Agilent Technologies 7000 Triple Quadrupole GC/MS, Maintenance Manual

Page: 124 / 214

124 Troubleshooting and Maintenance Manual
5
CI Maintenance
To Minimize Foreline Pump Damage from Ammonia
Air ballasting for an hour every day removes most of the ammonia from the
pump oil. This will greatly increase the life of the pump.
Procedure
1 Turn the ballast valve on the foreline pump ( Figure 17 ) until the 1 s are
aligned. The sound of the pump will get much louder.
2 Leave the ballast valve open for one hour. You can continue to run samples
while the pump is ballasting.
3 Close the ballast valve by aligning the 0 s. Leaving the ballast valve open all
the time will result in loss of pump oil and damage to the pump.
C A U T I O N
Only perform this procedure if the pump is at normal operating temperature. The water
vapor in air can cause condensation of the ammonia at the ballast valve if the pump is
cold.
Figure 17 Minimizing ammonia damage
Ballast valve
C A U T I O N
Always purge the flow module with methane after flowing ammonia. The use of
ammonia reagent gas also requires that the foreline pump oil be changed every 2 to
3 months instead of the usual 6 months.