Chromatography Forum

I have a question as too how many instruments can share 1/8" helium and FID Air lines until the lines can't support the flow demand and pressure drop is an issue?

We tend to do a lot of 200:1 injections so that puts a fair demand on the helium line at times if multiple instruments are injecting at the same time.

Obviously FID air requires 400ml/min per FID.

We set the regulators at 80 PSI for the gas lines.

It will partly depend on how far the tanks are from the GCs, due to line pressure drop. What's the distance?

Would you be able to move up to larger lines and then decrease to 1/8" right at the GCs?

They are a pretty good distance probably 20' or more and they go inside the wall so replumbing with 1/4" would be tough.