Happy Friday All!
A few Valco switching valve details:
>1) did you drill your own 2 hole ferrules or were you able to find a
>supplier? (I've got the Valco 4 way with 1/16" swage ports).
GVF16(2) 005-003 "off the shelf" work just fine. (direct from SGE or via
>2) did you attach your waste line(s) to a vacuum? I have planned to do so
>under the assumption that there won't be any flow unless I pull through the
>capillaries. In my case there is an open split between both peripherals and
>the Valco (the GC-C III o/s and a Conflo II o/s) so unless there is a
>vacuum I'm not sure there will be any flow. If you found this unnecessary,
>then maybe I can skip it ...
Nope. Maybe pulling a flow would be better? There is still a water
background when I open the SGE (maybe ~1V at mass 18). I have never tried
switching from GC to GasBench directly without closing the SGE, so I don't
know how long that recovery takes. Steve will have to try it and let us all
know how it works!
Fun with Valves!
>>I have had good luck (touch wood) with Valco 4 port zero volume switching
>>valves. To get four peripherals on our system we have two SGE valves (from
>>the factory) with a Valco up stream of each SGE. The "EA Valco" switches a
>>TC/EA and an EA (before the Conflo) and the "GC Valco" switches a GasBench
>>and a GC-C. I even get a nice leak free connection using the two hole
>>composite GC ferrules with the Valco nuts. We mounted the "GC Valco" under
>>the hood with about 1 foot of stainless tubing connecting it to the SGE.
>>The "GC Valvo" configuration:
>>port2= GasBench sample and reference capillaries (2 hole ferrule)
>>port3= to SGE #1 (1/16" stainless tubing)
>>port4= GCC sample and reference capillaries (2 hole ferrule)
>>Everyone (the peripherals) seems pretty happy with this set-up and the
>>chromatography is not degraded. With gas flowing continuously through
>>all peripheral capillaries in stand-by, the recovery time after switching
>>is fairly short. On the "EA Valco" we have a long chunk of capillary at the
>>waste port to restrict He flow of the TC/EA in stand-by.
>>I think the manual Valco runs ~$400. If you want to get super tricky, for a
>>bit more cash you could get the electrical actuator and operate switching
>>through ISODAT NT.... theoretically.
>>Don't recall specific part numbers etc., but I would be glad to look them
>>up if you are interested. Of course I will probably be busy for the next 3
>>months trying to fix a nasty leak at the Valco having now said that it all
>>works so well!!
>>At 09:59 AM 12/9/2003 -0800, you wrote:
>>>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,
>>>Paul D. Brooks,
>>>Center for Stable Isotope Biogeochemistry,
>>>Dept. Integrative Biology MC3140,
>>>3060 Valley Life Sciences Building,
>>>UC Berkeley, Ca. 94720-3140.
>>>[log in to unmask]
>>Department of Earth and Environmental Sciences
>>University of Illinois at Chicago (MC-186)
>>845 West Taylor Street
>>Chicago, Illinois 60607-7059
>>email: [log in to unmask]
>Stephen W. Taylor
>Isotope Science Laboratory
>Dept. of Physics & Astronomy
>University of Calgary
>2500 University Dr. N.W.
>Calgary, Alberta, Canada
>(t) 403 220 8268
>(f) 403 220 7773
>[log in to unmask]
Department of Earth and Environmental Sciences
University of Illinois at Chicago (MC-186)
845 West Taylor Street
Chicago, Illinois 60607-7059
email: [log in to unmask]