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Leaking Viper fitting

Posted: Fri Oct 26, 2018 7:05 pm
by brinker
Hi, I have an UltiMate 3000 LC system. The Viper fitting between the sample loop and the injector valve is leaking slightly. I've tried tightening the fitting, then switched out the sample loop for a new one, but it's still leaking. Does anyone have any suggestions? Thanks!

Re: Leaking Viper fitting

Posted: Tue Oct 30, 2018 12:05 pm
by gaumit
Hi,
if nut and ferrule already changed but still leak, maybe you could consider 10 port stator face valve issue, maybe need to check and change this stator face
Image

Re: Leaking Viper fitting

Posted: Tue Oct 30, 2018 1:09 pm
by Consumer Products Guy
Try a vespel type ferrule ?

Re: Leaking Viper fitting

Posted: Thu Nov 08, 2018 6:40 pm
by LCwatcherGE
Hello,

If you le the pump rund and switch the Inject valve of the WPS from Load to Inject, do you see a significant pressure increase?
If yes: either the valve is internally blocked or you have a blockage after the sample loop, e.g. needle and/or inject port and/or inject port capillary. Please refer to OpMan where they are located and how to access them.
Other possibility could be that the valve stator itself is defective, the thread coating of the sample loop port could be impacted. I know Rheodyne had an issue in the past.

Greetings
J

Re: Leaking Viper fitting

Posted: Sat Nov 17, 2018 5:14 pm
by dickmuoki@gmail.com
Your rotor seal may be blocked, backing up pressure. Also loot at the tip of the viper and if the small plastic ring at the end is broken then you have to replace it, but you need to open up the face and make sure it has no debri

Re: Leaking Viper fitting

Posted: Sun Nov 18, 2018 10:23 pm
by BostonFSE
As someone else suggested, find the delta psi between LOAD and INJECT. This is best way to troubleshoot any high pressure issue from any split loop sampler from any manufacturer.
(Manually switch the valve icon in Chromeleon)
The difference should be ~2 bar maximum, more like <1 bar

INJECT mode adds 4 more components to the flowpath which should increase the pressure slightly ( 2 bar max) the needle, needle seat capillary, sample loop and needle seat frit into the flowpath. Your description likely points to a clogged viper needle which is finding relief through the sample loop. (leaking)
Replace.... OR
Disconnect port 5 from the inj valve (PUMP OUT)and put the sampler into maintenance mode.
THis will move the arm to the left, remove the needle and connect directly to the pump out viper capillary and blast the pump to remove the blockage. Switch mobile phases to find the best solvent to dissolve it. be sure to dilute your samples and filter if necessary. The opening on a Viper needle is very tiny compared to an Agilent needle and clogs easily.