Chromatography Forum

We have recently bought an used HP5890 cromatograph with three valves. The problem is that only one of the valves works properly and closes correctly. The other two either do not close or close in part (gas leakage). We have checheked all connections and appear to be OK. Valve leakage is indicating that should be replaced?
Thanks!!

Hello

If you have valve box (on the top of GC) you need to check:
- solenoid valves that switch air (side panel of GC)
- actuators (pins) and valves rotor.
- air tubing (from solenoid valves to valves on the top of GC)

Regards

Tomasz Kubowicz

Gishydrogen,

It is often the case that you hear leaking at the solenoid valve when the real problem is that the valve actuator is actually leaking past it's seals. The way you identify this is to pull the tubing off the valve actuator and plug it. If the leaking at the solenoid stops then the problem is likely to be in the actuator valve.

Best regards,

AICMM

We used to have a column switching valve on top of the 5890 GC. The seals would get hard from the heat and would need to be replaced (if memory serves). So the issue for us was not in the actuator solenoids.

Hello everybody, I have read all comments, we are following them and checking everything as suggested

As soon as I have the solution, I will write to you

Thanks!!!!