ABB GLA451 User Manual page 101

USER MANUAL | ICOS | INSTRUCTIONS | UM/ICOS-EN REV. B.2
Figure 96 shows the plumbing diagram of a GLA451-AAQC.
Figure 96: Plumbing diagram for Fast -Flow Mode (AAQC)
During high-flow mode, the External pump is on and then Internal pump is off. The external
throttle valve (Figure 97) is used in conjunction with the electronic pressure controller to
adjust the flow through the analyzer. The throttle valve reduces the pressure of the gas to
the pressure controller, while the pressure controller regulates the fine adjustments to
maintain cell pressure. The high-flow throttle valve:

Provides coarse manual control of the flow to compensate for various external inlet
configurations.

Optimizes the pressure at the target set point (≈140 Torr) during high flow
operation.
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