Pressure - Thermo Scientific thermoscientific Vanquish UHPLC System Operating Manual

8 • Troubleshooting
8.2.5

Pressure

Pressure pulsation or inconstant pressure
Possible Cause
Air trapped in the
system
Inlet and/or outlet
check valve
contaminated or
defective
Pump inline filter (or
static mixer) clogged
Solvent line filter
clogged
Pump head
compression values not
reached
System clogged with
particles
High backpressure
Possible Cause
One or more capillaries
in the system clogged
or damaged by bending
Pump inline filter (or
static mixer) clogged
Pre-heater clogged
Column switching valve
clogged
Post-column cooler
clogged or defective
Flow cell clogged
Contamination in the
system
Low backpressure
Possible Cause
Leak in system
Page 120
Remedial Action
Purge the pump (refer to Pump Operating Manual).
Clean the inlet check valve or outlet check valve, and replace the check valve if
necessary (refer to Pump Operating Manual).
Check the permeability of the inline filter (or static mixer). Replace the inline filter
(or static mixer) if necessary (refer to Pump Operating Manual).
Check the solvent line filters for permeability. Replace the filter frits if necessary
(refer to Pump Operating Manual).
Check the compression values and take remedial action (refer to Pump Operating
Manual).
Samples and insufficient solvent purity are frequently the source for particles
clogging the system. Follow the instructions for resolving clogging in the
autosampler (refer to Split Sampler Operating Manual).
Remedial Action
Check the capillaries in the system systematically from the detector to the pump.
Replace the capillaries as needed.
Check the permeability of the inline filter (or static mixer). Replace the inline filter
(or static mixer) if necessary (refer to Pump Operating Manual).
Rinse the pre-heater capillary in reverse direction, using an appropriate solvent. If
necessary, replace the pre-heater (refer to Column Compartment Operating
Manual).
Check the valve for indications of blockage. Replace the valve if necessary (refer to
Column Compartment Operating Manual).
Rinse the post-column cooler capillary in reverse direction using an appropriate
solvent. If necessary, replace the post-column cooler (refer to Column
Compartment Operating Manual).
Clean the flow cell. Replace the flow cell if necessary (refer to Detector Operating
Manual).
Flush the system with an appropriate solvent.
Remedial Action
Find and eliminate the leak.
UHPLC System
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