Emerson Rosemount 370XA, System Reference Manual

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370XA Gas Chromatograph System Reference Manual
APRIL 2014 7P00370-H01
3 - 25
3.6 Actuation gas
The analytical valves require actuation gas to operate. When helium
is used as a carrier gas, the default configuration is to also use helium
as the actuation gas. When hydrogen is used as a carrier gas, or if
there is a desire to minimize helium usage, another clean dry gas
such as nitrogen or clean-dry air should be used as the actuation gas.
NOTICE
If you intend to use locally generated instrument air, ensure that the pressure is
sufficient and use filters and dryers to ensure the actuation gas will meet the above
specifications in order to avoid excessive maintenance.
3.6.1 Helium actuation gas
When the carrier gas is also used as the actuation gas, the actuation
gas supply connection should be teed from the helium supply after the
moisture filter.
3.6.2 Alternative actuation gas
If a gas other than the carrier gas is to be used as the actuation gas,
the supply should be connected directly to the actuation gas port on
the 370XA gas manifold. The actuation gas should be nitrogen, dry
air, or some other non-hazardous gas.
Actuation gas specifications
Moisture content Less than 5 ppm
Particulate Less than 2 microns
Supply pressure 90 PSI (620 kPaG)