Joel,

I have carefully disassembled Thermo valves for cleaning and occasionally
have not had to replace any of the parts.  When reassembling, it is
important to try and keep the orientation of the gold stamp and the valve
body the same since the stamp is press formed to the valve orifice at first
use.  The Oring and slide gasket that you mentioned are only replaced when
looking unusually worn (this would probably be done within 3years of heavy
use).  The gold Oring usually has a couple of lives if not too disturbed.
Valves within the Kiel are usually attended to more often than others.  When
changeover valves are worked on, parts are usually replaced with new.

All of our valves are either at room temp or slightly elevated (depending on
how warm the inside of your DeltaV is).  I haven’t seen anything about
keeping valves at that elevated of a temp (65C).

Andy




-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of Joel UGHETTO
Sent: Wednesday, March 04, 2009 6:09 AM
To: [log in to unmask]
Subject: [ISOGEOCHEM] Air leak on valve

Dear List Members,
We have been working with our Delta V advantage + Kiel carbonate device for
3 years (April 2006). We have now some air leaks through the vent on
different valves, when we dismantle those valves we find the O ring (ref
0553140) very brittle and breaking. We had to change the Oring (and stamps
and gold gasket...)on the four valves of the change over.All the valves
(kiel and dual inlet) are heated at 65°C .
Is it a normal lifespan of the rings in this conditions ?
Should we turn off the heater or decrease temperature ?
Is it mandatory to change the stamp and gold gasket everytime you change the
viton ring ?
Thank you very much for your answers.

Joël UGHETTO
CNRS – Muséum national d’Histoire naturelle Archéozoologie, Archéobotanique
: Sociétés, Pratiques et Environnements (UMR 7209) Département Ecologie et
Gestion de la Biodiversité du Muséum
55 rue Buffon, F-750 05 Paris, France
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