Bill, and others who might have answers:

I am just adding a PreCon to our Delta Plus XL which already has a Gas
Bench and Conflo II attached.  The Gas Bench and Conflo II each have a SGE
valve, but it will be necessary to unscrew the capillary from the Gas Bench
to attach the Precon, and vise versa.  It is immediately apparent that this
is going to be tedious and not a good idea in the long term.  Has anyone
successfully attached three valves for three continuous flow peripherals to
a Delta Plus XL?

Thanks in advance,


At 01:07 PM 11/24/03 -0500, you wrote:
>Several of you have emailed me off-line and asked for details regarding the
>Nupro valve arrangement on our Delta+ XL.  We use a Nupro SS-4H bellows
>valve swagelocked to the 1/4" SS tube on top of the source.  We then use a
>1/4-1/8 swagelock adaptor to connect a Nurpro SS-2H bellows valve behind
>the SS-4H.  Then we use a 1/8-1/16" swagelock adaptor, and a regular
>vespule graphite ferrule to connect into the silica capillary.  Leak check
>everything with a He sniffer to make sure that there are no leaks that can
>entrain atm. into your source (not a good thing). The direction the valves
>are connected is the arrows point in the direction of the He flow. We were
>worried at first about the volume of the valves compared to the SGE, but
>that does not seem to be a problem since the vacuum in the IRMS is so much
>lower than the He flow in the capillaries.  We open and close the SS-2H,
>the SS-4H is a backup.  If there are problems with the SS-2H, you can shut
>off the SS-4H and replace the SS-2H valve or ferrule, or what ever is
>needed without venting the IRMS.  Works for us.
>Hope this is useful to some of you that have asked.
>Bill Showers

Paul D. Brooks,
Center for Stable Isotope Biogeochemistry,
Dept. Integrative Biology MC3140,
3060 Valley Life Sciences Building,
UC Berkeley, Ca. 94720-3140.

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