
Chapter - 3
MNL000442.doc
Revision 00
09/19/2016
© Versum Materials, Inc. as of the revision and date shown. All rights reserved.
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The purge gas source for the GASGUARD
Distribution System should be used only to
purge other gas source systems or VMBs
handling the same process gas. It must not
be used to purge systems handling
incompatible process gases. It is
recommended that the purge gas cylinders
be placed in an exhausted enclosure. Purge
gas must not be supplied from a low
pressure bulk gas source.
3.6
Pneumatic Supply
A pneumatic supply of inert gas without oxygen is recommended for our
controllers.
It is strongly recommended to not use clean dry air for pneumatic
supply.
The pneumatic supply may be shared in the controller between the
pneumatic solenoids and the enclosure inerting/pressurizing service (Z-purge).
Clean dry air may promote the corrosion of electrical connectors for
interconnecting power cables. The presence of oxygen enhances the corrosion
effect and may result in deterioration of controller performance.
This nitrogen supply needs to be regulated to 85-95 psig (5.9-6.6 barg). The flow
rate required for pneumatic valve operation is negligible. If compressed air is used
as the pneumatic source, the compressor shall be located in a non-classified area. If
the air intake line for the compressor passes through a classified location, the line
shall be made of a non-combustible material designed to prevent leakage and
protect against mechanical damage. If electrical power for the purge air is required,
this power shall be on a separate disconnect or before the gas distribution system
disconnect.