Chromatography Forum

varian cp-3800 GC When I installed the mainboard and loaded the method on it, the flow is zero and pressure is 0.3psi , while I set the pressure to 2. Why?

Kindly help

Dear Sir, you have installed mainboard, which would be OK.
Before coming to any conclusion, please confirm the following main things.
1) Replace the Septa
2) Tight the nuts (Inlet/outlet)
3) Is enough gas pressure is there?
4) Gas valves are opened.
5) Once shut down all system and restart.
6) Check the method parameters once and apply.
7) Confirm that Column is uniform.
Change the glass wool of liner.
9) If possible, kindly pull the board little up and again fit at given position.
10) If all above mentioned points are OK and then also, no pressure, then concern is about main board.

Thank you very much for your guidance

I did the above tips, the problem is still not solved, but the device with its previous mainboard is ok with pressure and flow, but after changing the mainboard, the problem of flow and pressure occurs. Is it possible to guide me?

Its confirming that second main board is concern.

It is very likely that the new board needs initializing and calibrating for pressure and gas flow. Consult your user's manual.

Thanks a lot