Leaking Injection Valve

Issue

Injection valve leaks

Environment

For all Ion Chromatography injection valves

Resolution

There are many reasons for the injection valve to be leaked on the IC systems, It might only a symptom/result of a problem in another side of the system, like a plugged column or capillary after the injection valve. so you must check all of the fluidic parts and see if there is any abnormality in the system pressure profile, check with the customer if they are using filtered samples, it’s always good to ask and get more info from the customers.

First, we must observe and check the place of leaking, is it coming from the capillaries connections to the valve, and are we using the legacy PEEK tubing or the Viper connection.

• If using legacy PEEK tubing, start by re-cutting the PEEK tubing that might be causing the leak, and replacing the frit and ferules, try not to re-tide the connection using a power of wrench, only 1/4 turn after a good hand tide will be fine.
   
• If you are using the viper capillaries you must inspect this capillary as it might be compromised and need to be exchange, these are pre-made and cannot be cut of modify in the field.
   
• If the leaking of the injection valve coming from the body of the valve itself, you must check and open the injection valve and observe the integrity of the stater/rotor of the injection its might be the grove plugged and it’s time to replace it. always use new rebuild injection valve kit. 
• Always filter the samples before injection, Preform the maintenance on the injection valve regularly.

Cause

This could be caused by:

• Poor maintenance schedule on the valve for a long time 
• Injection of high volume of samples that contain particles
• The wrong use of PEEK tubing or loop 
• Additional high pressure on the valve coming from plugged tubes or column