Hi

With the valve closed, you can change the twin hole ferrule without 
venting the system but don't forget the ferrule goes in back to front. 
However if the valve is leaking then this tends to be the PTFE seat and 
the system would have to be vented.

John Hill
UCL


I think I am having a leak where the capillary enters the SGE valve 
setup.  When the SGE
valve is open, spraying argon where the capillary enters the double 
holed ferrule indicates a
leak.  There is no leak when the SGE valve is closed and argon is 
sprayed in the same
place.  I want to change the double holed ferrule, but can this be done 
without venting the
system?  Even with the SGE valve closed, it looks risky to unscrew that 
nut and change the
ferrule...

Alternatively I could be having issues with one of the seals in the SGE 
valve itself, but I
wanted to first check the double holed ferrule without venting the 
system, if its possible.