Agilent Technologies 7000 Triple Quadrupole GC/MS, Maintenance Manual

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Vacuum System
6
Troubleshooting and Maintenance Manual 133
Foreline Pump
The foreline pump reduces the pressure in the analyzer chamber so the
high-vacuum pump can operate. It also pumps away the gas load from the
high-vacuum turbo pump. The foreline pump is connected to the high-vacuum
pump by a 130-cm hose called the foreline hose.
Figure 20 shows the standard pump; the high-throughput pump is similar.
The foreline pump is a two-stage rotary-vane pump. The pump turns on when
the MS power is turned on. The foreline pump has a built-in check valve to
help prevent backstreaming in the event of a power failure.
The foreline pump is usually on the floor below the MS.
An oil trap (not shown) is available for the pump that can be used to filter
pump oil out of the foreline pump exhaust. This trap stops
only pump oil. Do
not use the trap if you are analyzing toxic chemicals or using toxic solvents.
Instead, install an 11-mm id hose to remove the exhaust from your lab.
Figure 20 The foreline pump
Ballast control
Fill cap
Exhaust outlet
Oil drip tray
Power switch
Oil level window
with oil mist filter
Drain plug (on front)
Foreline pump (shown without safety cage)
Foreline hose from turbo pump