you
will see a tan-colored plastic disk. This disk has a groove machined into one side (the
side facing you) and three small, drilled holes.
5. Turn the check valve body over and tap it on the benchtop to remove the plastic disk.
6. Carefully pry the rubber disk from the insert.
7. Rinse the check valve parts thoroughly in water and examine for damage; replace if
damaged.
8. Replace the plastic disk in the check valve body, with the groove facing toward you.
9. Replace the rubber disk in the threaded insert — it is the same on both sides.
10. Thread the check valve insert into the check valve body and tighten, using the two
wrenches as described in step 3 above.
Note: Do not overtighten the insert.
11. Thread the assembled check valve into the pump body, and tighten with a 9/16"
open-end wrench; do not overtighten.
12. Reconnect the tubes and fittings to the top of the check valves.
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