Sample Injection System ( 8890-0678)

Hi

Share valve timing of old and new gc from method to understand better.

Purging means continuous flow of sample in and sample out line, correct or not..

Actually, in ur old system, one 4 port valve is installed as to shut the flow in going to GC in Off condition but in new system there is no 4 port valve.

So either installed one new 4 port valve or adjust valve timing of new system...

Feroje, ISH is correct.  You are missing a 4-port valve to stop the sample flow to the gas sample valve.  Fortunately you do have an extra heated zone in your valve oven to add this valve in your valve oven.  Please work with your local Account Manager to get a quote for adding the additional 4-port valve, to be plumbed to your gas sample loop in a stop flow configuration.  While you are waiting you could install a manual shutoff valve external to the GC, between your GC and your sample source.  Have a wonderful day.