Dear Steve and others interested,

on my pretty conventional CO2 extraction line here in Pretoria I use Y-shaped
reaction tubes with a 19/26mm ground glass fitting on top. By means of these
fittings the tubes are connected to 9mm Lowers Hapert (LH) stopcocks (the
ones with the 3 viton O-rings) using Apiezon grease (not too thick!) as a
sealant for the glass/glass connections. I fill the acid in one arm of the
tube with a specially bend pipette. Ground glass fittings are also used to
connect the assembled reaction vessel to the extraction line.

So far I never had problems with this setup. The LH stopcocks seal perfect
with just their viton O-rings with out any grease.

LH stopcocks are perhaps not the cheapest, but they save you a lot of
problems.

Cheers,
Uwe


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Dr. Uwe E. Horstmann
Council for Geoscience
P/Bag X112
0001 Pretoria
South Africa

Tel.: +27 12 841 1361
Fax.: +27 12 841 1278

e-mail: [log in to unmask]
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