Print

Print


Hey all,

We're currently trying to get our GasBench up and running after a long
period of inactivity. We've plumbed the 0.3% CO2 in He line directly into
the GC column (and saw CO2!) and into the bulkhead that normally holds the
sampling needle capillary (and we don't see any CO2). The issue seems to be
with the valco 8-way valve and leaks initiating with it. We now have the
water trap plumbed into port 5 on the 8-way valve so it feeds directly into
the GC in load mode, but again see nothing. Our helium leak detector is
showing major leaks at both screws, but the ferrules are biting the
capillary well in both cases and we've remade the connections a few times
to no avail. We're currently using FS1.5 ferrules for fused silica running
in and out of the 8-way valve and ZRF1.5 ferrules for the silcosteel. Have
other folks had this issue before? Are there other ferrules we should be
using for the 8-way valve? Thoughts or suggestions are highly appreciated!

Scott
--
Scott Wieman, M.A.
Planetary Environments Laboratory, Code 699
NASA GSFC | UMBC | CRESST II