5
Troubleshooting
28
Pump P-960
User Manual 18-1172-73 Edition AA
5.2
Removing trapped air bubbles from the sample pump
During routine operation, the presence of air bubbles in the pump
heads is seen as an erratic flow, a flow that is lower than expected, or
an irregular pressure recording. If the sample pump is completely dry,
it might fail pumping liquid.
If the air has accumulated due to a leaking tubing connector, tighten the
connector or replace it if necessary.
To remove small amounts air from the sample flow path, try running
the pump manually with buffer according to section 5.2.1.
If the pump is dry or if there is plenty of air in the sample inlet tubing,
it must be purged with a purge tubing according to section 5.2.2.
5.2.1
Removing air by running the sample pump manually
If there are only small amounts of air in the sample flow path, remove
the air as follows:
1
Immerse the end of the sample inlet tubing in a suitable buffer.
2
If using sample valve V5, set the valve to port 8 (buffer inlet).
3
Set the injection valve according to Table 5-1.
Table 5-1.
Settings for purging Pump P-960 automatically
4
Run the pump at the flow rate and time shown in Table 5-1.
If the pump fails pumping liquid, remove the air using a purge
tubing according to section 5.2.2 Removing air using a purge
tubing.
System tubing configuration
Injection valve position
Flow rate [ml/min]
Time [min]
Filling a sample loop
LOAD
5
1
Direct loading onto a column
WASTE
40
1
Loading a Superloop
INJECT
40
1
WARNING! OVER-PRESSURE.
The injection valve must be set to
position INJECT in the "Loading a Superloop" configuration. If not, the
Superloop might rupture due to over-pressure when running the
sample pump, resulting in injury.
18117273aa.book Page 28 Thursday, July 3, 2003 5:13 PM