Air requirement in scfm for GC 7890 and GC 6890N

Hi dhanoag,

I updated the tags on your post for more visibility . To properly answer the request, we need to know what detectors you are using. Any valve switching by pneumatics? Valve box? In our instrument site prep documents we mention supply pressures for air . For FID 55 to 100 PSI, for FPD 100-120 PSI. If you had two FIDs on a system both would use an air flow of 450 x2 . 900 ml/min total. You usually want to have some reserve capacity. So lets say 1l/min per GC with detectors only with the generator able to maintain the supply pressure under flow. I hope that helps, we can clarify more if you have more detail on the instruments. I have attached a 7890 site prep for reference . The 6890 would have the same air requirements .

Regards

James

Related question.  Simple GC with a valco rotary valve, 10 position, 6 position, whatever.  what is the scfm requirement for that pneumatic device over the course of a method run where after half a minute the valve switches, then 15 minutes later switches back.  Would the round actuators mounted right on the valve have similar flow to those square brass valves that lurch?  trying to size an air handling system where pneumatic air is separated from fid air.

Related question.  Simple GC with a valco rotary valve, 10 position, 6 position, whatever.  what is the scfm requirement for that pneumatic device over the course of a method run where after half a minute the valve switches, then 15 minutes later switches back.  Would the round actuators mounted right on the valve have similar flow to those square brass valves that lurch?  trying to size an air handling system where pneumatic air is separated from fid air.

Hi patkinghorn,

The only spec we have is below .

. Internal Valco rotary Valve actuation requires a separate pressurized, dry air at 55 psi. I would suspect the consumption wouldn't be a lot, but there are no spec that I can find.

James