Install Additional Safety Equipment; Purge Gas Set Up - Edwards GXS Series Instruction Manual

3.12 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.

3.13 Purge gas set up

There are two types of gas module used on dry pumping systems. Refer to
page 18. The gas module configuration may be adjusted to suit process demands.
Contact our service personnel for instruction on how to access the gas valves menu (by
the PDT) and for the process‑specific recommendations.
For dry pumping systems using the medium‑duty gas module, there is an adjustable
needle valve fitted to the purge pipe which enables the adjustment of the level of gas
ballast to suit the application.
Use the following procedure to adjust the gas ballast:
1. Remove the left hand side panel of the dry pumping system.
2. Identify the adjustable needle valve on the purge pipe (contact us for guidance).
3. Adjust the needle valve until the required flow is met. Refer to
18 for the purge gas flows.
4. Refit the left side panel.
For GXS450 and GXS750 dry pumping systems with medium‑duty gas module, there is
an additional electronically controlled gas ballast available for harsh applications. By
default, these dry pumping systems are supplied with this additional gas ballast switched
off but it can be enabled using the PDT.
Use the following procedure to enable the additional gas ballast:
1. Press the SETUP button on the PDT to enter the SETUP menu.
2. Scroll using the UP/DOWN keys and select the FIT ACCESSORY menu.
M58800880_H - Installation
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Purge data on
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