Hi John.
I guess it is not the material of this ferrule, you can use PEEK or GVF 
like you want.
But the modification is the core through the ferrule.
First, I replaced the valve seat with an original GVF from SGE.
It was a bad performance, half signal height and so on.
So I and my colleague asked a different technician and we get nearly the 
same answer.
Thermo use the GVF from SGE with a bigger core of 0.8 mm.
So I made the core of our GVF bigger and get a good performance now.

Best,
Sven

John Hill schrieb:
> Sven
>
> This is interesting. I replaced the SGE needle valve a few months back 
> on our Delta V. SGE have modified the needle valve and it uses PEEK 
> ferrules whose ID must be around 0.4 to 0.5mm. So basically we need to 
> changed back to GVF ferrules with the larger ID, correct?
>
> John Hill
> UCL
>
> Sven Steinbrenner wrote:
>> Dear Istvan,
>> there is a modification at the needle valve seat ferrule.
>> Thermo use a ferrule with a bigger core inside (0,8 mm).
>> You can order it with the pn 1221460 GVF-ferrule for Needle valve id 
>> 0.8mm.
>>
>> I replaced at our 3 Deltas all seat ferrules and was wondering about 
>> the bad performance.
>> Lower signal height;  bad Ref gas peaks (round at the beginning).
>> After a few mails to the support, we get the info about this 
>> modification.
>>
>> I hope this helps.
>>
>> Best wishes
>> Sven
>>
>> Fórizs István schrieb:
>>> Dear Ulrich and others who helped us with advises,
>>>
>>> after all we have made the first measurements during the night. Now 
>>> it worked acceptable, although the peak height has not encreased (it 
>>> is about half than was before). But now the H3 factor is far better. 
>>> After the cleaning of the ion source the H3 factor varied between 16 
>>> and 24!!
>>> Yesterday it was between 6.3 and 6.4, and looked stable. Today it 
>>> was 6.15 and 6.05 (we have measured it two times), and looks stable.
>>>
>>> What we have found are:
>>>
>>> 1) One plate in the ion source was 90 degrees off. It is the closest 
>>> one to the ionization box, no. 02, and without wire connection 
>>> (there is a metal ring between this plate and the ionization box). 
>>> When we put it to the proper position we expected a significant 
>>> encrease in the peak height, but it did not happen. We do not 
>>> understand why.
>>>
>>> 2) The connections of the high voltage cable (red) on the outer part 
>>> of the ion source were (and are) loose. Practically after may 
>>> disassembling and reassembling one of these connections was 
>>> disconnected. When we discovered it, we realized that all these 
>>> connections are loose a priori. So we have to be very careful when 
>>> cleaning the source.
>>>
>>> What we have not checked is the needle valve on the input port of 
>>> the MS. We have noticed that now it is more difficult (needs more 
>>> force) to close and open it then before. May be that it causes the 
>>> half height peak?
>>> What is your experience with the needle valve?
>>>
>>> Thank you very much for the help provided by many of you!
>>>
>>> Best wishes
>>> Istvan
>>>
>
>

-- 
Sven Steinbrenner

Max Planck Institute for Evolutionary Anthropology
Department of Human Evolution 
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D-04103  Leipzig
Germany

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