Leaking Viper fitting

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

6 posts Page 1 of 1
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!
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
GiMiTEC | https://gimitec.com/catalog
Try a vespel type ferrule ?

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.

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
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.
6 posts Page 1 of 1

Who is online

In total there are 15 users online :: 0 registered, 0 hidden and 15 guests (based on users active over the past 5 minutes)
Most users ever online was 599 on Tue Sep 18, 2018 9:27 am

Users browsing this forum: No registered users and 15 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry