Panametrics Aurora H2O, User Manual

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Chapter 6. Maintenance
12 Aurora H2O User’s Manual
6.3 Replacing the Filter Element
The Aurora H2O uses a membrane filter (see Figure 98 to the left) as the
secondary filter. This filter is intended to prevent liquid or particulate
contamination from entering the absorption cell. The Aurora should not be
operated without a filter train upstream of the unit. The membrane filter is
equipped with “Flow Block” which shuts off the flow if the filter element is heavily
loaded with contamination. A spring loaded check valve closes the outlet flow of
the sample if the differential pressure across the filter element exceeds a
threshold limit. At any given time the flow through the Aurora H2O can be
checked by observing the rotameter. If the “flow block” feature shuts off the flow,
do not increase the pressure. Replace the filter element and clean the filter.
Figure 98: Membrane Filter
If the flow is being shut off too frequently, additional sample condition schemes,
or the combination of the following, will have to be employed:
• Bypass flow - needed to sweep liquids or contamination off the filter. A 10:1 bypass flow rate should be
maintained.
• Additional upstream filtration
•
Heat - Heat tracing of the sample line and sample system components, sufficiently above both the water and
hydrocarbon dew point, will keep the sample in the gas phase.
To replace the filter element, complete the following steps:
1. Close the inlet isolation needle valve and allow the system to fully depressurize.
2. Turn the filter cap counter-clockwise (see Figure 99 below). You might need to use a channel-lock wrench to
assist in loosening the cap.
Figure 99: Removing the Filter Cap