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5890 inlet gas lines
Posted: Tue Sep 08, 2020 8:18 pm
by MichaelVW
Hello,
Simple question: on a 5890's injection port you have a line that goes out to the split/splitless inlet vent - it's connected to the bottom of the visible portion of the block.
The top part has two gas lines, one is the supply and one is the septum purge. Looking down at them, if the vent line is at 12:00, one is at 2:00 and one is at 4:00. Which is which? Does it matter?
Thanks as always,
Mike
Re: 5890 inlet gas lines
Posted: Wed Sep 09, 2020 4:05 pm
by James_Ball
I believe one of those lines is slightly larger diameter than the other, but I can't remember which is larger.
It makes a difference since one is bringing gas to the inlet and one is taking it away, and if you reversed them any bleed from the septa would be forced down into the inlet instead of being swept across the bottom of the septa and away through the line.
Re: 5890 inlet gas lines
Posted: Wed Sep 09, 2020 7:07 pm
by LALman
I just checked my 5890 which is split at the inlet to let me use either direct injection or an external P&T unit. Using your clock analogy: The smaller ID capillary inlet line is at 2 o'clock, the larger ID Purge line is at 4 o'clock.
In other words when flipping up the inlet nut assembly towards the two lines and looking along them towards the open side: the capillary inlet line is on the right and the purge gas line is on the left.
Re: 5890 inlet gas lines
Posted: Wed Sep 09, 2020 9:03 pm
by benhutcherson
Larger diameter is septum purge out, smaller diameter is carrier in.
AFAIK, this is true of 5890-8890 split/splitless inlets.
Re: 5890 inlet gas lines
Posted: Thu Sep 10, 2020 2:45 pm
by James_Ball
That would make the inlet line 1/16" and the septum purge slightly larger because I know the 1/16" ferrules will not fit on those lines, cut one once by mistake when installing a purge and trap. Luckily I had an extra top to replace it.