7890A Clog in Gas-Sampling Valve

I have a gas-phase reactor system that uses the FID of a 7980A to analyze the product mixture.  Currently, I have a pressure buildup (up to 30 psi - the carrier gas delivery pressure) when the system is stationary.  When the gas sampling valve actuates to take a sample, the pressure buildup is relieved over the course of the injection.  Based on these observations:

1) Where is the clog in my system?

2) What steps can I take to resolve this?

Thanks in advance for any suggestions.

  • Hello ,

    I’m sorry for the delayed reply to your message.  Do you still need assistance with this? If you do, please take into consideration the notes below. However, if the issue was resolved, could you please share what the resolution was? 

    Based on what you are describing it is quite possible it's a valve problem of sorts. It could be something else as well, but we would need to see a flow diagram/valve diagram to assess other potential avenues.

    You could try replacing the valve first and see if that eliminates the problem.

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