•
Pressure bolt(s) on column switching valve are too loose.
Follow the procedure below to tighten the pressure bolts:
1. Turn off the liquid flow.
2. Tighten each pressure bolt fingertight, then use an
open-end wrench to tighten an additional one-eighth turn.
NOTE
All eight pressure bolts must be evenly tightened
against the slider for optimum leak-free operation.
3. Turn on the liquid flow evenly and check for leaks.
Tighten pressure bolts further if leaks appear.
NOTE
Use a torque wrench to evenly tighten pressure bolts
for optimum leak-free operation. Refer to Installation
and Maintenance of the Dionex Inert High Pressure Valve
(Document No. 032678) for torque requirements.
•
A column select valve port is scratched.
Replace the port face.
4.2 Excessive System Backpressure
•
Restriction in the hydraulic system.
1. Check all liquid lines and valves for crimping or
blockage. Make sure ferrule fittings are not overtightened
into Tefzel tubing. Refer to Installation of Dionex Ferrule
Fittings (Document No. 034213) for details.
2. Verify that valves are being fully activated (not between
positions).
•
Flow rate through the columns is too high.
Reduce the flow rate.
LC20 Chromatography Enclosure
4-4
Doc. 034859-02 9/93
Summary of Contents for LC20
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Page 29: ...Figure 3 7 Drawing Sample 3 Operation and Maintenance Doc 034859 02 9 93 3 5 ...
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Page 65: ...Figure B 6 Electrochemical Cell Plumbing Schematic B Installation Doc 034859 02 9 93 B 11 ...