Install Additional Safety Equipment; Purge Gas Set Up; High Flow Purge And Solvent Flush Set Up - Edwards EXS Series Instruction Manual

5.13 Install additional safety equipment

WARNING:
If the control system needs to know the total flow rate of purge gas to the dry
pumping system for safety reasons, install suitable measurement equipment in the
purge gas supply pipeline.
WARNING:
If the gas purges are used to dilute dangerous gases to a safe level, ensure that the
dry pumping system shuts down if the purge gas supply to the dry pumping system
fails.
If the total flow rate of purge gas to the dry pumping system is required to be known for
safety reasons, suitable measurement equipment should be fitted in the purge gas
supply pipeline. If fitting a rotameter, ensure that it is suitable for use with the purge gas
and that it is correctly calibrated.
Ensure that the installation is configured so that it remains safe if there is a failure of the
purge gas supply to the dry pumping system.
If an alarm condition is detected, the dry pumping system will shut down automatically.
Ensure that the installation remains safe if the dry pumping system shuts down
automatically.

5.14 Purge gas set up

For the dry pumping system, the shaft seal purge is always on. The HV shaft seal purge is
default set to high vacuum mode to keep high ultimate performance of the pump. It can
be adjusted to high flow mode by the manual valve (MV3, refer to
when necessary, ultimate performance might be affected when MV3 is set to this mode.
There are also two manual valves for gas ballast control, they were set at the close
position as default. Different gas ballast flow rate can be achieved by adjusting MV1 and
MV2 manually, for details refer to

5.15 High flow purge and solvent flush set up

WARNING:
By default the DP clean high flow purge and solvent flush assembly draws the
atmospheric air into the dry pumping system. If air is not compatible with your
process then nitrogen or another inert gas may be used. It is your responsibility to
assess whether the DP clean purge gas is compatible with the process.
A41870880_A
A41870880_A - Installation
Table: Gas system flow
Page 47
Rear view on page 12)
option.
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