5.3 Restriction in the Hydraulic System
A restriction in the hydraulic system will cause excessive system
backpressure.
1. Begin pumping eluent through the system (including the
columns) at the flow rate normally used.
2. Follow the appropriate hydraulic schematic (see Figures B-4
through B-6) and work backward through the system, beginning
at the cell exit. One at a time, loosen each fitting and observe the
pressure. The connection at which the pressure drops indicates
the point of point of restriction.
3. Remove the restriction either by back flushing or by replacing
the section of tubing.
4. If the restriction is caused by the column select valve,
disassemble the valve and clean the slider (see Section Figure
2-4. Column Select Valve Slider Connections
5.4 Injection or Column Select Valve Liquid Leaks
A poor seal between the ferrule sealing surface and the valve
pressure bolt or between the port face and the valve slider may
cause the column select valve to leak (see Figure 2-3). The flow
rate through the system may be low, producing chromatograms
with longer than normal retention times and poor reproducibility.
1. Tighten any loose fittings fingertight, then an additional
one-eighth turn. Tighten further only if a leak continues.
DO NOT OVERTIGHTEN. Use an open end wrench to hold
the valve pressure bolts to prevent them from turning
when tightening connections to the valves.
LC20 Chromatography Enclosure
5-4
Doc. 034859-02 9/93
Summary of Contents for LC20
Page 6: ...Contents iv Doc 034859 02 9 93 ...
Page 8: ...LC20 Chromatography Enclosure 1 2 Doc 034859 02 9 93 ...
Page 12: ...LC20 Chromatography Enclosure 2 2 Doc 034859 02 9 93 ...
Page 24: ...LC20 Chromatography Enclosure 2 14 Doc 034859 02 9 93 ...
Page 26: ...LC20 Chromatography Enclosure 3 2 Doc 034859 02 9 93 ...
Page 29: ...Figure 3 7 Drawing Sample 3 Operation and Maintenance Doc 034859 02 9 93 3 5 ...
Page 32: ...LC20 Chromatography Enclosure 3 8 Doc 034859 02 9 93 ...
Page 34: ...LC20 Chromatography Enclosure 4 2 Doc 034859 02 9 93 ...
Page 40: ...LC20 Chromatography Enclosure 4 8 Doc 034859 02 9 93 ...
Page 42: ...LC20 Chromatography Enclosure 5 2 Doc 034859 02 9 93 ...
Page 50: ...LC20 Chromatography Enclosure 5 10 Doc 034859 02 9 93 ...
Page 52: ...LC20 Chromatography Enclosure A 2 Doc 034859 02 9 93 ...
Page 56: ...LC20 Chromatography Enclosure B 2 Doc 034859 02 9 93 ...
Page 65: ...Figure B 6 Electrochemical Cell Plumbing Schematic B Installation Doc 034859 02 9 93 B 11 ...