Do I need to purge the gas clean filter (CP17973) after I replace it? If yes, then how do I do this?

Hi

Purging means to pass same gas through gas filter that going to use.

So you can pass same gas for 5 to 10 minutes through filter but make sure outlet line under fumehood or connect gas line with gas filter to instrument and let it pass for 5 to 10 min to vent...

Filter has nitrogen in it when it ships.  When I set up new GCMS systems with this filter, I'll set the inlet split flow to 200-250 mL/min overnight.  By the next morning the filter is purged (nitrogen reading on GCMS is at acceptable level).

Hello!  For instructions on how to flush the Gas Clean Filter, refer to page 30 in the Gas Clean Filter System User Guide.    

Gas Clean Filter System User Guide (agilent.com)

Instructions to flush the filter (step 7).

Set the instrument split vent flow (purge flow) to 400 mL/min, then:

If using a Moisture filter in combination with an MS detector, purge for at least 60 minutes. This will flush the filter of dry nitrogen so that it does not appear as a background ion in your MS analysis.

For all other filter and detector combinations, purge for 4 minutes.