PCX5200 User’s Manual Chapter 4
4-3
The PCX5200 uses a custom-made Eldex reagent pump with piston wash. The piston
seals require periodic replacement. The length of service to be expected from the seal
depends on a wide variety of factors, including whether proper shutdown procedures
were followed, how often the system was turned on and off, and whether the piston-
wash system was wetted. It is critically important that the seal be replaced immediately
upon failure, or better yet, before failure, because the reagent can leak into the
mechanical housing of the pump and cause corrosion. When a leak occurs, you may
notice fluid on the side of the pump. However, a leak may not always be visible,
particularly at slow flow rates. A litmus paper can be placed in the drain slot (both sides
of the pump); the litmus paper should be removed periodically and checked for color
changes to see if leakage has occurred.
If you have the piston seal wash feature, and the pump pressure exceeds 2500 psi for
more than a couple minutes, the high-pressure piston seal will deform, and start to leak.
After you have corrected the high-pressure situation, replace the piston seal.
You will need to purchase a seal kit (3106-1310; including two seals, two back-up
washers, a 5/32˝ hex wrench, and a seal installation tool). Extra seals and a preventive
maintenance kit may also be ordered from Pickering Laboratories (see Appendix B).
Additional tools needed for piston seal change are 1/4˝ and 1/2˝ open-end wrench. Open-
end wrenches can be purchased at local hardware stores.
1. Flush the Eldex pump with water, then shut down the PCX5200, and let the reactor
cool. Turn off the gas valve and vent the reservoirs. Turn off the integrated 2-way
valve on the reservoir cap.
2. Open the column oven.
3. Remove the flow conditioner panels (center and right) by loosening the captive
screws. Remove one flow conditioner at a time. After removing the captive screw, flip
the flow conditioner upside down and place it behind the louver (in front of the
column oven). You do not need to disconnect any tubings yet. Repeat the same
procedures for the second flow conditioner panel.
4. Disconnect the reagent inlet line from the bottom of the pump head. Wipe up any
spilled liquid. Disconnect the outlet tubing from the top of the pump head (stabilize
the outlet check-valve with a 1/2˝ wrench when removing the 1/16˝ fitting to prevent
the check-valve from moving).
Routine
Maintenance
Reagent Pump
Pump Seal
Replacement
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