Thermo Scientific Dionex Aquion RFIC Operator's Manual page 98

6
Service
Replacing a Pump Piston Seal and Piston Rinse Seal
82 Dionex Aquion RFIC Operator's Manual
Figure 33. Filling the pump head cavity with deionized water
4. Reinsert the piston into the seal, and then push the piston into the head (see
Figure 34). This should hydraulically unseat the seal, causing it to pop out of the
head. When this occurs, remove the piston and pull off the seal.
5. If the seal does not pop out of the head, follow these steps:
a. Verify that the 10-32 fitting plugs in the inlet and outlet holes are tightened enough
to prevent any leaks from the pump head.
b. Fill the piston cavity with water and check for bubbles.
c. If there are no bubbles, repeat
Figure 34. Removing the piston seal from the pump head
d
Seal
6. Remove the 10-32 fitting plug(s).
To install the new piston seal

1. Open the priming valve knob (primary pump head) or waste valve knob (secondary
pump head) by turning the knob one-quarter to one-half turn counterclockwise.
2. Push the piston through the spacer and then through the new seal. Insert the piston and
seal into the pump head until the seal makes contact with the bottom of the counterbore.
Note If necessary, lubricate the seal with a small amount of 0.2 micron filtered
isopropyl alcohol to facilitate insertion.
Step 4.
Piston
Pump head
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